Hilo based JCMT astronomer wins prestigious NASA Fellowship

Dr. Alex Tetarenko wins prestigious NASA Fellowship

Dr. Alex Tetarenko, a Hilo-based astronomer who works at the James Clerk Maxwell Telescope (JCMT), has been selected as a new Fellow by NASA for its prestigious NASA Hubble Fellowship Program (NHFP). Dr. Tetarenko was one of 24 NHFP Fellows to be selected out of more than 400 applicants. The program enables outstanding postdoctoral scientists to pursue independent research in any area of NASA Astrophysics, using theory, observation, experimentation, or instrument development.

With the proposed research topic “Unraveling the Complex Nature of Black Holes and How They Power Explosive Outflows with Time-Domain Observations”, Tetarenko will help provide answers on how the universe works.

Alex Tetarenko was born and raised in Calgary, Alberta, Canada. She received her BSc in Astrophysics from the University of Calgary, and she pursued graduate school at the University of Alberta, obtaining her MSc in 2014 and her PhD in 2018. Alex’s PhD thesis was awarded the J.S. Plaskett Medal from the Canadian Astronomical Society for the most outstanding doctoral thesis in Canada. Following her PhD studies, Alex took up an independent fellowship at the Maunakea Observatories in Hawaiʻi, working at the East Asian Observatory’s James Clerk Maxwell Telescope, where she currently resides.

“I am super excited for this amazing opportunity, and while I will be sad to leave the island, I am incredibly grateful for my time here and for all the support I have received over the past several years, which most certainly played a big part in being able to win this Fellowship,” said Tetarenko.

Alex’s research focuses on studying relativistic jets launched from stellar-mass black hole systems in our galaxy, to understand the complex relationship between the mass plunging into a black hole and the material that is jettisoned away. The main goals of her research are to develop new ways to study jets launched from black holes, both in terms of designing observing techniques to gather new types of data, as well as building new computational and statistical tools to analyze this data.

As an Einstein fellow, Alex’s pioneering research program will implement a novel time-domain technique to observe galactic black hole systems at radio wavelengths. This innovative technique, adapting algorithms used in X-ray astronomy, allows her to directly measure the physical properties of black hole jets and how they evolve through measuring how the intensity of the light we receive from these jets varies over different time-scales. With this research, she will place constraints on jet speeds, energetics, and size-scales, in turn allowing her to begin to address key open questions in jet research, such as understanding the energy source of these jets and the impact they have on their environment. This work will also provide benefits to the broader scientific community, through developing statistical techniques that can be applied to big data problems, and building new observing methods applicable for the operations and data analysis at next-generation telescopes.

 

For more information: https://hubblesite.org/contents/news-releases/2021/news-2021-16

Contact: Dr. Alex Tetarenko a.tetarenko@eaobservatory.org

See this announcement in the West Hawaii Today.

Formation of the Hub–Filament System G33.92+0.11: Local Interplay between Gravity, Velocity, and Magnetic Field

Figure 1. B-field orientations (segments) sampled on a 12” grid overlaid on 850 μm dust continuum (color and contours), sampled on a 4” grid, of the G33.92+0.11 region. The segments are rotated by 90° to represent magnetic field orientations. The yellow and white segments display the larger than 3 and 2–3 polarization detections. The green contours show the total intensity at 20, 50, 200, 300, 500, 1000, and 
 2000 mJy beam-1.

Interstellar filaments are ubiquitous in molecular clouds, and they are a key intermediate stage toward the formation of stars. Previous observations found that many stars commonly form within clustered environments associated with hub–filament systems (HFSs), where they are formed in a dense hub with numerous radial filaments extending from the central hub (Myers 2009, ApJ, 700:1609). Understanding how HFSs form is a topic of considerable interest since HFSs are the possible transition stage connecting the evolution of filamentary clouds and the formation of protoclusters.

G33.92+0.11 is such an HFS, where two massive protoclusters have been discovered by ALMA within the central 0.6 pc area of a dense hub associated with several few pc- length converging filaments (Liu et al. 2019, ApJ, 871:185). Since the size of the entire HFS is well beyond the maximum recoverable scale of interferometers, JCMT observations are essential to investigate the large-scale environments where the massive HFS could form.

We performed polarization observations using JCMT POL-2 to probe the magnetic field morphology in this 5-pc HFS. It is widely known that this polarized continuum emission originates from the dichoric alignment of interstellar dust grains along magnetic field lines in the interstellar medium through the Radiative Alignment Torques (RATs), and so the observed polarization orientation traces the plane-of-sky magnetic field morphology (Andersson et al. 2015 ARA&A, 53:501).

The magnetic field structure inferred from our POL-2 observations reveals a converging pattern pointing toward the hub center (Figure 1), apparently similar to the converging filamentary structures identified from the dust continuum map shown in the top panel of Figure 2, implying that the evolution of the converging filaments is coupled with magnetic fields.

Figure 2: Differential orientation maps for filament vs. magnetic field, local gravity, and local velocity gradient (from top to bottom), overlaid on the 850 μm intensity. The cyan lines are the identified filaments. The yellow and white segments represent the magnetic field orientations, the red arrows are the projected local gravity, and the magenta arrows show the local velocity gradients. Filled color- coded circles (color wedge) are the pairwise differential orientations.

In order to evaluate the relative importance among gravity, turbulence, and magnetic fields, we used the modified Davis-Chandrasekhar-Fermi technique to estimate the energy scale of these physical parameters (Houde et al. 2009, ApJ, 706:1504). By combining our POL-2 polarization data and the velocity information extracted from the IRAM 30-m C18O (2-1) data, the obtained ratio of kinematic to gravitational energy is 0.10–0.20, and the ratio of magnetic to gravitational energy is 0.05–0.10. Hence, the global gravitational energy dominates the kinematic and magnetic energy and appears to be the major driving factor in the evolution of these filaments on a global scale.

The Davis-Chandrasekhar-Fermi technique only describes the averaged global properties over the entire system. It is important to note that many physical parameters, such as densities however, the physical parameters, including densities, gas velocities, magnetic field strengths, etc., are far from being homogeneous but actually vary by orders of magnitudes in such a dynamical HFS. Therefore, an analysis merely focusing on the global aspect might lack information on spatial variations which is essential for us to understand how the physical condition evolves from the ambient material to the converging filaments, and to the central hub. Hence, we additionally developed an approach aiming at studying the detailed local interplay between the spatial properties of the filamentary structures, the magnetic fields, the local gravitational force, and the local velocity gradient.

As a first step to investigate the spatial properties, we performed an all-pairwise comparison of the relative orientation among filaments, magnetic fields, local gravitational force, and local velocity gradient on the dust continuum map (Figure 2). This comparison reveals systematic changes of these relative orientations from diffuse extending filaments toward the densest hub center. With statistics based on the Kolmogorov-Smirnov test, we conclude that the filaments tend to align with the magnetic field and local gravity in the dense hub. In the low-density areas, we find that the local velocity gradients tend to be perpendicular to both the magnetic field and local gravity, although the filaments still tend to align with local gravity.

Combining local and global aspects, we propose a scenario where G33.92+0.11 is a multiscale gravitationally collapsing cloud with relatively weak turbulence and magnetic field. The ambient gas in the diffuse environment is accreted onto the filaments, while the filaments drag the magnetic field lines and flow toward the gravitational center (illustrated in Figure 3). Due to the resolution limitation, the observed local velocity gradients mainly trace the gas accumulation from the surrounding to the filaments, especially in low-density areas, and are thus perpendicular to the filaments. The observed magnetic field is stretched by the accretion flows, especially in high-density areas, and is therefore aligned with filaments and gravity.

One challenge of this scenario is how these converging filaments remain stable without fragmenting into numerous cores before reaching the hub center. To answer this question, we estimate the variation of critical linear density along these filaments considering the support from both thermal, non-thermal, and magnetic support. We find that the non-thermal kinematic energy within these filaments, traced by the local velocity dispersion, is significantly increasing with the local density. In return, this can stabilize filaments from self-fragmenting until reaching the central hub. This mechanism might also explain how a massive star/protocluster can accumulate a significant amount of mass from the large-scale environment.

Figure 3: Cartoon illustrating observed features. The black arrows represent the directions of local gravity. The yellow curve shows a model-compatible magnetic field morphology, with the orange segments displaying the observed field segments with a spatial resolution (~0.5 pc) comparable to the filament widths (0.5–1 pc). The magenta arrows illustrate the directions of gas motion, with the white arrows depicting the observed velocity gradients at the resolved 0.5 pc scale. The background color displays local density. An outer subcritical and inner supercritical zone is indicated.

This research was published in The Astrophysical Journal at: https://iopscience.iop.org/article/10.3847/1538-4357/abc74e

Authors: Jia-Wei Wang1,2, Patrick M. Koch1, Roberto Galván-Madrid3, Shih-Ping Lai2, Hauyu Baobab Liu1, Sheng-Jun Lin2, and Kate Pattle2,4    

Edited by Steve Mairs

Author Affiliations:

1 Academia Sinica Institute of Astronomy and Astrophysics, No. 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan

2 Institute of Astronomy and Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan; jwwang@asiaa.sinica.edu.tw

3 Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Apdo. Postal 3-72 (Xangari), 58089 Morelia, Michoacán, Mexico

4 Centre for Astronomy, School of Physics, National University of Ireland Galway, University Road, Galway, Ireland

JCMT Astronomer helps size up the first black hole ever detected

Dr. Alex Tetarenko, a Hilo based astronomer who works at the James Clerk Maxwell Telescope (JCMT), has been collaborating with an international team of researchers to analyze new observations of the first black hole ever detected. Their discovery is leading astronomers to question what they know about the Universe’s most mysterious objects.

Dr. Alex Tetarenko, Credit: EAO

Published today in the journal Science, the research shows that the system known as Cygnus X-1, contains the most massive stellar-mass black hole ever detected without the use of gravitational waves. “Our new observations have shown us that Cygnus X-1 is further away from Earth than previously thought, which in turn tells us this black hole is much larger than previous estimates, weighing in at more than 20 times the mass of our own Sun” says Dr. Tetarenko.

 

The Cygnus X-1 binary system consists of a stellar-mass black hole that is pulling material off of a ‘donor star’. “Our new observations have shown us that Cygnus X-1 is further away from Earth than previously thought, which in turn tells us the black hole is much larger than previous estimates, weighing in at more than 20 times the mass of our own Sun.” Artist: Pete Wheeler (COMET) Credit: International Centre for Radio Astronomy Research.

Cygnus X-1 is one of the closest black holes to Earth. It was discovered in 1964 when a pair of Geiger counters were carried on board a sub-orbital rocket launched from New Mexico. This object was famously the focus of a scientific wager between physicists Stephen Hawking and Kip Thorne, with Hawking betting in 1974 that it was not a black hole and eventually conceding the bet in 1990.

In this latest work, astronomers observed a full orbit of the black hole over a six day period using the Very Long Baseline Array — a continent-sized radio telescope made up of 10 dishes spread across the United States — together with a clever technique to measure distances in space. “One of the telescopes in the Very Long Baseline Array is located in Hawaiʻi on the slopes of Maunakea, and this antenna plays a critical role in making it possible to do this kind of science” explains Dr. Tetarenko.

Lead researcher, Professor James-Miller Jones from Curtin University and the International Centre for Radio Astronomy Research (ICRAR) outlines the clever technique used by this team of researchers. “If we can view the same object from different locations, we can calculate its distance away from us by measuring how far the object appears to move relative to the background. If you hold your finger out in front of your eyes and view it with one eye at a time, you’ll notice your finger appears to jump from one spot to another. It’s exactly the same principle.”

“The domino effect of our new observations has led to fascinating new insights about how stars evolve and how black holes form” says co-author Dr. Arash Bahramian, who is also at Curtin University and ICRAR. Tetarenko and Bahramian are longtime colleagues, having both completed their PhDs at the University of Alberta in Canada.

In fact, this study has sparked two more companion papers. Co-author Professor Ilya Mandel from Monash University and the ARC Centre of Excellence in Gravitational Wave Discovery (OzGrav) further explains the wide reaching implications of this work.

“Cygnus X-1 in particular began life as a star approximately 60 times the mass of the Sun and collapsed tens of thousands of years ago. During their lifetime stars lose mass to their surrounding environment through stellar winds that blow away from their surface. But to make a black hole as heavy as Cygnus X-1, we need to dial down the amount of mass that bright stars lose during their lifetimes”.

The new measurements of distance and mass also tell us that the black hole in Cygnus X-1 is spinning incredibly quickly (very close to the speed of light), as shown in a second companion paper led by PhD candidate, Xueshan Zhao, at the Chinese Academy of Sciences.

“All of these exciting discoveries were made possible by the collaboration between a diverse group of international astronomers focused on different observational and theoretical aspects of black holes, all coming together for a new extensive and rigorous look at a known but previously elusive black hole.” adds Dr. Bahramian.

As the next generation of telescopes comes online, their improved sensitivity reveals the Universe in increasingly more detail, leveraging decades of effort invested by scientists and research teams around the world to better understand the cosmos and the exotic and extreme objects that exist.

“Studying black holes is like shining a light on the Universe’s best kept secret—it’s a challenging but incredibly exciting area of research” says Professor Miller-Jones. “There is so much left to discover about these enigmatic astrophysical objects” adds Dr. Tetarenko.

 

Original Publication:
‘Cygnus X-1 contains a 21-solar mass black hole – implications for massive star winds’, published in Science on February 18th, 2021.

Companion Papers:
‘Reestimating the Spin Parameter of the Black Hole in Cygnus X-1’, published in The Astrophysical Journal on February 18th, 2021.

‘Wind mass-loss rates of stripped stars inferred from Cygnus X-1’, published in The Astrophysical Journal on February 18th, 2021.

Contacts:

Dr. Alex Tetarenko, EAO Fellow, East Asian Observatory
a.tetarenko@eaobservatory.org

Dr. Jessica Dempsey, Deputy Director of the East Asian Observatory (EAO) and JCMT
j.dempsey@eaobservatory.org

 

Local Media Coverage

“Starspots” on Betelgeuse: JCMT Explains Star’s Record-Breaking Dimming

New data obtained using the Hawai`i-based James Clerk Maxwell Telescope (JCMT) revealed that the surface of Betelgeuse (commonly known as Orion’s shoulder), recently developed significant “Starspots” which caused an unprecedented dimming of the star. This result contrasts the previously accepted explanation that the reduction in brightness was due to a veil of newly created dust that obscured the star. The research was published today in the prestigious Astrophysical Journal Letters.

An artist’s rendering of Betelgeuse, Dr. Thavisha Dharmawardena from the Max Planck Institute for Astronomy, and Dr. Steve Mairs from the James Clerk Maxwell Telescope

Beginning in October, 2019, the Red Supergiant star, Betelgeuse, experienced a record-breaking dimming event where it became three times fainter than usual. This phenomenon captured the interest of both professional astronomers and the public, largely fuelled by curiosity in the red supergiant’s demise and whether this change in brightness was heralding an imminent supernova explosion. In an anti-climactic conclusion, however, the star eventually increased in brightness again to its regular appearance. The explanation that emerged at the time was that the dimming was caused by a newly formed cloud of dust that blocked some of the light before it reached our telescopes here on Earth. An independent study led by Dr. Thavisha Dharmawardena, postdoctoral researcher at the Max Planck Institute for Astronomy, Germany, and Dr. Steve Mairs, Senior Scientist at the James Clerk Maxwell Telescope, Hawai`i, USA, however, offers the more likely explanation that the surface of Betelgeuse itself underwent a significant change.

Like tuning to a different radio station in a car, telescopes are each tuned to observe different types of light. In this way, observations from different telescopes can be combined to help fill in the whole picture. “​By using the James Clerk Maxwell Telescope here in Hawai`i, we were able to collect a type of light called ‘submillimetre light’ that is not visible to the human eye,”​ Mairs explains, “​This provided the crucial information that allowed us to conclude that there was no dust in the way; Betelgeuse was feeling shy with a face full of spots.”​

An artist’s impression of the Red Supergiant Betelgeuse. Its surface is covered by large starspots, which reduce its brightness. During their pulsations, such stars regularly release gas into their surroundings, which condenses into dust. (Image: Graphics Department/MPIA).

New JCMT images were obtained in January, February, and March, 2020 while Betelgeuse was faint and they were compared with observations taken over the past 13 years. These previous observations include images obtained by the Atacama Pathfinder Experiment (APEX), a telescope in Chile that observes the same type of light as the JCMT. “​What surprised us was that Betelgeuse turned 20% darker during its dimming event even in submillimetre light,”​ Dharmawardena says “​This behaviour is not at all compatible with the presence of dust. It was very exciting to realise that the star itself had undergone this massive change​”.

According to the scientists, the simultaneous darkening in visible and submillimetre light is evidence for a reduction in the mean surface temperature of Betelgeuse by 200 °C (360 °F). ​“However, an asymmetric temperature distribution is more likely,”​ Dharmawardena explains, referring to corresponding high-resolution images of Betelgeuse from December 2019 that depict an uneven distribution of stellar brightness.​ “Together with our result, this is a clear indication of huge starspots covering between 50 and 70% of the visible surface, each having a lower temperature than the rest of the surface.”​ Starspots, similar to sunspots, are common in giant stars, but not on this scale. Not much is known about their lifetime. However, theoretical model calculations seem to be compatible with the duration of Betelgeuse’s dip in brightness.

The team will continue to track the brightness of Betelgeuse with the JCMT over the next year to uncover more details about how the star is physically changing over different timescales. ​“Previous generations of stars like Betelgeuse have physically manufactured most of the elements we find on Earth and indeed in our bodies, distributing them throughout the Galaxy in massive supernova explosions.”​ Mairs explains. ​“While we cannot predict when the star will explode, tracking its brightness will allow us not only to better understand the evolution of an interesting class of stars, but it also helps write a page in our own cosmic story.”

——-

Supplementary information about Betelgeuse:

Betelgeuse, known as Kauluakoko in `ōlelo Hawaii, is the nearest red supergiant star to the Earth at a distance of only 500 light years. It is the red shoulder of the constellation Orion. It is so large that if Betelgeuse were to be placed at the location of our Sun, Mercury, Venus, the Earth, Mars, and the asteroid belt, would all be contained inside the star. With such a close proximity, it acts as a unique laboratory to aid in the understanding of the late stages of red supergiant evolution. Massive stars (Betelgeuse is 11 times heavier than our Sun) are important to study as they are the main drivers of chemical evolution in the universe. Stars like Betelgeuse manufacture many of the elements that comprise our bodies and our planet and even before the explosive end of their lives, massive stars undergo episodes wherein they lose material, enriching their surroundings with newly formed chemical elements. These periods of mass loss are accompanied by pulsations with periods of up to a few years.

Supplementary Information about the JCMT:

With a diameter of 15m (50 feet) the James Clerk Maxwell Telescope (JCMT) is the largest astronomical telescope in the world designed specifically to operate in the submillimetre wavelength region of the electromagnetic spectrum. The JCMT is used to study our Solar System, interstellar and circumstellar dust and gas, evolved stars, and distant galaxies. It is situated in the science reserve of Maunakea, Hawai`i, at an altitude of 4092m (13,425 feet).

The JCMT is operated by the East Asian Observatory on behalf of NAOJ; ASIAA; KASI; CAMS as well as the National Key R&D Program of China. Additional funding support is provided by the STFC and participating universities in the UK and Canada​. Supplementary Information about SCUBA-2:

The James Clerk Maxwell Telescope (JCMT) observations were obtained using the “Submillimetre Common User Bolometer Array 2”, a specialised camera known by its acronym, SCUBA-2. SCUBA-2 consists of 10,000 superconducting Transition Edge Sensor (TES) bolometers that allow for simultaneous observations at wavelengths of 450 and 850 microns. Scientists regularly use SCUBA-2 to observe star-forming regions, Red Giant stars, and the most distant galaxies ever discovered. At an operating temperature of -459.5 degrees fahrenheit, SCUBA-2 at the JCMT is one of the coldest places in the known Universe.

Link to paper: https://ui.adsabs.harvard.edu/abs/2020ApJ…897L…9D/abstract

Contact Information:

Dr. Thavisha Dharmawardena
Max Planck Institute for Astronomy
Email: ​dharmawardena@mpia.de

Dr. Steve Mairs
James Clerk Maxwell Telescope
East Asian Observatory
Email: ​s.mairs@eaobservatory.org

Dr. Jessica Dempsey
James Clerk Maxwell Telescope
East Asian Observatory
Email: ​j.dempsey@eaobservatory.org

JCMT Telescope Operator Featured on CBS “Mission Unstoppable”

JCMT Telescope System Specialist Mimi Fuchs is on the front page of the Hawaii Tribune-Herald  today showcasing her appearance in an episode of “Mission Unstoppable” on CBS. As well as being an operator at the JCMT Mimi is an IF/THEN Ambassador for the AAAS – The American Association for the Advancement of Science.

Read the full Hawaii Tribune-Herald article here.

Watch the “Mission Unstoppable” segment here.

EAO and ‘Imiloa provide ‘Stellar’ Night to local Cub Scouts

On Saturday, March 7th, 2020, the ‘Imiloa Astronomy Center in Hilo, Hawai’i hosted 70 visitors for a special overnight event.  As part of the “Stellar Night at the Museum”, the Cub Scouts and their family members were treated to a unique visit at the East Asian Observatory base facility.

Courtesy photo provided to the Hawaii Tribune Herald from the Cub Scouts who attended the Scouts Stellar Night at the Museum overnight March 7 at ‘Imiloa Astronomy Center in Hilo.

 

Telescope System Specialist, Alexis Acohido, provided tours into the JCMT Control Room as live operations were taking place. Photo taken by Emily Peavy.

 

Extended Operator, Patrice Smith, engaged the visitors with a fun “Alien Eyes” activity that demonstrated how filters can help us sort out information that we wouldn’t be able to normally see with our eyes. Photo taken by Emily Peavy.

 

EAO Visiting Scientist, Pablo Torne, used spectral tubes and diffraction gratings to explore spectral lines from different molecules. Photo taken by Emily Peavy.

 

In the UKIRT control room, Telescope Operators Jess Stasik and Michael Pohlen used an infrared camera and a cell phone to explore heat. Photo taken by Emily Peavy.

An article was released in the local Hawaii Tribune Herald newspaper about the event, and can be read here:

www.hawaiitribune-herald.com/2020/04/14/community/scouts-have-a-stellar-night-at-the-museum/?fbclid=IwAR1_Glc82elyoAlbRh84_q4z6x_-1J3FlZ0kuGoXuE4jYoJrgM1sgMH9B9E

 

The Event Horizon Telescope brings the world together to observe new mysteries in quasar 3C 279

First Event Horizon Telescope Observations of a Black-Hole Powered Jet announced as Maunakea Observatories offer MKO@Home online resources

Two Hawai’i-based telescopes, the James Clerk Maxwell Telescope (JCMT), operated by the East Asian Observatory, and the Submillimeter Array (SMA), operated by the Smithsonian Astrophysical Observatory and the Academia Sinica Institute for Astronomy and Astrophysics, have once again provided crucial information in the global effort to understand Black Holes. The JCMT and SMA linked up with six other telescopes around the world to form the Event Horizon Telescope (EHT), in an effort involving hundreds of astronomers and engineers. The black hole targeted in these observations resides at the centre of a galaxy called 3C 279. This galaxy is 5 billion light years away in the direction of the Virgo constellation.

Nearly one year ago, the JCMT and the SMA played a vital role in the groundbreaking EHT observational campaign to observe the very first image of a black hole, which was given the Hawaiian name Pōwehi. The EHT collaboration is excited to announce this new result from data obtained at the same time as the Pōwehi result.

For the first time, astronomers have observed a jet travelling at close to the speed of light, that is believed to originate from the vicinity of a supermassive black hole, in unprecedented detail. In their analysis, led by astronomer Jae-Young Kim from the Max Planck Institute for Radio Astronomy in Bonn (MPIfR), the collaboration studied the exquisite detail of the jet’s shape close to the base. The jet base is a fascinating region where highly variable, high energy gamma-ray emission is thought to originate.

The results will be published in the coming issue of the prestigious journal ​Astronomy & Astrophysics​.

 

Fig. 1: Illustration of 3C 279 jet structure in April 2017. The observing epochs, arrays, and frequencies are noted at the top of each panel. Credit: J.Y. Kim (MPIfR) & the Event Horizon Telescope Collaboration

 

The black hole targeted in these observations is called 3C 279. It resides at the centre of a galaxy 5 billion light years away in the direction of the constellation Virgo. Scientists classify this galaxy as a quasar because it shines ultra-bright and flickers, signifying that massive amounts of gases and stars are falling into the giant black hole at the centre. The black hole in 3C 279 is about one billion times the mass of our own sun. Any material such as stars, gas, or dust that comes close to this black hole is shredded by strong gravitational forces, causing a large donut-shaped structure known as an accretion disc to form around the object. But not all of this shredded material stays in the accretion disc or ends up falling into the Super Massive Black Hole. Some of the material will be squirted back out into space in two fine fire-hose-like jets of plasma, travelling at speeds near the speed of light. These jets are powerful and demonstrate the enormous forces at play in the centre of this galaxy.

Through linking up many telescopes across the globe, using a technique known as very long baseline interferometry (VLBI), the astronomers are able to see the jet and accretion disc in action, distinguishing the sharpest-ever details in the jet. The new jet images, probing size scales finer than a light-year, show an unexpected twisted shape at its base, and features perpendicular to the jet, which could represent the poles of the accretion disc from where jets are ejected. Through comparing the images of 3C 279 over subsequent days, the astronomers see the finest details changing, opening up the possibility that we are actually seeing both the rotation of the accretion disc (with the shredding and infall of material), and the jet ejection, that has previously only been modeled in computer simulations of these objects.

Jae-Young Kim, leader of the analysis, is enthusiastic and at the same time puzzled: “We knew that every time you open a new window to the Universe you can find something new. Here, where we expected to find the region where the jet forms by going to the sharpest image possible, we find a kind of perpendicular structure. This is like finding a very different shape by opening the smallest Matryoshka doll.” Furthermore, the fact that the images change so fast has also surprised astronomers. “These jets show apparent motions faster than the speed of light (called superluminal motion), as an optical illusion, but this, perpendicular to the expectation, is new and requires careful analysis”, adds Jae-Young-Kim.

The interpretation of these observations is challenging. In particular, observing apparent motions of about 20 times the speed of light in the jet are difficult to reconcile with the early understanding of the source. These results paint a complex picture, where disturbances in the flow of material, known as shocks, are travelling down a bent (and possibly rotating) jet, and producing incredibly high energy gamma-rays.

“To announce this incredible result exactly a year after we brought Pōwehi to the world makes it so special,” offers Jessica Dempsey, Deputy Director of the James Clerk Maxwell Telescope – one of the two Hawaii-based observatories that are part of the EHT. “For our staff here in Hawaii, it is a reminder of the ground-breaking work they continue to contribute to – even if we aren’t up at the summit right now. Like Pōwehi before it, this beautiful image of 3C 279 gives me hope, for us and for our future.”

Fig. 2: The James Clerk Maxwell Telescope (JCMT) located on the slopes of Maunakea, Hawai`i is pictured in the foreground. The JCMT is operated by the East Asian Observatory. Credit: Will Montgomerie

Anton Zensus, Director at the MPIfR and Chair of the EHT Collaboration Board, stresses the achievement as a global effort: “Last year we could present the first image of the shadow of a black hole. Now we see unexpected changes in the shape of the jet in 3C 279, and we are not done yet. We are working on the analysis of data from the centre of our Galaxy in Sgr A*, and on other active galaxies such as Centaurus A, OJ 287, and NGC 1052. As we told last year: this is just the beginning.”

The March/April 2020 observing campaign of the EHT was cancelled due to the CoViD-19 global outbreak. The EHT Collaboration is now determined on the next steps to follow both in new observations and in the analysis of existing data. Geoff Bower, EHT Project Scientist based at the SMA facility in Hilo concludes: ​“This is a small piece of good news during this challenging time. We’re very happy to share with the world results from telescopes on Maunakea and around the globe the insights that we have made into black holes, the most exotic objects in the Universe. Both the SMA and the JCMT produced essential data to make these spectacular images, just as they did for Pōwehi. Stay tuned for new discoveries in the year still to come!”

Here in Hawaii, the state’s effort to “flatten the curve” in the fight against CoViD-19 means that many families now have children – keiki – distance learning at home. Together the Maunakea Observatories are supporting our community by providing online STEM resources for schools, teachers and families. The MKO@Home initiative was launched on March 23rd providing educational videos each Monday, Wednesday and Friday. Topics covered include careers, the solar system, recent discoveries, arts and crafts and more. This week MKO@Home will offer a range of activities and lessons involving Black Holes with a culminating event on April 10th, the State of Hawaiʻi’s Pōwehi Day. Four astronomy professionals will host a live panel discussion at 1:00pm HST answering viewers’ questions on all things astronomy and Black Hole related.

 

Further Information (Links):

Event Horizon Telescope
http://www.eventhorizontelescope.org/

First Image of a black hole, Poōwehi, obtained by the EHT (April 2019)
https://www.eaobservatory.org/jcmt/2019/04/powehi/

James Clerk Maxwell Telescope
https://www.eaobservatory.org/jcmt/

Pōwehi Day proclamation
Governor Ige declares April 10th – Pōwehi Day

MKO@Home on YouTube
http://bit.ly/mkoathome

 

Background Information:

The international collaboration announced the first-ever image of a black hole, Pōwehi, by creating a virtual Earth-sized telescope at the heart of the radio galaxy Messier 87 on April 10, 2019. Supported by considerable international investment, the EHT links existing telescopes using novel systems — creating a new instrument with the highest angular resolving power that has yet been achieved.

The individual telescopes involved in the EHT collaboration are at present: the James Clerk Maxwell Telescope (JCMT), the Submillimeter Array (SMA), ALMA, APEX, the IRAM 30-meter Telescope, the IRAM NOEMA Observatory (expected 2021), the Kitt Peak Telescope (expected 2021), , the Large Millimeter Telescope (LMT),, the Submillimeter Telescope (SMT), the South Pole Telescope (SPT), and the Greenland Telescope (GLT, since 2018).

The telescopes work together through a VLBI technique. This synchronises facilities around the world and exploits the rotation of our planet to form one huge, Earth-size telescope. VLBI allows the EHT to achieve a resolution of 20 micro-arcseconds — equivalent to identifying an orange on Earth as seen by an astronaut from the Moon. The data analysis to transform raw data to an image required specific computers (or correlators), hosted by the MPIfR in Bonn and the MIT Haystack Observatory.

The EHT consortium consists of 13 stakeholder institutes; the Academia Sinica Institute of Astronomy and Astrophysics, the University of Arizona, the University of Chicago, the East Asian Observatory, Goethe-Universität Frankfurt, Institut de Radioastronomie Millimétrique, Large Millimeter Telescope, Max-Planck-Institut für Radioastronomie, MIT Haystack Observatory, National Astronomical Observatory of Japan, Perimeter Institute for Theoretical Physics, Radboud University and the Smithsonian Astrophysical Observatory.

 

Original Paper:

J.Y. Kim, T.P. Krichbaum, A.E. Broderick, et al.: Event Horizon Telescope imaging of the archetypal blazar 3C 279 at an extreme 20 microarcsecond resolution, in: Astronomy & Astrophysics, April 2020
https://doi.org/10.1051/0004-6361/202037493

 

Contact:

Dr. Jessica Dempsey
James Clerk Maxwell Telescope, East Asian Observatory
Email: j.dempsey@eaobservatory.org

Dr. Jae-Young Kim
Max-Planck-Institut für Radioastronomie, Bonn.
Fon: +49 228 525-431
E-mail: jykim@mpifr-bonn.mpg.de

Explore the universe from home with Maunakea Observatories

This article appeared in the University of Hawai’i News on April 6th

In response to the interruption of hands-on science education and outreach during the COVID-19 crisis, the Maunakea Observatories (MKO) have unveiled a distance learning program, MKO@Home online. The virtual project consists of short weekly videos that feature astronomy related activities, demonstrations and interviews.

“The Maunakea Observatories recognize the severe educational difficulties that COVID-19 is creating for the community, and we are doing as much as we can to address this challenge. We are rallying all of our outreach resources and will be presenting as much content as possible during this unprecedented crisis,” said Bob McLaren, University of Hawaiʻi Institute for Astronomy interim director.

MKO@Home videos featuring scientists and educators are designed to allow K–12 students and families to explore the universe from home.

Content for the pilot program ranges from lessons on the night sky, to Pōwehi, the now-famous supermassive black hole. The cosmic wonder was given a name in ʻōlelo Hawaiʻi or Hawaiian language by UH Hilo professor Larry Kimura. The name recognizes the instrumental role that observatories on Maunakea played in the worldwide effort to capture an image of a black hole for the first time in history.

Dr Harriet Parsons, presents “exploring Shadows” as part of MKO@Home

April 6–10, MKO@Home will celebrate Black Hole Week and feature demonstrations by Maunakea astronomers about the mysterious objects.

MKO@Home videos are uploaded three times a week on Mondays, Wednesdays and Fridays.

  • For more, go to Maunakea Observatories.
  • To watch all of the EAO videos on MKO@Home and more, visit our Videos page here.
  • Subscribe to the MKO@Home videos on the Maunakea Observatories YouTube Channel here.

JCMT Astronomer helps shed new light on black hole ejections

Dr. Alexandra Tetarenko

Maunakea astronomer, Dr. Alexandra Tetarenko, who works at the James Clerk Maxwell Telescope, has been collaborating with a research group led by Oxford’s Department of Physics which has observed a black hole ejecting material at close to the speed of light, out to some of the largest separations ever seen. These observations have allowed a deeper understanding into how black holes interact with their environment.

Dr. Tetarenko’s research uses a number of telescopes around the world, including the facilities here on Maunakea, to study transient astrophysical systems – objects that change brightness on short timescales. “The system we studied in this instance contains a dynamically confirmed black hole within our Galaxy and another star (not too dissimilar from our sun) orbiting one another. The black hole, due to its strong gravitational pull, syphons material from its companion star in a process known as accretion” says Dr. Tetarenko.

Lead author, Joe Bright, a PhD student at Oxford University’s Department of Physics explains: “Most importantly to this work is the fact that the material is not all lost into the black hole. Outflows are launched away from the black hole at extreme velocities – almost the speed of light – and can be observed with radio telescopes.

“Our research group, consisting of many international astronomers, led an extensive observing campaign on this particular system, known as MAXI J1820+070, after it went into a bright outburst in the summer of 2018. This in itself was remarkable as this type of transient astrophysical system mostly accretes a very small amount of material and so can’t be seen; they do however occasionally go into outburst and only then are they observable.”

A series of images of the black hole MAXI J1820+070 throughout its 2018 outburst, taken with several different radio telescopes. The solid white line marks the position of the black hole, and the dotted lines show the movement of two ejections of plasma launched during the outburst.

The observing campaign of MAXI J1820+070 used the Very Long Baseline Array (VLBA), which has an antenna located in Hawaii on the slopes of Maunakea, along with other telescopes in the UK, USA, and the newly operational MeerKAT telescope in South Africa. “With these facilities we were able to track the connection between accretion and outflows. More excitingly, we were able to observe the system launching ejections of material, and to track these ejections over a wide range of separations from the black hole” explains Dr. Tetarenko.

The group successfully continuously tracked these ejections to extreme distances from the black hole with a range of radio telescopes and the final angular separation is among the largest seen from such systems. The ejections are moving so fast that they appear to be moving faster than the speed of light – they are not, rather this is a phenomenon known as apparent superluminal motion.

Co-lead on the project, Dr. Rob Fender said “We’ve been studying these kinds of jets for over 20 years and never have we tracked them so beautifully over such a large distance. To see them so early on in the operation of a new facility like MeerKAT is fantastic, and – as is often the case – teaches us not to confidently predict what we’re going to see in the future”.

Using the series of radio observations in this study, the authors were able to better estimate how much energy is contained in these ejections using a novel method for this type of system. “Galactic black holes, such as MAXI J1820+070, are thought to be miniature versions of the supermassive black holes that are found at the centre of galaxies. The feedback from these supermassive black holes is thought to be a vital component regulating the growth of galaxies – but these systems evolve on timescales much longer than a human lifetime. Their galactic counterparts, however, evolve quickly and are therefore the perfect systems to study the feedback process and its connection to accretion” explains lead author Joe Bright.

This work is published in the journal Nature Astronomy: https://www.nature.com/articles/s41550-020-1023-5

-20200302

Maunakea Wonders Teacher Workshop 2019

October 30th, 2019 kicked off the fourth “Maunakea Wonders Teacher Workshop” in collaboration with the University of Hawaii Hilo Masters of Arts in Teaching program.  The “Maunakea Wonders Teacher Workshop” program gives participants a background on the existing Maunakea Observatories, the scientific discoveries being made, the engineering/instrumentation capabilities, the jobs and career paths available to our island’s students, and our Education and Public Outreach efforts. EAO staff had a great time talking story with the students and sharing hands-on activities that they can take back to their own classrooms. A big mahalo to Alyssa from Gemini Observatory for giving an ‘out of this world’ demonstration on how to use the portable starlab planetarium for many different lessons and age ranges. On Saturday, November 2nd participants had a fantastic time at the Imiloa Astronomy Center where they were treated to a custom planetarium show, a special cultural presentation with Kumu Leilehua Yuen, and a Maunakea Resource presentation by the Office of Maunakea Management.  On our final day in the classroom, November 13th, Senior Scientist Steve Mairs had us recreating the scale of our solar system with a golf ball. Telescope System Specialist Miriam Fuchs got us to do a dance battle between gravity and fusion. Our panel of five EAO/JCMT employees shared stories and experiences that set them on their career path. It’s been a fantastic workshop and we’ve had a blast connecting with these passionate soon-to-be teachers.

   

First Light with new JCMT receiver `Ū`ū

Congratulations to both ASIAA and JCMT staff! We achieved first light with our receiver `Ū`ū on Friday, October 4th, 2019. `Ū`ū is part of the Nāmakanui instrument and works at wavelengths around 1.2mm. Our first observation was taken of CRL2688, a bright sub-mm source between a red giant and planetary nebulae.

Nāmakanui has been offered to JCMT users for single dish observing, initially at 230GHz and later at 345GHz.`Ū`ū is a dual polarization 2-sideband receiver with up to 8GHz of bandwidth (less when using ACSIS). `Ū`ū will be much faster than Rx3Am (which was retired in June 2018) for similar observations. The JCMT Heterodyne Integration Time Calculator https://proposals.eaobservatory.org/jcmt/calculator/heterodyne/ has been updated for `Ū`ū observing.

 

-20191005

Event Horizon Telescope Collaboration Wins 2020 Breakthrough Prize in Fundamental Physics

On Thursday, September 5th, 2019, the Event Horizon Telescope Collaboration was announced the winner of the prestigious Breakthrough Prize in Fundamental Physics. The $3 million prize, also known as the “Oscars of Science”, will be shared equally with 347 scientists co-authoring any of the six papers published by EHT. JCMT staff feel truly honored to have contributed to the Event Horizon Telescope Consortium that captured the first ever image of the Black Hole, Pōwehi, and look forward to our next EHT observing run in Spring of 2020. Deputy Director of JCMT, Jessica Dempsey, will be donating her portion of the award to the A Hua He Inoa program committed to propelling Hawaiian language and traditions to the global astronomical stage.

 

Event Horizon Telescope Collaboration: Winner of the 2020 Breakthrough Prize in Fundamental Physics

We’re pleased to announce that this year's Breakthrough Prize in Fundamental Physics goes to the Event Horizon Telescope Collaboration. The prize recognizes the team's extraordinary achievement in producing the first photograph of the “shadow" of a black hole. The experiment involved hundreds of collaborators across 8 telescopes, 60 institutions and 20 countries. Tune in to the Breakthrough Prize ceremony on the National Geographic channel November 3. More at https://breakthroughprize.org/News/54.

Posted by Breakthrough on Thursday, September 5, 2019

 

-20190909

Discovering Magnetized Inflow Accreting to the center of Milky Way Galaxy – An important force to transport gas to the supermassive black hole Sagittarius A*

Is magnetic field an important guiding force for gas accreting to supermassive black hole (SMBH) — for example, the one that our Milky Way Galaxy hosts? The role of magnetic field in this subject is little understood and trying to observe it has been challenging to astronomers. Researchers at the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), Taiwan, led by Dr. Pei-Ying Hsieh, have utilized a measurement of high resolution data by using the instruments on the James Clerk Maxwell Telescope (JCMT). Their result provides clear evidences in showing that the orientation of the magnetic field is in alignment with the molecular torus and ionized streamers rotating with respect to Sagittarius A* – the black hole our home galaxy hosts. The findings are published in Astrophysical Journal in 2018 August 2nd (2018, ApJ, 862, 150).

Color-composite images of the SMA map tracing the molecular gas of the CND (blue) and the Very Large Array (VLA) 6 cm map tracing the mini-spiral (red). The magnetic field of the JCMT-SCUPOL data and the model are overlaid with the white segments in the upper right and low left panel, respectively. The location of SgrA* is labeled with the black cross. The CND is a molecular torus (ring) rotating with respect to the supermassive black hole SgrA* in our Galaxy. The mini-spiral is hypothesized to be originated from the inner edge of the CND. The alignment of the magnetic field line along with the CND and the mini-spiral tells us that they are linked with a coherent magnetic field. The team found the magnetic field is able to guide the ionized particles from the CND to the mini-spiral, which suggests a picture the footprint of inflow near SgrA*. In the lower right panel, the latest dust polarization data taken in 2017 measured with the new instruments POL-2 installed in JCMT is shown. The magnetic field is shown with the white segments. An improved spatial coverage and sensitivity clearly reveal the connection between the CND and the mini-spiral at even higher spatial sampling than the JCMT-SCUPOL data, which confirm the picture the team proposed.


SgrA* – the best laboratory to study black hole feeding in the sky

Sagittarius A* (SgrA*),  being the closest SMBH in our home in the universe, the Milky Way Galaxy, has been targeted by many scientists to understand the nature of gas accretion in the past decades. Observing the gas accretion onto SMBH is critical to help us to understand how it releases tremendous energy.

The circumnuclear disk (CND) is a molecular torus rotating with respect to SgrA*, within which are the ionized gas streamers called mini-spiral (also called SgrA West) filling the molecular cavity. The mini-spiral is hypothesized to be originated from the inner edge of the CND. The CND, being the closest “food reservoir” of SgrA*, is therefore critical on the understanding of the feeding of SgrA*. However, looking for the physical evidences to connect the CND and the mini-spiral puzzles astronomers since they were discovered a few decades ago.

Intensive measurements of dynamical movements orbiting SgrA* have been done in the past decades, but another important force – the magnetic field – is rarely probed. This is solely because the weak polarized signal generated by the magnetic field from dust emission is difficult to measure. However, the magnetic field is expected to be important for material orbiting within and around the CND as the magnetic stress acting on the rotating disk can exert a torque to extract angular momentum from rotating gas, and thus drive gas inflows. Besides, The magnetic tension force is also possible to draw the gas back from the gravitational pull. Taking advantage of excellent atmospheric conditions of Mauna Kea summit at 4000 m, and large aperture size of the JCMT (15 m in diameter), the submillimeter polarization experiments were successfully obtained toward the Galactic Center to understand the role of magnetic field.

Tracing Magnetized Accreting Inflow

The team utilized the dust polarization data obtained by the JCMT-SCUPOL instrument to image the orientation of the magnetic field. A detailed comparison with higher-resolution interferometric maps from the Submillimeter Array (SMA) reveals that the magnetic field aligns with the CND.  Moreover, the innermost observed magnetic field lines also appear to trace and align with the mini-spiral coherently. This is the first attempt to reveal the footprint of inflow linking the CND and the mini-spiral since they were discovered a few decades ago. The comparison of the model and data reinforces the key idea that the CND and the mini-spiral can be treated as a coherent inflow-system.

The team found that the magnetic field is dynamically significant towards the CND and the mini-spiral. This finding tells us that the magnetic field is able to guide the motion of the ionized particles originated in the CND, and produce the observed spiral pattern of the mini-spiral. Dr. Hsieh said, “We found the magnetic field is critical to explain the inflow structure and will also help to understand the inflow picture in other galaxies hosting black hole similar to SgrA*. “

Paper and research team:

These observation results were published as Hsieh et al. “A Magnetic Field Connecting the Galactic Center Circumnuclear Disk with Streamers and Mini-spiral -Implications from 850 micron Polarization Data” in the Astrophysical Journal (published in the Astrophysical in August 2nd).

This research was conducted by:

Hsieh, Pei-Ying (ASIAA); Koch, Patrick M. (ASIAA); Kim, Woong-Tae (SNU); Ho, Paul T. P. (ASIAA; EAO); Tang, Ya-Wen (ASIAA); Wang, Hsiang-Hsu (CUHK)

This research is supported by the Ministry of Science and Technology (MoST) of Taiwan through the grants MoST 105-2811-M-001-141, MoST 106-2811-M-001-136, MoST 104-2119-M-001-019-MY3, MOST 105-2112-M-001-025-MY3, Academia Sinica Career Development Award, and the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST; No. 3348-20160021).

Related Links:

https://sites.google.com/asiaa.sinica.edu.tw/newsite/ASIAA_TAIWAN_News/20180817

https://www.asiaa.sinica.edu.tw/news/shownews.php?i=0e2af7b8c43775f78802f11ca0063488

-20180816

RxA3m Retires

     We are only as good as the instruments we have. With this sentiment in mind, we make way for the next generation of instruments as we retire one of our long-serving heterodyne receivers, RxA3. 

RxA3m in the receiver cabin at JCMT

     RxA3 (http://www.eaobservatory.org/jcmt/instrumentation/heterodyne/rxa/) has been a stable source of great science for the JCMT since it was built by the Herzberg Institute of Astrophysics and delivered in 1998. It has served our JCMT user community well and the data collected from RxA3 will be utilized still for years to come. 

The GLT receiver installed at the JCMT when it was being tested in August 2017.

      With the retirement of RxA3, JCMT prepares for it’s replacement to arrive in January 2019 and hopes to be on sky by April 2019 in time for the next Event Horizon Telescope observing run. The replacement will be a three-receiver cryostat identical to that installed on the Greenland Telescope (GLT), and is estimated to be able to complete observations in approximately 1/4 of the time required by RxA3.
                      -2018/07/05

First observations of the magnetic field inside the Pillars of Creation: Results from the BISTRO survey

The BISTRO (B-Fields in Star-Forming Region Observations) Survey has for the first time mapped the magnetic field in the dense gas of the ‘Pillars of Creation’, using instruments on the James Clerk Maxwell Telescope (JCMT). The Pillars of Creation, in the Messier 16 star-forming region, which is also known as the Eagle Nebula, were the subject of one of the most iconic images taken by the Hubble Space Telescope (HST). The Pillars are a set of columns of cold, dense gas protruding into a region of hot, ionized plasma. The Pillars have nurseries of new stars forming at their tips, and are a particularly dramatic example of a feature found in many regions of interstellar space in which high-mass stars are forming.

We present the first high-resolution observations of the Pillars in polarized light at submillimeter wave- lengths – submillimeter light being on the cusp between infrared and radio waves, where the cold, dense dust and gas which will form the next generation of stars emits most of its light. Light emitted from these dusty regions is polarized perpendicular to the direction of its local magnetic field, and so we can use our observations to directly probe the magnetic field morphology within the dense gas of the Pillars of Creation. Our observations were taken at a wavelength of 0.85 mm as part of the BISTRO Survey, using the POL-2 polarimeter on the SCUBA-2 submillimeter camera at the JCMT. They show that the magnetic field runs along the length of the pillars, at a significantly different angle to the field in the surrounding ionized plasma, and has an estimated strength of approximately 170 − 320 microGauss (1.7 − 3.2 × 10−8 Tesla), an intermediate magnetic field strength for a region of space which is forming stars.

An illustrative figure of the BISTRO magnetic field vectors observed in the Pillars of Creation, overlaid on a HST 502 nm, 657 nm and 673 nm composite – HST imaging from Hester et al. (1996, AJ 111, 2349).

Young hot stars, with masses more than eight times that of the Sun, produce large numbers of high-energy photons. These high-energy photons ionize a volume of the region within which they form, splitting hydrogen atoms into pairs of protons and elections. As the shock front between the material ionized by the young stars and the untouched neutral material advances, complex structures form in the dense gas at the interface. Particularly, pillars of dense, neutral gas like those in M16 are found protruding into the ionized region, apparently left behind by the advancing shock front. The formation and evolution of these pillars is not well-understood – debate continues as to whether these pillars form behind obstructions to the shock front, or whether they can form from turbulent instabilities in the shock front itself. The role of the magnetic field in the formation of the Pillars is particularly uncertain, since the strength of the magnetic field in the dense parts of the Pillars has not been measured until now.

BISTRO magnetic field vectors overlaid on a HST 502 nm, 657 nm and 673 nm composite image of Pillar II. The magnetic field runs roughly parallel to the Pillar’s axis. No polarization is detected at the Pillar’s tip – this depolarization is consistent with a horseshoe-shaped magnetic field morphology on scales smaller than the beam.

Our observations of the magnetic field running along the length of the Pillars are consistent with the Pillars being formed by compression of gas with an initially weak magnetic field: the magnetic field has not had the strength to resist being dragged into its current configuration by the motions of the gas. However, the magnetic field strength appears to have been increased by being compressed in the forming pillars. The magnetic field strength that we estimate is large enough to magnetically support the sides of Pillars against collapsing radially under pressure from the surrounding hot plasma, and to prevent the Pillars collapsing under their own gravity. It is important to note though that the Pillars are still being destroyed by the same shock interaction that created them: the magnetic field that we measure is not strong enough to prevent the Pillars being gradually eroded from their tips by the effects of the young stars in the region. Our results suggest that the evolution and lifetime of the Pillars may thus be strongly influenced by the strength and orientation of their magnetic field: the Pillars’ longevity results from magnetic support.

Our proposed evolutionary scenario: (a) an ionization front moving perpendicular to the am- bient magnetic field approaches an existing over-density in the molecular gas. (b) The ionization front is slowed by the over-density. The flux-frozen magnetic field ‘bows’ into the forming pillar. (c) The com- pressed magnetic field supports the pillar against further gas-pressure- and gravity-driven radial collapse, but cannot support against longitudinal erosion of the over-density by ionizing photons. Throughout, dark blue shading represents molecular gas and light blue shading represents ionized material. The ionization front is shown as a black line. Grey dashed lines indicate the local magnetic field direction. Red arrows represent photon flux, black arrows represent magnetic pressure, and green arrows represent thermal gas pressure.

The James Clerk Maxwell Telescope, located on Mauna Kea in Hawaii, is operated by the East Asian Observatory. The BISTRO Survey is a large team of scientists working to understand the role of mag- netic fields in the formation of stars, with members from across the partner regions of the East Asian Observatory: China, Japan, South Korea, Taiwan and Vietnam, and from participating universities in the United Kingdom and Canada.

This research has been accepted for publication by The Astrophysical Journal Letters. A pre-print is available at http://arxiv.org/abs/1805.11554.

Kate Pattle, Derek Ward-Thompson, Tetsuo Hasegawa, Pierre Bastien, Woojin Kwon, Shih-Ping Lai, Keping Qiu, Ray Furuya, David Berry and the JCMT BISTRO Survey Team

Inquiries about this research: Email: kpattle@gapp.nthu.edu.tw

The “Pillars of Creation” is one of the most well-known images in astronomy, and it is very exciting to be able to add to what is known about this part of the sky.  The pillars are beautiful structures – remarkable for their highly coherent structure within the dynamic and highly energetic environment of a region forming high-mass stars.  We have found that the magnetic field within the Pillars is well-ordered, running along the length of the pillars, and is strong enough to influence the future evolution of the pillars, helping to support them against collapse.  This is an intriguing result because it shows us that the magnetic field is important to the region now, but also that it was likely not very important during the period when the pillars were forming.  The field appears to have changed significantly from its original direction to run along the pillars as they were formed by a shock interaction caused by nearby young stars.  This could not have happened if the magnetic field were strong enough to resist being moved.  Our results suggest that the importance of the magnetic field to the Pillars of Creation has evolved over time along with the Pillars themselves.

The JCMT is the only telescope in the world which could have made these observations – the JCMT’s POL-2 polarimeter and SCUBA-2 camera are a unique combination of instruments, observing at the wavelengths at which cold dust in star-forming regions emits most of its light.  POL-2 provides information on the magnetic field on the scale of objects such as the Pillars of Creation which is not available anywhere else.

We have already had a proposal accepted by the Submillimeter Array (SMA) on Mauna Kea to observe the magnetic field in the tips of the pillars in more detail.  In our JCMT observations we see the magnetic field disappear at the tips of the pillars.  This “depolarization” could be caused by tangled magnetic field lines or a complete reversal of magnetic field direction in the pillars’ tips causing the field to cancel out in our observations.  By observing at higher resolution with the SMA we will be able to see what the magnetic field looks like on these small scales, and to better understand what role the magnetic field is playing in the shock interaction which is driving the pillars’ evolution.  We could also potentially look in more detail still at the magnetic field in clumps in the pillars’ tips using the Atacama Millimeter/submillimeter Array (ALMA) in Chile, or observe the pillars in polarized near-infrared light using the airborne SOFIA observatory.

-2018/06/05

SMU Removal

Check out our hardworking staff carefully removing the Secondary Mirror Unit (SMU). JCMT is currently closed (2.5 weeks in May 2018) as the SMU undergoes some important maintenance. The basics of the work being done:
1. Chopper performance and XYZ tables measurements
2. Remove the chopper and service the SMU tables (strip down, clean, lubricate, change belts)
3. Reassemble SMU tables, reattach chopper and service (balance, vibrators, flex pivots, LVDTs, stingers)
4. Finalize and implement new zero points, rollover points, and limits
**Many thanks to our TSS Kevin Silva for putting together this awesome timelapse compilation.**

-20180514

International Women’s Day 2018


March 8th, 2018 was International Women’s Day. The EAO celebrated by hosting a special event at the ‘Imiloa Astronomy Center that gathered together all of the women who contribute to the Maunakea organizations. We strongly believe that the future of Maunakea lies in the hands of the young people of these islands. The bright and talented young women of our community are enabled and empowered by seeing women in successful roles at all levels of scientific, political and business enterprise. This event provided one more step, in what we hope will be many, towards gender equity in the Maunakea organizations and beyond. We are thrilled with the amount of support we received following the event. See below for links to articles and news features.

VIDEO: Maunakea Observatories Mark International Women’s Day

 

Hawaii News Now video: Maunakea Observatories honor International Women’s Day by Celebrating its Female Astronomers

Hawaii Tribune Herald article: Women Astronomers Hope to Inspire Girls to Take Up Science

Big Island Now article: Women of Hawai‘i Astronomy Community Gather to ‘Press for Progress’

– 20180315

Membrane back on!

January 10, 2018  The JCMT’s protective membrane is back in place after our month of commissioning without it. Now we can go back to observing in reasonable wind and during the daytime!

 

-20180111

18-month twinkle in a forming star suggests
 the existence of a very young planet

Discovery made possible by a leap in submillimetre radio astronomy technology,
 comparable to viewing videos instead of photos.

November 1, 2017 — An international team of researchers have found an infrequent variation in the brightness of a forming star. This 18-month recurring twinkle is not only an unexpected phenomenon for scientists, but its repeated behavior suggests the presence of a hidden planet.

This discovery is an early win for the James Clerk Maxwell Telescope (JCMT) Transient Survey, just one-and-a-half years into its three-year mandate to monitor eight galactic stellar nurseries for variations in the brightness of forming stars. This novel study is critical to understanding how stars and planets are assembled. The survey is led by Doug Johnstone, Research Officer at the National Research Council of Canada and Greg Herczeg, Professor at Peking University (China), and is supported by an international team of astronomers from Canada, China, Korea, Japan, Taiwan and the United Kingdom.

“This variation in the brightness or twinkle of the star EC53 suggests that something large is disrupting the gravitational pull of the forming star. The fact that it recurs every 18 months suggests that this influence is orbiting around the star – it’s quite likely a hidden, forming planet,” says Doug Johnstone. It is thought that a companion planet is orbiting the star, and its passing gravitational pull disrupts the rate of the gas falling onto the forming star, providing a variation in the observed brightness, or light curve, of the star.

 

Young stars are born in regions of the galaxy where molecular gas is abundant. When the star is young, gas and dust form a thick cloud that surrounds the star. Some of this material quickly flattens into a disk, in which planets will form. The cloud blocks the star itself from optical view, so astronomers study the star indirectly by using the cloud to learn details about the star growing inside. The star builds up its mass as gravity attracts gas to move from the disk onto the star, a process that also releases significant energy that heats up the surrounding gas cloud. Astronomers use telescopes sensitive to sub-millimetre wavelengths, like the JCMT, to measure the cloud brightness and reveal details about the growth of the star.

EC53’s light curve anomaly was discovered by Hyunju Yoo, graduate student at Chungnam National University and advisor Jeong-Eun Lee, Professor at Kyung Hee University (South Korea), through careful analysis of monthly observations of Serpens Main, a stellar nursery known to contain many forming stars. Although the brightness of EC53 has been observed to vary periodically at near-infrared wavelengths for some time, these sub-millimetre observations were essential in validating that the brightness variation was due to heating from gas accreting onto the forming star, rather than variations in the cloudiness of the environment.

“What caught my eye was a new round of data that showed a sudden brightness that hadn’t existed in previous observations,” says Lee. “I knew that something unique and interesting must be happening around this forming star. It turned out that it is indeed a very special object, providing a new window into how stars and planets form.”

A deeper understanding of the formation of stars and planets

For the remainder of the three-year sub-millimetre survey, the team will continue to monitor EC53 and will also be searching for additional young stars showing variations in growth to learn more about how stars and planets assemble. There are already a half-dozen additional candidate variables within the survey. By studying these stars, and using additional telescope facilities such as the powerful Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, the study will provide new and unique insight into the timescale for the formation of stars and planets, including whether planets form during or after the assembly of the star.

“This discovery marks a turning point; in a sense, it’s like sub-millimetre astronomy is moving from taking pictures of our galaxy to taking videos,” says Greg Herczeg. “The last 25 years have been devoted to perfecting observing techniques and instruments to allow us to see early star formation. But with recent advances in technology, we can now observe regions changing over time, for a deeper understanding of how stars form. This discovery is just one example of how much more we can now learn.”

Monitoring the brightness of forming stars over time using sub-millimetre wavelengths is an unconventional approach to observing that has been made possible by recent advances in imaging technology, like SCUBA-2, and data reduction processing which enables precise calibration and measurement.

The JCMT resides at the summit of Maunakea in Hawaii and is the largest single-dish sub- millimetre telescope in the world. The JCMT is operated by the East Asian Observatory, a partnership between China, Taiwan, South Korea and Japan, with support from the astronomy communities in Canada and the United Kingdom. The university-led contributions from Canada are supplemented by the NRC’s support for the JCMT archive at the Canadian Astronomy Data Centre.

This discovery has been accepted for publication in Astrophysical Journal and is available online.

This story is distributed on behalf of: The National Research Council of Canada, Peking University and Kyung Hee University.

Contacts

Media Relations Team
National Research Council of Canada
1-855-282-1637 (in Canada)
1-613-991-1431 (elsewhere in North America)
001-613-991-1431 (International)
media@nrc-cnrc.gc.ca
Twitter: @nrc_cnrc

The Kavli Institute for Astronomy and Astrophysics (KIAA)
Peking University
Shuyan Liu
+86-10-6275-6630
shuyan@pku.edu.cn

Kyung Hee University
Min-Jae Jung
Communications team
+82-10-6626-6694
ddubi17@khu.ac.kr

James Clerk Maxwell Telescope
Steve Mairs
1-808-969-6572
s.mairs@eaobservatory.org

– 20171101

Upcoming IAU

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The largest gathering of astronomers from around the world will be happening this August in Hawaii!  The International Astronomical Union will assemble at the Honolulu Convention Center for six symposia and 22 focus meetings that will cover everything from the “Search for Water and Life’s Building Blocks in the Universe” to “Advances in Stellar Physics from Asteroseismology” and everything in between.  Of course we will be there!  For more information visit the event website at http://astronomy2015.org/

Save the Date: AstroDay

astrodayAstroDay is one of the most engaging outreach events on the Big Island and fun for the whole family!  Come on down to the Prince Kuhio Plaza in Hilo, Hawaii on Saturday, May 2nd from 10am – 4pm for a celebration of Astronomy and Hawaiian Culture.  The mall will be packed with exciting exhibits and interactive displays, live music and performances on a main stage, plus tons of free handouts and chances to win cool prizes.  We hope to see you there!

Successful “Journey”

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Telescope System Specialist, Callie Matulonis, visiting Mrs. Thatcher’s 5th grade class at Connections Elementary School. Photo Credit: Pam Thatcher

The Journey Through the Universe program is always an enormous success in Hawaii, and this year was no different.  Over the past 11 years, scientists, astronomers, and engineers have engaged over 50,000 students while visiting over 3,000 classrooms on the Big Island during the annual “Journey” week.  This March, several EAO staff presented exciting information and activities to over 100 students in grades 5-8 in the Hilo-Waikea Complex.  For more information on Journey Through the Universe visit http://www.gemini.edu/journey.

Upcoming “Journey”

Journey Through the Universe

Journey Through the Universe is February 27th – March 6th! A nationally recognized week long event in which astronomers visit local classrooms around the island while sharing their passion for physics and astronomy.  Several EAO staff members will be representing the JCMT and hoping to inspire a future generation of scientists!  Visit the Journey Through the Universe website for a complete listing of upcoming local events associated with Journey.