The 2019 JCMT Users Meeting is underway at ASIAA in Taiwan. If you wish to watch the talks remotely please visit the program pages. This link will also provide the pdfs of the talk being given, and pdfs of the poster presentations. EAO staff members Mark Rawlings, Sarah Graves and Alex Tetarenko are there in person throughout the meeting to answer any questions you might have about JCMT observing and data analysis.
JCMT has began a new era. Starting November 1st all data obtained at the JCMT will be observed remotely from Hilo. The first night of Remote Observing was staffed by JCMT Telescope Operator Mimi Fuchs.
JCMT astronomers who obtain data on a given night will now receive an automated email to inform them of observation being taken. At that time users are welcome to “eavesdrop” on operations by joining a remote connection directly to the JCMT Remote Observing Control room (JROC) in Hilo via the link provided in the automated email.
Dear JCMT Community,
We are pleased to announce that we have resumed night time operations at the JCMT. Our first night on sky way Sunday August 11th where we did a functional check out of our systems, took some engineering observations, followed by observations for the Large Program Queue. Our beloved Jim Hoge was the telescope operator in charge and was very happy to be back collecting precious scientific data. Currently we are limited to SCUBA-2 observing only whilst HARP undergoes engineering work. We hope to have it back on sky in September.
We would like to say a big thank you to our JCMT community for their support, patience and understanding. As always the safety of everyone on the mountain is of paramount importance to us.
East Asian Observatory is excited to announce that JCMT will be moving to fully remote operation from November 1st, 2019. From that date forward, JCMT will not require visiting observers to staff observing runs at the telescope.
The close collaboration between our user community and the Observatory is one of the greatest strengths of the JCMT. EAO will continue to enhance this relationship in the new era of fully remote operations via visiting young student programs, online real-time access to nighttime observing, and a range of other initiatives. We welcome your ideas and need your contributions to continue to produce the high impact science that we are all so proud of at JCMT. EAO welcomes short- and long-term visits to the Observatory to meet and collaborate with staff and learn about data reduction and analysis techniques. Astronomers wanting to work with our upcoming new instrument suite or utilize complex observing modes (e.g. VLBI) will also be encouraged to visit the JCMT to assist with commissioning efforts to ensure high quality science is produced.
In addition to welcoming visiting astronomers, the EAO will continue to host the JCMT Users Meeting yearly (this year in Taiwan) and will continue to send observatory staff to our regions when requested for workshops.
Remote operation is not a new concept for the JCMT, having been done in the past on occasion, and routinely via Extended Observing shifts since 2013/2014 (for more see the January 2014 Newsletter). Progress towards fully remote observing has been moving at an excellent pace. The observatory’s engineering team has been working hard this summer to overhaul and upgrade JCMT systems – including an overhaul of the roof and door hydraulics – and this work is on schedule to be complete well in advance of our planned switchover in November.
The Observatory appreciates your support and understanding as we advance into to this exciting new era for JCMT science. If you have any questions or concerns, please email our email@example.com.
As a reminder, to get up-to-date information about the JCMT please send an e-mail to firstname.lastname@example.org.
At the meeting the JCMT observatory had two major announcements:
1) The Observatory is seeking White Papers in support of a new 850 micron camera
The observatory seeks community input in the form of scientific White Papers in support of a new 850 micron camera for the JCMT. More information regarding the white papers will be provided at the EAO Futures Discussion wiki. Specifically White papers will be sought for:
The observatory is also soliciting for additional White Papers in addition to the above. All White Papers are to be submitted (visit the EAO wiki for a comprehensive list that have already been proposed). Deadline June 30th. A detailed description of the specification for the new 850 micron camera can be found here.
2) Announcing the JCMT Call for Large Programs (III)
The East Asian Observatory is pleased to provide an announcement of the third Call for JCMT Large Programs. At this time 4,800 hours will be available for Large Programs up until the end of the 2022B semester. This information is being provided ahead of the opening of the 20A Call in order for current and new teams to pursue discussion and planning. Submissions will be accepted from August 15th up until the September 15th deadline. This will likely coincide with the 20A PI Call. Fore more details click here. To reach the proposal handling system, Hedwig, and submit a proposal click here:
For further details visit our proposal web pages.
MAUNAKEA, HAWAIʻI –– Two of the world’s most powerful telescopes, located atop Maunakea, played a vital role in producing the world’s very first image of a black hole. Hawai‘i-based James Clerk Maxwell Telescope (JCMT) and Submillimeter Array (SMA) are part of the unprecedented Event Horizon Telescope (EHT) project. JCMT is operated by the East Asian Observatory; SMA is operated by the Smithsonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics.
In April 2017, a groundbreaking observational campaign brought together eight telescopes at six locations around the globe to capture an image of Pōwehi, a supermassive black hole at the center of the Messier 87 galaxy.
“Maunakea makes this discovery and the spectacular image of Pōwehi possible,” said Dr. Jessica Dempsey, deputy director of East Asian Observatory’s James Clerk Maxwell Telescope. “It’s perfect remote position, and the dry conditions on Maunakea’s summit, allow JCMT and SMA to collect the tiny amount of light that only touches our planet in a few very special places. Like the mountain itself, every drop of light we gather is precious.”
Astronomers collaborated with renowned Hawaiian language and cultural practitioner Dr. Larry Kimura for the Hawaiian naming of the black hole. Pōwehi, meaning embellished dark source of unending creation, is a name sourced from the Kumulipo, the primordial chant describing the creation of the Hawaiian universe. Pō, profound dark source of unending creation, is a concept emphasized and repeated in the Kumulipo, while wehi, or wehiwehi, honored with embellishments, is one of many descriptions of pō in the chant.
“It is awesome that we, as Hawaiians today, are able to connect to an identity from long ago, as chanted in the 2,102 lines of the Kumulipo, and bring forward this precious inheritance for our lives today,” said Dr. Kimura, associate professor at University of Hawai‘i at Hilo Ka Haka ‘Ula o Ke‘elikolani College of Hawaiian Language. “To have the privilege of giving a Hawaiian name to the very first scientific confirmation of a black hole is very meaningful to me and my Hawaiian lineage that comes from pō, and I hope we are able to continue naming future blackholes from Hawai‘i astronomy according to the Kumulipo.”
The SMA and JCMT telescopes are key members of the Event Horizon Telescope project, which links together strategically placed radio telescopes across the globe to form a larger, Earth-sized telescope powerful enough to see a Lehua flower petal on the moon.
“SMA and JCMT, working together as one ‘ohana, pioneered the revolutionary technique to see such tiny and faint objects and they were critical in capturing the image of Pōwehi,” said Geoff Bower, chief scientist for Hawai‘i operations of Academia Sinica Institute of Astronomy and Astrophysics. “The spirit of aloha required to unite scientists and observatories across the world was born right here on Maunakea. And powerful new capabilities coming soon at SMA and JCMT mean that Hawai‘i’s groundbreaking contributions to understanding our universe are just beginning.”
The participation of the SMA and JCMT as the far-west anchor point of EHT’s telescope array allowed astronomers to effectively observe and “photograph” supermassive black holes, among the most mysterious and powerful objects in the cosmos.
About James Clerk Maxwell Telescope
Operated by the East Asian Observatory, the James Clerk Maxwell Telescope (JCMT) is the largest astronomical telescope in the world designed specifically to operate in the submillimeter wavelength region of the spectrum. The JCMT has a diameter of 15 meters and is used to study our Solar System, interstellar and circumstellar dust and gas, and distant galaxies. It is situated near the summit of Maunakea, Hawai‘i, at an altitude of 4,092 meters.
The JCMT is operated by the East Asian Observatory on behalf of The National Astronomical Observatory of Japan; Academia Sinica Institute of Astronomy and Astrophysics, Taiwan; the Korea Astronomy and Space Science Institute; Center for Astronomical Mega-Science, China. Additional funding support is provided by the Science and Technology Facilities Council of the United Kingdom and participating universities in the United Kingdom and Canada. The East Asian Observatory also proudly partners with Vietnam, Thailand, Malaysia, Indonesia, and India. Click here for more information.
About Event Horizon Telescope
The EHT collaboration involves more than 200 researchers from Africa, Asia, Europe, North and South America. The international collaboration is working to capture the first-ever image of a black hole by creating a virtual Earth-sized telescope. Supported by considerable international investment, the EHT links existing telescopes using novel systems — creating a fundamentally new instrument with the highest angular resolving power that has yet been achieved.
The individual telescopes involved are; ALMA, APEX, the IRAM 30-meter Telescope, the IRAM NOEMA Observatory, the James Clerk Maxwell Telescope (JCMT), the Large Millimeter Telescope Alfonso Serrano (LMT), the Submillimeter Array (SMA), the Submillimeter Telescope (SMT), the South Pole Telescope (SPT), the Kitt Peak Telescope, and the Greenland Telescope (GLT).
The EHT collaboration 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-Universitaet Frankfurt, Institut de Radioastronomie Millimétrique, Large Millimeter Telescope, Max Planck Institute for Radio Astronomy, MIT Haystack Observatory, National Astronomical Observatory of Japan, Perimeter Institute for Theoretical Physics, Radboud University and the Smithsonian Astrophysical Observatory.
This research was presented in a series of six papers published today in a special issue of The Astrophysical Journal Letters.
- Paper I: The Shadow of the Supermassive Black Hole
- Paper II: Array and Instrumentation
- Paper III: Data processing and Calibration
- Paper IV: Imaging the Central Supermassive Black Hole
- Paper V: Physical Origin of the Asymmetric Ring
- Paper VI: The Shadow and Mass of the Central Black Hole
Dylan Beesley, Director, Bennet Group Strategic Communications
dylan at bennetgroup.com
Dr Jessica Dempsey, Deputy Director
j.dempsey at eaobservatory.org
Reactions to the news
- Representative Ed Case praised the work of Hawaii astronomers on capturing image of black hole
- Govenor Ige declares April 10th – Pōwehi Day
Selection of Media
- New York Times: “That First Black Hole Seen in an Image Is Now Called Pōwehi, at Least in Hawaii”
- Big Island Video Now: Hawaii Helps See, Name Black Hole
- NPR: Introducing Pōwehi, The World-Famous Black Hole
Regional Press Releases (in local language)
Additional resources including animations
The Women of Maunakea once again met to celebrate their achievements and seek more advancements at this years International Women’s Day event held on March 3rd at Imiloa Astronomy Centre, Hilo, Hawai`i.
At the event our organization introduced a new equality challenge for the entire astronomy community on Hawai‘i Island, pledging to support equality and diversity within their ranks. Jessica Dempsey, Deputy Director of EAO/JCMT stated that
“Living in one of the most diverse states in the country, host to the most female astronomers in the world, we are uniquely positioned to serve as a model of progress toward gender equity and diversity in the workplace”
Jessica seeks to get to gender parity within the ranks of the organization by 2024 .
The event has been followed with a number of social media posts by the Maunakea Observatories within Hawai`i in support of International Women’s Day 2019 held on March 8th (#IWD2019).
Big Island Video News – International Women’s Day Mixer At Imiloa
A new year and a new JCMT Observing Tool! This JCMTOT update includes support for Namakanui and a check of the distance between source and reference position during position switch observations.
If you are using the JCMTOT we hope you have also checked out this pdf presentation titled: “JCMT Observing Tool Tips and Tricks” it is highly recommended by support staff here at the observatory.
The birth of giant elliptical galaxies is a violent process, with most stars originating from incredible star-forming episodes and several galaxy mergers within large-scale structures (dubbed protoclusters). This formation process happened in the early epochs, when the Universe was only a few billion years old. Currently, researchers using the James Clerk Maxwell Telescope (JCMT) on Maunakea, Hawaiʻi are trying to locate the progenitors of elliptical galaxies, and thus protoclusters, using several observational techniques.
Astronomers have recently discovered a handful of rare, enormous nebulae that copiously emit in the Hydrogen Lyman-alpha transition, a tracer of intergalactic gas. These emissions cover vast distances, up to 30 times larger than the Milky Way. Most of these Enormous Lyman-Alpha Nebulae (ELANe) host multiple active galactic nuclei and are surrounded by several Lyman-alpha emission galaxies. These ELANe are prime candidates for progenitors of elliptical galaxies and massive protoclusters in the early stages of assembly. While these regions are promising, researchers are now tasked with determining the presence of protoclusters and of heavy star formation associated with each ELAN.
An international team of researchers started using the SCUBA-2 instrument on JCMT to characterize these protoclusters and the associated ELAN. Observing at 450 and 850 microns allows SCUBA-2 to capture the emission from dust powered by violent episodes of star formation, something that is not possible with optical telescopes.
Results from the targeted ELAN MAMMOTH-1 field (Fig. 1) revealed the presence of a violent starburst galaxy and emission from a veiled active galactic nuclei (Fig. 2). These sources likely power the extended Lyman-alpha emission, and could be the progenitor of an elliptical galaxy.
In addition, researchers find four times the number of dust-obscured sources in ELAN
MAMMOTH-1 compared to other standard regions. This likely confirms the presence of a rich structure surrounding ELAN MAMMOTH-1, and hints at the presence of a protocluster, hosting the progenitor of an elliptical galaxy. Figure 3 shows the distribution of Lyman-alpha emitting galaxies compared to the SCUBA-2 detections within the observed field. Hopefully, follow-up observations will confirm the relationship between these newly detected sources and a protocluster surrounding the ELAN. For now, these findings seem to agree with the expected theoretical characterizations of cosmic nurseries of giant elliptical galaxies.
European Southern Observatory/Max-Planck Institute for Astrophysics
Fabrizio Arrigoni Battaia
farrigon at eso.org
European Southern Observatory
ccchen at eso.org
James Clerk Maxwell Telescope
h.parsons at eaobservatory.org
About The Authors
The international authors of this paper are from European Southern Observatory, Germany, Durham University, UK, University of California, USA, Leiden University, Netherlands, Tsinghua University, China, and the Korea Astronomy and Space Science Institute, South Korea.
Comet 46P/Wirtanen is known as a hyperactive comet. Hyperactive comets are a small family of comets whose activity levels are higher than expected. In addition to being hyperactive 46P/Wirtanen will make the 10th closest ever cometary approach to Earth of modern times (0.08au) this month.
JCMT astronomers will take this opportunity to map the distribution of chemicals like hydrogen cyanide and methanol in this comet’s coma, to try and determine if these chemicals emerged directly from the comet nucleus or were formed in the coma from other chemicals. This mapping will be performed by the JCMT spectral line instrument; HARP. In addition to observing these chemicals the astronomers are hoping the comet will be bright enough to make other measurements that that will shed light on the original location and conditions of the comet’s formation within the very early stages of what we now know to be our Solar System.
For more information on comet 46P/Wirtanen visit: http://wirtanen.astro.umd.edu/46P/
This past week the JCMT was host to a film crew from the Australian Broadcasting Corporation, based in Sydney. The crew were visiting Hawaii as part of a science television program called Catalyst. Specifically they were out visiting the JCMT as part of a program about the Black Hole at the centre of our Milky Way, and how JCMT, along telescopes from around the world are coming together to form the Event Horizon Telescope – looking to take an image of the shadow around the Black Hole at the centre of our Galaxy.
The EAO Outreach Team was thrilled to be invited to help out at the 2018 STEM Fest event held in Waimea at the Kahilu Town Hall for Big Island Girl Scouts. The event, attended by 75 girls on November 17th, provided the opportunity to experience hands on activities from a variety of science and engineering fields.
JCMT staff members Alexis Achohido and Mimi Fuchs worked with Girl Scouts to discover how astronomers know what stars are made of. In particular we highlighted the work of Cecilia Payne-Gaposchkin, who proposed a theory for the composition of stars in her 1925, her PhD Thesis!
As well as looking at what stars are made of we also looked at what dense interstellar dust clouds are made of and made our very own candy molecules.
In July 2018, the Maunakea Gender Equity and Diversity Committee distributed a survey to the staff at the Maunakea astronomical organizations. The survey was intended to invite opinion on the current state of equity and diversity in the Maunakea astronomy community and seed conversation and ideas for enhancing diversity and inclusion in our organizations across our islands.
The report on the results of the survey is here:
and the Appendix A, listing the survey questions, is provided for reference:
The first results are presented by Jessica Dempsey at the Maunakea Users’ Meeting on October 4th, 2018. A PDF of the talk is linked here for convenience. For usage or distribution of these data, please contact Jessica Dempsey: j.dempsey “at” eaobservatory.org.
POL-2 is the JCMT’s sub-millimeter polarimeter working at both 450 and 850 microns. POL-2 is a polarimeter not a detector, and so requires SCUBA-2 for use. It is used to trace the alignment of dust particles at sub-millimeter wavelengths and thus the magnetic field orientation and strength (with some additional physics added into the mix) of regions in our Universe!
Recently it has been found that sometime there is a loss of synchronisation between data values and pointing information in the data reduction process (CALCQU, run by pol2map as part of step 1). This loss of synchronisation is triggered by anomalous values in the array of HWP (Half Wave Plate) angles stored in the raw data. The result is blurring (or smoothing) of sources in some POL-2 maps (see figure below).
The fix is to download our rsync this build of the starlink software and re-reduce your data. If you look at your re-reduce data you may find that some of your maps improve, depending on whether any of your observations suffered from the blurring problem. The size of the improvement will depend on how many blurred observations you have.
For regions where multiple observations were used to produce the final maps the issue may have been less pronounced if obsweight=yes was used.
In addition, users wishing to reduce POL-2 450 micron data are asked to ensure the data have been reduced using the latest starlink 2018A software prior to this release there was a bug in the software which caused a 4 degree difference in the angular zero point at 850 and 450, so all 450 vector maps produced so far will have a systematic error of 4 degrees in the vector angle, unless updated software (rsync starlink or 2018A starlink) was used.
Also did you know you can combine various I maps into a cube to view as a movie? You can do this (assuming you ran pol2map with “mapdir=maps”) by running:
paste in=maps/\*Imap out=Icube shift=\[0,0,1\]
Then in gaia, in the pop-up window that holds the cube visualisation controls, drag the “Index of plane” slider left or right to step through the planes in the cube!
You can do the same for the Q or U maps by replacing “I” with “Q” or “U” above (note, that’s an upper case “I” for the externally masked I maps – use a lower case “i” for the auto-masked I maps).
In May our engineering staff undertook major maintenance work of the Secondary Mirror Unit on the JCMT. After this work it was noted that the Secondary mirror was sometimes vibrating, which lead to beam deformation. This was noticed due to sporadic increased FCF values – and could also be seen in the aspect ratio of our calibrators (see image below). Observers who collected data between UT dates May 24th 2018 and 08:10UT on June 30th 2018 should be aware of this issue. Astronomers who may have affected observations should check their data closely. This issue was noted to be intermittent. If you have questions about the data quality please contact your Support Scientist or the observatory directly.
On June 30th, we applied a temporary work-around to account for these SMU vibrations. To implement a more permanent solution, the observatory briefly removed the GoreTex membrane to work on the Secondary Mirror Unit. This work was performed between Tuesday July 24th, and Monday, July 30th. The PI and Large Program time were unaffected.
Below is a plot showing the aspect ratios of calibrator CRL 2688 over time. The blue, shaded region represents the nominal values. Note that the high aspect ratios observed in between the temporary and permanent fix (boxed in red) were part of a low elevation, poor weather (wet grade 5), poor seeing engineering and commissioning project. Regular observing was unaffected.
Members of the CHIMPS-2 Large Program met for a two day meeting in Liverpool on June 28th and 29th. The meeting covered data collection, reduction and analysis with astronomers from all over the globe. For more information on the CHIMPS-2 project click here. We wish the team “clear skies” as they look to expand the JCMT CO heterodyne data towards the Galactic Centre this summer.
We are always striving to do better at the JCMT and that means we often update our software. One software update that uses should be aware of is a new version of the JCMT Observing Tool.
It is particularly important to note that the OT version used for all semester 18B MSB preparation must be 20180516 (or newer). This may be checked via the OT start-up splash screen and also via the “Help -> About” menu option.
The JCMT 2018 User Meeting held in Seoul, South Korea was a success last week, with 39 science talks spread over two days. The pdf’s of the talks and posters can be found at the following link: User Meeting Program.
From time to time the JCMT is closed due to major maintenance work. The next scheduled closure of the JCMT will occur from April 30th 2018 to mid May 2018. During this time the Gore-Tex membrane windblind will be removed to provide access to the Secondary Mirror Unit for maintenance work. As the telescope will be unavailable for science during this time the SCUBA-2 Gas Handling System will also be worked on. SCUBA-2 will be warm during this period and should back to operational temperature/available for science use by the end of May.
The staff at EAO would like to announce that we are planning an approximately month-long observing campaign without our iconic Gore-Tex membrane windblind.
The removal of the membrane is due to the high demand for sub-mm polarimetry. Currently the instrument POL-2 is commissioned and working beautifully at 0.85mm, with some fantastic science results. POL-2 science at 0.85 mm has been so successful that we are keen to see if operating without the membrane – which can limit the throughput and increase instrumental polarization – we can commission POL-2 at 0.45 mm.
Observing without the membrane is not our normal mode of operation and the telescope will have additional operational limitations during this time. The JCMT will not take daytime observations and the operational wind limits will be reduced.
We expect to remove the membrane early in December and thank the JCMT astronomical community for their support.
The Greenland Telescope (GLT) is a novel project; taking a 12-meter radio antenna – prototype for the Atacama Large Millimeter/Submillimeter Array (ALMA) project from Chile, and relocating this telescope to Greenland.
By repurposing this telescope astronomers can take advantage of the near-ideal conditions of the Arctic to study the Universe at specific radio frequencies. Whilst the telescope is being commissioned the initial receiver that will be used at the GLT is being tested at the JCMT in Hawaii. Last week the alignment of the instrument was performed this morning using the Sun as a source – and at the JCMT the first astronomical source for this instrument!
The EAO Mid Term Review committee are meeting this week in Hilo to discuss the future of the JCMT. When the East Asian Observatory took over operation of the JCMT back in 2015 it was for an initial 5 years. Since that time we have had 5 semesters of great science. We have successfully completed three large programs (S2COSMOS, SCOPE, MALATANG). We have uncovered new star-forming events in the sub-mm. We have discovered stellar mass black holes. Our EAO regions have gained access to both Subaru and SMA. Recently we welcomed Vietnam as an observing partner in the JCMT. So much to celebrate!
EACOA Fellow Dr Tie Liu is the first EACOA Fellow to come to work at the EAO office in Hilo, Hawaii from KASI.
Tie Liu’s main research interest is high-mass star formation and molecular clouds. Tie is the head of a large consortium undertaking the SCOPE, SCUBA-2 Continuum Observations of Pre-protostellar Evolution, program studying Planck cold clumps at JCMT. This program is now (as of July 2017) complete after 300 hours of SCUBA-2 time over the past year and a half.
Tie is now turning the focus of this study to follow-up observations with JCMT (e.g. POL-2) as well as many other telescopes (e.g., ALMA, SMA, NRO 45-m, KVN, FAST 500m …).
The Staff at EAO are pleased to welcome Tie Liu into the scientific division and hope many more astronomers decide to visit JCMT in the future as long term visitors, to engage directly with JCMT staff.
A research team led by Japanese astronomers using data taken with the James Clerk Maxwell Telescope (JCMT), have conducted detailed radio spectral observations of molecular gas around the nucleus of our Milky Way Galaxy, Sgr A*.
As a result, the team has discovered two compact molecular clouds that have extremely broad velocity widths at distances of approximately 20 light years from Sgr A*. Despite the fact that these peculiar clouds have large kinetic energies, no energy source has been found there. Thus, the team interprets that each of the clouds is driven by the high-velocity plunge of an isolated (invisible) black hole without a companion star into a giant molecular cloud. This implies that multiple “stray black holes” are floating around a supermassive black hole lurking at the Galactic center.
1. Important Points
- The team studied two unusual molecular clouds. These two clouds were discovered in the vicinity of the Galactic nucleus of the Milky Way, Sgr A*. Their motions and physical properties were studied and their motions were deemed to be abnormal.
- The origin of each of unusual clouds cannot be explained by an interaction with a supernova. The clouds are also not explained by a bipolar outflow from a protostar. This implies that the origin is likely to be an obscure astrophysical phenomena.
- As a result of the large kinetic energies observed combined with no a lack of an obvious energy source, the team theorizes that the driving sources may be black holes rapidly plunging into molecular clouds.
2. Research Background
The Galactic nucleus Sgr A* is located at a distance of approximately 26,000 light years from the Earth, and recognized as a supermassive black hole with 4 million solar masses. The origin of the supermassive black hole remains unresolved. In contrast, a stellar mass black hole, which has a mass ranging from about three to several tens of solar masses, is known to be formed by the gravitational collapse of a massive star heavier than 30 solar masses. It is theoretically predicted that several hundred million stellar mass black holes lurk in the Milky Way.
However, the number of black hole candidates currently detected in the Milky Way is only 60. In general, gas and dust drawn by the gravitational force of a black hole constitute an accretion disk around it. After the materials are sufficiently accreted and the accretion disk gets hotter and emits intense electromagnetic waves. Typically stellar mass black holes in the Milky Way have been found by detection of X-ray radiation from their accretion disks. In order for an accretion disk to be continuously shining, a fueling source, i.e. a companion star, must be in the close vicinity of a black hole. However, such black holes (those with close companions) are very rare. Most of back holes are likely to be isolated and inactive. Thus, countless “stray black holes” should be floating in the Milky Way.
3. Research Results
The research team conducted spectral line observations of the Galactic central region within 30 light years of the Galactic nucleus Sgr A* to investigate kinematics and physical properties of molecular gas surrounding the nucleus, using the JCMT. In the observations, the team discovered two unusual molecular clouds (HCN–0.009–0.044 and HCN–0.085–0.094) with diameters of about 3 light years and extremely broad velocity widths wider than 40 km/s (See Figure b below). Each of these unusual clouds appears to stem from a larger cloud. Their motions seem to be different from those of well-known molecular clouds around the nucleus (See Figure a, and c below).
These motions imply enormous kinematic energies (>1047 erg). Such enormous kinetic energy may be produced by an interaction with a supernova explosion or a bipolar outflow form a bright massive protostar. However, no evidence of a supernova or a bright protostar was found toward these peculiar clouds. The origin is probably “something” other than well-known astrophysical phenomena; inactive stellar mass Black Holes.
The team proposes that the high kinematic energy results from: “a high-speed compact gravitational source plunging into a molecular cloud and the gas is dragged along by the gravity of the compact source to form a gas stream.”
According this “plunge scenario”, such unusual clouds can be formed in two cases as follows:
- A massive compact object with a mass larger than about 10 time the mass of our Sun plunges with a high velocity of about 100 km/s into a molecular cloud.
- A compact object with a mass similar to that of the Sun plunges with a ultra high velocity of about 1000 km/s into a molecular cloud.
In the case 1), the candidate for the plunging object is a massive star or black hole. In the case 2), the candidate is a hypervelocity star which moves so fast that it can escape from the gravity of the Galaxy. However, no hypervelocity star has been found in the Galactic center and the number is theoretically predicted to be much less than that of black holes. Therefore, the driving sources of the two discovered clouds are likely to be massive stars or black holes. In addition, no bright massive stars have been found toward these clouds. Thus, a “stray black hole” floating around the supermassive black hole is the most plausible candidate for each of the driving sources of the two clouds.
4. Research Significance
This work is very meaningful since the possibility that a number of “stray black holes” are floating around a supermassive black hole at the Galactic center was indicated by the observational study for the first time.
The team has already discovered the peculiar molecular cloud in the Galactic disk (Bullet) that may also be driven by a high-velocity plunge of a stray black hole (Yamada et al. 2017, https://www.nao.ac.jp/en/news/science/2017/20170202-aste.html).
These studies which are based on spectral line observations of molecular gas suggest a new method of potentially discovering inactive isolated black holes that are undetected by traditional method such as X-ray observations. The number of black hole candidates is expected to dramatically increase by applying research methods similar to this work.
Recently, by detection of gravitational waves, it has been confirmed that black holes merge and grow. The team has also discovered a candidate for an intermediate mass black hole with a mass of 100 thousand solar masses at a distance of about 200 light years from the Galactic nucleus
(Oka et al. 2017, https://www.nao.ac.jp/en/news/science/2016/20160115-nro.html).
This intermediate mass black hole and stray black holes discovered in this work possibly contribute to growth of the supermassive black hole in future.
Inquiries about the research
Professor Tomoharu Oka
Department of Physics
Keio University Science and Technology
TEL: +81-45-566-1833 FAX: +81-45-566-1833
These observation results were published as Takekawa et al. “Discovery of Two Small High-velocity Compact Clouds in the Central 10 pc of Our Galaxy” in the Astrophysical Journal Letters in July 2017.
The team behind this work are Shunya Takekawa, a Ph.D. student at Keio University, Japan, and Tomoharu Oka, a professor at Keio University.
This study was supported by a Grant-in-Aid for Research Fellow from the Japan Society for the Promotion of Science (15J04405).
Hawaii Island Inquiries about the research
Dr Harriet Parsons
660 North A’Ohoku Place
Hilo, Hawaii, 96720
Astronomers from the East Asian Observatory/JCMT are in Taipei, Taiwan this week for the Asia Pacific Meeting of the International Astronomical Union (APRIM). If you are there please pop by our booth and say hello!
For two days at the end of June EAO/JCMT hosted its first “Maunakea Wonders Teacher Workshop” primarily aimed at newly qualified teachers here on the island of Hawai’i. One day was spent learning about the cultural, environmental and astronomical role Maunakea plays combined with a trip to visit the CFHT (Canada France Hawai’i Telescope), and the JCMT. The second day was spent in the classroom discovering what Hawaii more about astronomy on the big island and the resources available to the community, teachers and students in Hawaii.
The workshop was kindly supported by MKAOC/CFHT and the University of Hawai’i Hilo’s School of Education.
Open enrollment to any of the new or extended JCMT Large Programs has opened. To sign up visit:
Please note only astronomers from EAO regions and partners will be permitted to join. This open enrollment period will end at 8am HST on August 1st 2017.
SCUBA-2 has been back on the sky for the past month producing excellent data, following both planned engineering down time to work on the instrument cryogenics and unplanned – to fix a vacuum leak.
The end of 2016 was a busy time for the EAO ETIS (Engineering, Technical Information Systems) staff. From the middle of the 2016 we were aware of a change in performance of one of the (two) pulse tube coolers (PTC) that cools the SCUBA-2 inner radiation shields and internal mirrors to below 4K. We were able to continue to use SCUBA-2 without any impact on the quality of the data, while we planned the major task of taking the 3 tonne instrument off the antenna and replacing both of the instrument PTC cold heads with new remote motor models.
The dilution fridge mixture was removed and the warm-up started on October 5th. SCUBA-2 was back on the sky with new PTCs and was operational by November 18th, 1 week ahead of schedule. However, during the subsequent cooldown, the cryostat vacuum was found not to be as good as expected.
Later in December, when we temporarily warmed-up (to 4K) to replace a small pump in the dilution refrigerator (DR) gas handling system – a regular procedure, the poor vacuum became a serious issue. Additional problems with pumps in the GHS and too high a pressure in the DR still prevented cooling below 1K. This is well above the operating temperature of the TES detectors.
The only course was to warm the instrument to ambient temperature and to then carry out extensive leak checking of the cryostat. A leak was found that we could fix. However, on detailed inspection, we discovered that the O-ring between the feedthrough and the top plate of the DR insert was cracked and would fail soon if we did not replace it.
Two weeks of skill and persistence was required to replace this O-ring to enable SCUBA-2 to be yet-again pumped, leak checked and cooled prior to the end of January. With the vacuum leak fixed, the cause of the second issue with the GHS that prevented cooling below 1K became apparent. This issue was caused by a particle filter on the input of the pump. After removing the offending filter SCUBA-2 was operational by February 5th.
The loss of an additional 6 weeks of observing with SCUBA-2 impacted our users. However, by catching the failing O-ring before a total loss of vacuum, we avoided the potential for more serious consequences to the instrument and a bigger disruption of the observing schedule. An extended period of good stable weather in recent weeks has allowed some of the affected programs to makeup for the missed nights.
In addition to the cryogenic work, new improved thermal blocking filters have been installed between the instrument window and the band defining filters for the detector arrays. We are now investigating the change in optical power on the detector arrays, to see if this has modified the stray light environment within the 4K box and improved SCUBA-2’s performance.
Over the past two weekends the JCMT has been open and observing during the day. These daytime observations are needed to observe the middle atmosphere (altitude 70-110 km) of Venus.
The aim is to better understand atmospheric physics and chemistry. The way to advance understanding of fundamental atmospheric physics and chemistry in general is to study the atmospheres of individual planets – specifically in this case Venus!
The JCMT is used for this study because sub-millimeter spectroscopy is uniquely powerful for investigations of this altitude range on Venus. JCMT’s location on Maunakea, its ability to safely point arbitrarily close to the sun, and its observation flexibility (capability to modify observing strategies in as little as 5 minutes, during the observations) make it uniquely well-suited to Venus research.
Congratulations to Harriet Parsons who was nominated for 2016 Employee of the Year award. All nominees were awarded at a lunch on March 6th 2017. To see the video for all the RCUH nominees click here.
We are currently recruiting for an Electronic Engineer to join the EAO/JCMT Engineering Group. This group ensures that the telescopes and associated instruments are at a high level of operational readiness at all times. They apply technical knowledge in support of the testing, modification, maintenance, repair, and upgrading of EAO mechanical, electronic and electrical systems.
CLOSING DATE: March 24, 2017
For more information visit the EAO Jobs homepage.
The 2017 JCMT Users meeting was held in Nanjing, China. The two day meeting was held on Monday, 13th and Tuesday 14th of February. An additional 1 half-day data reduction workshop was held immediately after the meeting on Wednesday 15th of February. The meeting was well attended and all talks are now available online here. We hope you have a good productive 2017 and hope to see you at our JCMT 2018 Users meeting in South Korea next January.
The East Asian Observatory is happy to invite PI observing proposals for semester 17B at JCMT (for details see here). Semester 17B runs from 01 August 2017 to 31 January 2018.
In addition the East Asian Observatory is happy to accept proposals for Large Programs – running from 01 August 2017 to 31 January 2019. More details about the Large Programs (II) call can be found here.
You can reach the proposal handling system, Hedwig, and find complete details of this Call at:
Any further questions should be directed to our help desk: email@example.com
If this is your first visit to Hedwig, you should go to ‘Log in’ and generate an account. There is a ‘Help’ facility at the upper right corner, and individual Help tags at many other places.
The 17B Call and Large Program (II) call for Proposals closes on the 15th of March 2017.
The East Asian Observatory is pleased to partner with the Subaru Telescope to enable astronomers from an East Asian participant region to have access to Subaru time. The East Asian Observatory proposals are considered by the Subaru scientific panel alongside regular Subaru proposals, with a guaranteed award of time of a total of 3 nights of observing in the semester.
The EAO/JCMT is currently seeking an astronomer to join its team of support scientists. Duties include: Assists visiting astronomers in obtaining high-quality observational data; provides technical, scientific, and logistical support to astronomers before, during, and after their observing runs, and assists with their data analysis. Performs general and specific support of the telescope operations and/or instruments and their development. Undertakes a program of astronomical research, which may or may not be related to using the James Clerk Maxwell Telescope (JCMT).
CLOSING DATE: February 28, 2017
For more information visit the EAO Jobs homepage.
The Staff at JCMT are proud to share the news that our Director General Paul Ho has been awarded a Humboldt Research Award by the Alexander von Humboldt Foundation in recognition of his lifetime achievements in research. For more information see: www.sinica.edu.tw/en/news/4273
The East Asian Observatory is pleased to provide an early announcement of the second Call for JCMT Large Programs. This information is being provided ahead of the opening of the Call in order for current and new teams to pursue discussion and planning. Submissions will be accepted from February 15th up until the March 15th deadline. This will coincide with the 17B PI Call.
For more information please visit:
To help cultivate ideas discussions on potential new JCMT Large Programs EAO have provided a wiki for interested JCMT users:
Please also be reminded that the 2017 JCMT Users meeting will be held February 13th and 14th in Nanjing, China. For more details on the Users meeting please visit:
At the start of October the JCMT held a Data Reduction workshop for JCMT astronomers. The workshop was held at the Shanghai Astronomical Observatory in China. Over 20 astronomers attended with a variety of backgrounds. The material presented at the workshop can be found here. Information on past workshops can be found here. If you are interested in having JCMT staff visit your institution for such an event please contact firstname.lastname@example.org.
Dear JCMT users
You are invited to attend the second EAO JCMT Users Meeting. This 2017 JCMT Users meeting will be held in Nanjing, China. The two day meeting will be held on Monday, 13th and Tuesday 14th of February. An additional 1 half-day data reduction workshop will be held immediately after the meeting on Wednesday 15th of February.
To register for the 2017 Users Meeting please use the online registration form.
Note: If you cannot access the registration form (which is a Google document), then please use this text form and email to jcmt_um_2017 “at” eaobservatory.org.
Note: All participants coming from outside of mainland China will likely require a visa. Therefore to request a letter of invitation to attend this meeting please email: jcmt_um_2017 “at” eaobservatory.org This process can be lengthy. You are encouraged to request this invitation letter and begin the visa application process as soon as possible.
For more information visit: www.eaobservatory.org/jcmt/science/nanjing2017/
The JCMT would like to announce that the Shanghai Astronomical Observatory will hold 1-day workshop on JCMT data reductions and analysis on Oct. 16 at SHAO in Shanghai. JCMT staff, Dr. Harriet Parsons and Dr. Mark Rawlings, will give these tutorials. The agenda can be found below.
This workshop is scheduled before JINGLE team meeting in Shanghai (Oct. 17-18) and MALATANG team meeting in Nanjing (Oct. 19-21) as a united conference. We aim to open this tutorial to all interested researchers and students, and high priority will be given to members of JINGLE, MALATANG and other JCMT large programs due to space limitation. If you are interested to attend, please contact Ting Xiao (email@example.com) as soon as possible to help us get a rough head account.
Agenda for the workshop on Oct. 16:
- introduction to STARLINK
- introduction to HARP and RxA3m
- Heterodyne beginner
- Heterodyne advanced
- introduction to SCUBA-2
- SCUBA-2 basic
- SCUBA-2 advanced
In addition if requested we could cover any of the following (time permitting):
- Hedwig session – Proposal submission to the JCMT
- JCMTOT – how to submit JCMT project MSBs
- POL-2 introduction and basic data reduction in an extended session
- General JCMT project support for existing users
If you are interested in any additional topics listed above, please inform us in the email.
The Planck satellite has discovered more than ten thousand Galactic cold clumps, the so-called “Planck Galactic Cold Clumps” (PGCCs). The PGCC catalog, covering the whole sky, hence probes wildly different environments, and represents a real goldmine for investigations of the early phases of star formation. After the successful start of the pioneer survey with the PMO 14-m telescope, we are conducting a joint survey (“SAMPLING-TOP- SCOPE”) towards 1000-2000 PGCCs with the SMT 10-m, TRAO 14-m, and JCMT 15-m telescopes. “SAMPLING” (SMT “All-sky” Mapping of PLanck Interstellar Nebulae in the Galaxy) is an ESO public survey inJ=2-1 12CO/13CO emission using the SMT 10-m telescope. “TOP” (TRAO Observations of Planck cold clumps) aims at an unbiased J=1-0 12CO/13CO survey of 2000 Planck Galactic Cold Clumps with the Taeduk Radio Astronomy Observatory 14-meter telescope. “SCOPE” (SCUBA-2 Continuum Observations of Pre-protostellar Evolution) is a legacy survey using SCUBA-2 at the James Clerk Maxwell Telescope (JCMT) of the East Asia Observatory (EAO) to survey 1000 Planck galactic cold clumps at 850 micron. We are also actively developing follow-up observations towards the SCUBA-2 cores detected in “SCOPE” with other ground-based telescopes (e.g. KVN 21-m, NRO 45-m, Effelsberg 100-m, Arecibo 300-m, SMA, and ALMA). Through these observations, we will study how dense cores form and how star formation varies as a function of environment, the universality of filaments in the cold ISM and their roles in generating dense cores, the existence of a density threshold for dense core formation, how dust properties change in different environments, and how dust properties affect the chemical evolution of dense cores.
To promote collaborations among team members on using the survey data for science, we will hold a face-to-face workshop on Dec. 14-16 at Peking University, Beijing, China. To indicate your interest in attending the workshop, please sign your name on the following doodle page:
More details of the workshop can be found on our wiki page:
Dec 14: registration and reception
Dec 15: talks and discussions
Dec 16: talks and discussions
SOC: Tie Liu; Mark Thompson; Sheng-Yuan Liu; Gary Fuller; Ken Tatematsu; Yuefang Wu; Di Li; James di Francesco; Kee-Tae Kim; Ke Wang; Isabelle Ristorcelli; Mika Juvela
The EAO’s latest Newsletter is now available for reading:
For previous JCMT Newsletters and articles visit out Newsletter page.
The JINGLE Team meeting and JCMT Data Reduction & Analysis Workshop will be held on Oct. 16-18 in Shanghai at the Shanghai Astronomical Observatory, China.
JINGLE (The JCMT dust and gas In Nearby Galaxies Legacy Exploration) began in Dec. 2015, and the overall program completion is about 1/4. Team members are encouraged to join the team meeting on Oct. 17-18 to discuss the survey status and plan, data reduction and evaluation, data analysis, and most importantly the scientific projects based on survey data. The JINGLE meeting and MALATANG meeting are scheduled in one week for a united conference focusing on two main themes: 1) cold gas and dust in large sample of galaxies and 2) dense gas and gas/dust in the nearest 20+ brightest infrared galaxies.
Before the JINGLE team meeting, we will have 1-day tutorial on JCMT data reductions and analysis provided by JCMT staff. We will open this tutorial to all interested researchers and students. But due to space limitation, high priority will be given to JINGLE members and members of JCMT large programs .
If you need an invitation letter for VISA application, please contact the LOC as soon as possible!
SOC: Amelie Saintonge, Chris Wilson, Ting Xiao, Cheng Li, Yu Gao, Lihwai Lin, Ho Seong Hwang, Tomoka Tosaki
Please visit the wiki page and add your name there if you plan to attend the meeting:
The coordinators for the MALATANG Large Program invite you to attend thier first face-to-face team meeting on Oct. 19-21 in Nanjing. Team members are highly encouraged to join the meeting, to discuss survey status, data reduction and evaluation, data analysis, future observations, and all the potential scientific projects.
To indicate your interest in attending the meeting please add your name to the following doodle page:
If you need an invitation letter for VISA application, please contact the LOC as soon as possible!
Note that prior to the MALATANG meeting, the JINGLE meeting will be held on Oct 16-18 in Shanghai, including a JCMT tutorial on Oct 16. Further details regarding the JINGLE meeting will follow soon.
MALATANG and JINGLE share some common/related subjects and overlap members, so you may consider attending both!
Oct 19: reception
Oct 20: MALATANG discussion 1
Oct 21: MALATANG discussion 2
Hongjun Ma (hjma at pmo.ac.cn)
Xuejian Jiang (xjjiang at pmo.ac.cn)
Qinghua Tan (qhtan at pmo.ac.cn)
It only takes less than 2 hours from Shanghai to Nanjing by high speed trains
train schedule: http://english.ctrip.com/trains/schedule/shanghai/
The 2016 JCMT Users Meeting, held in Japan was a great success. If you couldn’t make it in person you can access all the slides from the talks here.
We welcoming Jessica Dempsey to the role of Deputy Director of the JCMT. In addition to this we are proud to announce she has been also just been recognized with a Women Who Mean Business award for “Women to Watch”.
The East Asian Observatory is happy to invite PI observing proposals for semester 16A at JCMT (for details see here).
Semester 16A runs from 01 February 2016 to 31 July 2016. We are launching this Call through a new proposal handling system: Hedwig. You can reach Hedwig and find complete details of this Call at:
At your first visit, you should go to ‘Log in’ and generate an account. We hope you will find Hedwig easy to use: there is a ‘Help’ facility at the upper right corner, and individual Help tags at many places on the proposal pages.
The 16A Call for Proposals closes on the 22nd of September, 2015.
In addition, it should be noted that we will embark on survey observing in the 16A semester – and as such, PI time is more limited than the current semester, however we still strongly encourage PI submissions as at least 800 hours of time will be available to EAO and partner region investigators. Some alterations have also been made to the PI eligibility for Canada – please see the Call for details.
2015 IAU Splinter Session
August 6th 6pm-8pm
Room 312 Hawaii Convention Center
The East Asian Observatory has forged a new path for the JCMT following the successful transfer of operation to EAO in March 2015. Operations immediately resumed with an EAO Pilot Science semester initiated in late March, taking successful science with JCMT’s signature instruments, and recommencing commissioning of the additional instrument elements (Pol-2 and FTS-2) for SCUBA-2. In this special session, we will present the latest results from the JCMT Legacy Surveys, completed in early 2015. We will also show some of the recent results from Pilot Science, and discuss the plans EAO and its partners have for continuing to keep the JCMT at the cutting edge of sub-millimeter science.
Organizer: Jessica Dempsey
6:00pm: Welcome and introduction (Paul Ho)
JCMT Legacy Science: New Insights
6:10pm: The Cosmology Legacy Survey (Jim Geach)
6:25pm: Current and future directions in star formation research with the JCMT (Derek Ward-Thompson)
6:40pm: The Nearby Galaxies Survey (Christine Wilson)
6:55pm: The JCMT Legacy Archive (Sarah Graves)
EAO Pilot Science
7:05pm: Highlights from Taiwan (Sheng-Yuan Liu)
7:15pm: Highlights from China (Yu Gao)
7:25pm: Highlights from Korea (Woojin Kwon)
Instrument Directions for JCMT:
7:35pm – 8:00pm: Panel discussion and question and answer session on future instrument upgrades and new instrument concepts.
The EAO’s latest Newsletter is now available for reading:
For previous JCMT Newsletters and articles visit out Newsletter page.
To all JCMT users a reminder that the Call for Proposals for semester 15B closes Friday, May 15th, 15:00 Hawaiian Standard Time. For more information click here.
It is with great enthusiasm that the East Asian Observatory (EAO) announces its first day of operations of the James Clerk Maxwell Telescope (JCMT). The JCMT is the largest astronomical telescope in the world designed to operate in the sub-millimetre wavelength region of the spectrum. EAO is now in charge of JCMT operations in partnership with the UK and Canadian research communities.
Paul Ho the Director General of the East Asian Observatory said “It is a great opportunity for the East Asian Observatory to take over the operation of JCMT which is an excellent facility with extremely powerful instrumentation. Many of our astronomers in East Asia have long been involved in pursuing the most important problems in astronomy by utilizing the amazing telescopes on top of Mauna Kea. It is a great privilege for us to be able to work at the best site for ground based astronomy in the Northern Hemisphere. For all of us at the JCMT, we look forward to an exciting future in continuing to deliver frontier science to our communities.”
EAO would like to thank the people of Hawaii for allowing our astronomers to work on top of one of the most beautiful places on earth.
As a memento of this transfer Will Montgomerie, an operator at the JCMT, has released this beautiful night sky time-lapse montage featuring the Telescope:
The Science and Technology Facilities Council of the UK have also issued their own statement about this occasion. The statement can be found here.