{"id":7085,"date":"2017-06-13T14:02:03","date_gmt":"2017-06-14T00:02:03","guid":{"rendered":"http:\/\/www.eaobservatory.org\/jcmt\/?page_id=7085"},"modified":"2022-04-15T18:54:19","modified_gmt":"2022-04-16T04:54:19","slug":"hashtag","status":"publish","type":"page","link":"https:\/\/www.eaobservatory.org\/jcmt\/science\/large-programs\/hashtag\/","title":{"rendered":"HASHTAG: HARP and SCUBA-2 High Resolution Terahertz Andromeda Galaxy Survey"},"content":{"rendered":"

HASHTAG<\/a> is a new Large Program on the JCMT to observe the entirety of Andromeda with SCUBA-2 at 450 and 850\u03bcm, and we will also observe selected regions in CO(=3-2) with HARP. The project will start in summer 2017 and will use approximately 280 hours to complete observations. Our survey will make it possible, for the first time, to investigate dust, the ISM and star formation from the scale of a galaxy down to sub-GMC scales. With a resolution of approximately 25 parsecs, we will be able to study Andromeda with five times better resolution than studies based on data. The figure below shows the results of our pilot SCUBA-2 observations, and indicates the image quality that will be obtained with the full survey.<\/p>\n

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The 850\u03bcm (left) and 450\u03bcm map (middle) from our pilot programme which observed a 30\u00b4 region of M31. For both bands, we use data from either Planck or SPIRE to add in large-scale structure. The improvement in resolution from 36\u02dd for SPIRE 500\u03bcm to 7\u02dd for SCUBA-2 450\u03bcm is clearly apparent in the zoomed plot. To aid visualisation we have convolved the SCUBA-2 maps with a Gaussian with the same FWHM as the PSF. The full sensitivity is only achieved in the central part of the image.<\/p><\/div>\n

Andromeda is an ideal laboratory for studying star-formation, the ISM and the properties of dust. As it is in the Local Group it has been intensely studied with observatiosn spanning the entire spectrum, and its proximity means in optical it is possible to detect individual stars. Within the Local Group M31 is special because it is the other big spiral, with a mass slightly larger than the Milky Way (Yin et al., 2009). Although similar in many ways to the Milky Way, it is also a useful contrast because it has a much larger bulge and less obvious spiral arms, with most star formation occuring in a ring.
\nThe main science aims of HASHTAG are:<\/p>\n