Sánchez-Gallego, J. R.; Knapen, J. H.; Heiner, J. S.; Wilson, C. D.; Warren, B. E.; Allen, R. J.; Azimlu, M.; Barmby, P.; Bendo, G. J.; Comerón, S.; Israel, F. P.; Serjeant, S.; Tilanus, R. P. J.; Vlahakis, C. and van der Werf, P.
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|DOI (Digital Object Identifier) Link:||https://doi.org/10.1051/0004-6361/201014930|
|Google Scholar:||Look up in Google Scholar|
We present the first complete 12CO J = 3−2 map of M 81, observed as part of the Nearby Galaxies Legacy Survey being carried out at the James Clerk Maxwell Telescope. We detect nine regions of significant CO emission located at different positions within the spiral arms, and confirm that the global CO emission in the galaxy is low. We combine these data with a new Hα map obtained using the Isaac Newton Telescope and archival H I, 24μm, and FUV images to uncover a correlation between the molecular gas and star forming regions in M 81. For the nine regions detected in CO J = 3−2, we combine our CO J = 3−2 data with existing CO J = 1−0 data to calculate line ratios. We find that the ratio J = (3−2)/(1−0) is in agreement with the range of typical values found in the literature (0.2−0.8). Making reasonable assumptions, this allows us to constrain the hydrogen density to the range (103 −104) cm-3. We also estimated the amount of hydrogen produced in photo-dissociation regions near the locations where CO J = 3−2 was detected.
|Item Type:||Journal Article|
|Copyright Holders:||2011 ESO|
|Extra Information:||10 pp.|
|Keywords:||galaxies; star formation; Hii regions|
|Academic Unit/Department:||Faculty of Science, Technology, Engineering and Mathematics (STEM) > Physical Sciences
Faculty of Science, Technology, Engineering and Mathematics (STEM)
|Interdisciplinary Research Centre:||Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)|
|Depositing User:||Astrid Peterkin|
|Date Deposited:||04 May 2011 15:27|
|Last Modified:||07 Oct 2016 19:02|
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