%0 Generic %1 Michałowski2011 %A Michałowski, Michał J. %A Dunlop, James S. %A Cirasuolo, Michele %A Hjorth, Jens %A Hayward, Christopher C. %A Watson, Darach %D 2011 %K galaxies main sequence sfr submm %T The stellar masses and specific star-formation rates of submillimetre galaxies %U http://arxiv.org/abs/1108.6058 %X Establishing the stellar masses (M*), and hence specific star-formation rates (sSFRs) of submillimetre galaxies (SMGs) is crucial for determining their role in the cosmic history of galaxy/star formation. However, there is no consensus over the typical M* of SMGs with the widely differing results reported from studies of z~2-3 SMGs. Specifically, even for the same set of SMG, the reported average M* have ranged over an order of magnitude, from 5x10^10 Mo to 5x10^11 Mo. Here we study how different methods of analysis can lead to such widely varying results. We find that, contrary to recent claims in the literature, potential contamination of 3-8um photometry from hot dust associated with an active nucleus is not the origin of the discrepancies in derived M*. Instead, we expose in detail how inferred M* depends on assumptions of intial mass function, different evolutionary synthesis models, and different star-formation histories. We review current observational evidence for and against these alternatives as well as clues from the hydrodynamical simulations, and conclude that, for the most justifiable choices of these model inputs, the average M* of luminous (S_850>5 mJy) SMG is 2x10^11 Mo. We also check and confirm that this number is perfectly reasonable in the light of the latest measurements of their dynamical masses (2-6x10^11 Mo from CO(1-0) observations), and the evolving M* function of the overall galaxy population. Stellar masses of this order imply that the average sSFR of SMG is comparable to that of other star-forming galaxies at z>2, at 2-3 Gyr^-1. This supports the view that, while rare outliers may be found at any M*, most SMG simply form the top end of the main-sequence of star-forming galaxies at these redshifts. Conversely, this argues strongly against the viewpoint that SMG are extreme pathological objects, of little relevance in the cosmic history of star-formation.

@misc{Michałowski2011, abstract = { Establishing the stellar masses (M*), and hence specific star-formation rates (sSFRs) of submillimetre galaxies (SMGs) is crucial for determining their role in the cosmic history of galaxy/star formation. However, there is no consensus over the typical M* of SMGs with the widely differing results reported from studies of z~2-3 SMGs. Specifically, even for the same set of SMG, the reported average M* have ranged over an order of magnitude, from 5x10^10 Mo to 5x10^11 Mo. Here we study how different methods of analysis can lead to such widely varying results. We find that, contrary to recent claims in the literature, potential contamination of 3-8um photometry from hot dust associated with an active nucleus is not the origin of the discrepancies in derived M*. Instead, we expose in detail how inferred M* depends on assumptions of intial mass function, different evolutionary synthesis models, and different star-formation histories. We review current observational evidence for and against these alternatives as well as clues from the hydrodynamical simulations, and conclude that, for the most justifiable choices of these model inputs, the average M* of luminous (S_850>5 mJy) SMG is 2x10^11 Mo. We also check and confirm that this number is perfectly reasonable in the light of the latest measurements of their dynamical masses (2-6x10^11 Mo from CO(1-0) observations), and the evolving M* function of the overall galaxy population. Stellar masses of this order imply that the average sSFR of SMG is comparable to that of other star-forming galaxies at z>2, at 2-3 Gyr^-1. This supports the view that, while rare outliers may be found at any M*, most SMG simply form the top end of the main-sequence of star-forming galaxies at these redshifts. Conversely, this argues strongly against the viewpoint that SMG are extreme pathological objects, of little relevance in the cosmic history of star-formation. }, added-at = {2011-09-01T18:26:01.000+0200}, author = {Michałowski, Michał J. and Dunlop, James S. and Cirasuolo, Michele and Hjorth, Jens and Hayward, Christopher C. and Watson, Darach}, biburl = {https://www.bibsonomy.org/bibtex/2d67de4526c646fa2fdec35c4b5c571fe/miki}, description = {[1108.6058] The stellar masses and specific star-formation rates of submillimetre galaxies}, interhash = {213d99f7a9fd8ceac6be7d03fa314ae1}, intrahash = {d67de4526c646fa2fdec35c4b5c571fe}, keywords = {galaxies main sequence sfr submm}, note = {cite arxiv:1108.6058Comment: Resubmitted to A&A after responding to referee's comments. 12 pages, 4 figures, 2 tables. Comments welcome}, timestamp = {2011-09-01T18:26:01.000+0200}, title = {The stellar masses and specific star-formation rates of submillimetre galaxies}, url = {http://arxiv.org/abs/1108.6058}, year = 2011 }