%0 Generic %1 livermore2012observational %A Livermore, R. C. %A Swinbank, A. M. %A Smail, I. %A Bower, R. G. %A Coppin, K. E. K. %A Crain, R. A. %A Edge, A. C. %A Geach, J. E. %A Richard, J. %D 2012 %K co fraction gas high-z %T Observational limits on the gas mass of a z=4.9 galaxy %U http://arxiv.org/abs/1210.0899 %X We present the results of a search for molecular gas emission from a star-forming galaxy at z = 4.9. The galaxy benefits from magnification of 22 +/- 5x due to strong gravitational lensing by the foreground cluster MS1358+62. We target the CO(5-4) emission at a known position and redshift from existing Hubble Space Telescope/ACS imaging and Gemini/NIFS OII3727 imaging spectroscopy, and obtain a tentative detection at the 4.3sigma level with a flux of 0.104 +/- 0.024Jkm/s. From the CO line luminosity and assuming a CO-to-H2 conversion factor alpha=2, we derive a gas mass M_gas ~ 1^+1_-0.6 x 10^9 M_sun. Combined with the existing data, we derive a gas fraction Mgas/(Mgas + M*) = 0.59^+0.11_-0.06. The faint line flux of this galaxy highlights the difficulty of observing molecular gas in representative galaxies at this epoch, and suggests that routine detections of similar galaxies in the absence of gravitational lensing will remain challenging even with ALMA in full science operations.

@misc{livermore2012observational, abstract = {We present the results of a search for molecular gas emission from a star-forming galaxy at z = 4.9. The galaxy benefits from magnification of 22 +/- 5x due to strong gravitational lensing by the foreground cluster MS1358+62. We target the CO(5-4) emission at a known position and redshift from existing Hubble Space Telescope/ACS imaging and Gemini/NIFS [OII]3727 imaging spectroscopy, and obtain a tentative detection at the 4.3sigma level with a flux of 0.104 +/- 0.024Jkm/s. From the CO line luminosity and assuming a CO-to-H2 conversion factor alpha=2, we derive a gas mass M_gas ~ 1^{+1}_{-0.6} x 10^9 M_sun. Combined with the existing data, we derive a gas fraction Mgas/(Mgas + M*) = 0.59^{+0.11}_{-0.06}. The faint line flux of this galaxy highlights the difficulty of observing molecular gas in representative galaxies at this epoch, and suggests that routine detections of similar galaxies in the absence of gravitational lensing will remain challenging even with ALMA in full science operations.}, added-at = {2012-10-04T15:33:33.000+0200}, author = {Livermore, R. C. and Swinbank, A. M. and Smail, I. and Bower, R. G. and Coppin, K. E. K. and Crain, R. A. and Edge, A. C. and Geach, J. E. and Richard, J.}, biburl = {https://www.bibsonomy.org/bibtex/21d4c4fe0db6d1382ce7ff60f5ee2ed1b/miki}, description = {[1210.0899] Observational limits on the gas mass of a z=4.9 galaxy}, interhash = {12d9d89a1e04b1b4f7d7dc0621a56259}, intrahash = {1d4c4fe0db6d1382ce7ff60f5ee2ed1b}, keywords = {co fraction gas high-z}, note = {cite arxiv:1210.0899Comment: 14 pages, 4 figures, published in ApJL}, timestamp = {2012-10-04T15:33:33.000+0200}, title = {Observational limits on the gas mass of a z=4.9 galaxy}, url = {http://arxiv.org/abs/1210.0899}, year = 2012 }