%0 Generic %1 sargent2015direct %A Sargent, Mark T. %A Daddi, E. %A Bournaud, F. %A Onodera, M. %A Feruglio, C. %A Martig, M. %A Gobat, R. %A Dannerbauer, H. %A Schinnerer, E. %D 2015 %K early-type gas molecular %T A direct constraint on the gas content of a massive, passively evolving elliptical galaxy at z = 1.43 %U http://arxiv.org/abs/1502.00003 %X In comparison to gas and dust in star-forming galaxies at the peak epoch of galaxy assembly, which are presently the topic of intense study, little is known about the interstellar medium (ISM) of distant, passively evolving galaxies. We report on a deep 3 mm-band search with IRAM/PdBI for molecular gas in a massive ($M_\star\sim6\times10^11M_ødot$) elliptical galaxy at z=1.4277, the first observation of this kind ever attempted. We place a 3$\sigma$ upper limit of 0.30 Jy km/s on the flux of the CO($J$=$2\rightarrow$1) line or $L'_CO$$<$8.3$\times$10$^9$ K km/s pc$^2$, assuming a line width in accordance with the stellar velocity dispersion of $\sigma_\star\sim330$ km/s. This translates to a molecular gas mass of $<$3.6$\times$10$^10$($\alpha_CO$/4.4)$M_ødot$ or a gas fraction of $łesssim$5% assuming a Salpeter initial mass function (IMF) and an ISM dominated by molecular gas, as observed in local early-type galaxies (ETGs). This low gas fraction approaches that of local ETGs, suggesting that the low star formation activity in massive, high-z passive galaxies reflects a true dearth of gas and a secondary role for inhibitive mechanisms like morphological quenching.

@misc{sargent2015direct, abstract = {In comparison to gas and dust in star-forming galaxies at the peak epoch of galaxy assembly, which are presently the topic of intense study, little is known about the interstellar medium (ISM) of distant, passively evolving galaxies. We report on a deep 3 mm-band search with IRAM/PdBI for molecular gas in a massive ($M_{\star}{\sim}6{\times}10^{11}M_{\odot}$) elliptical galaxy at z=1.4277, the first observation of this kind ever attempted. We place a 3$\sigma$ upper limit of 0.30 Jy km/s on the flux of the CO($J$=$2\rightarrow$1) line or $L'_{\rm CO}$$<$8.3$\times$10$^{9}$ K km/s pc$^2$, assuming a line width in accordance with the stellar velocity dispersion of $\sigma_{\star}{\sim}330$ km/s. This translates to a molecular gas mass of $<$3.6$\times$10$^{10}$($\alpha_{\rm CO}$/4.4)$M_{\odot}$ or a gas fraction of $\lesssim$5% assuming a Salpeter initial mass function (IMF) and an ISM dominated by molecular gas, as observed in local early-type galaxies (ETGs). This low gas fraction approaches that of local ETGs, suggesting that the low star formation activity in massive, high-z passive galaxies reflects a true dearth of gas and a secondary role for inhibitive mechanisms like morphological quenching.}, added-at = {2015-02-03T10:08:28.000+0100}, author = {Sargent, Mark T. and Daddi, E. and Bournaud, F. and Onodera, M. and Feruglio, C. and Martig, M. and Gobat, R. and Dannerbauer, H. and Schinnerer, E.}, biburl = {https://www.bibsonomy.org/bibtex/2d5c71879a3ca276868a8b25855c28f96/miki}, description = {[1502.00003] A direct constraint on the gas content of a massive, passively evolving elliptical galaxy at z = 1.43}, interhash = {279186dbb770bd93982859e104e2599f}, intrahash = {d5c71879a3ca276868a8b25855c28f96}, keywords = {early-type gas molecular}, note = {cite arxiv:1502.00003Comment: 6 pages, 3 figures & 1 table. Submitted to ApJL}, timestamp = {2015-02-03T10:08:28.000+0100}, title = {A direct constraint on the gas content of a massive, passively evolving elliptical galaxy at z = 1.43}, url = {http://arxiv.org/abs/1502.00003}, year = 2015 }