A direct constraint on the gas content of a massive, passively evolving elliptical galaxy at z = 1.43

摘要: Gas and dust in star-forming galaxies at the peak epoch of galaxy assembly are presently topic intense study, but little is known about interstellar medium (ISM) distant, passively evolving galaxies. We report on a deep 3 mm-band search with IRAM/PdBI for molecular (H$_2$) gas massive ($M_{\star}{\sim}6{\times}10^{11}M_{\odot}$) elliptical z=1.4277, first observation this kind ever attempted. place 3$\sigma$ upper limit 0.32 Jy km/s flux CO($J$=2$\rightarrow$1) line or $L'_{\rm CO}$$<$8.8$\times$10$^{9}$ K pc$^2$, assuming disk-like CO-morphology circular velocity scaling stellar dispersion as local early-type (ETGs). This translates to an H$_2$ mass $<$3.9$\times$10$^{10}$($\alpha_{\rm CO}$/4.4)$M_{\odot}$ fraction $\lesssim$6% Salpeter initial function (IMF) ISM dominated by H$_2$, observed many local, high-mass ellipticals. low value approaches that ETGs, suggesting star formation activity massive, high-z passive reflects true dearth lesser role inhibitive mechanisms like morphological quenching.