학술논문
Keck-I MOSFIRE spectroscopy of compact star-forming galaxies at z$\gtrsim$2: High velocity dispersions in progenitors of compact quiescent galaxies
Document Type
Working Paper
Author
Barro, G.; Trump, J. R.; Koo, D. C.; Dekel, A.; Kassin, S. A.; Kocevski, D. D.; Faber, S. M.; van der Wel, A.; Guo, Y.; Perez-Gonzalez, P. G.; Toloba, E.; Fang, J. J.; Pacifici, C.; Simons, R.; Campbell, R D.; Ceverino, D.; Finkelstein, S. L.; Goodrich, B.; Kassis, M.; Koekemoer, A. M.; Konidaris, N. P.; Livermore, R. C.; Lyke, J. E.; Mobasher, B.; Nayyeri, H.; Peth, M.; Primack, J. R.; Rizzi, L.; Somerville, R. S.; Wirth, G. D.; Zolotov, A.
Source
Subject
Language
Abstract
We present Keck-I MOSFIRE near-infrared spectroscopy for a sample of 13 compact star-forming galaxies (SFGs) at redshift $2\leq z \leq2.5$ with star formation rates of SFR$\sim$100M$_{\odot}$ y$^{-1}$ and masses of log(M/M$_{\odot}$)$\sim10.8$. Their high integrated gas velocity dispersions of $\sigma_{\rm{int}}$=230$^{+40}_{-30}$ km s$^{-1}$, as measured from emission lines of H$_{\alpha}$ and [OIII], and the resultant M$_{\star}-\sigma_{\rm{int}}$ relation and M$_{\star}$$-$M$_{\rm{dyn}}$ all match well to those of compact quiescent galaxies at $z\sim2$, as measured from stellar absorption lines. Since log(M$_{\star}$/M$_{\rm{dyn}}$)$=-0.06\pm0.2$ dex, these compact SFGs appear to be dynamically relaxed and more evolved, i.e., more depleted in gas and dark matter ($<$13$^{+17}_{-13}$\%) than their non-compact SFG counterparts at the same epoch. Without infusion of external gas, depletion timescales are short, less than $\sim$300 Myr. This discovery adds another link to our new dynamical chain of evidence that compact SFGs at $z\gtrsim2$ are already losing gas to become the immediate progenitors of compact quiescent galaxies by $z\sim2$.
Comment: 12 pages, 7 figures, submitted to ApJ
Comment: 12 pages, 7 figures, submitted to ApJ