Keck-I MOSFIRE spectroscopy of compact star-forming galaxies at z ≳ 2: high velocity dispersions in progenitors of compact quiescent galaxies

Journal Article · Mon Nov 10 00:00:00 EST 2014 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/795/2/145· OSTI ID:22370228

Barro, Guillermo; Koo, David C.; Faber, Sandra M.; Guo, Yicheng; Toloba, Elisa; Fang, Jerome J. ^[1]; Trump, Jonathan R. ^[2]; Dekel, Avishai ^[3]; Kassin, Susan A.; Koekemoer, Anton M. ^[4]; Kocevski, Dale D. ^[5]; Van der Wel, Arjen ^[6]; Pérez-González, Pablo G. ^[7]; Pacifici, Camilla ^[8]; Simons, Raymond ^[9]; Campbell, Randy D.; Goodrich, Bob; Kassis, Marc ^[10]; Ceverino, Daniel ^[11]; Finkelstein, Steven L. ^[12] ; others, and

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1. University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States)
2. Pennsylvania State University, University Park, State College, PA 16802 (United States)
3. Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel)
4. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
5. University of Kentucky, Lexington, KY 40506 (United States)
6. Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany)
7. Universidad Complutense de Madrid, Avda. de Sneca, 2 Ciudad Universitaria, E-28040 Madrid (Spain)
8. Yonsei University Observatory, Yonsei University 50, Yonsei-ro, Seodaemun-gu, Seoul 120-749 (Korea, Republic of)
9. Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218-2683 (United States)
10. W. M. Keck Observatory, California Association for Research in Astronomy, 65-1120 Mamalahoa Highway, Kamuela, HI 96743 (United States)
11. Universidad Autonoma de Madrid, Ciudad Universitaria de Cantoblanco, E-28049 Madrid (Spain)
12. The University of Texas at Austin, Austin, TX 78712 (United States)

We present Keck-I MOSFIRE near-infrared spectroscopy for a sample of 13 compact star-forming galaxies (SFGs) at redshift 2 ≤ z ≤ 2.5 with star formation rates of SFR ∼ 100 M {sub ☉} yr{sup –1} and masses of log(M/M {sub ☉}) ∼10.8. Their high integrated gas velocity dispersions of σ{sub int} =230{sub −30}{sup +40} km s{sup –1}, as measured from emission lines of Hα and [O III], and the resultant M {sub *}-σ{sub int} relation and M {sub *}-M {sub dyn} all match well to those of compact quiescent galaxies at z ∼ 2, as measured from stellar absorption lines. Since log(M {sub *}/M {sub dyn}) =–0.06 ± 0.2 dex, these compact SFGs appear to be dynamically relaxed and evolved, i.e., depleted in gas and dark matter (<13{sub −13}{sup +17}%), and present larger σ{sub int} than their non-compact SFG counterparts at the same epoch. Without infusion of external gas, depletion timescales are short, less than ∼300 Myr. This discovery adds another link to our new dynamical chain of evidence that compact SFGs at z ≳ 2 are already losing gas to become the immediate progenitors of compact quiescent galaxies by z ∼ 2.

• OSTI ID: 22370228
• Journal Information: Astrophysical Journal, Vol. 795, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ABSORPTION
ABSORPTION SPECTROSCOPY
COMPACTS
DISPERSIONS
EMISSION
GALAXIES
INFRARED SPECTRA
INFUSION
MASS
NEAR INFRARED RADIATION
NONLUMINOUS MATTER
PHOTOMETRY
RED SHIFT
STARS
VELOCITY