The dynamical masses, densities, and star formation scaling relations of Lyα galaxies

James E. Rhoads, Sangeeta Malhotra, Mark L A Richardson, Steven L. Finkelstein, Johan P U Fynbo, Emily M. McLinden, Vithal S. Tilvi

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

We present the first dynamical mass measurements for Lyα galaxies at high redshift, based on velocity dispersion measurements from rest-frame optical emission lines and size measurements from Hubble Space Telescope imaging, for nine galaxies drawn from four surveys. We use these measurements to study Lyα galaxies in the context of galaxy scaling relations. The resulting dynamical masses range from 109 to 1010 M. We also fit stellar population models to our sample and use them to place the Lyα sample on a stellar mass versus line width relation. The Lyα galaxies generally follow the same scaling relation as star-forming galaxies at lower redshift, although, lower stellar mass fits are also acceptable in ∼1/3 of the Lyα galaxies. Using the dynamical masses as an upper limit on gas mass, we show that Lyα galaxies have unusually active star formation for their gas mass surface density. This behavior is consistent with what is observed in starburst galaxies, despite the typically smaller masses and sizes of the Lyα galaxy population. Finally, we examine the mass densities of these galaxies and show that their future evolution likely requires dissipational ("wet") merging. In short, we find that Lyα galaxies are low-mass cousins of larger starbursts.

Original languageEnglish (US)
Article number20
JournalAstrophysical Journal
Volume780
Issue number1
DOIs
StatePublished - Jan 1 2014

Fingerprint

star formation
galaxies
scaling
stellar mass
starburst galaxies
gas
gases
Hubble Space Telescope
light emission
stars

Keywords

  • galaxies: evolution
  • galaxies: formation
  • galaxies: high-redshift

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Rhoads, J. E., Malhotra, S., Richardson, M. L. A., Finkelstein, S. L., Fynbo, J. P. U., McLinden, E. M., & Tilvi, V. S. (2014). The dynamical masses, densities, and star formation scaling relations of Lyα galaxies. Astrophysical Journal, 780(1), [20]. https://doi.org/10.1088/0004-637X/780/1/20

The dynamical masses, densities, and star formation scaling relations of Lyα galaxies. / Rhoads, James E.; Malhotra, Sangeeta; Richardson, Mark L A; Finkelstein, Steven L.; Fynbo, Johan P U; McLinden, Emily M.; Tilvi, Vithal S.

In: Astrophysical Journal, Vol. 780, No. 1, 20, 01.01.2014.

Research output: Contribution to journalArticle

Rhoads, JE, Malhotra, S, Richardson, MLA, Finkelstein, SL, Fynbo, JPU, McLinden, EM & Tilvi, VS 2014, 'The dynamical masses, densities, and star formation scaling relations of Lyα galaxies', Astrophysical Journal, vol. 780, no. 1, 20. https://doi.org/10.1088/0004-637X/780/1/20
Rhoads JE, Malhotra S, Richardson MLA, Finkelstein SL, Fynbo JPU, McLinden EM et al. The dynamical masses, densities, and star formation scaling relations of Lyα galaxies. Astrophysical Journal. 2014 Jan 1;780(1). 20. https://doi.org/10.1088/0004-637X/780/1/20
Rhoads, James E. ; Malhotra, Sangeeta ; Richardson, Mark L A ; Finkelstein, Steven L. ; Fynbo, Johan P U ; McLinden, Emily M. ; Tilvi, Vithal S. / The dynamical masses, densities, and star formation scaling relations of Lyα galaxies. In: Astrophysical Journal. 2014 ; Vol. 780, No. 1.
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