Early-type galaxies at intermediate redshift observed with hubble space telescope WFC3: Perspectives on recent star formation

Michael J. Rutkowski, Hyunjin Jeong, Seth H. Cohen, Sugata Kaviraj, Rogier Windhorst, Russell E. Ryan, Anton Koekemoer, Sukyoung K. Yi, Nimish P. Hathi, Michael A. Dopita

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

We present an analysis of the stellar populations of 102 visually selected early-type galaxies (ETGs) with spectroscopic redshifts (0.35 ≲ z ≲ 1.5) from observations in the Early Release Science program with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). We fit one- and two-component synthetic stellar models to the ETGs UV-optical-near-IR spectral energy distributions and find that a large fraction (∼40%) are likely to have experienced a minor (fYC ≲ 10% of stellar mass) burst of recent (tYC ≲ 1 Gyr) star formation. The measured age and mass fraction of the young stellar populations do not strongly trend with measurements of galaxy morphology. We note that massive (M > 1010.5 M ) recent star-forming ETGs appear to have larger sizes. Furthermore, high-mass, quiescent ETGs identified with likely companions populate a distinct region in the size-mass parameter space, in comparison with the distribution of massive ETGs with evidence of recent star formation (RSF). We conclude that both mechanisms of quenching star formation in disk-like ETGs and (gas-rich, minor) merger activity contribute to the formation of young stars and the size-mass evolution of intermediate redshift ETGs. The number of ETGs for which we have both HST WFC3 panchromatic (especially UV) imaging and spectroscopically confirmed redshifts is relatively small, therefore, a conclusion about the relative roles of both of these mechanisms remains an open question.

Original languageEnglish (US)
Article number101
JournalAstrophysical Journal
Volume796
Issue number2
DOIs
StatePublished - Dec 1 2014

Fingerprint

Hubble Space Telescope
star formation
cameras
galaxies
young population
merger
stars
stellar models
spectral energy distribution
stellar mass
gas
bursts
energy
quenching
trends
distribution
gases

Keywords

  • galaxies: elliptical and lenticular, cD
  • galaxies: evolution
  • galaxies: star formation
  • ultraviolet: galaxies

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Early-type galaxies at intermediate redshift observed with hubble space telescope WFC3 : Perspectives on recent star formation. / Rutkowski, Michael J.; Jeong, Hyunjin; Cohen, Seth H.; Kaviraj, Sugata; Windhorst, Rogier; Ryan, Russell E.; Koekemoer, Anton; Yi, Sukyoung K.; Hathi, Nimish P.; Dopita, Michael A.

In: Astrophysical Journal, Vol. 796, No. 2, 101, 01.12.2014.

Research output: Contribution to journalArticle

Rutkowski, MJ, Jeong, H, Cohen, SH, Kaviraj, S, Windhorst, R, Ryan, RE, Koekemoer, A, Yi, SK, Hathi, NP & Dopita, MA 2014, 'Early-type galaxies at intermediate redshift observed with hubble space telescope WFC3: Perspectives on recent star formation', Astrophysical Journal, vol. 796, no. 2, 101. https://doi.org/10.1088/0004-637X/796/2/101
Rutkowski, Michael J. ; Jeong, Hyunjin ; Cohen, Seth H. ; Kaviraj, Sugata ; Windhorst, Rogier ; Ryan, Russell E. ; Koekemoer, Anton ; Yi, Sukyoung K. ; Hathi, Nimish P. ; Dopita, Michael A. / Early-type galaxies at intermediate redshift observed with hubble space telescope WFC3 : Perspectives on recent star formation. In: Astrophysical Journal. 2014 ; Vol. 796, No. 2.
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