ENHANCED STAR FORMATION OF LESS MASSIVE GALAXIES IN A PROTOCLUSTER AT z = 2.5
- Optical and Infrared Astronomy Division, National Astronomical Observatory, Mitaka, Tokyo 181-8588 (Japan)
- Subaru Telescope, National Astronomical Observatory of Japan, 650 North A’ohoku Place, Hilo, HI 96720 (United States)
- Department of Astronomical Science, SOKENDAI (The Graduate University for Advanced Studies), Mitaka, Tokyo 181-8588 (Japan)
- Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany)
We investigate a correlation between star formation rate (SFR) and stellar mass for H α emission-line galaxies (HAEs) in one of the richest protoclusters ever known at z∼2.5, the USS 1558-003 protocluster. This study is based on a 9.7 hr narrowband imaging data with MOIRCS on the Subaru telescope. We are able to construct a sample in combination with additional H -band data taken with WFC3 on the Hubble Space Telescope , of 100 HAEs reaching the dust-corrected SFRs down to 3 M {sub ⊙} yr{sup −1} and the stellar masses down to 10{sup 8.0} M {sub ⊙}. We find that while the star-forming galaxies with ≳10{sup 9.3} M {sub ⊙} are located on the universal SFR-mass main sequence (MS) irrespective of the environment, less massive star-forming galaxies with ≲10{sup 9.3} M {sub ⊙} show a significant upward scatter from the MS in this protocluster. This suggests that some less massive galaxies are in a starburst phase, although we do not know yet if this is due to environmental effects.
- OSTI ID:
- 22654262
- Journal Information:
- Astrophysical Journal Letters, Vol. 826, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
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