The slowly evolving role of environment in a spectroscopic survey of star formation in M∗ > 5 × 108 M⊙ galaxies since z ∼ 1

Greene, C.R.; Gilbank, D.G.; Balogh, M.L.; Glazebrook, K.; Bower, R.G.; Baldry, I.K.; Hau, G.K.T.; Li, I.H.; McCarthy, P.

Abstract

We present a deep [O II] emission-line survey of faint galaxies (22.5< KAB <24) in the Chandra Deep Field South (CDFS) and the Faint Infra-Red Extragalactic Survey (FIRES) field. With these data we measure the star formation rate (SFR) in galaxies in the stellar mass range 8.85 ≲ log (M*/M⊙) ≲ 9.5 at 0.62 < z < 0.885, to a limit of SFR ∼ 0.1 M⊙ yr−1. The presence of a massive cluster (MS1054−03) in the FIRES field, and of significant large-scale structure in the CDFS field, allows us to study the environmental dependence of SFRs amongst this population of low-mass galaxies. Comparing our results with more massive galaxies at this epoch, with our previous survey [Redshift One LDSS-3 Emission Line Survey (ROLES)] at the higher redshift z ∼ 1, and with Sloan Digital Sky Survey (SDSS) Stripe 82 data, we find no significant evolution of the stellar mass function of star-forming galaxies between z = 0 and z ∼ 1, and no evidence that its shape depends on environment. The correlation between specific star formation rate (sSFR) and stellar mass at z ∼ 0.75 has a power-law slope of β ∼ −0.2, with evidence for a steeper relation at the lowest masses. The normalization of this correlation lies as expected between that corresponding to z ∼ 1 and the present day. The global SFR density is consistent with an evolution of the form (1 + z)2 over 0 < z < 1, with no evidence for a dependence on stellar mass. The sSFR of these star-forming galaxies at z ∼ 0.75 does not depend upon the density of their local environment. Considering just high-density environments, the low-mass end of the sSFR–M* relation in our data is steeper than that in Stripe 82 at z = 0, and shallower than that measured by ROLES at z = 1. Evolution of low-mass galaxies in dense environments appears to be more rapid than in the general field.

Citation

Greene, C., Gilbank, D., Balogh, M., Glazebrook, K., Bower, R., Baldry, I., …McCarthy, P. (2012). The slowly evolving role of environment in a spectroscopic survey of star formation in M∗ > 5 × 108 M⊙ galaxies since z ∼ 1. Monthly Notices of the Royal Astronomical Society, 425(3), 1738-1752. https://doi.org/10.1111/j.1365-2966.2012.21654.x

• Journal Article Type: Article
• Publication Date: Sep 21, 2012
• Deposit Date: Apr 5, 2013
• Publicly Available Date: Aug 21, 2014
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 425
• Issue: 3
• Pages: 1738-1752
• DOI: https://doi.org/10.1111/j.1365-2966.2012.21654.x
• Keywords: Galaxies: dwarf, Galaxies: evolution, Galaxies: general.
• Public URL: https://durham-repository.worktribe.com/output/1489080