Cosmic Evolution of Star Formation Enhancement in Close Major-merger Galaxy Pairs Since z = 1

November 2012 • 2012ApJ...760...72X

Authors • Xu, C. K. • Shupe, D. L. • Béthermin, M. • Aussel, H. • Berta, S. • Bock, J. • Bridge, C. • Conley, A. • Cooray, A. • Elbaz, D. • Franceschini, A. • Le Floc'h, E. • Lu, N. • Lutz, D. • Magnelli, B. • Marsden, G. • Oliver, S. J. • Pozzi, F. • Riguccini, L. • Schulz, B. • Scoville, N. • Vaccari, M. • Vieira, J. D. • Wang, L. • Zemcov, M.

Abstract • The infrared (IR) emission of "M _* galaxies" (10^10.4 <= M _star <= 10^11.0 M _⊙) in galaxy pairs, derived using data obtained in Herschel (PEP/HerMES) and Spitzer (S-COSMOS) surveys, is compared to that of single-disk galaxies in well-matched control samples to study the cosmic evolution of the star formation enhancement induced by galaxy-galaxy interaction. Both the mean IR spectral energy distribution and mean IR luminosity of star-forming galaxies (SFGs) in SFG+SFG (S+S) pairs in the redshift bin of 0.6 < z < 1 are consistent with no star formation enhancement. SFGs in S+S pairs in a lower redshift bin of 0.2 < z < 0.6 show marginal evidence for a weak star formation enhancement. Together with the significant and strong sSFR enhancement shown by SFGs in a local sample of S+S pairs (obtained using previously published Spitzer observations), our results reveal a trend for the star formation enhancement in S+S pairs to decrease with increasing redshift. Between z = 0 and z = 1, this decline of interaction-induced star formation enhancement occurs in parallel with the dramatic increase (by a factor of ~10) of the sSFR of single SFGs, both of which can be explained by the higher gas fraction in higher-z disks. SFGs in mixed pairs (S+E pairs) do not show any significant star formation enhancement at any redshift. The difference between SFGs in S+S pairs and in S+E pairs suggests a modulation of the sSFR by the intergalactic medium (IGM) in the dark matter halos hosting these pairs.

Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

Links

• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2012ApJ...760...72X
• PDF https://iopscience.iop.org/article/10.1088/0004-637X/760/1/72/pdf
• PREPRINT http://arxiv.org/abs/1210.2362
• DATA http://archives.esac.esa.int/hsa/whsa/?ACTION=PUBLICATION&ID=2012ApJ...760...72X
• DATA https://irsa.ipac.caltech.edu/bibdata/2012/X/2012ApJ...760...72X.html
• ELECTR https://iopscience.iop.org/article/10.1088/0004-637X/760/1/72
• SPIRES http://inspirehep.net/search?p=find+eprint+arXiv:1210.2362