A GALEX/Spitzer survey of the Cl 0016+16 supercluster at z=0.55: acceleration of the onset of star formation in satellite groups
Abstract
We present the results of a panoramic (15 Mpc scale) survey of the Cl 0016+16 (z= 0.55) supercluster using Spitzer Space Telescope Multiband Infrared Photometer (MIPS) 24-μm and Galaxy Evolution Explorer near-ultraviolet (2500 Å; NUV) imaging. The supercluster regions probed are characterized by several dense nodes connected by a pronounced intermediate-density filamentary structure. We have studied the mid-infrared and NUV properties of potential cluster members within a Δz= 0.1 photometric redshift slice compared to an identical blank field selection. We have two main findings: (i) the star formation rates of individual star-forming galaxies throughout the cluster are not significantly different from identically selected field galaxies, and (ii) the cluster harbours pockets of 'accelerated' activity where galaxies have an enhanced probability of undergoing star formation. This observation could be explained in a simple model of 'pre-processing' of galaxies during cluster infall: galaxies in satellite groups have an increased chance of having star formation triggered via gravitational tidal interactions compared to their counterparts in the field, but there is no environmental mechanism boosting the individual star formation rates of galaxies. We estimate a lower limit for the total star formation rate of galaxies in the supercluster as ~850 M_⊙ yr^(−1) (field corrected). If this rate is maintained over the typical infall time of a few Gyr, then the infall population could contribute ~1–2 × 10^(12) M_⊙ of stellar mass to the structure.
Additional Information
© 2011 The Authors. Monthly Notices of the Royal Astronomical Society © 2011 RAS. Accepted 2010 November 28. Received 2010 November 18; in original form 2010 September 22. Article first published online: 10 Feb 2011. We thank the referee for a constructive report. The authors wish to thank Masayuki Tanaka, Taddy Kodama and Yusei Koyama for providing a merged catalogue of spectroscopic and photometric redshifts for the extended cluster region, Subaru SuprimeCam (PISCES) imaging and useful comments, and Peter Capak for helpful discussions on the COSMOS data. JEG acknowledges the National Science and Engineering Council (NSERC) of Canada and the UK Science and Technology Facilities Council (STFC). IS also acknowledges STFC. JEG thanks the Royal Society for the award of an International Travel Grant and the hospitality of the California Institute of Technology during March 2010, which expedited the completion of this work. This research has been based on observations made with the SST and the GALEX which are operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA.Attached Files
Published - Geach2011p13720Mon_Not_R_Astron_Soc.pdf
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Additional details
- Eprint ID
- 23647
- Resolver ID
- CaltechAUTHORS:20110512-085753780
- Natural Sciences and Engineering Research Council of Canada (NSERC)
- Science and Technology Facilities Council (STFC)
- Royal Society
- NASA/JPL/Caltech
- Created
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2011-05-12Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)