Published January 1, 2008 | Version Published
Journal Article Open

Starburst Galaxies in Cluster-feeding Filaments Unveiled by Spitzer

Abstract

We report the first direct detection with Spitzer of galaxy filaments. Using Spitzer and ancillary optical data, we have discovered two filamentary structures in the outskirts of the cluster Abell 1763. Both filaments point toward Abell 1770, which lies at the same redshift as Abell 1763 (z = 0.23), at a projected distance of ~13 Mpc. The X-ray cluster emission is elongated along the same direction. Most of the far-infrared emission is powered by star formation. According to the optical spectra, only one of the cluster members is classified as an active galactic nucleus. Star formation is clearly enhanced in galaxies along the filaments: the fraction of starburst galaxies in the filaments is more than twice than that in other cluster regions. We speculate that these filaments are feeding the cluster Abell 1763 by the infall of galaxies and galaxy groups. Evidence for one of these groups is provided by the analysis of galaxy kinematics in the central cluster region.

Additional Information

© 2008. The American Astronomical Society. Received 2007 October 8; accepted 2007 November 14; published 2008 January 1. Print publication: Issue 1 (2008 January 1). This work is based in part on observations made with Spitzer, a space telescope operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech. Funding for the SDSS and SDSS-II has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the US Department of Energy, NASA, the Japanese Monbukagakusho, the Max Planck Society, and the Higher Education Funding Council for England. The SDSS is managed by the Astrophysical Research Consortium for the Participating Institutions (see list at http://www.sdss.org/collaboration/credits.html). Facilities: Spitzer (MIPS), Spitzer (IRAC), Palomar 200in (LFC), Palomar 200in (WIRC), WIYN (Hydra), TNG (Dolores)

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Identifiers

Eprint ID
12998
Resolver ID
CaltechAUTHORS:FADapjl08

Funding

NASA
Alfred P. Sloan Foundation
Participating Institutions
NSF
Department of Energy (DOE)
Japanese Monbukagakusho
Max Planck Society
Higher Education Funding Council for England

Dates

Created
2009-01-15
Created from EPrint's datestamp field
Updated
2021-11-08
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Infrared Processing and Analysis Center (IPAC)