Submillimeter galaxies behind the Bullet cluster (1E 0657-56)
Artikel i vetenskaplig tidskrift, 2010

Context. Clusters of galaxies are effective gravitational lenses able to magnify background galaxies and making it possible to probe the fainter part of the galaxy population. Submillimeter galaxies, which are believed to be star-forming galaxies at typical redshifts of 2 to 3, are a major contaminant to the extended Sunyaev-Zeldovich (SZ) signal of galaxy clusters. For a proper quantification of the SZ signal the contribution of submillimeter galaxies needs to be quantified. Aims. The aims of this study are to identify submillimeter sources in the field of the Bullet cluster (1E 0657-56), a massive cluster of galaxies at z similar or equal to 0.3, measure their flux densities at 870 mu m, and search for counterparts at other wavelengths to constrain their properties. Methods. We carried out deep observations of the submillimeter continuum emission at 870 mu m using the Large APEX BOlometer CAmera (LABOCA) on the Atacama Pathfinder EXperiment (APEX) telescope. Several numerical techniques were used to quantify the noise properties of the data and extract sources. Results. In total, seventeen sources were found. Thirteen of them lie in the central 10 arcmin of the map, which has a pixel sensitivity of 1.2 mJy per 22 '' beam. After correction for flux boosting and gravitational lensing, the number counts are consistent with published submm measurements. Nine of the sources have infrared counterparts in Spitzer maps. The strongest submm detection coincides with a source previously reported at other wavelengths, at an estimated redshift z similar or equal to 2.7. If the submm flux arises from two images of a galaxy magnified by a total factor of 75, as models have suggested, its intrinsic flux would be around 0.6 mJy, consistent with an intrinsic luminosity below 10(12) L-circle dot.

infrared galaxies

galaxies: clusters: individual:


degree extragalactic

infrared galaxy

scuba super-map

galaxies: individual: MMJ065837-5557.0

imaging survey



submillimeter: galaxies

millimetre/submillimetre waveband

source extraction

1E 0657-56

background experiment search


number counts



Daniel Dahlin

Chalmers, Institutionen för radio- och rymdvetenskap, Radioastronomi och astrofysik

Cathy Horellou

Chalmers, Institutionen för radio- och rymdvetenskap, Radioastronomi och astrofysik

M. W. Sommer

Argelander-Institut für Astronomie

K. Basu

Max Planck-institutet

Argelander-Institut für Astronomie

F. Bertoldi

Argelander-Institut für Astronomie

M. Birkinshaw

University of Bristol

K. Lancaster

University of Bristol

O. Lopez-Cruz

Instituto Nacional de Astrofisica Optica y Electronica

H. Quintana

Pontificia Universidad Catolica de Chile

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 514 A77


Astronomi, astrofysik och kosmologi