Publication Date:
2016-06-26
Description:
We present a Herschel /Spectral and Photometric Imaging Receiver (SPIRE) survey of three protoclusters at z = 2–3 (2QZCluster, HS1700, SSA22). Based on the SPIRE colours ( S 350 / S 250 and S 500 / S 350 ) of 250 μm sources, we selected high-redshift dusty star-forming galaxies potentially associated with the protoclusters. In the 2QZCluster field, we found a 4 overdensity of six SPIRE sources around 4.5 arcmin (~2.2 Mpc) from a density peak of H α emitters at z = 2.2. In the HS1700 field, we found a 5 overdensity of eight SPIRE sources around 2.1 arcmin (~1.0 Mpc) from a density peak of Lyman-break galaxies at z = 2.3. We did not find any significant overdensities in SSA22 field, but we found three 500 μm sources are concentrated 3 arcmin (~1.4 Mpc) east to the Ly α emitters overdensity. If all the SPIRE sources in these three overdensities are associated with protoclusters, the inferred star formation rate densities are 10 3 –10 4 times higher than the average value at the same redshifts. This suggests that dusty star formation activity could be very strongly enhanced in z ~ 2–3 protoclusters. Further observations are needed to confirm the redshifts of the SPIRE sources and to investigate what processes enhance the dusty star formation activity in z ~ 2–3 protoclusters.
Print ISSN:
0035-8711
Electronic ISSN:
1365-2966
Topics:
Physics
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