Submillimeter observations of the J2142-4423 Lyα protocluster at z = 2.38

July 2008 • 2008A&A...485..645B

Authors • Beelen, A. • Omont, A. • Bavouzet, N. • Kovács, A. • Lagache, G. • De Breuck, C. • Weiss, A. • Menten, K. M. • Colbert, J. W. • Dole, H. • Siringo, G. • Kreysa, E.

Abstract • Aims: We present observations aimed at exploring both the nature of Lyα emitting nebulae (“Lyα blobs”) at z=2.38 and the way they trace large scale structure (LSS), by exploring their proximity to “maximum starbursts” through submillimeter emission. Our most important objectives are to make a census of associated submillimeter galaxies (SMGs), check their properties, and look for a possible overdensity in the protocluster J2142-4426 at z=2.38.
Methods: We used the newly commissioned Large APEX Bolometer Camera (LABoCa) on the Atacama Pathfinder EXperiment (APEX) telescope, in its Science Verification phase, to carry out a deep 10 arcmin × 10 arcmin map at 870 μ m}, and we performed multiple checks of the quality of data processing and source extraction.
Results: Our map, the first published deep image, confirms the capabilities of APEX/LABoCa as the most efficient current equipment for wide and deep submm mapping. Twenty-two sources were securely extracted with 870 {μ m} flux densities in the range 3-21 mJy, rms noise 0.8-2.4 mJy, and far-IR luminosities probably in the range {∼5-20× 10¹² L_⊙. Only one of the four 50 kpc-extended Lyα blobs has a secure 870 {μ m} counterpart. The 870 {μ m} source counts in the whole area are marginally higher than in the SHADES SCUBA survey, with a possible over-density around this blob. The majority of the 3.6-24 {μ m}SEDs of the submillimeter sources indicate they are starburst dominated, with redshifts mostly ≳2. However, there is evidence of a high-z AGN in 30% of the sources.

This work is based on observations made with the APEX Telescope. APEX is a collaboration between the Max-Planck-Institut für Radioastronomie, the European Southern Observatory, and the Onsala Space Observatory.

Links

• PREPRINT http://arxiv.org/abs/0803.1615
• NED https://ned.ipac.caltech.edu/uri/NED::InRefcode/2008A%26A...485..645B
• POSTSCRIPT https://www.aanda.org/10.1051/0004-6361:200809500/postscript
• ELECTR http://www.aanda.org/htbin/resolve?bibcode=2008A%26A...485..645BFUL
• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2008A%26A...485..645B
• PDF https://www.aanda.org/10.1051/0004-6361:200809500/pdf
• DATA http://archive.eso.org/bin/ads2eso?2008A%26A...485..645B
• DATA https://irsa.ipac.caltech.edu/bibdata/2008/B/2008A&A...485..645B.html