An ALMA Survey of Sub-millimeter Galaxies in the Extended Chandra Deep Field South: Sub-millimeter Properties of Color-selected Galaxies

Decarli, R.; Smail, I.; Walter, F.; Swinbank, A.M.; Chapman, S.; Coppin, K.E.K.; Cox, P.; Dannerbauer, H.; Greve, T.R.; Hodge, J.A.; Ivison, R.; Karim, A.; Knudsen, K.K.; Lindroos, L.; Rix, H.-W.; Schinnerer, E.; Simpson, J.M.; van der Werf, P.; Weiß, A.

Abstract

We study the sub-millimeter properties of color-selected galaxies via a stacking analysis applied for the first time to interferometric data at sub-millimeter wavelengths. We base our study on 344 GHz ALMA continuum observations of ~20''-wide fields centered on 86 sub-millimeter sources detected in the LABOCA Extended Chandra Deep Field South (ECDFS) Sub-millimeter Survey. We select various classes of galaxies (K-selected, star-forming sBzK galaxies, extremely red objects, and distant red galaxies) according to their optical/near-infrared fluxes. We find clear, >10σ detections in the stacked images of all these galaxy classes. We include in our stacking analysis Herschel/SPIRE data to constrain the dust spectral energy distribution of these galaxies. We find that their dust emission is well described by a modified blackbody with T dust ≈ 30 K and β = 1.6 and infrared luminosities of (5-11) × 1011 L ☉ or implied star formation rates of 75-140 M ☉ yr–1. We compare our results with those of previous studies based on single-dish observations at 870 μm and find that our flux densities are a factor 2-3 higher than previous estimates. The discrepancy is observed also after removing sources individually detected in ALESS maps. We report a similar discrepancy by repeating our analysis on 1.4 GHz observations of the whole ECDFS. Hence, we find tentative evidence that galaxies that are associated in projected and redshift space with sub-mm bright sources are brighter than the average population. Finally, we put our findings in the context of the cosmic star formation rate density as a function of redshift.

Citation

Decarli, R., Smail, I., Walter, F., Swinbank, A., Chapman, S., Coppin, K., …Weiß, A. (2014). An ALMA Survey of Sub-millimeter Galaxies in the Extended Chandra Deep Field South: Sub-millimeter Properties of Color-selected Galaxies. Astrophysical Journal, 780(2), Article 115. https://doi.org/10.1088/0004-637x/780/2/115

• Journal Article Type: Article
• Publication Date: Jan 10, 2014
• Deposit Date: Apr 15, 2014
• Publicly Available Date: Jun 23, 2014
• Journal: Astrophysical Journal
• Print ISSN: 0004-637X
• Electronic ISSN: 1538-4357
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 780
• Issue: 2
• Article Number: 115
• DOI: https://doi.org/10.1088/0004-637x/780/2/115
• Keywords: Galaxies: high-redshift, Galaxies: star formation, Submillimeter: galaxies, Techniques: interferometric.
• Public URL: https://durham-repository.worktribe.com/output/1434339