TY - JOUR
T1 - An ALMA survey of submillimetre galaxies in the Extended Chandra Deep Field South
T2 - High resolution 870um source counts
AU - Karim, Alexander
AU - Swinbank, Mark
AU - Hodge, Jackie
AU - Smail, Ian
AU - Walter, Fabian
AU - Biggs, Andy
AU - Simpson, James
AU - Danielson, Alice
AU - Alexander, David
AU - Bertoldi, Frank
AU - de Breuck, Carlos
AU - Chapman, Scott
AU - Coppin, Kristen
AU - Dannerbauer, Helmut
AU - Edge, Alastair
AU - Greve, Thomas
AU - Ivison, Rob
AU - Knudsen, Kirsten
AU - Menten, Karl
AU - Schinnerer, Eva
AU - Wardlow, Julie
AU - Weiß, Axel
AU - van der Werf, Paul
PY - 2013/6
Y1 - 2013/6
N2 - We report the first counts of faint submillimetre galaxies (SMG) in the 870-um band derived from arcsecond resolution observations with the Atacama Large Millimeter Array (ALMA). We have used ALMA to map a sample of 122 870-um-selected submillimetre sources drawn from the (0.5x0.5)deg^2 LABOCA Extended Chandra Deep Field South Submillimetre Survey (LESS). These ALMA maps have an average depth of sigma(870um)~0.4mJy, some ~3x deeper than the original LABOCA survey and critically the angular resolution is more than an order of magnitude higher, FWHM of ~1.5" compared to ~19" for the LABOCA discovery map. This combination of sensitivity and resolution allows us to precisely pin-point the SMGs contributing to the submillimetre sources from the LABOCA map, free from the effects of confusion. We show that our ALMA-derived SMG counts broadly agree with the submillimetre source counts from previous, lower-resolution single-dish surveys, demonstrating that the bulk of the submillimetre sources are not caused by blending of unresolved SMGs. The difficulty which well-constrained theoretical models have in reproducing the high-surface densities of SMGs, thus remains. However, our observations do show that all of the very brightest sources in the LESS sample, S(870um)>12mJy, comprise emission from multiple, fainter SMGs, each with 870-um fluxes of 1 galaxies with gas masses in excess of ~5x10^10 M_Sun is
AB - We report the first counts of faint submillimetre galaxies (SMG) in the 870-um band derived from arcsecond resolution observations with the Atacama Large Millimeter Array (ALMA). We have used ALMA to map a sample of 122 870-um-selected submillimetre sources drawn from the (0.5x0.5)deg^2 LABOCA Extended Chandra Deep Field South Submillimetre Survey (LESS). These ALMA maps have an average depth of sigma(870um)~0.4mJy, some ~3x deeper than the original LABOCA survey and critically the angular resolution is more than an order of magnitude higher, FWHM of ~1.5" compared to ~19" for the LABOCA discovery map. This combination of sensitivity and resolution allows us to precisely pin-point the SMGs contributing to the submillimetre sources from the LABOCA map, free from the effects of confusion. We show that our ALMA-derived SMG counts broadly agree with the submillimetre source counts from previous, lower-resolution single-dish surveys, demonstrating that the bulk of the submillimetre sources are not caused by blending of unresolved SMGs. The difficulty which well-constrained theoretical models have in reproducing the high-surface densities of SMGs, thus remains. However, our observations do show that all of the very brightest sources in the LESS sample, S(870um)>12mJy, comprise emission from multiple, fainter SMGs, each with 870-um fluxes of 1 galaxies with gas masses in excess of ~5x10^10 M_Sun is
U2 - 10.1093/mnras/stt196
DO - 10.1093/mnras/stt196
M3 - Article
SN - 0035-8711
VL - 432
SP - 2
EP - 9
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 1
ER -