literature
Literature
Authors
Jobs
Seminars
Conferences
DataBETA

The Nature of 500 Micron Risers II: Sub-mm Faint Dusty Star Forming Galaxies

Mar 2, 2022
20 pages
e-Print:
View in:
pdf
reference search1 citation

Citations per year

20202021202201
Abstract: (arXiv)
We present SCUBA-2 and SMA follow-up observations of four candidate high redshift Dusty Star-Forming Galaxies, selected as sources with rising SEDs in the 250, 350 and 500μ\mum Herschel SPIRE bands. Previous SMA observations showed no counterparts to these sources, but in our deeper sub-mm observations we detect counterparts to all four 500μ\mum risers, with three resolving into multiple systems. For these three multiple systems, the SMA 345GHz (≈870μ\approx 870\mum) observations recover 123±73%123 \pm 73\%, 60±15%60 \pm 15\% and 19±4%19 \pm 4\% respectively of the integrated 850μ\mum flux density from SCUBA-2, indicating that there may be additional sources below our SMA detection limit making up a dense, protocluster core. The fourth 500μ\mum riser was observed at a lower frequency and so we cannot make a similar comparison. We estimate photometric redshifts based on FIR/sub-mm colours, finding that 3/4 likely lie at z≥2z \geq 2. This fits with the interpretation that the 500μ\mum riser selection criterion selects both intrinsically red, individual galaxies at z>4z > 4, and multiple systems at more moderate redshifts, artificially reddened by the effects of blending. We use the SCUBA-2 850μ\mum maps to investigate the environments of these 500μ\mum risers. By constructing cumulative number counts and estimating photometric redshifts for surrounding SCUBA-2 detections, we find that one of our 500μ\mum risers could plausibly reside in a z≥2z \geq 2 protocluster. We infer that bright 500μ\mum risers with faint 850μ\mum flux densities are typically multiple systems at z≥2z \geq 2 that may reside in overdensities of bright sub-mm galaxies.
Note:
  • 20 pages, 13 figures, 3 tables. Submitted to MNRAS