A SCUBA-2 selected Herschel-SPIRE dropout and the nature of this population

A SCUBA-2 selected Herschel-SPIRE dropout and the nature of this populationGreenslade, J.Aguilar, E.Clements, D. L.Dannerbauer, H.Cheng, T.Petitpas, GlenYang, C.Messias, H.Oteo, I.Farrah, D.Michałowski, M. J.Pérez Fournon, I.Aretxaga, I.Yun, M. S.Eales, S.Dunne, L.Cooray, A.Andreani, P.Hughes, D. H.Velázquez, M.Sánchez-Argüelles, D.Ponthieu, N.DOI: info:10.1093/mnras/stz2850v. 4905317–5334
Greenslade, J., Aguilar, E., Clements, D. L., Dannerbauer, H., Cheng, T., Petitpas, Glen, Yang, C., Messias, H., Oteo, I., Farrah, D., Michałowski, M. J., Pérez Fournon, I., Aretxaga, I., Yun, M. S., Eales, S., Dunne, L., Cooray, A., Andreani, P., Hughes, D. H., Velázquez, M., Sánchez-Argüelles, D., and Ponthieu, N. 2019. "A SCUBA-2 selected Herschel-SPIRE dropout and the nature of this population." Monthly Notices of the Royal Astronomical Society 490:5317– 5334. https://doi.org/10.1093/mnras/stz2850
ID: 154512
Type: article
Authors: Greenslade, J.; Aguilar, E.; Clements, D. L.; Dannerbauer, H.; Cheng, T.; Petitpas, Glen; Yang, C.; Messias, H.; Oteo, I.; Farrah, D.; Michałowski, M. J.; Pérez Fournon, I.; Aretxaga, I.; Yun, M. S.; Eales, S.; Dunne, L.; Cooray, A.; Andreani, P.; Hughes, D. H.; Velázquez, M.; Sánchez-Argüelles, D.; Ponthieu, N.
Abstract: Dusty star-forming galaxies (DSFGs) detected at z > 4 provide important examples of the first generations of massive galaxies. However, few examples with spectroscopic confirmation are currently known, with Hershel struggling to detect significant numbers of z > 6 DSFGs. NGP6_D1 is a bright 850 μm source (12.3 ± 2.5 mJy) with no counterparts at shorter wavelengths (a SPIRE dropout). Interferometric observations confirm it is a single source, with no evidence for any optical or NIR emission, or nearby likely foreground lensing sources. No >3σ detected lines are seen in both LMT Redshift Search Receiver and IRAM 30 m EMIR spectra of NGP6_D1 across 32 GHz of bandwidth despite reaching detection limits of ̃ 1 mJy/500 km s^{-1}, so the redshift remains unknown. Template fitting suggests that NGP6_D1 is most likely between z = 5.8 and 8.3. SED analysis finds that NGP6_D1 is a ULIRG, with a dust mass ̃108-109 M and a star-formation rate of ̃500 M yr-1. We place upper limits on the gas mass of NGP6_D1 of MH2 11 M, consistent with a gas-to-dust ratio of ̃100-1000. We discuss the nature of NGP6_D1 in the context of the broader sub-mm population, and find that comparable SPIRE dropouts account for ̃20 per cent of all SCUBA-2 detected sources, but with a similar flux density distribution to the general population.