학술논문
A dusty proto-cluster surrounding the binary galaxy HerBS-70 at $z = 2.3$
Document Type
Working Paper
Author
Bakx, Tom J. L. C.; Berta, S.; Dannerbauer, H.; Cox, P.; Butler, K. M.; Hagimoto, M.; Hughes, D. H.; Riechers, D. A.; van der Werf, P. P.; Yang, C.; Baker, A. J.; Beelen, A.; Bendo, G. J.; Borsato, E.; Buat, V.; Cooray, A. R.; Dunne, L.; Dye, S.; Eales, S.; Gavazzi, R.; Harris, A. I.; Ismail, D.; Ivison, R. J.; Jones, B.; Krips, M.; Lehnert, M. D.; Marchetti, L.; Messias, H.; Negrello, M.; Neri, R.; Omont, A.; Perez-Fournon, I.; Nanni, A.; Chartab, N.; Serjeant, S.; Stanley, F.; Tamura, Y.; Urquhart, S. A.; Vlahakis, C.; Weiß, A.; Young, A. J.
Source
Subject
Language
Abstract
We report on deep SCUBA-2 observations at 850$\mu$m and NOEMA spectroscopic measurements at 2 mm of the environment surrounding the luminous, massive ($M_{*} \approx 2 \times 10^{11}$ M$_{\odot}$) Herschel-selected source HerBS-70. This source was revealed by previous NOEMA observations to be a binary system of dusty star-forming galaxies at $z= 2.3$, with the East component (HerBS-70E) hosting an Active Galactic Nucleus (AGN). The SCUBA-2 observations detected, in addition to the binary system, twenty-one sources at $> 3.5 \sigma$ over an area of $\sim 25$ square comoving Mpc with a sensitivity of $\sigma_{850} = 0.75$ mJy. The surface density of continuum sources around HerBS-70 is three times higher than for field galaxies. The NOEMA spectroscopic measurements confirm the protocluster membership of three of the nine brightest sources through their CO(4 - 3) line emission, yielding a volume density 36 times higher than for field galaxies. All five confirmed sub-mm galaxies in the HerBS-70 system have relatively short gas depletion times ($80 - 500$ Myr), indicating the onset of quenching for this protocluster core due to the depletion of gas. The dark matter halo mass of the HerBS-70 system is estimated around $5 \times{} 10^{13}$ M$_{\odot}$, with a projected current-day mass of $10^{15}$ M$_{\odot}$, similar to the local Virgo and Coma clusters. These observations support the claim that DSFGs, in particular the ones with observed multiplicity, can trace cosmic overdensities.
Comment: 19 pages, 13 figures, accepted for publication in MNRAS
Comment: 19 pages, 13 figures, accepted for publication in MNRAS