Kinematics and star formation of high-redshift hot dust-obscured quasars as seen by ALMA
| Autor: | Jingwen Wu, Peter R. Eisenhardt, Sean E. Lake, Manuel Aravena, J. González-López, Roberto J. Assef, Hyunsung David Jun, Tanio Díaz-Santos, Andrew Blain, Chao-Wei Tsai, Daniel Stern, G. C. Jones |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Physics
Luminous infrared galaxy education.field_of_study 010308 nuclear & particles physics Star formation Population Continuum (design consultancy) FOS: Physical sciences Astronomy and Astrophysics Quasar Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics Astrophysics - Astrophysics of Galaxies 01 natural sciences Galaxy Redshift Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics Emission spectrum education 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics |
| Zdroj: | Astronomy & Astrophysics. 654:A37 |
| ISSN: | 1432-0746 0004-6361 |
| Popis: | Hot, dust-obscured galaxies (Hot DOGs) are a population of hyper-luminous obscured quasars identified by WISE. We present ALMA observations of the [CII] fine-structure line and underlying dust continuum emission in a sample of seven of the most extremely luminous (EL; L$_{\rm bol}$ $\ge$ 10$^{14}$ L$_\odot$) Hot DOGs, at redshifts z ~ 3.0-4.6. The [CII] line is robustly detected in four objects, tentatively in one, and likely red-shifted out of the spectral window in the remaining two based on additional data. On average, [CII] is red-shifted by ~ 780 km/s from rest-frame ultraviolet emission lines. EL Hot DOGs exhibit consistently very high ionized gas surface densities, with $\Sigma_{\rm [CII]}$ ~ 1-2 x 10$^{9}$ L$_\odot$ kpc$^{-2}$; as high as the most extreme cases seen in other high-redshift quasars. As a population, EL Hot DOG hosts seem to be roughly centered on the main-sequence of star forming galaxies, but the uncertainties are substantial and individual sources can fall above and below. The average, intrinsic [CII] and dust continuum sizes (FWHMs) are ~ 2.1 kpc and ~ 1.6 kpc, respectively, with a very narrow range of line-to-continuum size ratios, 1.61 $\pm$ 0.10, suggesting they could be linearly proportional. The [CII] velocity fields of EL Hot DOGs are diverse: from barely rotating structures, to resolved hosts with ordered, circular motions, to complex, disturbed systems that are likely the result of ongoing mergers. In contrast, all sources display large line-velocity dispersions, FWHM $\gtrsim$ 500 km/s, which on average are larger than optically and IR-selected quasars at similar or higher redshifts. We argue that one possible hypothesis for the lack of a common velocity structure, the systematically large dispersion of the ionized gas, and the presence of nearby companion galaxies may be that, rather than a single event, the EL Hot DOG phase could be recurrent. Comment: 31 pages, 13 figures. Accepted for publication in A&A |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|