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ALMA and HST kiloparsec-scale imaging of a quasar-galaxy merger at $z\approx 6.2$
- Source :
- The Astrophysical Journal
- Publication Year :
- 2019
-
Abstract
- We present kpc-scale ALMA and HST imaging of the quasar PJ308-21 at $z$=$6.2342$, tracing dust, gas (via the [CII] 158 $��$m line) and young stars. At a resolution of $\sim0.3''$ ($\approx1.7$ kpc), the system is resolved over $>4''$ ($>$20 kpc). In particular, it features a main component, identified to be the quasar host galaxy, centered on the accreting supermassive black hole; and two other extended components on the West and East side, one redshifted and the other blueshifted relative to the quasar. The [CII] emission of the entire system stretches over $>$1500 km/s along the line of sight. All the components of the system are observed in dust, [CII], and rest-frame UV emission. The inferred [CII] luminosities [(0.9-4.6)$\times 10^9$ L$_\odot$], dust luminosities [(0.15-2.6)$\times10^{12}$ L$_\odot$], and rest-frame UV luminosities [(6.6-15)$\times10^{10}$ L$_\odot$], their ratios, and the implied gas/dust masses and star formation rates [11-290 M$_\odot$ yr$^{-1}$] are typical of high-redshift star-forming galaxies. A toy model of a single satellite galaxy that is tidally stripped by the interaction with the quasar host galaxy can account for the observed velocity and spatial extent of the two extended components. An outflow interpretation of the unique features in PJ308-21 is not supported by the data. PJ308-21 is thus one of the earliest galaxy mergers imaged at cosmic dawn.<br />9 pages, 6 figures. Accepted for publication in ApJ
- Subjects :
- 010504 meteorology & atmospheric sciences
Astrophysics::High Energy Astrophysical Phenomena
FOS: Physical sciences
Astrophysics
Astrophysics::Cosmology and Extragalactic Astrophysics
Galaxy merger
01 natural sciences
Submillimeter Array
galaxies: high-redshift
quasars: general
0103 physical sciences
Satellite galaxy
Astrophysics::Solar and Stellar Astrophysics
010303 astronomy & astrophysics
Astrophysics::Galaxy Astrophysics
0105 earth and related environmental sciences
Physics
Supermassive black hole
Star formation
Astronomy and Astrophysics
Quasar
Astrophysics - Astrophysics of Galaxies
Galaxy
Redshift
Space and Planetary Science
Astrophysics of Galaxies (astro-ph.GA)
galaxies: interaction
galaxies: star formation
Astrophysics::Earth and Planetary Astrophysics
galaxies: ISM
Subjects
Details
- Language :
- English
- ISSN :
- 0004637X, 00670049, and 15383881
- Database :
- OpenAIRE
- Journal :
- The Astrophysical Journal
- Accession number :
- edsair.doi.dedup.....420595134da236daf0a0649088e41ef5