ALMA observations of PKS 1549-79: a case of feeding and feedback in a young radio quasar
| Autor: | Tom Oosterloo, Tasso Tzioumis, Raffaella Morganti, Cormac Reynolds, Clive Tadhunter, J. B. Raymond Oonk, Hayley Bignall |
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| Přispěvatelé: | Astronomy |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
galaxies: individual: PKS 1549-79
Astrophysics::High Energy Astrophysical Phenomena galaxies: active FOS: Physical sciences DUST Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics GALACTIC OUTFLOWS I 01 natural sciences 0103 physical sciences Very-long-baseline interferometry RELATIVISTIC JET FEEDBACK Astrophysics::Solar and Stellar Astrophysics 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics Physics radio lines: galaxies 010308 nuclear & particles physics Astronomy and Astrophysics Quasar DRIVEN OUTFLOWS Astrophysics - Astrophysics of Galaxies Accretion (astrophysics) GALAXIES ISM: jets and outflows Outflow rate Space and Planetary Science GAS Astrophysics of Galaxies (astro-ph.GA) WINDS PKS-1549-79 Outflow EMISSION |
| Zdroj: | Astronomy and astrophysics, 632(December 2019):A66. EDP Sciences Astronomy and Astrophysics (0004-6361), 632, A66 |
| ISSN: | 0004-6361 |
| Popis: | We present CO(1-0) and CO(3-2) ALMA observations of the molecular gas in PKS 1549-79, as well as mm and VLBI 2.3-GHz continuum observations of its radio jet. PKS 1549-79 is one of the closest young, radio-loud quasars caught in an on-going merger in which the AGN is in the first phases of its evolution. We detect three structures tracing the accretion and the outflow of molecular gas: kpc-scale tails of gas accreting onto PKS 1549-79, a circumnuclear disc (CND) in the inner few hundred parsec, and a very broad (>2300 \kms) component detected in CO(1-0) at the position of the AGN. Thus, in PKS 1549-79 we see the co-existence of accretion and the ejection of gas. The line ratio CO(1-0)/CO(3-2) suggests that the gas in the CND has both high densities and high kinetic temperatures. We estimate a mass outflow rate of at least 650 msun/yr. This massive outflow is confined to r < 120 pc, which suggests that the AGN drives the outflow. Considering the amount of molecular gas available in CND and the observed outflow rate, we estimate a time scale of ~10^5 yr over which the AGN would be able to destroy the CND, although gas from the merger may come in from larger radii, rebuilding this disc at the same time. The AGN appears to self-regulate gas accretion onto the super-massive black hole. From a comparison with HST data, we find that the ionised gas outflow is more extended. Nevertheless, the warm outflow is about two orders of magnitude less massive than the molecular outflow. PKS 1549-79 does not seem to follow the scaling relation between bolometric luminosity and the relative importance of warm ionised and molecular outflows claimed to exist for other AGN. We argue that, although PKS 1549-79 hosts a powerful quasar nucleus and an ultra-fast outflow, the radio jet plays a significant role in producing the outflow. Accepted for A&A Main Journal |
| Databáze: | OpenAIRE |
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