Physical conditions of iron-peak low-ionization lines in the FeLoBAL quasar Q0059-2735
| Autor: | Timothy R. Miller, Nahum Arav, Xinfeng Xu, Kirk T. Korista, Chris Benn |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Monthly Notices of the Royal Astronomical Society. 506:2725-2738 |
| ISSN: | 1365-2966 0035-8711 |
| DOI: | 10.1093/mnras/stab1866 |
| Popis: | Quasar Q0059–2735, one of the first known iron low-ionization broad-absorption-line quasars (FeLoBAL), has a plethora of outflow absorption features at different velocities. Given multiple outflow systems, their troughs from high-ionization transitions form very wide BAL features, e.g. C iv troughs extend from ∼−1000 to −25 000 km s−1. The troughs from low-ionization transitions show more than 1000 narrow absorption lines (NALs) with velocities from −1000 to −3000 km s−1. These include troughs from iron-peak elements, e.g. Fe ii, Fe iii, Cr ii, Mn ii, Ni ii, and Co ii, which are rarely detected in quasar outflows. Most of these troughs are non-black saturated. We constrain the physical conditions of the NALs by fitting the observed Fe ii and Fe iii absorption troughs. We find that the Fe ii absorption arises from a region with an electron temperature (Te) of ∼8000 K and an electron number density (ne) of ∼108 cm−3. The same model also fits well the troughs from other iron-peak elements. In contrast to the Fe ii lines, Fe iii lines are formed in a hotter region, i.e. Te ∼20 000 K. To fit the Fe ii and Fe iii lines simultaneously in a single photoionized cloud, they require a supersolar iron abundance and/or other heating mechanisms for the Fe iii region. The distance (R) of the outflows to the central quasar is determined to be ∼40 pc. The high-resolution data afforded by the Very Large Telescope (VLT)/UVES observations from 2006 and 2018, along with the narrow lines, allow us to constrain the smallest outflow deceleration in any known quasars. |
| Databáze: | OpenAIRE |
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