Breaking the rules at $z\simeq$0.45: the rebel case of RBS 1055
| Autor: | A. Marinucci, G. Vietri, E. Piconcelli, S. Bianchi, M. Guainazzi, G. Lanzuisi, D. Stern, C. Vignali |
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| Přispěvatelé: | Marinucci, A., Vietri, G., Piconcelli, E., Bianchi, S., Guainazzi, M., Lanzuisi, G., Stern, D., Vignali, C. |
| Rok vydání: | 2022 |
| Předmět: |
High Energy Astrophysical Phenomena (astro-ph.HE)
supermassive black hole [quasars] Space and Planetary Science Astrophysics::High Energy Astrophysical Phenomena Astrophysics of Galaxies (astro-ph.GA) active [galaxies] individual: RBS 1055 [quasars] FOS: Physical sciences Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics - High Energy Astrophysical Phenomena Astrophysics - Astrophysics of Galaxies Astrophysics::Galaxy Astrophysics |
| DOI: | 10.48550/arxiv.2209.01575 |
| Popis: | We report on a long (250 ks) NuSTAR observation of the bright quasar RBS 1055 performed in March 2021, and archival XMM-Newton pointings (185 ks) taken in July 2014. An optical spectrum of the source taken with the Double Spectrograph at the Palomar Observatory, quasi-simultaneous with the NuSTAR observations, is also analyzed. We find that the two-coronae model, in which a warm and hot corona coexist, well reproduces its broad band spectrum, with temperatures kT$_e=0.12^{+0.08}_{-0.03}$ keV, kT$_e=30^{+40}_{-10}$ keV and Thomson optical depths $\tau$=30$_{-10}^{+15}$ and $\tau$=3.0$_{-1.4}^{+1.0}$ for the former and the latter component, respectively. We confirm the presence of an intense Fe K$\alpha$ emission line (EW=55$\pm$6 eV) and, when a toroidal model is considered for reproducing the Compton reflection, a Compton-thin solution with N$_{\rm H}=(3.2^{+0.9}_{-0.8})\times10^{23}$ cm$^{-2}$ for the circumnuclear reflector is found. The analysis of the optical spectrum reveals a likely peculiar configuration of our line of sight with respect to the nucleus, and the presence of a broad [O III] component, tracing outflows in the NLR, with a velocity shift $v=$1500$\pm100$ km s$^{-1}$, leading to a mass outflow rate $\dot{M}_{\rm out}=25.4\pm1.5$ M$_{\odot}$ yr$^{-1}$ and outflow kinetic power $\dot{E}_{\rm kin}$/L$_{\rm Bol}$ $\sim$0.33%. We estimate the BH mass to be in the range 2.8$\times$10$^{8}$-1.2$\times$10$^{9}$ M$_{\odot}$, according to different BLR emission lines, with an average value of =6.5$\times$10$^{8}$ M$_{\odot}$. With an Fe K$\alpha$ which is 3$\sigma$ above the value predicted from the EW-L$_{2-10\ \rm keV}$ relation and an extreme source brightness at 2 keV (a factor 10-15 higher than the one expected from the optical/UV), RBS 1055 confirms to be an outlier in the X-rays, compared to other objects in the same luminosity and redshift range. Comment: 11 pages, 10 figures, 4 tables. Accepted for publication in Astronomy & Astrophysics |
| Databáze: | OpenAIRE |
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