Breaking the rules at $z\simeq$0.45: the rebel case of RBS 1055

Abstract

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${}_e=0.12_{-0.03}^{+0.08}$ keV, kT${}_e=30_{-10}^{+40}$ 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$6 eV) and, when a toroidal model is considered for reproducing the Compton reflection, a Compton-thin solution with N${}_{\mathrm{H}}=(3.2_{-0.8}^{+0.9})\times 10^{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=$1500$\pm 100$ km s${}^{-1}$, leading to a mass outflow rate ${\dot{M}}_{\mathrm{out}}=25.4\pm 1.5$ M${}_{\odot }$ yr${}^{-1}$ and outflow kinetic power ${\dot{E}}_{\mathrm{kin}}$/L${}_{\mathrm{Bol}}$ $\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 <$M{}_{\mathrm{BH}}$>=6.5$\times$10${}^8$ M${}_{\odot }$. With an Fe K$\alpha$ which is 3$\sigma$ above the value predicted from the EW-L${}_{2-10\mathrm{keV}}$ 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.

11 pages, 10 figures, 4 tables. Accepted for publication in Astronomy & Astrophysics

References in corpus (32)

• HI4PI: A full-sky HI survey based on EBHIS and GASS
• A Catalog of Quasar Properties from SDSS DR7
• BAT AGN Spectroscopic Survey - V. X-ray properties of the Swift/BAT 70-month AGN catalog
• The X-ray-to-Optical Properties of Optically-Selected Active Galaxies Over Wide Luminosity and Redshift Ranges
• Kiloparsec-scale outflows are prevalent among luminous AGN: outflows and feedback in the context of the overall AGN population
• The X-ray Properties of the Most-Luminous Quasars from the Sloan Digital Sky Survey
• Fe II Emission in 14 Low-Redshift Quasars: I - Observations
• The WISSH Quasars Project I. Powerful ionised outflows in hyper-luminous quasars
• On the Iwasawa-Taniguchi effect of radio-quiet AGN
• Properties of the Multiphase Outflows in Local (Ultra)luminous Infrared Galaxies
• Properties of AGN coronae in the NuSTAR era II: hybrid plasma
• The Complete Infrared View of Active Galactic Nuclei from the 70-month Swift/BAT Catalog
• Iron K$\alpha$ emission in type-I and type-II Active Galactic Nuclei
• The WISSH Quasars Project III. X-ray properties of hyper-luminous quasars
• The M_BH - M_star relation for X-ray obscured, red QSOs at 1.2< z <2.6
• Determining the covering factor of Compton-thick active galactic nuclei with NuSTAR
• Discovery of Kiloparsec Extended Hard X-ray Continuum and Fe K alpha from the Compton Thick AGN ESO428-G014
• NuSTAR Survey of Obscured Swift/BAT-selected Active Galactic Nuclei: II. Median High-energy Cutoff in Seyfert II Hard X-ray Spectra
• On the X-ray Baldwin effect for narrow Fe Kalpha emission line
• The structure of the Mg II broad line emitting region in Type 1 AGNs
• NuSTAR/XMM-Newton monitoring of the Seyfert 1 galaxy HE 1143-1810. Testing the two-corona scenario
• Compton-thick AGN in the NuSTAR era III: A systematic study of the torus covering factor
• The soft excess of the NLS1 galaxy Mrk 359 studied with an XMM-Newton-NuSTAR monitoring campaign
• MgII Line Variability of High Luminosity Quasars
• X-ray Constraint on Location of AGN Torus in Circinus Galaxy
• Nustar Measurement Of Coronal Temperature In Two Luminous, High Redshift Qsos
• Extended X-ray Emission in Compton Thick AGN with Deep Chandra Observations
• BAT AGN Spectroscopic Survey-XXIII. A New Mid-Infrared Diagnostic for Absorption in Active Galactic Nuclei
• The kpc Scale Fe K$\alpha$ Emission in the Compton Thin Seyfert 2 Galaxy NGC 4388 resolved by Chandra
• The properties of the X-ray corona in the distant ($z=3.91$) quasar APM 08279+5255
• Coronal properties of the luminous radio-quiet quasar QSO B2202$-$209
• Chandra Observations of Excess Fe K$\alpha$ Line Emission in Galaxies with High Star Formation Rates: X-ray Reflection on Galaxy Scales?

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