Estimating black hole masses: Accretion disk fitting versus reverberation mapping and single epoch
| Autor: | Tullia Sbarrato, Annalisa Celotti, Samuele Campitiello, Gabriele Ghisellini |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Accretion
Active galactic nucleus Astrophysics::High Energy Astrophysical Phenomena FOS: Physical sciences Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics 01 natural sciences Settore FIS/05 - Astronomia e Astrofisica 0103 physical sciences 010303 astronomy & astrophysics Scaling Astrophysics::Galaxy Astrophysics High Energy Astrophysical Phenomena (astro-ph.HE) Physics Supermassive black hole Accretion (meteorology) 010308 nuclear & particles physics Astronomy and Astrophysics Galaxies: active Black hole physics Scale factor Astrophysics - Astrophysics of Galaxies Quasars: general Black hole Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) Accretion disks Reverberation mapping Astrophysics - High Energy Astrophysical Phenomena Dimensionless quantity |
| Zdroj: | Astronomy & Astrophysics. 640:A39 |
| ISSN: | 1432-0746 0004-6361 |
| DOI: | 10.1051/0004-6361/201936218 |
| Popis: | We selected a sample of 28 Type 1 AGNs for which a black hole mass has been inferred using the reverberation mapping technique and single epoch scaling relations. All 28 sources show clear evidence of the "Big Blue Bump" in the optical-UV band whose emission is produced by an accretion disk (AD) around a supermassive black hole. We fitted the spectrum of these sources with the relativistic thin AD model KERRBB in order to infer the black hole masses and compared them with those from Reverberation mapping and Single epoch methods, discussing the possible uncertainties linked to such a model by quantifying their weight on our results. We find that for the majority of the sources, KERRBB is a good description of the AD emission for a wide wavelength range. The overall uncertainty on the black hole mass estimated through the disk fitting procedure is $\sim 0.45$ dex (which includes the uncertainty on fitting parameters such as e.g. spin and viewing angle), comparable to the systematic uncertainty of reverberation mapping and single epoch methods; however, such an uncertainty can be $\leq 0.3$ dex if one of the parameters of the fit is well constrained. Although all of the estimates are affected by large uncertainties, the masses inferred using the three methods are compatible if the dimensionless scale factor $f$ (linked to the unknown kinematics and geometry of the Broad Line Region) is assumed to be larger than one. For the majority of the sources, the comparison between the results coming from the three methods favors small spin values. To check the goodness of the KERRBB results, we compared them with those inferred with other models, such as AGNSED, a model that also accounts for the emission originating from an X-ray corona: using two sources with a good data coverage in the X band, we find that the masses estimated with the two models differ at most by a factor of $\sim 0.2$ dex. 25 pages, 35 figures, accepted for publication in A&A |
| Databáze: | OpenAIRE |
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