Broad-line region in active galactic nuclei: Dusty or dustless?

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F23%3A00134415" target="_blank" >RIV/00216224:14310/23:00134415 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.aanda.org/articles/aa/full_html/2023/12/aa47819-23/aa47819-23.html" target="_blank" >https://www.aanda.org/articles/aa/full_html/2023/12/aa47819-23/aa47819-23.html</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202347819" target="_blank" >10.1051/0004-6361/202347819</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Broad-line region in active galactic nuclei: Dusty or dustless?

Popis výsledku v původním jazyce

Context. Dust in active galactic nuclei is clearly present right outside the broad-line region (BLR) in the form of a dusty molecular torus. However, some models of the BLR predict that dust may also exist within the BLR. Aims. We study the reprocessing of radiation by the BLR with the aim of observing how the presence of dust affects the reprocessed continuum and the line properties. Methods.We calculated a range of models using the CLOUDY photoionisation code for dusty and dustless plasma. We paid particular attention to the well-studied object NGC 5548, and we compared the line equivalent width predictions with the data from observations for this object. Results. We obtained a rough agreement between the expected equivalent widths of the Hβ and Mg II lines and the observed values for NGC 5548 for the line distances implied by the time-delay measurement (for Hβ) and the radius-luminosity relation (for Mg II) when the medium is dusty. We found the incident radiation to be consistent with the radiation seen by the observer, so no shielding between the inner disc and the BLR is required. High ionisation lines such as He II, however, clearly form in the inner dustless region. When the additional absorber is present, the Hβ emitting region moves closer to the dustless part of the accretion disc surface.

Název v anglickém jazyce

Broad-line region in active galactic nuclei: Dusty or dustless?

Popis výsledku anglicky

Context. Dust in active galactic nuclei is clearly present right outside the broad-line region (BLR) in the form of a dusty molecular torus. However, some models of the BLR predict that dust may also exist within the BLR. Aims. We study the reprocessing of radiation by the BLR with the aim of observing how the presence of dust affects the reprocessed continuum and the line properties. Methods.We calculated a range of models using the CLOUDY photoionisation code for dusty and dustless plasma. We paid particular attention to the well-studied object NGC 5548, and we compared the line equivalent width predictions with the data from observations for this object. Results. We obtained a rough agreement between the expected equivalent widths of the Hβ and Mg II lines and the observed values for NGC 5548 for the line distances implied by the time-delay measurement (for Hβ) and the radius-luminosity relation (for Mg II) when the medium is dusty. We found the incident radiation to be consistent with the radiation seen by the observer, so no shielding between the inner disc and the BLR is required. High ionisation lines such as He II, however, clearly form in the inner dustless region. When the additional absorber is present, the Hβ emitting region moves closer to the dustless part of the accretion disc surface.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

<a href="/cs/project/GX21-13491X" target="_blank" >GX21-13491X: Zkoumání žhavého vesmíru a porozumění kosmické zpětné vazbě</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2023

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Astronomy and Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Svazek periodika

680

Číslo periodika v rámci svazku

December 2023

Stát vydavatele periodika

FR - Francouzská republika

Počet stran výsledku

10

Strana od-do

1-10

Kód UT WoS článku

001125494400022

EID výsledku v databázi Scopus

2-s2.0-85180811711