Modeling of the Quasar Main Sequence in the Optical Plane
PBN-AR
Instytucja
Centrum Fizyki Teoretycznej Polskiej Akademii Nauk
Informacje podstawowe
Główny język publikacji
en
Czasopismo
ASTROPHYSICAL JOURNAL (40pkt w roku publikacji)
ISSN
0004-637X
EISSN
Wydawca
IOP PUBLISHING LTD
DOI
URL
Rok publikacji
2018
Numer zeszytu
2
Strony od-do
115
Numer tomu
866
Link do pełnego tekstu
Identyfikator DOI
Liczba arkuszy
Autorzy
Pozostali autorzy
+ 3
Słowa kluczowe
en
accretion
accretion disks
galaxies: active
quasars: emission lines
radiative transfer
Streszczenia
Język
en
Treść
The concept of the quasar main sequence is very attractive since it stresses correlations between various parameters and implies the underlying simplicity. In the optical plane defined by the width of the Hβ line and the ratio of the equivalent width of the Fe II to Hβ observed objects form a characteristic pattern. In this paper, we use a physically motivated model to explain the distribution of quasars in the optical plane. Continuum is modelled as an accretion disk with a hard X-ray power law uniquely tight to the disk at the basis of observational scaling, and the broad-line region distance is determined also from observational scaling. We perform the computations of the Fe II and Hβ line production with the code CLOUDY. We have only six free parameters for an individual source, the maximum temperature of an accretion disk, Eddington ratio, cloud density, cloud column density, microturbulence, and iron abundance, and only the last four remain as global parameters in our modelling of the whole sequence. Our theoretically computed points cover well the optical plane part populated with the observed quasars, particularly if we allow for a supersolar abundance of heavy elements. Explanation of the exceptionally strong Fe II emitter requires a stronger contribution from the dark sides of the clouds. Analyzing the way our model covers the optical plane, we conclude that there is no single simple driver behind the sequence, as neither the Eddington ratio nor broadband spectrum shape plays the dominant role. Also, the role of the viewing angle in providing the dispersion of the quasar main sequence is apparently not as strong as expected.
Cechy publikacji
discipline:Astronomia
discipline:Astronomy
Original article
Original article presents the results of original research or experiment.
Oryginalny artykuł naukowy
Oryginalny artykuł naukowy przedstawia rezultaty oryginalnych badań naukowych lub eksperymentu.
Inne
System-identifier
PBN-R:895335
CrossrefMetadata from Crossref logo
Cytowania
Liczba prac cytujących tę pracę
Brak danych
Referencje
Liczba prac cytowanych przez tę pracę
Brak danych