Universität zu Köln

Bhat, Harshitha K., Chakravorty, Susmita, Sengupta, Dhrubojyoti, Elvis, Martin, Datta, Sudeb Ranjan, Roy, Nirupam, Bertemes, Caroline, Ferland, Gary and Ezhikode, Savithri H. (2020). Hypermassive black holes have faint broad and narrow emission lines. Mon. Not. Roy. Astron. Soc., 497 (3). S. 2992 - 3011. OXFORD: OXFORD UNIV PRESS. ISSN 1365-2966

Full text not available from this repository.

Abstract

The extreme ultraviolet region (EUV) provides most of the ionization that creates the high equivalent width (EW) broad and narrow emission lines (BELs and NELs) of quasars. Spectra of hypermassive Schwarzschild black holes (HMBHs; M-BH >= 10(10) M-circle dot) with a-discs, decline rapidly in the EUV suggesting much lower EWs. Model spectra for BHs of mass 10(6)-10(12) M-circle dot and accretion rates 0.03 <= L-bol/L-Edd <= 1.0 were input to the CLOUDY photoionization code. BELs become similar to 100 times weaker in EW from M-BH similar to 108 M-circle dot to M-BH similar to 1010 M-circle dot. The high-ionization BELs (O VI 1034 angstrom, C IV 1549 A, and He II 1640 A) decline in EW from MBH = 106 M-circle dot, reproducing the Baldwin effect, but regain EW for M-BH >= 1010 M-circle dot. The low-ionization lines (Mg II 2798 A, H beta 4861 A, and H alpha 6563 angstrom) remain weak. Lines for maximally spinning HMBHs behave similarly. Line ratio diagrams for the BELs show that high OVI/H beta and low C IV/H alpha may pick out HMBH, although OVI is often hard to observe. In NEL BPT diagrams, HMBHs lie among star-forming regions, except for highly spinning, high accretion rate HMBHs. In summary, the BELs expected from HMBHs would be hard to detect using the current optical facilities. From 100 to 10(12) M-circle dot, the emission lines used to detect active galactic nuclei (AGNs) only have high EW in the 106-109 M-circle dot window, where most AGNs are found. This selection effect may be distorting reported distributions of MBH.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Bhat, Harshitha K. UNSPECIFIED UNSPECIFIED UNSPECIFIED Chakravorty, Susmita UNSPECIFIED UNSPECIFIED UNSPECIFIED Sengupta, Dhrubojyoti UNSPECIFIED UNSPECIFIED UNSPECIFIED Elvis, Martin UNSPECIFIED UNSPECIFIED UNSPECIFIED Datta, Sudeb Ranjan UNSPECIFIED UNSPECIFIED UNSPECIFIED Roy, Nirupam UNSPECIFIED UNSPECIFIED UNSPECIFIED Bertemes, Caroline UNSPECIFIED UNSPECIFIED UNSPECIFIED Ferland, Gary UNSPECIFIED UNSPECIFIED UNSPECIFIED Ezhikode, Savithri H. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-320523
DOI:	10.1093/mnras/staa2002
Journal or Publication Title:	Mon. Not. Roy. Astron. Soc.
Volume:	497
Number:	3
Page Range:	S. 2992 - 3011
Date:	2020
Publisher:	OXFORD UNIV PRESS
Place of Publication:	OXFORD
ISSN:	1365-2966
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language X-RAY-SPECTRA; OPTIMALLY EMITTING CLOUDS; ACTIVE GALACTIC NUCLEI; ACCRETION DISKS; HOST GALAXIES; QUASAR; CONTINUUM; REDSHIFT; CLASSIFICATION; MODELS Multiple languages Astronomy & Astrophysics Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/32052