Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Evidence for a supermassive black hole in the nucleus of the Seyfert galaxy NGC 5548

Journal Article · · Astrophysical Journal; (USA)
DOI:https://doi.org/10.1086/185774· OSTI ID:6478769
;  [1]
  1. Computer Sciences Corp., Lanham, MD (USA)

The international campaign to monitor the variable Seyfert 1 galaxy NGC 5548 with the IUE has provided an extensive and well-sampled set of spectroscopic observations. These observations are used to study the response of the C IV 1550 A emission-line profile to changes in the photoionizing continuum. Near the end of the IUE campaign, the continuum flux at 1440 A and the total C IV flux dopped by factors of 2.9 and 1.8, respectively, in 16 days. The red wing of the C IV profile responded more rapidly to the sharp continuum drop than the blue wing, indicating that clouds in the inner broad-line region (BLR) are undergoing gravitational infall. These results provide direct evidence that the central engine is a supermassive object, presumably a black hole, with a mass on the order of 10 to the 7th solar masses. Analysis of the profile variations also demonstrates that excess emission in the blue wing of C IV is from a component that is physically distinct from the bulk of the BLR. 16 refs.

OSTI ID:
6478769
Journal Information:
Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 358; ISSN ASJOA; ISSN 0004-637X
Country of Publication:
United States
Language:
English