BROAD COMPONENTS IN OPTICAL EMISSION LINES FROM THE ULTRA-LUMINOUS X-RAY SOURCE NGC 5408 X-1

Journal Article · Thu Feb 10 00:00:00 EST 2011 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/728/1/L5· OSTI ID:21560513

Cseh, D; Corbel, S ^[1]; Grise, F; Kaaret, P ^[2]

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1. Laboratoire Astrophysique des Interactions Multi-echelles (UMR 7158), CEA/DSM-CNRS-Universite Paris Diderot, CEA Saclay, F-91191 Gif sur Yvette (France)
2. Department of Physics and Astronomy, University of Iowa, Van Allen Hall, Iowa City, IA 52242 (United States)

High-resolution optical spectra of the ultra-luminous X-ray source (ULX) NGC 5408 X-1 show a broad component with a width of {approx}750 km s{sup -1} in the He II and H{beta} lines in addition to the narrow component observed in these lines and [O III]. Reanalysis of moderate-resolution spectra shows a similar broad component in the He II line. The broad component likely originates in the ULX system itself, probably in the accretion disk. The central wavelength of the broad He II line is shifted by 252 {+-} 47 km s{sup -1} between the two observations. If this shift represents motion of the compact object, then its mass is less than {approx}1800 M{sub sun}.

• OSTI ID: 21560513
• Journal Information: Astrophysical Journal Letters, Vol. 728, Issue 1; Other Information: DOI: 10.1088/2041-8205/728/1/L5; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ACCRETION DISKS
BLACK HOLES
EMISSION
SPECTRA
X-RAY SOURCES
RADIATION SOURCES