The ultraviolet spectrum and continuum energy distribution of the bright quasar H1821 + 643

Details The ultraviolet spectrum and continuum energy distribution of the bright quasar H1821 + 643 The ultraviolet spectrum and continuum energy distribution of the bright quasar H1821 + 643

May 1991

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1991apj...373...57k&link_type=abstract

Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 373, May 20, 1991, p. 57-65.

Astronomy and Astrophysics

Astrophysics

31

Continuous Radiation, Quasars, Spectral Energy Distribution, Stellar Spectra, Ultraviolet Spectra, Absorption Spectra, Accretion Disks, Emission Spectra, Line Spectra, X Ray Spectra

Scientific paper

The first UV observations of the bright QSO H1821 + 643 are reported. With V = 14.2 mag and z = 0.297, H1821 + 643 is the second brightest object in the sky at z above 0.1. The IUE data are combined with new optical spectroscopy, and existing IR and X-ray data, to reveal a strong optical/UV 'big bump', which continues past the Lyman limit in the rest frame of the QSO. A possible turnover at the high-frequency side of the UV continuum constrains fits of a thin accretion disk model to a large black hole mass and high accretion rate, but a small disk size. The shape of the UV continuum was found to be variable, with a hardening of the spectrum when the source was brighter. Because of its location, only 3 deg from the ecliptic pole, H1821 + 643 will be an important object for simultaneous UV and soft X-ray monitoring to test for a common origin of the UV bump and soft X-ray excess.

Affiliated with

Also associated with

No associations

Rating

The ultraviolet spectrum and continuum energy distribution of the bright quasar H1821 + 643 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The ultraviolet spectrum and continuum energy distribution of the bright quasar H1821 + 643, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The ultraviolet spectrum and continuum energy distribution of the bright quasar H1821 + 643 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1036883