Extreme spectral variations of the Seyfert galaxy Markarian 993

Details Extreme spectral variations of the Seyfert galaxy Markarian 993 Extreme spectral variations of the Seyfert galaxy Markarian 993

Dec 1992

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1992aj....104.2072t&link_type=abstract

Astronomical Journal (ISSN 0004-6256), vol. 104, no. 6, p. 2072-2077.

Astronomy and Astrophysics

Astronomy

30

Galactic Nuclei, Markarian Galaxies, Seyfert Galaxies, Balmer Series, Charge Coupled Devices, Emission Spectra, H Lines

Scientific paper

The nuclear spectrum of the broad-line Seyfert galaxy Mrk 993 was observed to display strong variations in the strengths of the broad H-alpha and H-beta emission lines, changing its classification from a Seyfert 1 to a Seyfert 1.9. Moderate to high resolution spectra were obtained with the IDS and CCD spectrograph on the 3 m Shane telescope at Lick Observatory in four different epochs spanning a period of approximately eight years. Using a spectral decomposition method which isolates the pure emission component of the active nucleus from the contaminating underlying host galaxy, our analysis indicates that the broad-line fluxes varied such that the Balmer decrement steepens whenever broad H-alpha and H-beta decrease in strength, and that the ionizing continuum correspondingly reddens in slope. These direct observational evidences suggest that variation in extinction along the line of sight to the broad-line region of Mrk 993 provides a simple explanation to the behavior of its spectrum, although a combination of possibilities may also be possible.

Affiliated with

Also associated with

No associations

Rating

Extreme spectral variations of the Seyfert galaxy Markarian 993 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 Extreme spectral variations of the Seyfert galaxy Markarian 993, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Extreme spectral variations of the Seyfert galaxy Markarian 993 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1113007