Variability of AGN & Quasars

Active Galactic Nuclei (AGN) are among the most luminous objects known in the universe. Located in the center of a galaxy they can emit a comparable amount of energy or even more as the entire host galaxy. One characterizing feature of an AGN is variability of the continuum flux over the entire electromagnetic spectrum and in response of the broad emission lines on times scales, ranging from minutes to years. Intensive multiwavelength monitoring campaigns have shown that variability studies provide an excellent tool to investigate the innermost region of active galactic nuclei (AGNs). Detailed studies of the continuum and emission-line variations have revealed new insights about the size, structure, and dynamics of the broad-line region (BLR) in these sources (see Peterson 1993, 1999, or Netzer & Peterson 1997 for a review). Over the last decade, a number of large space-based and ground-based AGN monitoring programs have been undertaken by the International AGN Watch consortium (Alloin et al. 1994) on several Seyfert galaxies, including programs on NGC3783, NGC4051, NGC4151, NGC5548, NGC7469, Mkn279, Mkn509, Akn564, Fairall 9, and 3C390.3. With the new generation of 10m class telescopes and instruments in earth's orbit it will be possible to address more specific questions and applying more sophisticated methodes like 2D reverberation mappping to data of higher quality.

(Dietrich et al. 1998, ApJS, 115, 185)

(Peterson et al. 1999, ApJ, 510, 659)

Publications

This page is under construction. Last update: April 30, 2005.

This page created by Matthias Dietrich
Questions or comments should be sent to: dietrich@astronomy.ohio-state.edu

	Return to Astronomy Department Home Page
	For comments and suggestions contact the department at webmaster@astronomy.ohio-state.edu About this site (department disclaimer, logo and recommended web browser)