Book contents
- Frontmatter
- Contents
- Preface
- List of Participants
- I INTRODUCTION
- II THE INNER PARSEC
- Angular Momentum Transfer in the Inner Parsec (Invited paper)
- Can Supernovae and Accretion Disks be Distinguished Spectroscopically?
- Low Ionization Broad Absorption Lines in Quasars
- The Aftermath of Tidal Disruption
- The Galactic Center — an AGN on a Starvation Diet (Poster talk)
- A Central Black Hole in M32? (Poster paper)
- Stars and Disks around Massive Black Holes (Poster paper)
- Accretion onto Massive Binary Black Holes (Poster paper)
- Profile Variations of Broad-Line Radio Galaxies (Poster paper)
- The Budget of Energy in AGNs and Quasars (Poster paper)
- The Detection of Microvariations for Akn 120 (Poster paper)
- The Contribution of Cool-Wind Reprocessing to AGN Spectra (Poster paper)
- III THE CIRCUMNUCLEAR REGION
- IV GAS DYNAMICS AND STAR FORMATION IN BARRED AND NORMAL GALAXIES
- V NUCLEAR GAS AND LARGE-SCALE PROPERTIES OF AGN AND STARBURST HOSTS
- VI HOST GALAXY-AGN-NUCLEAR STARBURST CONNECTION
- VII GALAXY INTERACTIONS AND INDUCED ACTIVITY
- VIII GAS DYNAMICS IN ELLIPTICALS
- IX AGN AND STARBURST HOSTS AT LARGE REDSHIFTS
- X CONFERENCE SUMMARY
- Subject Index
- Object Index
- Author Index
The Detection of Microvariations for Akn 120 (Poster paper)
Published online by Cambridge University Press: 05 May 2010
- Frontmatter
- Contents
- Preface
- List of Participants
- I INTRODUCTION
- II THE INNER PARSEC
- Angular Momentum Transfer in the Inner Parsec (Invited paper)
- Can Supernovae and Accretion Disks be Distinguished Spectroscopically?
- Low Ionization Broad Absorption Lines in Quasars
- The Aftermath of Tidal Disruption
- The Galactic Center — an AGN on a Starvation Diet (Poster talk)
- A Central Black Hole in M32? (Poster paper)
- Stars and Disks around Massive Black Holes (Poster paper)
- Accretion onto Massive Binary Black Holes (Poster paper)
- Profile Variations of Broad-Line Radio Galaxies (Poster paper)
- The Budget of Energy in AGNs and Quasars (Poster paper)
- The Detection of Microvariations for Akn 120 (Poster paper)
- The Contribution of Cool-Wind Reprocessing to AGN Spectra (Poster paper)
- III THE CIRCUMNUCLEAR REGION
- IV GAS DYNAMICS AND STAR FORMATION IN BARRED AND NORMAL GALAXIES
- V NUCLEAR GAS AND LARGE-SCALE PROPERTIES OF AGN AND STARBURST HOSTS
- VI HOST GALAXY-AGN-NUCLEAR STARBURST CONNECTION
- VII GALAXY INTERACTIONS AND INDUCED ACTIVITY
- VIII GAS DYNAMICS IN ELLIPTICALS
- IX AGN AND STARBURST HOSTS AT LARGE REDSHIFTS
- X CONFERENCE SUMMARY
- Subject Index
- Object Index
- Author Index
Summary
ABSTRACT
Rapid optical variations have been detected for the Seyfert 1 galaxy Akn 120 with time scales shorter than an hour. These variations are the most rapid which have been detected for any Seyfert galaxy, and, for the first time, clearly demonstrate that radio-quiet AGNs exhibit the phenomenon of microvariability. This result suggests that these variations are indepentent of the radio properties of these objects and are thus unlikely to be associated with any disturbance in a relativistic jet.
INTRODUCTION
Akn 120 was first identified as a Seyfert galaxy by Arakelian (1975) in a survey of high surface brightness galaxies. It has long been known to exhibit optical variations with time scales ranging from years to days (Miller 1979). In this paper, we report the first results of a program to determine if radio-quiet AGNs exhibit optical variations on time scales much shorter than a day.
OBSERVATIONS
The high time resolution optical observations of Akn 120 reported here were obtained with the 42-inch telescope at Lowell Observatory equipped with a direct CCD camera and an autoguider. The observations were made through a V filter with an RCA CCD. Repeated exposures of 60 seconds were obtained for the star field containing Akn 120 and several comparison stars. These standard stars, located on the same CCD frame as Akn 120 provide comparison stars for use in the data reduction process. The observations were reduced using the method described in Carini and Miller (1992).
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- Mass-Transfer Induced Activity in Galaxies , pp. 59 - 60Publisher: Cambridge University PressPrint publication year: 1994
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