Long Term Monitoring of Active Galactic Nuclei with Bell Astrophysical Observatory
1
Long Term Monitoring of Active Galactic Nuclei with Bell Astrophysical Observatory Abstract Active galactic nuclei (AGN) are some of the most energetic objects in the Universe. They are composed of an ordinary elliptical galaxy with a super massive black hole at the center. A disk of material, called an accretion disk, surrounds the super massive black hole, and jets of material moving at nearly relativistic speeds are emitted perpendicular to the disk. In the BL Lacertae class of AGN jets are pointed almost directly along the line of sight, resulting in large amplitude, erratic brightness variations. Our primary goal is the monitoring of the brightness variations of BL Lac objects and using these variations to investigate the physics at work in these objects. BL Lacs are the most extreme example of an AGN with highly variable continuum emission as one of their defining characteristics. We have undertaken a program to monitor these continuum variations by using the Bell Observatory 0.6m telescope. Undergraduate students run the sessions from WKU’s campus via the Internet or on-site. The telescope is equipped with CCD camera, which is used to obtain data that is then transferred to WKU’s campus where it is archived and analyzed by undergraduate students. Students at Work Telescope Status •Telescope is fully functional •Remote and onsite observing capability •WKU undergraduate students routinely operating telescope What is an AGN? Take a normal Galaxy At the center add: 1 supermassive Black Hole (m=10 5 -10 9 times mass of the sun) 1 accretion disk 2 relativistic jets of material = 1 Active Galactic Nucleus (AGN) Telescope Specifies •0.6m primary mirror, f/11 •Manufactured by Group 128 •Equatorial mount •True Cassegrain •Apogee Ap2p CCD camera Why Study BL Lac? •Featureless continuum means continuum radiation is the only diagnostic •They vary due to extremely highly energetic physical processes •Variability is not regular, can’t get a few cycles and be finished •Verified aspect unified AGN model What is a BL Lac Object? •Most extreme example of an AGN •Highly variable continuum emission at all wavelengths •Featureless optical spectra •Highly variable polarization Data Reduction •Used Image Reduction and Analysis Facility (IRAF) Software •Removed background and thermal noise from the picture •Removed non-linearity •Measured the brightness inside a circular aperture centered on the star Results •X-Ray and Optical light curve for MRK 501 have same trend •Observed and produced light curves for 40 BL Lac •Trained 5 WKU students to observe regularly Whitney Wills, Dr. Michael Carini, Dr. David Barnaby, Ashley Atkerson, Wesley T. Ryle, Tala Monroe M R K 501 O p tic a l L ig h t C u rv e 1 2.8 1 2.9 13 1 3.1 1 3.2 1 3.3 1 3.4 1 3.5 1 3.6 1 3.7 1 3.8 2001 .2 2001 .4 2001 .6 2001 .8 2002 2002.2 2002.4 2002.6 2002.8 2003 F r a c tio n a l Y ear Acknowledgments This project has been supported by NASA the Kentucky Space Grant Consortium and the Applied Research and Technology Program at WKU Tala Monroe cleaning mirror covers External view of Bell Observatory Internal view of Bell Observatory Whitney Wills observing onsite Wes Ryle observing remotely
description
Long Term Monitoring of Active Galactic Nuclei with Bell Astrophysical Observatory. Whitney Wills, Dr. Michael Carini, Dr. David Barnaby, Ashley Atkerson, Wesley T. Ryle, Tala Monroe. Abstract - PowerPoint PPT Presentation
Transcript of Long Term Monitoring of Active Galactic Nuclei with Bell Astrophysical Observatory
Long Term Monitoring of Active Galactic Nuclei with Bell Astrophysical Observatory
Abstract
Active galactic nuclei (AGN) are some of the most energetic objects in the Universe. They are composed of an ordinary elliptical galaxy with a super massive black hole at the center. A
disk of material, called an accretion disk, surrounds the super massive black hole, and jets of material moving at nearly relativistic speeds are emitted perpendicular to the disk. In the BL
Lacertae class of AGN jets are pointed almost directly along the line of sight, resulting in large amplitude, erratic brightness variations. Our primary goal is the monitoring of the brightness variations of BL Lac objects and using these variations to investigate the physics at work in
these objects. BL Lacs are the most extreme example of an AGN with highly variable continuum emission as one of their defining characteristics. We have undertaken a program to
monitor these continuum variations by using the Bell Observatory 0.6m telescope. Undergraduate students run the sessions from WKU’s campus via the Internet or on-site. The telescope is equipped with CCD camera, which is used to obtain data that is then transferred to
WKU’s campus where it is archived and analyzed by undergraduate students.
Students at Work
Telescope Status
•Telescope is fully functional
•Remote and onsite observing capability
•WKU undergraduate students routinely operating telescope
What is an AGN?
Take a normal Galaxy
At the center add:
1 supermassive Black Hole (m=105-109 times mass of the sun)
1 accretion disk
2 relativistic jets of material
= 1 Active Galactic Nucleus (AGN)
Telescope Specifies
•0.6m primary mirror, f/11
•Manufactured by Group 128
•Equatorial mount
•True Cassegrain
•Apogee Ap2p CCD camera
Why Study BL Lac?
•Featureless continuum means continuum radiation is the only diagnostic
•They vary due to extremely highly energetic physical processes
•Variability is not regular, can’t get a few cycles and be finished
•Verified aspect unified AGN model
What is a BL Lac Object?
•Most extreme example of an AGN
•Highly variable continuum emission at all wavelengths
•Featureless optical spectra
•Highly variable polarization
Data Reduction
•Used Image Reduction and Analysis Facility (IRAF) Software
•Removed background and thermal noise from the picture
•Removed non-linearity
•Measured the brightness inside a circular aperture centered on the star
Results
•X-Ray and Optical light curve for MRK 501 have same trend
•Observed and produced light curves for 40 BL Lac
•Trained 5 WKU students to observe regularly
Whitney Wills, Dr. Michael Carini, Dr. David Barnaby, Ashley Atkerson, Wesley T. Ryle, Tala Monroe
MRK 501 Optical Light Curve
12.8
12.9
13
13.1
13.2
13.3
13.4
13.5
13.6
13.7
13.8
2001 .2 2001 .4 2001 .6 2001 .8 2002 2002.2 2002.4 2002.6 2002.8 2003
Fr ac ti onal Y ear
Acknowledgments
This project has been supported by NASA the Kentucky Space Grant Consortium and
the Applied Research and Technology Program at WKU
Tala Monroe cleaning mirror covers
External view of Bell Observatory
Internal view of Bell Observatory
Whitney Wills observing onsite
Wes Ryle observing remotely
