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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 What is an AGN? 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. 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) Why Study BL Lac? What is a BL Lac Object? •Most extreme example of an AGN Students at Work •Highly variable continuum emission at all wavelengths External view of Bell Observatory •Featureless continuum means continuum radiation is the only diagnostic •They vary due to extremely highly energetic physical processes •Featureless optical spectra •Variability is not regular, can’t get a few cycles and be finished •Highly variable polarization •Verified aspect unified AGN model Whitney Wills observing onsite Tala Monroe cleaning mirror covers Wes Ryle observing remotely Internal view of Bell Observatory Telescope Specifies Telescope Status •0.6m primary mirror, f/11 •Telescope is fully functional •Manufactured by Group 128 •Remote and onsite observing capability •Equatorial mount •WKU undergraduate students routinely operating telescope •True Cassegrain •Apogee Ap2p CCD camera Acknowledgments This project has been supported by NASA the Kentucky Space Grant Consortium and the Applied Research and Technology Program at WKU Data Reduction Results •Used Image Reduction and Analysis Facility (IRAF) Software •X-Ray and Optical light curve for MRK 501 have same trend •Removed background and thermal noise from the picture •Observed and produced light curves for 40 BL Lac •Removed non-linearity •Trained 5 WKU students to observe regularly •Measured the brightness inside a circular aperture centered on the star