35,000 Square Degrees and Counting: Optical follow-up of the XMM Slew Survey

Monday, 17 March 2014 9 a.m. — 10 a.m. MST

AURA Lecture Hall

NOIRLab South Colloquia
KAREN T. LEWIS (Assistant Professor of Physics, College of Wooster and SOAR Visiting Astronomer)

Active Galactic Nuclei (AGN) are among the most energetic objects in the Universe and are commonly used as cosmic "lighthouses" to study the growth and evolution of galaxies in the early universe. However there are still many unanswered questions about the physical structure of these objects that are best answered by the study of AGN in our own backyard. The XMM-Newton Slew Survey, built up over the past 14 years, now covers 65% of the sky to a hard X-ray flux limit of 4x10^-12 erg/s. This is an order of magnitude lower than previous hard-band all sky X-ray surveys and is sufficient to pick up a typical Seyfert galaxy at z~0.06, along with more distant and powerful AGN. Thus, the XMM Slew Survey can provide a census of the nearby X-ray selected AGN population, which can be the basis of a variety of multi-wavelength studies. Although many of the sources are known AGN, quite a large fraction of the objects have not yet been classified. In this talk, I will describe the results of optical spectroscopic follow-up of the unclassified objects in the XMM Slew Survey. To date, over 50 AGN have been discovered which previously had evaded detection in other surveys.