* Astronomy

Title: The Magellanic Quasars Survey. II. Confirmation of 145 New AGN Behind the Southern Edge of the Large Magellanic Cloud
Authors: Szymon Kozlowski (1), C. S. Kochanek (2,3), A. M. Jacyszyn (1), A. Udalski (1), M. K. Szymanski (1), R. Poleski (1), M. Kubiak (1), I. Soszynski (1), G. Pietrzynski (1,4), L. Wyrzykowski (1,5), K. Ulaczyk (1), P. Pietrukowicz (1) ((1) Warsaw University Observatory, Poland, (2) Department of Astronomy, The Ohio State University, USA, (3) Center for Cosmology and Astroparticle Physics, The Ohio State University, USA, (4) Universidad de Concepcion, Departamento de Fisica, Chile, (5) Institute of Astronomy, University of Cambridge, UK)

We quadruple the number of quasars known behind the Large Magellanic Cloud (LMC) from 55 (42 in the OGLE-III LMC fields) to 200 by spectroscopically confirming 169 (145 new) quasars from a sample of 845 observed candidates in four ~3 deg^2 AAT/AAOmega fields south of the LMC center. The candidates were selected based on their Spitzer mid-infrared colours, X-ray emission, and/or optical variability properties in the database of the OGLE microlensing survey. The contaminating sources can be divided into 112 young stellar objects (YSOs), 17 planetary nebulae (PNe), 39 Be and 24 blue stars, and 66 red stars. There are also 401 targets with either featureless spectra or too low signal-to-noise ratio for source classification. While our quasar sample is relatively complete for I<19.2 mag, it is incomplete for fainter quasars. We would expect to find an additional ~200 AGNs if the sample was complete to our target depth of I<21 mag. The newly discovered AGNs provide many additional reference points for proper motion studies of the LMC, and the sample includes 10 bright AGNs (I<18 mag) potentially suitable for absorption line studies. Their primary use, however, is for detailed studies of quasar variability, as they all have long-term, high cadence, continuously growing light curves from the microlensing surveys of the LMC. Completing the existing Magellanic Quasars Survey (MQS) fields in the LMC and SMC should yield a sample of ~700 well-monitored AGNs, and expanding it to the larger regions covered by the OGLE-IV survey should yield a sample of ~3600 AGNs.

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