The Magellanic Quasars Survey. I. Doubling the Number of Known Active Galactic Nuclei Behind the Small Magellanic Cloud

Abstract

We report the spectroscopic confirmation of 29 new, 12 plausible, and three previously known quasars behind the central ~1.5 deg² region of the Small Magellanic Cloud (SMC). These were identified in a single 2DF/AAOMEGA observation on the Anglo-Australian Telescope of 268 candidates selected primarily based on their mid-IR colors, along with a smaller number of optically variable sources in OGLE-II close to known X-ray sources. The low detection efficiency was partly expected from the high surface density of SMC as compared with the Large Magellanic Cloud targets and the faintness of many of them (149 with I>20 mag). The expected number of I < 20 mag quasars in the field is sime38, and we found 15 (40%). We did not attempt to determine the nature of the remaining sources, although several appear to be new planetary nebulae. The newly discovered active galactic nuclei can be used as reference points for future proper-motion studies, to study absorption in the SMC interstellar medium, and to study the physics of quasar variability with the existing long-term, highly cadenced OGLE light curves.