Home
Scholarly Works
Variability-selected Quasars in MACHO Project...
Journal article

Variability-selected Quasars in MACHO Project Magellanic Cloud Fields

Abstract

We present 47 spectroscopically confirmed quasars discovered behind the Magellanic Clouds identified via photometric variability in the MACHO database. Thirty-eight quasars lie behind the Large Magellanic Cloud and nine behind the Small Magellanic Cloud, more than tripling the number of quasars previously known in this region. The quasars cover the redshift interval 0.2 < z < 2.8 and have apparent mean magnitudes 16.6 ≤ ≤ 20.1. We discuss the details of quasar candidate selection based on time variability in the MACHO database and present results of spectroscopic follow-up observations. Our follow-up detection efficiency was 20%; the primary contaminants were emission-line Be stars in Magellanic Clouds. For the 47 quasars discovered behind the Magellanic Clouds, plus an additional 12 objects previously identified in this region, we present 7.5 yr MACHO V- and R-band light curves with average sampling times of 2–10 days.

Authors

Geha M; Alcock C; Allsman RA; Alves DR; Axelrod TS; Becker AC; Bennett DP; Cook KH; Drake AJ; Freeman KC

Journal

The Astronomical Journal, Vol. 125, No. 1, pp. 1–12

Publisher

American Astronomical Society

Publication Date

January 1, 2003

DOI

10.1086/344947

ISSN

0004-6256

Contact the Experts team