2005/07/08 by A. Dobrzycki, L. Eyer, K. Z. Stanek +2
Engineering · Physics and Astronomy · #Astronomical Observations and Instrumentation #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1051/0004-6361:20053494
published as Astron.Astrophys.442:495,2005 · 7 pages, 6 figures, submitted to Astronomy and Astrophysics
arxiv created 2005/07/08 · openalex publication_date 2005/10/07 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We present the discovery of nine quasars behind the Large Magellanic Cloud, with emission redshifts ranging from 0.07 to 2.09. Six of them were identified as part of the systematic variability-based search for QSOs in the objects from the OGLE-II database. Combination of variability-based selection of candidates with the candidates' colours appears to be a powerful technique for identifying quasars, potentially reaching ~50% efficiency. We report an apparent correlation between variability magnitude and variability timescale, which – if confirmed – could put even more constraints on QSO candidate selection. The remaining three quasars were identified via followup spectroscopy of optical counterparts to X-ray sources found serendipitously by the Chandra X-ray Observatory satellite. Even though the locations of the candidates were quite uniformly distributed over the LMC bar, the confirmed QSOs all appear near the bar's outskirts.