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A. Dobrzycki (CfA), P.J. Groot (U.of Nijmegen), L.M. Macri (NOAO), K.Z. Stanek (CfA)
Quasars behind nearby galaxies are of great astronomical interest. They can provide fixed reference points for proper motion studies and they can serve as background sources for the analysis of absorption in the foreground galaxy. X-ray bright and variable quasars may enable direct determination of distance to the galaxies.
Until recently, only very few quasars were known in the general direction of the Magellanic Clouds, and practically all of them were behind the outer, sparse parts of the Clouds. Superb spatial resolution of the Chandra X-ray Observatory and availability of data from optical monitoring campaigns (such as OGLE and MACHO) have recently led to the discoveries of several quasars behind the inner, dense parts of the Clouds, resulting in a spectacular improvement in both the total number of objects and the spatial coverage.
We present the results of our ongoing projects for identifications of quasars behind the Magellanic Clouds. So far, we have discovered 14 previously unknown quasars behind the dense parts of the LMC and SMC, utilizing both X-ray- and variability-based selection. We present the analysis of spectral and timing properties of the quasars in both X-rays and the optical range. We discuss the application of the objects for follow-up studies. We also discuss the prospects for searches for quasars behind other dense stellar fields.
This research was supported in part by NASA Contract No. NAS8-39073 (Chandra X-ray Center).
Bulletin of the American Astronomical Society,
© 2003. The American Astronomical Soceity.