Variability-selected QSO candidates in OGLE-II Galactic Bulge fields
Abstract
We present 97 QSO candidates in 48 Galactic Bulge fields of the Optical Gravitational Lensing Experiment II (OGLE-II) covering about 11 square degrees, which are selected via their variability. We extend light curves of variable objects which were detected in 3-year baseline in the OGLE-II variable star catalog to 4th year. We search for objects which are faint (16<I_0<18.5) and slowly variable during 4 years in this catalog by using the variogram/structure function. Finding the QSOs in such stellar-crowded and high extinction fields is challenging, but should be useful for the astrometric reference frame. Spectroscopic follow-up observations are required to confirm these QSO candidates. Follow-up observations are being prepared for four of these fields (BUL_SC1, 2, 32 and 45). Follow-up observations for other fields are strongly encouraged. The complete list and light curves of all 97 candidates are available in electronic format at http://www.astro.princeton.edu/~sumi/QSO-OGLEII/.
Keywords
Cite
@article{arxiv.astro-ph/0407302,
title = {Variability-selected QSO candidates in OGLE-II Galactic Bulge fields},
author = {T. Sumi and P. R. Wozniak and L. Eyer and A. Dobrzycki and A. Udalski and M. K. Szymanski and M. Kubiak and G. Pietrzynski and I. Soszynski and K. Zebrun and O. Szewczyk and L. Wyrzykowski},
journal= {arXiv preprint arXiv:astro-ph/0407302},
year = {2009}
}
Comments
6 pages, 3 figures, MNRAS in press