PI: Jifeng Liu, SAO, firstname.lastname@example.org
Address: 60 Garden St, Cambridge, MA 02138, US
CoI: Rosanne Di Stefano, SAO
CoI: Jeffrey McClintock, SAO
Title: In search of black hole binaries in quiescence and low state
Abstract: Here we propose a program to test our new method of searching for black holes in quiescent/low states. Four decades of X-ray observations have discovered and confirmed 20+ stellar mass black holes, only a tip of a tip of the iceberg as compared to the millions of black holes expected in the Milky Way. This is because these discoveries rely on the X-ray outbursts of the black hole binaries, thus missing the majority that have remained in quiescent or low states in the past. We are working to discover those quiet black holes by combining GALEX, SDSS and Chandra, because they are expected to show a stellar component, a UV- excess, and X-ray luminosities of 1e32-34 erg/s. Here we propose a program to observe ten qLMXB candidates with CTIO-1.3m in queue mode to obtain light curves. These observations will confirm whether they are ellipsoidal light curves as expected for quiet BH/NS X-ray binaries. Once confirmed as ellipsoidal binaries, we will initiate spectroscopic monitoring observations to obtain radial velocity curves, which will allow us to compute the masses of the primary and determine whether they are black holes or neutron stars.
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