0 Assigned ID: 1911 ----- Attempting Submission 1 (Fri Mar 01 23:05:13 GMT 2013) ----- During the coalescence of a supermassive black hole (SMBH) binary in a major galaxy merger, the asymmetric emission of gravitational waves can displace the newly merged SMBH from the host center, significantly affecting the SMBH-galaxy co-evolution. The kick velocity may be significantly higher than the escape velocity of the galaxy (up to 5000 km/s), but for realistic spin and mass ratio distributions, most recoil velocities should be lower. If the recoil kick is large enough to substantially displace/eject the SMBH from the galaxy center, it may be observable as an offset active SMBH, before its fuel is exhausted. While extensive simulations have been performed, only 7 candidate recoiling SMBHs have been discovered so far. We propose to perform the first systematic search for spatially-offset (with v<~v_esc) recoiling SMBHs using COSMOS, the largest contiguous HST/ACS imaging survey ever taken with high spatial resolution data (0.03"/pixel). According to model predictions, we expect to find at least 1 (up to several tens) recoiling SMBHs. Any number of detections, including zero, will be promptly compared and used to tune models and simulations, and will help to constrain the SMBH merger rates. We will select candidates by using accurate 2D fitting imaging analysis on a sample of ~50,000 COSMOS galaxies (z<1 and F814W(AB)<24). We will isolate sources with disturbed morphologies and significant residuals outside the central region. A pilot study on a 10 times smaller sample confirms the feasibility of this analysis. The properties of the candidate recoiling SMBHs will be compiled using the COSMOS database. Spectroscopic follow-ups will be performed with SALT. AGN/QUASARS Default Medium false false false false false SUPPORTED