Research

Research Interests

Active Galactic Nuclei / X-ray surveys / X-ray background /High Redshift Universe/ Type 2 QSO / Extremely Red Objects / Contribution of AGN to the XRB / X-ray emitting Galaxies / XBONGs / Luminosity function/ Absorption Distribution/ AGN Pairs/ Recoiling SMBHs

A Candidate Recoiling SMBH

Analyzing the optical counterparts of X-ray selected active Black Holes, I serendipitously discovered an interesting source, CID-42. In Civano et al. 2010 and 2012 (Astrophysical Journal), we report the discovery of the best candidate Gravitational Wave recoiling Black Hole, with both spectroscopic and imaging signature. Despite predicted by theoretical models, these recoiling Black Holes are extremely rare and only 6 sources have been candidate so far.  This Black Hole has been ejected at a velocity of more than 2 millions miles/hr from the center of the newly formed galaxy, due to the asymmetric emission of Gravitational Waves in a major merger between two galaxies.
A video from Blecha et al. 2012 simulations shows how CID-42 could have formed and theBlack Hole ejected from the center of the galaxy.

In order to confirm the nature of this source I obtained time at several observatories:

  • Chandra X-ray Satellite 80,000 seconds of observing time with the High Resolution Camera to obtain high resolution imaging
  • Hubble Space Telescope: 1 orbit of observation with the spectrograph STIS to obtain a high resolution optical spectrum of each source in CID-42
  • XMM-Newton Satellite: 123,000 seconds of observing time (1 telescope orbit) to obtain a high resolution X-ray spectrum

Research Summary

During my PhD at the Bologna University I joined the Cosmic Evolution Survey (COSMOS) collaboration.
I mainly work on the association of the optical and Infrared counterparts to the X-ray sources detected in the  Chandra-COSMOS survey. I  study the multiwavelength properties of these X-ray sources to have a better understanding on the formation and the co-evolution of high redshift active Black Holes and their hosts galaxies. I am the PI of the COSMOS Legacy Survey (2.8 Ms with Chandra). I have gained observational experience  at the Magellan Telescope with the instrument for multi-slit spectroscopy IMACS and at the Keck Telescope with the instrument for multi-slit spectroscopy DEIMOS, as part of the COSMOS spectroscopic AGN survey.

I am also a member of the The Ultimate XMM Extragalactic Survey (XXL), a 50 sq.deg extragalactic survey performed with XMM-Newton, the best place to collect a uniform sample of more than 10,000 X-ray selected Active Galactic Nuclei.