Identifying Spatially Offset Active Galactic Nuclei from the Very Large Array Sky Survey: Tracing the Growth of Massive Black Holes in Galaxy Mergers

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

Active Galactic Nuclei (AGNs) that are offset from the center of their host galaxies are likely the products of galaxy mergers. Such objects are probably massive black holes (MBHs) that are accreting mass and growing. The current program seeks to make observations of up to 1,100 of these objects using the Very Large Array Sky Survey (VLASS). When completed, this survey will be the largest sample of these objects known, and the first large and uniform sample. The team seek to answer fundamental question about offset AGNs, including how common they are, what the role they might have in constraining masses of MBHs, and what role they might have in the merger-driven growth of MBHs. The Principal Investigator will conduct a series of outreaches at a community center in Flagstaff, AZ. This program is expected to reach 300 to 400 children, of whom approximately 60% will be from underrepresented groups. The team will use data from the Very Large Array Sky Survey (VLASS) to search for offset AGNs. VLASS is a uniform survey of the radio sky using the Janssky Very Large Array Radio Observatory in a bandpass of 2 to 4GHz and covers the whole sky above a declination of 40 degrees South. For variability studies, VLASS is being conducted in three epochs, each of which consists of the same pointings. The first epoch of observations (Epoch 1) is now complete, and catalogs of sources from the Epoch 1 images are now available. This work will be based on the VLASS Epoch 1 Catalog. The team will crossmatch the sample of clean VLASS sources with the catalog of galaxies from the Sloan Digital Sky Survey (SDSS) Data Release 16 (DR16) that overlaps with approximately 45% of the VLASS Epoch 1 Catalog. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.