But Wait There's More: Watching Supermassive Black Holes Grow More Massive in Galaxies at z<2
Abstract
In the Sloan Digital Sky Survey Stripe 82X field, the Accretion History of AGN (AHA) collaboration has assembled a multiwavelength dataset of thousands of X-ray luminous AGN. From this parent population, we select AGN in host galaxies at z<2 which are also strongly star forming, as measured with far-IR Herschel detections. This yields 63 AGN which have far-IR derived star formation rates, X-ray luminosities, and SDSS optical spectra covering the broad emission line region. Seven of the galaxies exhibit broadening of the Hα emission with an additional 16 exhibiting a broadening of the [Mg II] emission line, both of which we use to measure black hole mass. We fit a multiple Gaussian model to the emission lines in order to separate the physically distinct components. We also fit a model to the [O III] emission line and use its luminosity and a bolometric correction to estimate the accretion rate of our AGN. Additionally, we characterize the ionization of our galaxies utilizing Baldwin, Phillips & Terlevich (BPT) Diagrams. We observe a trend that the more massive black holes are accreting mass at a higher rate. We also observe a correlation between accretion rate and star formation and a weaker correlation between black hole mass and stellar mass. Lastly, we observe that the ratio of star formation rate to stellar mass of the sources remains fairly constant while the ratio of accretion rate to black hole mass increases. Our data seems to indicate that some of the black holes of the sources are beginning to outgrow the star formation of their host galaxies.
- Publication:
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American Astronomical Society Meeting Abstracts
- Pub Date:
- January 2021
- Bibcode:
- 2021AAS...23753202E