A Bayesian Analysis of SDSS J0914+0853, a Low-Mass Dual AGN Candidate
  We present the first results from BAYMAX (Bayesian AnalYsis of Multiple AGN
in X-rays), a tool that uses a Bayesian framework to quantitatively evaluate
whether a given Chandra observation is more likely a single or dual point
source. Although the most robust method of determining the presence of dual
AGNs is to use X-ray observations, only sources that are widely separated
relative to the instrument PSF are easy to identify. It becomes increasingly
difficult to distinguish dual AGNs from single AGNs when the separation is on
the order of Chandra's angular resolution (<1''). Using likelihood models for
single and dual point sources, BAYMAX quantitatively evaluates the likelihood
of an AGN for a given source. Specifically, we present results from BAYMAX
analyzing the lowest-mass dual AGN candidate to date, SDSS J0914+0853, where
archival Chandra data shows a possible secondary AGN ~0.3'' from the primary.
Analyzing a new 50 ks Chandra observation, results from BAYMAX shows that SDSS
J0914+0853 is most likely a single AGN with a Bayes factor of 13.5 in favor of
a single point source model. Further, posterior distributions from the dual
point source model are consistent with emission from a single AGN. We find the
probability of SDSS J0914+0853 being a dual AGN system with a flux ratio f>0.3
and separation r>0.3'' to be very low. Overall, BAYMAX will be an important
tool for correctly classifying candidate dual AGNs in the literature, and
studying the dual AGN population where past spatial resolution limits have
prevented systematic analyses.
