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SUMMARY:Neural Network Classification of BL Lacs and FSRQs among X-ray/Gam
 ma-ray Blazars discovered in the Fermi 4FGL-DR4 Unassociated Catalog
DTSTART;VALUE=DATE-TIME:20261028T181900Z
DTEND;VALUE=DATE-TIME:20261028T182000Z
DTSTAMP;VALUE=DATE-TIME:20261025T203216Z
UID:indico-contribution-3695@nyx.physics.mcgill.ca
DESCRIPTION:Speakers: Sierra Deppe (McGill University\, Penn State Univers
 ity)\nOf the 2423 unassociated sources in the fourth data release of the f
 ourth Fermi Large Area Telescope catalog (4FGL-DR4)\, 748 had also been ob
 served by the Neil Gehrels Swift Observatory's X-ray telescope for $>4$~ks
 . Neumann et al. (2026) recently used a neural network classifier to ident
 ify new local pulsars and high-energy blazars from these unassociated sour
 ces\, and they classified 173 likely blazars from $\\gamma$-ray sources wi
 th singular X-ray counterparts. We adopt these new likely blazar singlets\
 , along with the 4FGL-DR4 blazar candidates of uncertain types\, to search
  for further classifications of 281 total sources into BL Lac (BLL) and fl
 at spectrum radio quasar (FSRQ) categories.  From those 281 sources\, 218 
 of them had not been previously analyzed by an earlier attempt to classify
  blazars into these dominant sub-classifications (Kaur et al. 2023). Using
  infrared to $\\gamma$-ray parameters\, we identify 136 likely BL Lac obje
 cts (Probability of BLL\, $P_{\\text{bll}}>0.99$) and 29 likely FSRQs (wit
 h $P_{\\text{bll}}<0.01$) using a multilayer perceptron neural network cla
 ssifier\, while the remaining 116 sources remain ambiguous. A majority of 
 these new sources are observationally much fainter than existing sources\,
  by one or two magnitudes\, enabling a direct probe into the lower-flux re
 gion of the existing blazar population. We propose further investigation i
 nto the optical spectra of these new\, faint FSRQs to obtain spectroscopic
  confirmation and redshift estimates. Confirming these new sources will te
 st how far into the observationally faint-source region the FSRQ populatio
 n extends\, and when coupled with redshifts\, have the potential to extend
  the low-luminosity end of the blazar sequence.\n\nhttps://nyx.physics.mcg
 ill.ca/event/587/contributions/3695/
LOCATION:Online 
URL:https://nyx.physics.mcgill.ca/event/587/contributions/3695/
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