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SUMMARY:Modelling Variable Broad Absorption Line Quasar Outflows Using Sim
 BAL
DTSTART;VALUE=DATE-TIME:20261028T182100Z
DTEND;VALUE=DATE-TIME:20261028T182200Z
DTSTAMP;VALUE=DATE-TIME:20261025T174652Z
UID:indico-contribution-3673@nyx.physics.mcgill.ca
DESCRIPTION:Speakers: Nicolas Frisella (Western University)\nActive galact
 ic nuclei (AGN) are supermassive black holes in the centers of massive gal
 axies with large inflows of gas and dust collisionally heating up and radi
 ating away energy. Quasars are a type of AGN that outshine their host gala
 xies by several magnitudes\, capable of releasing high velocity outflows (
 or winds) of material due to the intense radiation being emitted. When the
 se outflows are directed along the observer's line of sight\, their ultrav
 iolet spectra will present with broad absorption lines (BALs). These types
  of objects are categorized as BAL quasars\, and these BALs in their spect
 ra have been observed to vary over time for select quasars. The origin of 
 this variability is not yet fully understood\, though spectral fitting alg
 orithms such as SimBAL (Leighly et al.\, 2018) have proven successful in m
 odelling the physical properties of quasar winds using a forward-modelling
  and Markov Chain Monte Carlo approach. This software package fits synthet
 ic spectra to observed spectra for a given quasar\, producing detailed phy
 sical and kinematical descriptions of these outflows. The fits of these sp
 ectra constrain the values of parameters including the density integrated 
 along the line of sight (column density)\, the ionization of the outflows 
 (ionization parameter)\, and the obscuration of the quasar's radiation fro
 m intervening clouds (covering fraction). My quasar of choice for modellin
 g using SimBAL has three epochs of available data from the Sloan Digital S
 ky Survey\, each separated by six years. The earliest epoch has the widest
  and deepest absorption lines for Carbon IV\, Silicon IV\, and Lyman Alpha
 \, however for each later epoch the lines are becoming weaker and narrower
 . As of now\, the leading candidates for the source of the BAL variability
  appear to be the column density and the ionization parameter. The relativ
 e impacts of each parameter on the differing absorption structure are yet 
 to be determined\, and that will be the next focus of my master's work.\n\
 nhttps://nyx.physics.mcgill.ca/event/587/contributions/3673/
LOCATION:Online 
URL:https://nyx.physics.mcgill.ca/event/587/contributions/3673/
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