BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Lighting up a new Standard Candle: calibration of AGNs - Anastasia
  Shlentsova / Pontificia Universidad Católica de Chile
DTSTART:20260128T131500Z
DTEND:20260128T134000Z
UID:TALK242911@talks.cam.ac.uk
CONTACT:Xander Byrne
DESCRIPTION:Exploring new/alternative standard candles is crucial for adva
 ncing cosmology. One spanning a wide redshift range\, like quasars (QSOs)\
 , can provide orthogonal constraints on model parameters\, among which H0\
 , with its current tension\, is particularly relevant. The 2 keV to 2500 
 Å flux ratio in QSOs shows great potential as a cosmological tool (e.g.\,
  Lusso+20\, Sacchi+22) if suitable subsets are identified\, akin to the co
 rrections applied to supernovae. We investigate various properties of QSOs
  to deepen our understanding of QSO physics and refine the selection crite
 ria for a new cosmological quasar sample.\nWe specifically examine the mos
 t luminous QSOs exhibiting strong outflows in the C IV emission line to cl
 arify the relation between the strength of the outflows and X-ray emission
 \, thereby enhancing our understanding of the mechanisms within active gal
 actic nuclei (AGN) engines. Using targeted observations with Chandra\, we 
 determine the slope of the 2 keV to 2500 Å luminosity relation and explor
 e how the C IV blueshift correlates with the steepness of the UV-to-X-ray 
 spectral energy distribution. To gain insights into the fundamental proces
 ses underlying the 2 keV to 2500 Å luminosity relation\, we analyse the s
 lopes of the relation measured using multi-epoch XMM observations of speci
 fic sources. Finally\, to investigate the correlations between the dispers
 ion of the 2 keV to 2500 Å luminosity relation\, fundamental AGN properti
 es\, and optical variability\, we assess several variability features from
  the ZTF optical light curves and conduct a dimension reduction analysis.
LOCATION:Hoyle Lecture theatre + Zoom 
END:VEVENT
END:VCALENDAR