Abstract for Proposal 092386
Tracking the X-ray Evolution of on-going SDSS-V Changing-look AGN
SDSS-V, currently ramping up to full operation, will obtain repeated
optical spectroscopy for thousands of AGN. This will allow for the optical
identification of currently transitioning changing-look AGN. We request
6 ToOs using XMM-Newton and Swift to follow the X-ray and UV evolution
of the ongoing optical transition. XMM-Newton will deliver X-ray spectra
in its visibility windows, while Swift provides X-ray flux constraints
in the time between. The obtained X-ray, UV, and optical datasets will
explore how the X-ray corona, accretion disc, and broad-emission line
region interact with each other. It will deliver valuable insights into
how accretion flows evolve during AGN ignitions and depletions. We will
compare our results with the outcomes of a program on X-ray-selected
changing-look AGN.
Details on Observing Strategy and Trigger Criteria
Trigger criteria: ignition - 25 ks: based on the SDSS-V spectra if i) the
blue continuum increased by a factor of at least 3 with a significance of
at least 3sigma, or/and ii) the AGN typical broad-emission lines change
their integrated flux by at least a factor of 3 with least 3sigma, and/or
full-width-half max (FWHM) changes by more than 30% with 3sigma; redshift
< 0.2 depletion - 50 ks: based on the SDSS-V spectra if i) the blue
continuum decreased by a factor of at least 3 with a significance of at
least 3sigma, or/and ii) the AGN typical broad-emission lines change
their integrated flux by at least a factor of 3 with least 3sigma,
and/or full-width-half max (FWHM) changes by more than 30% with 3sigma;
redshift < 0.2 reaction time: for ignition and depletion: up to 14
days observing strategy: XMM-Newton ToO, primary instrument PN, large
window mode; OM: UVM2 filter between the XMM-Newton visibility windows
every second month Swift XRT/UVOT observations (PC mode)