Changing State QSO's: a clue to understand their physics

62-509 Tapio Pursimo

Summary:

Extreme photometric variations in AGN's are often accompagnied by large spectral changes whose origin is not yet understood. This includes Changing Look or Changing State Quasars (changes in the BLR), candidate Tidal Disruption Events, Erratic Blazar Variability, etc.. Spectral analysis of more cases with large photometric changes, is necessary to disantangle the role of reddening variations, changes in the structure of the BLR or variations in the accretion rate, among others. The Gaia Alerts provide an all-sky photometric transient survey, based on the repeated, high-precision measurements made by the Gaia satellite. We propose to do systematic spectroscopy of selected new cases coming up, at a rate of ten per semester, over 2 years, to significantly increase the available sample and detail the timescales and physical changes occuring in those extreme objects. These variable sources likely include heterogeneous classes of object, and hence a long term programme is necessary in order to obtain meaningful statistics.

Calibrations

Internal flats, arcs and bias frames from alfosc-calibs and "standard" twilight flats for photometry

Observations

The PI will send the target and observing information when this ToO is triggered.

Available scripts

Go to the directory
cd ~/scripts/62-509

execute the requested scripts.

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