Abstract for Proposal 086524

Gamma-ray flares from supermassive black holes at high redshift

We propose a 80 ks ToO observation of a high-redshift (z>=3) blazar during a gamma-ray flare detected by Fermi/LAT. So far, only 12 high-redshift blazars have been detected in γ-rays. These objects are the most luminous and massive objects in the Universe, which allow to study the formation of active galactic nuclei in the early Universe. Because the high-energy hump of their SED peaks in the MeV range, X-ray and gamma-ray data is needed to constrain the hump s shape. We propose to get high-sensitivity, simultaneous X-ray data during enhanced γ-ray activity of a blazar at high redshift. The data will be complemented by triggered radio observations. The resulting multiwavelength data set will yield important knowledge on the behaviour of flaring MeV blazars for future MeV telescopes.



Details on Observing Strategy and Trigger Criteria
We want to trigger on a detection of a blazar with redshift >=3 in the gamma- rays, observed by FermiLAT. We will monitor our candidate list on a daily basis by a prompt analysis of the average gamma-ray flux of the last 30 days. We will trigger the observation on the day the monthly-averaged signal first rises above this threshold. We ask for an XMM-Newton observation of 80ks to be executed within 3 days.