Title: The Physics of AGN: a Deep Understanding of the Quasar 3C 273
Proposal ID: 0120023
Subject category: Extragalactic Object
Principal investigator: Courvoisier
Institute: ISDC
Abstract
We propose to observe 3C 273 during each of its visibility periods (twice per year) for two long (200 ksec)
observations, one at the beginning and the other at the end of the period and several short (10 ksec)
observations in between. This will provide us with a set of data to investigate the high energy emission of
the brightest quasar with unprecedented sensitivity and time sampling from few keV to several MeV.
We will
study both the Seyfert type emission and the jet related emission. We will see at which energies each of
these components dominates and how it varies. We will thus establish the nature of the high energy emission,
measure the temperature of the Comptonising medium, measure the properties of the electrons and positrons
in the jet and measure the properties of the "MeV" spectral break. Our programme will be coordinated with a
large multi-wavelength set of observations to relate the high energy components with those observed at lower
energies, specifically the synchrotron emission of the jet and the blue bump.