Tobias Jogler Max-Planck Institut für Physik IMPRS YSW Ringberg 2007 VHE emission from binary systems Outline Binary systems Microquasar Pulsar binaries The MAGIC telescope Observations of LS I Conclusions

Tobias Jogler Max-Planck Institut für Physik IMPRS YSW Ringberg 2007 Binary systems System of two stellar objects or one stellar and one compact object More interesting star + compact object Compact objects: Black Hole Neutron Star HMXB High Mass X-ray Binaries LMXB Low Mass X-ray Binaries

Tobias Jogler Max-Planck Institut für Physik IMPRS YSW Ringberg 2007 Microquasar Companion star O or B star relativistic jets with v ~ 0.6c Special Binaries: Accretion powered Relativistic plasma outflow (jet) emitting at radio frequencies Downscaled versions of the extragalactic quasars

Tobias Jogler Max-Planck Institut für Physik IMPRS YSW Ringberg 2007 Microquasars Very interesting objects: Timescales of processes scale with the mass of the black hole!

Tobias Jogler Max-Planck Institut für Physik IMPRS YSW Ringberg 2007 Accretion the central engine Two mayor types of accretion possible depending on the companion star. Strong stellar wind which is accreted by the compact object moving in the wind Companion star overfills its roche lobe and mater flows onto compact object

Tobias Jogler Max-Planck Institut für Physik IMPRS YSW Ringberg 2007 The different states

Tobias Jogler Max-Planck Institut für Physik IMPRS YSW Ringberg 2007 Energy spectrum of Cygnus X1 Different components: unscattered black body Fe K α / compton reflection main comptonization component (scattered by e) different compton scattering not in the hot disc low hard state high soft state

Tobias Jogler Max-Planck Institut für Physik IMPRS YSW Ringberg 2007 Jet as the source of VHE  -rays Details of Jet formation unknown! Magneto hydrodynamic simulations (MHD) show relativistic plasma outflows. Radio jetsX-ray jets

Tobias Jogler Max-Planck Institut für Physik IMPRS YSW Ringberg 2007 Particle acceleration in jets SSC (Self Synchrotron inverse Compton) model TeV energetic electrons in the jet emit synchrotron radiation TeV electrons up scatter (IC) the synchrotron γ to VHE

Tobias Jogler Max-Planck Institut für Physik IMPRS YSW Ringberg 2007 Binary pulsars Rotational powered Pulsar creates relativistic Pulsar Wind Nebula (PWN) PWN are emitter of VHE γ - rays (maybe the dominant) Variability of source due to absorption Very interesting to understand colliding winds and shock formation

Tobias Jogler Max-Planck Institut für Physik IMPRS YSW Ringberg 2007 The MAGIC telescope La Palma, asl. 2200m 17 m diameter Mirror 3.5 ° FoV Camera Trigger Threshold of E = 60 GeV Sensitivity of 2.2 % Crab flux Can operate under moonlight conditions Very sensitive Instrument to study faint VHE gamma ray sources

Tobias Jogler Max-Planck Institut für Physik IMPRS YSW Ringberg 2007 Imaging Air Cherenkov Telescopes ~ 10 km Particle shower ~ 1 o Cherenkov light ~ 120 m Gamma ray Cherenkov light Image of particle shower in telescope camera Reconstruct: arrival direction, energy reject hadron background

Tobias Jogler Max-Planck Institut für Physik IMPRS YSW Ringberg 2007 Observations of LS I Observed during two cycles with the MAGIC telescope Variable source which emits mostly around phase 0.6

Tobias Jogler Max-Planck Institut für Physik IMPRS YSW Ringberg 2007 Spectral behavior Spectra for different orbital phases Spectral behavior is stable even if flux changes by factor of 3 Sensitivity to shape of the spectrum is limited by statistics LS I is more luminous in VHE than in the x-ray band!

Tobias Jogler Max-Planck Institut für Physik IMPRS YSW Ringberg 2007 Short time variability Search for short time variability on timescales min Two long nights with t > 5h No short time variabillity found within the sensitivity of MAGIC

Tobias Jogler Max-Planck Institut für Physik IMPRS YSW Ringberg 2007 Conclusions Different Binary types can produce VHE γ- rays Very interesting field with unique possibilities Many open questions Detailed studies need a lot of observation time With detailed, simultaneous studies at different wavelength models can be constrained