Search

There are several types of Galactic sources that can potentially accelerate charged particles up to GeV and TeV energies. These accelerated particles can produce Very High Energy (VHE, E >100 GeV) γ-ray emission through different processes like for example inverse Compton scattering of ambient photon fields by accelerated electrons. We present here the results of our observations of the source class of γ-ray binaries and the subclass of binary systems known as novae with the MAGIC telescopes. The focus lies on the five sources: nova V339 Del, AE Aquarii, SS 433, MWC656 and LS I +61°303. The binary system LS I +61°303 was observed in a long-term monitoring campaign for 8 years. We show the newest results on our search for superorbital variability also in context with contemporaneous optical observations. MWC656 is a unique detected high-mass X-ray binary system, since it is up to now the only one known composed of a Be star and a black hole. Furthermore, we present the observations of the only super-critical accretion system known in our galaxy: SS 433. Finally, results of our multiwavelength observation campaign regarding the cataclysmic variable AE Aquarii and the results of the follow-up observations of the nova V339 Del will be discussed in these proceedings. [ABSTRACT FROM AUTHOR]

We present the results of the 2011 multi-wavelength campaign on the BL Lac object 1ES 1215+303. Observations were triggered by an optical outburst and resulted in the first detection of the very high energy (VHE, > 100GeV) gamma-ray emission from this source. We performspectral modeling of the simultaneous and quasi-simultaneous radio, optical, X-ray, HE and VHE emission and compare it with the spectra obtained from a low emission state observed in 2010. The optical photo-polarimetric data seem to suggest that the high state could be caused by a shock traveling down the jet and colliding with a standing shock with different magnetic field orientation. The spectral energy distribution obtained with the 2011 data can be modeled with a simple one zone SSC model, but it requires extreme values for the Doppler factor or the electron energy distribution. This suggests a more complicated scenario than a simple SSC one to occur in this source. [ABSTRACT FROM AUTHOR]

The commonly used detection test statistic for Cherenkov telescope data is Li & Ma (1983), Eq. 17. It evaluates the compatibility of event counts in an on-source region with those in a representative off-region. It does not exploit the typically known gamma-ray point spread function (PSF) of a system, and in practice its application requires either assumptions on the symmetry of the acceptance across the field of view, or Monte Carlo simulations. MAGIC has an azimuth-dependent, asymmetric acceptance which required a careful review of detection statistics. Besides an adapted Li & Ma based technique, the recently presented generalized LRT statistic of [1] is now in use. It is more flexible, more sensitive and less systematics-affected, because it is highly customized for multi-pointing Cherenkov telescope data with a known PSF. We present the application of this new method to archival MAGIC data and compare it to the other, Li&Ma-based method. [ABSTRACT FROM AUTHOR]

The detection of Flat Spectrum Radio Quasars (FSRQs) in the Very High Energy (VHE, E>100 GeV) range is challenging, mainly because of their steep soft spectra. Often neither the emission nor the variability features of recently discovered VHE-FSRQs can be explained with the models developed so far for BL Lacs. Here we present the latest MAGIC results for all the three FSRQs known to be VHE emitters. We start with the 2010 discovery of PKS 1222+21 (z = 0.432), whose fast variability challenges simple one-zone emission models, requiring a more complicated scenario. Second, we present the latest results on 3C 279, the most distant AGN (z = 0.536) and first FSRQ detected in very high energies. It was observed in 2011, first during a monitoring campaign and later observations were triggered by a flare detected with Fermi-LAT. Finally, we report the 2012 detection of PKS 1510-089 (z = 0.36). This summary of VHE observations is the first step for a forthcoming study of multiwavelength spectral properties of these sources aimed at identifying the physical processes responsible for their emission and at explaining their observed variability. [ABSTRACT FROM AUTHOR]

The Perseus cluster of galaxies is a nearby cool-core cluster with an intra-clustermedium (ICM) characterized by very high central densities. The observation of the Perseus cluster with the MAGIC telescopes, during 85 h from 2009 to 2011, resulted in the discovery of 2 point-like sources at very high energy (>100 GeV, VHE) coinciding with the central radio galaxy NGC1275 and the radio galaxy IC310. The γ-ray properties of these 2 sources are presented, taking into account contemporaneous Fermi-LAT as well as multi-wavelength data. Flux variability and spectral energy distribution shapes indicate that the VHE γ-rays do not originate from large-scale interaction of the radio galaxies with ICM but more likely from the active nuclei of these two galaxies. They could be both misaligned version of BL Lac objects, the most common TeV AGN. Our results provide vital clues to understand emission mechanisms of such misaligned objects, and how they may be related to the beamed emission seen in BL Lacs. No evidence of large-scale VHE γ-ray emission from hadronic cosmic ray (CR) interactions with the ICM has been found. The flux upper limit above 1 TeV reaches the signal expected by some theoretical models, constraining the cluster CR physics. In the framework of the hadronicmodel of the radiomini-halos, this limit implies aminimal magnetic field ranging from 4-9μG for the central cluster region. [ABSTRACT FROM AUTHOR]