Daniel Mazin - IFAE

Daniel Mazin
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Daniel Mazin
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IFAE
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High Energy Astrophysical Phenomena (11)
 
Instrumentation and Methods for Astrophysics (10)
 
Cosmology and Nongalactic Astrophysics (7)
 
Astrophysics (3)
 
Physics - Instrumentation and Detectors (2)
 
High Energy Physics - Experiment (1)
 
Physics - Data Analysis; Statistics and Probability (1)

Publications Authored By Daniel Mazin

The wealth of recent data from imaging air Cherenkov telescopes (IACTs), ultra-high energy cosmic-ray experiments and neutrino telescopes have fuelled a renewed interest in hadronic emission models for gamma-loud blazars. We explore physically plausible solutions for a lepto-hadronic interpretation of the stationary emission from high-frequency peaked BL Lac objects (HBLs). The modelled spectral energy distributions are then searched for specific signatures at very high energies that could help to distinguish the hadronic origin of the emission from a standard leptonic scenario. Read More

Imaging atmospheric Cherenkov telescopes (IACTs) such as the Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescopes endeavor to reach the lowest possible energy threshold. In doing so the trigger system is a key element. Reducing the trigger threshold is hampered by the rapid increase of accidental triggers generated by ambient light, the so-called Night Sky Background (NSB). Read More

The Cherenkov Telescope Array (CTA) is the the next generation facility of imaging atmospheric Cherenkov telescopes; two sites will cover both hemispheres. CTA will reach unprecedented sensitivity, energy and angular resolution in very-high-energy gamma-ray astronomy. Each CTA array will include four Large Size Telescopes (LSTs), designed to cover the low-energy range of the CTA sensitivity ($\sim$20 GeV to 200 GeV). Read More

MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located on the Canary island of La Palma, Spain. During summer 2011 and 2012 it underwent a major upgrade. The main subsystems upgraded were the MAGIC-I camera and its trigger system and the readout system of both telescopes. Read More

The MAGIC telescopes are two Imaging Atmospheric Cherenkov Telescopes (IACTs) located on the Canary island of La Palma. With 17m diameter mirror dishes and ultra-fast electronics, they provide an energy threshold as low as 50 GeV for observations at low zenith angles. The first MAGIC telescope was taken in operation in 2004 whereas the second one joined in 2009. Read More

In this contribution we describe the design of the Data AcQuisition (DAQ) and online analysis software of the MAGIC telescopes after the 2012 upgrade. Although the final stereo trigger requires coincidence between the two telescopes, the actual data acquisition is performed independently, producing two separate data streams. Events are first readout and built from the front-end electronics and then stored in the DAQs' internal ring buffer for further processing: pre-calibration and signal extraction. Read More

MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located at the Canary Island of La Palma, designed to observe gamma rays with energies above 50 GeV. Recently it has undergone an upgrade of the camera, digital trigger and readout systems. The upgrade has led to an improvement in the performance of the telescopes, especially in the lower energy range. Read More

Recently the readout of the MAGIC telescopes has been upgraded to a new system based on the Domino Ring Sampler version 4 chip. We present the analysis techniques and the signal extraction performance studies of this system. We study the behaviour of the baseline, the noise, the cross-talk, the linearity and the time resolution. Read More

Very high energy (VHE, E >100 GeV) gamma-rays are absorbed via interaction with low-energy photons from the extragalactic background light (EBL) if the involved photon energies are above the threshold for electron-positron pair creation. The VHE gamma-ray absorption, which is energy dependent and increases strongly with redshift, distorts the VHE spectra observed from distant objects. The observed energy spectra of the AGNs carry, therefore, an imprint of the EBL. Read More

The unfolding program TRUEE is a software package for the numerical solution of inverse problems. The algorithm was first applied in the FORTRAN77 program RUN. RUN is an event-based unfolding algorithm which makes use of the Tikhonov regularization. Read More

The large majority of extragalactic very high energy (VHE; E>100 GeV) sources belongs to the class of active galactic nuclei (AGN), in particular the BL Lac sub-class. AGNs are characterized by an extremely bright and compact emission region, powered by a super-massive black hole (SMBH) and an accretion disk, and relativistic outflows (jets) detected all across the electro-magnetic spectrum. In BL Lac sources the jet axis is oriented close to the line of sight, giving rise to a relativistic boosting of the emission. Read More

Very high energy (VHE, energy $E \gtrsim 100$\,GeV) \gamma-rays from cosmological sources are attenuated due to the interaction with photons of the extragalactic background light (EBL) in the ultraviolet to infrared wavelength band. The EBL, thus, leaves an imprint on the observed energy spectra of these objects. In the last four years, the number of extragalactic VHE sources discovered with imaging atmospheric Cherenkov telescopes (IACTs), such as MAGIC, H. Read More

MAGIC has been performing optically triggered Target of Opportunity observations of flaring blazars since the beginning of its scientific operations. The alerts of flaring blazars originate from Tuorla Blazar Monitoring Programme, which started the optical monitoring of candidtate TeV blazars in 2002 and has now collected up to eight years of data on more than 60 blazars. These ToO observations have resulted in the discovery of five new VHE gamma-ray emitting blazars (S5 0716+714, 1ES 1011+496, Mrk 180, ON 325 and B3 2247+381). Read More

The Crab Pulsar Wind Nebula is the best studied source of $\gamma$-ray astrophysics. The contribution of the various soft radiation fields to the Inverse Compton component of its high energy emission, the strenght of the internal magnetic field and the maximum energies reached by primary electrons are however still matter of study. The MAGIC stereoscopic system recorded almost 50 hours of Crab Nebula data in the last two years, between October 2009 and April 2011. Read More

In the spring of 2008 MAGIC organised multi-wavelength (MWL) observations of the blazar 1ES 1011+496. 1ES 1011+496 is a high-frequency peaked BL Lac object discovered at VHE gamma-rays by MAGIC in spring 2007 during an optical outburst reported by the Tuorla Blazar Monitoring Programme. MAGIC re-observed the source during the 2008 MWL campaign which also included the Mets\"ahovi, KVA, Swift and AGILE telescopes. Read More

The diffuse meta-galactic radiation field at ultraviolet to infrared wavelengths - commonly labeled extragalactic background light (EBL) - contains the integrated emission history of the universe. Difficult to access via direct observations, indirect constraints on its density can be derived through observations of very-high energy (VHE; E>100 GeV) gamma-rays from distant sources: the VHE photons are attenuated via pair-production with the low energy photons from the EBL, leaving a distinct imprint in the VHE spectra measured on earth. Discoveries made with current-generation VHE observatories like H. Read More

2010May
Affiliations: 1Institute for Experimental Physics, University of Hamburg, Hamburg, Germany, 2Institut de Fisica d'Altes Energies

The diffuse meta-galactic radiation field at ultraviolet to infrared wavelengths - commonly labeled extragalactic background light (EBL) - contains the integrated emission history of the universe. Difficult to access via direct observations indirect constraints on its density can be derived through observations of very-high energy (VHE; E>100 GeV) gamma-rays from distant sources: the VHE photons are attenuated via pair-production with the low energy photons from the EBL, leaving a distinct imprint in the VHE spectra measured on earth. Discoveries made with current generation VHE observatories like H. Read More

2009Jul
Affiliations: 1for the MAGIC Collaboration, 2for the MAGIC Collaboration, 3for the MAGIC Collaboration, 4for the MAGIC Collaboration, 5for the MAGIC Collaboration

The MAGIC telescope observed the region around the distant blazar 3C 66A for 54.2 hr in 2007 August-December. The observations resulted in the discovery of a gamma-ray source centered at celestial coordinates R. Read More

2009Jul
Affiliations: 1for the MAGIC collaroration, 2for the MAGIC collaroration, 3for the MAGIC collaroration, 4for the MAGIC collaroration, 5for the MAGIC collaroration, 6for the MAGIC collaroration, 7for the MAGIC collaroration

MAGIC has been performing optically triggered Target of Opportunity observations of flaring blazars since the beginning of its scientific operations. The alerts of flaring blazars originate from Tuorla blazar monitoring program, which started the optical monitoring of the candidate TeV blazars in 2002 and has now collected up to six years of data on 30 blazars. These Target of Opportunity observations have resulted in the discovery of three new VHE gamma-ray emitting blazars (Mrk180, 1ES1011+496 and S50716+714) and in addition the discoveries of BLLac and 3C279 were made during a high optical state. Read More

Very high energy gamma ray emission from the active galactic nucleus PG 1553+113 was observed during 2005 and 2006 by the MAGIC collaboration, for a total observation time of 18.8 hours. Here we present the results of follow up observations: more than 20 hours of good quality data collected by the MAGIC Telescope during the 2007 and 2008 campaigns. Read More

We present the results of X-ray observations of the well-studied TeV blazar Mrk 421 with the Suzaku satellite in 2006 April 28. During the observation, Mrk 421 was undergoing a large flare and the X-ray flux was variable, decreasing by ~ 50 %, from 7.8x10^{-10} to 3. Read More

2007Nov
Affiliations: 1MPI für Physik, München, Germany, 2Universität Würzburg, Germany, 3MPI für Physik, München, Germany, 4Humboldt-Universität zu Berlin, Germany, 5ETH Zurich, Switzerland, 6MPI für Physik, München, Germany, 7IFAE, Barcelona, Spain, 8MPI für extraterrestrische Physik, Garching, Germany, 9MPI für extraterrestrische Physik, Garching, Germany
Category: Astrophysics

The MAGIC telescope has observed very-high energy gamma-ray emission from the BL Lac object PG 1553+113 in 2005 and 2006 at an overall significance is 8.8 sigma. The light curve shows no significant flux variations on a daily timescale. Read More

2007Sep
Affiliations: 1for the MAGIC Collaboration, 2for the MAGIC Collaboration, 3for the MAGIC Collaboration, 4for the MAGIC Collaboration, 5for the MAGIC Collaboration, 6for the MAGIC Collaboration, 7for the MAGIC Collaboration, 8for the MAGIC Collaboration, 9for the MAGIC Collaboration, 10for the MAGIC Collaboration, 11for the MAGIC Collaboration, 12for the MAGIC Collaboration
Category: Astrophysics

The quasar 3C 279 is one of the best-studied flat spectrum radio quasars. It is located at a comparatively large redshift of z=0.536: E>100 GeV observations of such distant sources were until recently impossible both due to the expected steep energy spectrum and the expected attenuation of the gamma-rays by the extragalactic background light. Read More

Aims: We derive limits on the EBL density from the energy spectra of distant sources of very high energetic gamma-rays (VHE gamma-rays). Methods: VHE gamma-rays are attenuated by the photons of the EBL via pair production, which leaves an imprint in the measured spectra from distant sources. In this paper we present a new method to derive constraints on the EBL. Read More