相关论文: A new light boson from MAGIC observations?
The Gamma-Ray Large Area Space Telescope (GLAST), scheduled to be launched in Fall 2007, is a next generation high energy gamma-ray observatory. The Large Area Telescope (LAT) instrument on-board GLAST with a wide field of view ($>$ 2 sr),…
Very high energy gamma rays coming from extra-galactic sources can interact with intergalactic radiation fields. This process may result in electromagnetic cascades with the following cycle: the production of electron-positron pairs and…
In many Dark Matter (DM) scenarios, the annihilation of DM particles can produce gamma rays with a continuum spectrum that extends up to very high energies of the order of the electroweak symmetry breaking scale (hundreds of GeV).…
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. The…
Our understanding of the Universe today includes overwhelming observational evidence for the existence of an elusive form of matter that is generally referred to as dark. Although many theories have been developed to describe its nature,…
We describe the emission properties of blazars, i.e. the AGNs that, due to their peculiar orientation w.r.t. the observer, allow the most penetrating and direct view of their central engine. After showing that the extragalactic GeV-TeV sky…
Luminous high-redshift quasars can be used to probe of the intergalactic medium (IGM) in the early universe because their UV light is absorbed by the neutral hydrogen along the line of sight. They help us to measure the neutral hydrogen…
The diffuse glow of the cosmic web in Lyman-$\alpha$ emission has long been predicted, yet remained elusive to direct wide field detection. We present theoretical calculations that, when compared with recent observations made using the…
Here we report the discovery of very high energy gamma-ray emission from the radio emitting X-ray binary LS I +61 303 with the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescope. This high energy emission has been found to be…
The Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) experiment is an array of two 17-meter telescopes located in the Canary Island of La Palma that observes the very-high energy (VHE) gamma-ray sky in stereoscopic mode since 2009.…
High-energy photons (above the MeV) are a powerful probe for astrophysics and for fundamental physics under extreme conditions. During the recent years, our knowledge of the high-energy gamma-ray sky has impressively progressed thanks to…
Axionlike particles (ALPs) are a common prediction of theories beyond the Standard Model of particle physics that could explain the entirety of the cold dark matter. These particles could be detected through their mixing with photons in…
The extragalactic magnetic field could be detected by searching for signatures of the electromagnetic cascade initiated by high-energy photons on the intergalactic radiation and deflected by the field. This process produces a time delay and…
The focus of this presentation is to go through some of the remarkable observations concerning gamma-ray cosmic accelerators and diffuse emissions. Additionally, I will cover the status of the new generation of gamma-ray groundbased…
Recently, two nearby prominent starburst galaxies, M82 and NGC253, have been detected as point-like sources with gamma-ray telescopes at TeV energies [1] [2]. It has been claimed that these detections show that the cosmic ray intensity in…
Very high-energy gamma-ray measurements of distant blazars can be well explained by secondary gamma rays emitted by cascades induced by ultra-high-energy cosmic rays. The secondary gamma rays will enable one to detect a large number of…
With the discovery of evidence for neutrino mass, a vivid gamma ray sky at multi-TeV energies, and cosmic ray particles with unexpectedly high energies, astroparticle physics currently runs through an era of rapid progress and moving…
The MAGIC telescope, with its 17-m diameter mirror, is currently the largest single-dish Imaging Air Cherenkov Telescope. It is located on the Canary Island of La Palma, at an altitude of 2200 m above sea level, and is operating since 2004.…
The ground-based imaging atmospheric Cherenkov technique is currently the most powerful observation method for very high energy gamma rays. With its specially designed camera and readout system, the MAGIC Telescope is capable of observing…
Bright and fast gamma-ray flares with hard spectra have been recently detected from the blazar 3C 279, with apparent GeV luminosities up to $10^{49}$ erg/s. The source is observed to flicker on timescales of minutes with no comparable…