MAGIC observation of the GRB080430 afterglow

Abstract

Context: Gamma-ray bursts are cosmological sources emitting radiation from the gamma-rays to the radio band. Substantial observational efforts have been devoted to the study of gamma-ray bursts during the prompt phase, i.e. the initial burst of high-energy radiation, and during the long-lasting afterglows. In spite of many successes in interpreting these phenomena, there are still several open key questions about the fundamental emission processes, their energetics and the environment. Aim: Independently of specific gamma-ray burst theoretical recipes, spectra in the GeV/TeV range are predicted to be remarkably simple, being satisfactorily modeled with power-laws, and therefore offer a very valuable tool to probe the extragalactic background light distribution. Furthermore, the simple detection of a component at very-high energies, i.e. at $\sim 100$\,GeV, would solve the ambiguity about the importance of various possible emission processes, which provide barely distinguishable scenarios at lower energies. Methods: We used the results of the MAGIC telescope observation of the moderate resdhift ($z\sim 0.76$) \object{GRB\,080430} at energies above about 80\,GeV, to evaluate the perspective for late-afterglow observations with ground based GeV/TeV telescopes. Results: We obtained an upper limit of $F_{\rm 95%\,CL} = 5.5 \times 10^{-11}$\,erg\,cm${}^{-2}$\,s${}^{-1}$ for the very-high energy emission of \object{GRB\,080430}, which cannot set further constraints on the theoretical scenarios proposed for this object also due to the difficulties in modeling the low-energy afterglow. Nonetheless, our observations show that Cherenkov telescopes have already reached the required sensitivity to detect the GeV/TeV emission of GRBs at moderate redshift ($z\lesssim 0.8$), provided the observations are carried out at early times, close to the onset of their afterglow phase.

6 pages, 1 figure. Astronomy & Astrophysics, in press. Revision affects only the author list.

References in corpus (20)

• Gamma-Ray Bursts: Progress, Problems & Prospects
• Testing Einstein's special relativity with Fermi's short hard gamma-ray burst GRB090510
• Very-High-Energy Gamma Rays from a Distant Quasar: How Transparent Is the Universe?
• GRB Radiative Efficiencies Derived from the Swift Data: GRBs vs. XRFs, Long vs. Short
• REM observations of GRB 060418 and GRB 060607A: the onset of the afterglow and the initial fireball Lorentz factor determination
• "Late prompt" emission in Gamma Ray Bursts?
• Global Properties of X-Ray Flashes and X-Ray-Rich Gamma-Ray Bursts Observed by Swift
• MAGIC upper limits on the very high energy emission from GRBs
• High energy gamma-ray emission from Gamma-Ray Bursts -- before GLAST
• Prospects for GRB Science with the Fermi Large Area Telescope
• Flux upper limit of gamma-ray emission by GRB050713a from MAGIC Telescope observations
• H.E.S.S. Observations of the Prompt and Afterglow Phases of GRB 060602B
• High-energy emission as a test of the prior emission model for gamma-ray burst afterglows
• High energy afterglows and flares from Gamma-Ray Burst by Inverse Compton emission
• Interpretation and implication of the non-detection of GeV spectrum excess by Fermi gamma-ray Space Telescope in most GRBs
• Very High Energy Gamma-ray Afterglow Emission of Nearby Gamma-ray Bursts
• GeV emission from Gamma-Ray Burst afterglows
• Prospects for detection of very high-energy emission from GRB in the context of the external shock model
• Modeling gamma-ray burst observations by Fermi and MAGIC including attenuation due to diffuse background light
• Gamma-ray burst observations with new generation imaging atmospheric Cerenkov Telescopes in the FERMI era

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• The AllWISE Motion Survey and The Quest for Cold Subdwarfs
• Gamma-Ray Burst Science in the Era of the Cherenkov Telescope Array
• On the Implications of Late Internal Dissipation for Shallow-Decay Afterglow Emission and Associated High-Energy Gamma-Ray Signals
• TeV Gamma-ray Astronomy: A Summary
• Prospects for Detecting Gamma-Ray Bursts at Very High Energies with the Cherenkov Telescope Array
• MAGIC upper limits on the GRB 090102 afterglow
• Simulations of gamma-ray burst afterglows with a relativistic kinetic code
• A decade of GRB follow-up by BOOTES in Spain (2003-2013)
• High energy emission from transients
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