Naslov
MAGIC upper limits on the GRB 090102 afterglow

Autori
Aleksić, Jelena ; ... ; Babić, Ana ; ... ; Dominis Prester, Dijana ; ... ; Ferenc, Daniel ; ... ; Godinović, Nikola ; ... ; Hrupec, Dario ; ... ; Lelas, Damir ; ... ; Puljak, Ivica ; ... ; Surić, Tihomir ; ... ; Šnidarić, Iva ; ... ; Terzić, Tomislav ; ... ; Longo, F.

Izvornik
Monthly notices of the Royal Astronomical Society (0035-8711) 437 (2014), 4; 3103-3111

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
radiation mechanisms: non-thermal; gamma-rays bursts: general

Sažetak
Indications of a GeV component in the emission from GRBs are known since the EGRET observations during the 1990's and they have been confirmed by the data of the Fermi satellite. These results have, however, shown that our understanding of GRB physics is still unsatisfactory. The new generation of Cherenkov observatories and in particular the MAGIC telescope, allow for the first time the possibility to extend the measurement of GRBs from several tens up to hundreds of GeV energy range. Both leptonic and hadronic processes have been suggested to explain the possible GeV/TeV counterpart of GRBs. Observations with ground-based telescopes of very high energy photons (E>30 GeV) from these sources are going to play a key role in discriminating among the different proposed emission mechanisms, which are barely distinguishable at lower energies. MAGIC telescope observations of the GRB 090102 (z=1.547) field and Fermi Large Area Telescope (LAT) data in the same time interval are analysed to derive upper limits of the GeV/TeV emission. We compare these results to the expected emissions evaluated for different processes in the framework of a relativistic blast wave model for the afterglow. Simultaneous upper limits with Fermi and a Cherenkov telescope have been derived for this GRB observation. The results we obtained are compatible with the expected emission although the difficulties in predicting the HE and VHE emission for the afterglow of this event makes it difficult to draw firmer conclusions. Nonetheless, MAGIC sensitivity in the energy range of overlap with space-based instruments (above about 40 GeV) is about one order of magnitude better with respect to Fermi. This makes evident the constraining power of ground- based observations and shows that the MAGIC telescope has reached the required performance to make possible GRB multiwavelength studies in the very high energy range.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA