Bibcode
Ahnen, M. L.; Ansoldi, S.; Antonelli, L. A.; Antoranz, P.; Babic, A.; Banerjee, B.; Bangale, P.; Barres de Almeida, U.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Berti, A.; Biasuzzi, B.; Biland, A.; Blanch, O.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Buson, S.; Carosi, A.; Chatterjee, A.; Clavero, R.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Lotto, B.; de Oña Wilhelmi, E.; Di Pierro, F.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher Glawion, D.; Elsaesser, D.; Fallah Ramazani, V.; Fernández-Barral, A.; Fidalgo, D.; Fonseca, M. V.; Font, L.; Frantzen, K.; Fruck, C.; Galindo, D.; García López, R. J.; Garczarczyk, M.; Garrido Terrats, D.; Gaug, M.; Giammaria, P.; Godinović, N.; González Muñoz, A.; Gora, D.; Guberman, D.; Hadasch, D.; Hahn, A.; Hanabata, Y.; Hayashida, M.; Herrera, J.; Hose, J.; Hrupec, D.; Hughes, G.; Idec, W.; Kodani, K.; Konno, Y.; Kubo, H.; Kushida, J.; La Barbera, A.; Lelas, D.; Lindfors, E.; Lombardi, S.; Longo, F.; López, M.; López-Coto, R.; Majumdar, P.; Makariev, M.; Mallot, K.; Maneva, G.; Manganaro, M.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Miranda, J. M.; Mirzoyan, R.; Moralejo, A.; Moretti, E.; Nakajima, D.; Neustroev, V.; Niedzwiecki, A.; Nievas Rosillo, M. et al.
Bibliographical reference
Astronomy and Astrophysics, Volume 591, id.A138, 7 pp.
Advertised on:
6
2016
Journal
Citations
24
Refereed citations
19
Description
The Geminga pulsar, one of the brighest gamma-ray sources, is a
promising candidate for emission of very-high-energy (VHE > 100 GeV)
pulsed gamma rays. Also, detection of a large nebula has been claimed by
water Cherenkov instruments. We performed deep observations of Geminga
with the MAGIC telescopes, yielding 63 h of good-quality data, and
searched for emission from the pulsar and pulsar wind nebula. We did not
find any significant detection, and derived 95% confidence level upper
limits. The resulting upper limits of 5.3 × 10-13 TeV
cm-2 s-1 for the Geminga pulsar and 3.5 ×
10-12 TeV cm-2 s-1 for the surrounding
nebula at 50 GeV are the mostconstraining ones obtained so far at VHE.
To complement the VHE observations, we also analyzed 5 yr of Fermi-LAT
data from Geminga, finding that the sub-exponential cut-off is preferred
over the exponential cut-off that has been typically used in the
literature. We also find that, above 10 GeV, the gamma-ray spectra from
Geminga can be described with a power law with index softer than 5. The
extrapolation of the power-law Fermi-LAT pulsed spectra to VHE goes well
below the MAGIC upper limits, indicating that the detection of pulsed
emission from Geminga with the current generation of Cherenkov
telescopes is very difficult.