The bright and the slow - GRBs 100724B and 160509A with high-energy cutoffs at < 100 MeV

G. Vianello, R. Gill, Jonathan Granot, N. Omodei, J. Cohen-Tanugi, F. Longo

نتاج البحث: فصل من :كتاب / تقرير / مؤتمرمنشور من مؤتمرمراجعة النظراء


We analyze the prompt emission of two of the brightest Gamma-Ray Bursts (GRBs) observed by Fermi at MeV energies but surprisingly faint at > 100 MeV energies. Time-resolved spectroscopy reveals a sharp high-energy cutoff. We first characterize phenomenologically the cutoff and its time evolution. We then fit the data to two models where the high-energy cutoff arises from intrinsic opacity to pair production within the source. Alternative explanations for the cutoff, such as an intrinsic cutoff in the emitting electron energy distribution, appear to be less natural. Both models provide a good fit to the data with very reasonable physical parameters, providing a direct estimate of bulk Lorentz factors on the lower end of what is generally observed in Fermi GRBs. Particularly low Ec values may prevent detection by Fermi- LAT, thus introducing a bias in the Fermi- LAT GRB sample against GRBs with low Lorentz factors or variability times.

اللغة الأصليةالإنجليزيّة
عنوان منشور المضيفProceedings of Science
مستوى الصوت2017-October
المعرِّفات الرقمية للأشياء
حالة النشرنُشِر - 2017
الحدث7th International Fermi Symposium, IFS 2017 - Garmisch-Partenkirchen, ألمانيا
المدة: ١٥ أكتوبر ٢٠١٧٢٠ أكتوبر ٢٠١٧

سلسلة المنشورات

الاسمProceedings of Science
ناشرSissa Medialab Srl


!!Conference7th International Fermi Symposium, IFS 2017

ملاحظة ببليوغرافية

Publisher Copyright:
© Copyright owned by the author(s).


أدرس بدقة موضوعات البحث “The bright and the slow - GRBs 100724B and 160509A with high-energy cutoffs at < 100 MeV'. فهما يشكلان معًا بصمة فريدة.

قم بذكر هذا