* Astronomy

Title: Spectroscopic evidence for SN 2010ma associated with GRB 101219B
Authors: M. Sparre, J. Sollerman, J.P.U. Fynbo, D. Malesani, P. Goldoni, A. de Ugarte Postigo, S. Covino, V. D'Elia, H. Flores, F. Hammer, J. Hjorth, P. Jakobsson, L. Kaper, G. Leloudas, A.J. Levan, B. Milvang-Jensen, S. Schulze, G. Tagliaferri, N.R. Tanvir, D.J. Watson, K. Wiersema, R.A.M.J. Wijers

We report on the spectroscopic detection of supernova SN 2010ma associated with the long gamma-ray burst GRB 101219B. We observed the optical counterpart of the GRB on three nights with the X-shooter spectrograph at the VLT. From weak absorption lines, we measure a redshift of z=0.55. The first epoch UV--near-infrared afterglow spectrum, taken 11.6 hr after the burst, is well fit by a power law consistent with the slope of the X-ray spectrum. The second and third epoch spectra (obtained 16.4 and 36.7 days after the burst), however, display clear bumps closely resembling those of the broad-lined type-Ic SN 1998bw if placed at z=0.55. Apart from demonstrating that spectroscopic SN signatures can be observed for GRBs at these large distances, our discovery makes a step forward in establishing a general connection between GRBs and SNe. In fact, unlike most previous unambiguous GRB-associated SNe, GRB 101219B has a large gamma-ray energy (E_{iso}= 4.2 x 10^{51} erg), a bright afterglow, and obeys the "Amati" relation, thus being fully consistent with the cosmological population of GRBs.

Read more  (163kb, PDF)

CBET 2706
RA 00 48 55.35, Dec -34 33 59.5