Highly Energetic Expansion of SN2010bh Associated with GRB 100316D

Bufano Filomena

Pian Elena

Sollerman Jesper

Benetti Stefano

Pignata Giuliano

Valenti Stefano

Covino Stefano

Avanzo Paolo D'

Malesani Daniele

Cappellaro Enrico

Valle Massimo Della

Fynbo Johan

Hjorth Jens

Mazzali Paolo A.

Reichart Daniel E.

Starling Rhaana L. C.

Turatto Massimo

Vergani Susanna D.

Wiersema Klass

Amati Lorenzo

Bersier David

Campana Sergio

Cano Zach

Castro-Tirado Alberto J.

Chincarini Guido

Elia Valerio D'

Postigo Antonio de Ugarte

Deng Jinsong

Ferrero Patrizia

Filippenko Alexei V.

Goldoni Paolo

Gorosabel Javier

Greiner Jochen

Hammer Francois

Jakobsson Pall

Kaper Lex

Kawabata Koji S.

Klose Sylvio

Levan Andrew J.

Maeda Keiichi

Masetti Nicola

Milvang-Jensen Bo

Mirabel Felix I.

Moller Palle

Nomoto Ken'ichi

Palazzi Eliana

Piranomonte Silvia

Salvaterra Ruben

Stratta Giulia

Tagliaferri Gianpiero

Tanaka Masaomi

Tanvir Nial R.

Wijers Ralph A. M. J.

Astrophysical Journal

We present the spectroscopic and photometric evolution of the nearby (z = 0.059) spectroscopically confirmed Type Ic supernova, SN 2010bh, associated with the soft, long-duration gamma-ray burst (X-ray flash) GRB 100316D. Intensive follow-up observations of SN 2010bh were performed at the ESO Very Large Telescope (VLT) using the X-shooter and FORS2 instruments. Thanks to the detailed temporal coverage and the extended wavelength range (3000-24800 angstrom), we obtained an unprecedentedly rich spectral sequence among the hypernovae, making SN 2010bh one of the best studied representatives of this SN class. We find that SN 2010bh has a more rapid rise to maximum brightness (8.0 +/- 1.0 rest-frame days) and a fainter absolute peak luminosity (L-bol approximate to 3 x 10(42) erg s(-1)) than previously observed SN events associated with GRBs. Our estimate of the ejected Ni-56 mass is 0.12 +/- 0.02 M-circle dot. From the broad spectral features, we measure expansion velocities up to 47,000 km s(-1), higher than those of SNe 1998bw (GRB 980425) and 2006aj (GRB 060218). Helium absorption lines He I lambda 5876 and He I 1.083 mu m, blueshifted by similar to 20,000-30,000 km s(-1) and similar to 28,000-38,000 km s(-1), respectively, may be present in the optical spectra. However, the lack of coverage of the He I 2.058 mu m line prevents us from confirming such identifications. The nebular spectrum, taken at similar to 186 days after the explosion, shows a broad but faint [O I] emission at 6340 angstrom. The light curve shape and photospheric expansion velocities of SN 2010bh suggest that we witnessed a highly energetic explosion with a small ejected mass (E-k approximate to 10(52) erg and M-ej approximate to 3 M-circle dot). The observed properties of SN 2010bh further extend the heterogeneity of the class of GRB SNe.

supernovae: general

supernovae: individual (SN 2010bh, GRB 100316D)

Astronomy. Space sciences [ 440 ]

eng

IOP Publishing Ltd

(c) 2012. The American Astronomical Society. All rights reserved. Printed in the U.S.A.

[ISSN] 0004-637X

[DOI] 10.1088/0004-637X/753/1/67

[NCID] AA00553242

[DOI] http://dx.doi.org/10.1088/0004-637X/753/1/67