The GRB 060218/SN 2006aj event in the context of other gamma-ray burst supernovae

¹ Thüringer Landessternwarte Tautenburg, 07778 Tautenburg, Germany e-mail: ferrero@tls-tautenburg.de
² Istituto Nazionale di Astrofisica-OATs, 34131 Trieste, Italy
³ INAF, Istituto di Astrofisica Spaziale e Fisica Cosmica, Sez. di Bologna, 40129 Bologna, Italy
⁴ Clemson University, Department of Physics and Astronomy, Clemson, SC 29634-0978, USA
⁵ Dark Cosmology Center, Niels Bohr Institute, Copenhagen University, 2100 Copenhagen, Denmark
⁶ National Astronomical Observatories, CAS, Chaoyang District, Beijing 100012, PR China
⁷ Department of Astronomy, University of California, Berkeley, CA 94720-3411, USA
⁸ Max-Planck-Institut für extraterrestische Physik, 85741 Garching, Germany
⁹ Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield, AL10 9AB, UK
¹⁰ Max-Planck Institut für Astrophysik, 85748 Garching, Germany
¹¹ Department of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH, UK
¹² Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Birkenhead, CH41 1LD, UK

Received: 2 May 2006
Accepted: 13 July 2006

Abstract

The supernova SN 2006aj associated with GRB 060218 is the second-closest GRB-SN observed to date (). We present Very Large Telescope, Liverpool Telescope, and Katzman Automatic Imaging Telescope multi-color photometry of SN 2006aj. This supernova is found to be subluminous and rapidly evolving. Its early light curve includes an additional wavelength-dependent component, which can be interpreted as shock break-out. We compare the photometric evolution of multi-band light curves with the corresponding properties of the present sample of more than 10 GRB-SNe with precisely known redshifts. Using host-galaxy extinction measurements, we derive extinction-corrected GRB-SN luminosities and place SN 2006aj in the context of this GRB-selected supernova sample as well as in the context of local stripped-envelope supernovae.