Abstract
Optical spectroscopy and photometry of SN 2006aj have been performed with the Subaru telescope at t > 200 days after GRB 060218, the X-ray flash with which it was associated. Strong nebular emission lines with an expansion velocity of v ~ 7300 km s-1 were detected. The peaked but relatively broad [O I] λλ6300, 6363 suggests the existence of ~2 M☉ of materials in which ~1.3 M☉ is oxygen. The core might be produced by a mildly asymmetric explosion. The spectra are unique among SNe Ic in (1) the absence of [Ca II] λλ7291, 7324 emission and (2) a strong emission feature at ~7400 Å, which requires ~0.05 M☉ of newly synthesized 58Ni. Such a large amount of stable neutron-rich Ni strongly indicates the formation of a neutron star. The progenitor and the explosion energy are constrained to 18 M☉ ≲ Mms ≲ 22 M☉ and E ~ (1-3) × 1051 ergs, respectively.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
