[vsnet-campaign-sn 1010] SN 2004gt progenitor

[Taichi Kato]

SN 2004gt progenitor

   The progenitor of SN 2004gt seems to be fainter than has previously
assumed for an explosion of a WR-type star.  Are there known Galactic likely
counterparts of candidate more-stripped, faint WR-type stars, supposedly
a best candidate for an immediate supernova explosion?

Paper: astro-ph/0506472
Date: Tue, 21 Jun 2005 19:54:14 GMT   (781kb)

Title: A high angular-resolution search for the progenitor of the type Ic
  supernova SN 2004gt
Authors: A. Gal-Yam, D. B. Fox, S. R. Kulkarni, K. Matthews, D. C. Leonard, D.
  J. Sand, D.-S. Moon, S. B. Cenko, and A. M. Soderberg
Comments: Submitted to ApJ Letters
\\
  We report the results of a high-spatial-resoltion search for the progenitor
of type Ic supernova SN 2004gt, using the newly commissioned Keck laser-guide
star adaptive optics system (LGSAO) along with archival Hubble Space Telescope
data. This is the deepest search yet performed for the progenitor of any type
Ib/c event in a wide wavelength range stretching from the far UV to the near
IR. We determine that the progenitor of SN 2004gt was most likely less luminous
than M_V=-5.5 and M_B=-6.5 magnitudes. The massive stars exploding as
hydrogen-deficient core-collapse supernovae (SNe) should have lost their outer
hydrogen envelopes prior to their explosion, either through winds -- such stars
are identified within our Galaxy as as Wolf-Rayet (W-R) stars -- or to a binary
companion. The luminosity limits we set rule out more than half of the known
galactic W-R stars as possible progenitors of this event. In particular, they
imply that a W-R progenitor should have been among the more-evolved (highly
stripped, less luminous) of these stars, a concrete constraint on its
evolutionary state just prior to core collapse. The possibility of a less
luminous, lower-mass binary progenitor cannot be constrained. This study
demonstrates the power of LGS observations in furthering our understanding of
core collapse, and the physics powering supernovae, GRBs and XRFs.
\\ ( http://arXiv.org/abs/astro-ph/0506472 ,  781kb)