[seminar] Astro Journal Club on 30 September

[Oskari Miettinen]

Dear all,

Our Astro Journal Club will start this week and will be held on Wednesday
at 3pm in the seminar
room F-201 of the Physics Department. This time we will discuss about
failed supernova explosions.

Presenter: Oskari Miettinen
Paper title: Gone without a bang: an archival HST survey for disappearing
massive stars
Authors: Reynolds, T. M., Fraser, M., and Gilmore, G.

Summary:
It has been argued that a substantial fraction of massive stars may end
their lives without an optically bright supernova (SN), but rather
collapse to form a black hole. Such an event would not be detected by
current SN surveys, which are focused on finding bright transients.
Kochanek et al. proposed a novel survey for such events, using repeated
observations of nearby galaxies to search for the disappearance of a
massive star. We present such a survey, using the first systematic
analysis of archival Hubble Space Telescope images of nearby galaxies with
the aim of identifying evolved massive stars which have disappeared,
without an accompanying optically bright SN. We consider a sample of 15
galaxies, with at least three epochs of Hubble Space Telescope imaging
taken between 1994 and 2013. Within this data, we find one candidate which
is consistent with a 25-30 Msun yellow supergiant which has undergone an
optically dark core-collapse.

Link to the paper: http://adsabs.harvard.edu/abs/2015MNRAS.453.2886R

Hope to see you all on Wednesday!

Cheers,
Oskari