Neutral hydrogen compact absorption features in Cassiopeia A.

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

11

Ism: Supernova Remnants, Ism: Individual: Cas A, Stars: Mass Loss

Scientific paper

Very Large Array (VLA) observations of the λ21 cm H I line towards Cassiopeia A (Cas A) have been performed. The velocity interval observed was from -38 to -362(LSR)km/s, with a resolution of 2.6km/s and a beam size of 14.2"x11.4". Opacity images show the presence of a number of small absorption H I features in the velocity interval -62 to -69km/s (LSR) which, on the basis of several arguments, are postulated to be physically associated with Cas A. These cold H I knots have sizes of <0.1pc and show spatial substructure. Their velocities lie well outside the range of the intervening H I in the Perseus spiral arm, i.e. 0 to -55km/s. We demonstrate that the H I knots cannot be described as shocked interstellar cloudlets engulfed by the blast wave of the supernova remnant (SNR). Instead, we propose that these low velocity H I features are recombined wind driven clumps moving ahead of the supernova (SN) shock front. This hypothesis is supported by the ages derived for the knots, varying from 8x10^3^ to 5x10^4^years, which implies that these features were originally accelerated during the Wolf-Rayet (WR) phase of the precursor star.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Neutral hydrogen compact absorption features in Cassiopeia A. does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Neutral hydrogen compact absorption features in Cassiopeia A., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Neutral hydrogen compact absorption features in Cassiopeia A. will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1780621

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.