Change search
ReferencesLink to record
Permanent link

Direct link
Show others and affiliations
2011 (English)In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 732, no 1, 3- p.Article in journal (Refereed) Published
Abstract [en]

We report the first detection of asymmetry in a supernova (SN) photosphere based on SN light echo (LE) spectra of Cas A from the different perspectives of dust concentrations on its LE ellipsoid. New LEs are reported based on difference images, and optical spectra of these LEs are analyzed and compared. After properly accounting for the effects of finite dust-filament extent and inclination, we find one field where the He I lambda 5876 and Ha features are blueshifted by an additional similar to 4000 km s(-1) relative to other spectra and to the spectra of the Type IIb SN 1993J. That same direction does not show any shift relative to other Cas A LE spectra in the Ca II near-infrared triplet feature. We compare the perspectives of the Cas A LE dust concentrations with recent three-dimensional modeling of the SN remnant (SNR) and note that the location having the blueshifted He I and Ha features is roughly in the direction of an Fe-rich outflow and in the opposite direction of the motion of the compact object at the center of the SNR. We conclude that Cas A was an intrinsically asymmetric SN. Future LE spectroscopy of this object, and of other historical SNe, will provide additional insight into the connection of the explosion mechanism to SN then to SNR, as well as give crucial observational evidence regarding how stars explode.

Place, publisher, year, edition, pages
2011. Vol. 732, no 1, 3- p.
Keyword [en]
ISM: individual objects (Cas A), ISM: supernova remnants, supernovae: general
National Category
Astronomy, Astrophysics and Cosmology
URN: urn:nbn:se:su:diva-68546DOI: 10.1088/0004-637X/732/1/3ISI: 000289626500003OAI: diva2:472711
authorCount :24Available from: 2012-01-04 Created: 2012-01-04 Last updated: 2012-01-04Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text
By organisation
Department of Astronomy
In the same journal
Astrophysical Journal
Astronomy, Astrophysics and Cosmology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 22 hits
ReferencesLink to record
Permanent link

Direct link