Volume 541, May 2012
|Number of page(s)||5|
|Published online||18 April 2012|
Observations of infrared echoes around Cassiopeia A with WISE⋆
Max-Planck Institut für Astronomie,
Received: 21 February 2012
Accepted: 20 March 2012
Context. Light echoes of supernovae have proven to be a viable tool for characterizing both the supernova explosion mechanism and the surrounding circumstellar and interstellar medium.
Aims. We explore new possibilities for identifying infrared echoes with WISE data and extend the area of known echoes around the supernova remnant Cassiopeia A in different illumination conditions.
Methods. Preliminary release WISE data around Cassiopeia A is analyzed and compared to Spitzer-MIPS data. While Spitzer-WISE difference images directly show evidence of infrared light echoes, they can also be identified according to their 22/12 μm flux ratio.
Results. We find that WISE allows the detection of previously unknown infrared echoes in various illumination conditions. For the first time, infrared echoes at distances greater than 800 pc from a supernova remnant have been found. The 22/12 μm flux ratio criterion can be used as a conceptual factor for identifying infrared echoes around other supernovae as well as providing insights into the dust processing conditions of the interstellar medium.
Key words: ISM: general / dust, extinction / supernovae: individual: Cassiopeia A
Table 1 is available in electronic form at http://www.aanda.org
© ESO, 2012
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.