Facial reconstruction

Search LJMU Research Online

Browse Repository | Browse E-Theses

Flash Spectroscopy: Emission Lines from the Ionized Circumstellar Material Around <10-Day-Old Type II Supernovae

Khazov, D and Yaron, O and Gal-Yam, A and Manulis, I and Rubin, A and Kulkarni, SR and Arcavi, I and Kasliwal, MM and Ofek, EO and Cao, Y and Perley, DA and Sollerman, J and Horesh, A and Sullivan, M and Filippenko, AV and Nugent, PE and Howell, DA and Cenko, SB and Silverman, JM and Ebeling, H and Taddia, F and Johansson, J and Laher, RR and Surace, J and Rebbapragada, UD and Wozniak, PR and Matheson, T (2016) Flash Spectroscopy: Emission Lines from the Ionized Circumstellar Material Around <10-Day-Old Type II Supernovae. The Astrophysical Journal, 818 (1). ISSN 1538-4357

[img] Text
Khazov_2016_ApJ_818_3.pdf - Published Version

Download (1MB)

Abstract

The American Astronomical Society. All rights reserved.Supernovae (SNe) embedded in dense circumstellar material (CSM) may show prominent emission lines in their early-time spectra (≤10 days after the explosion), owing to recombination of the CSM ionized by the shock-breakout flash. From such spectra ("flash spectroscopy"), we can measure various physical properties of the CSM, as well as the mass-loss rate of the progenitor during the year prior to its explosion. Searching through the Palomar Transient Factory (PTF and iPTF) SN spectroscopy databases from 2009 through 2014, we found 12 SNe II showing flash-ionized (FI) signatures in their first spectra. All are younger than 10 days. These events constitute 14% of all 84 SNe in our sample having a spectrum within 10 days from explosion, and 18% of SNe II observed at ages <5 days, thereby setting lower limits on the fraction of FI events. We classified as "blue/featureless" (BF) those events having a first spectrum that is similar to that of a blackbody, without any emission or absorption signatures. It is possible that some BF events had FI signatures at an earlier phase than observed, or that they lack dense CSM around the progenitor. Within 2 days after explosion, 8 out of 11 SNe in our sample are either BF events or show FI signatures. Interestingly, we found that 19 out of 21 SNe brighter than an absolute magnitude MR = -18.2 belong to the FI or BF groups, and that all FI events peaked above MR = -17.6 mag, significantly brighter than average SNe II.

Item Type: Article
Uncontrolled Keywords: 0201 Astronomical And Space Sciences, 0305 Organic Chemistry, 0306 Physical Chemistry (Incl. Structural)
Subjects: Q Science > QB Astronomy
Q Science > QC Physics
Divisions: Astrophysics Research Institute
Publisher: American Astronomical Society
Date Deposited: 17 Feb 2017 12:35
Last Modified: 07 Sep 2017 13:15
DOI or Identification number: 10.3847/0004-637X/818/1/3
URI: http://researchonline.ljmu.ac.uk/id/eprint/5610

Actions (login required)

View Item View Item