Still brighter than pre-explosion, SN 2012Z did not disappear: Comparing hubble space telescope observations a decade apart

作     者：Mccully, Curtis Jha, Saurabh W. Scalzo, Richard A. Howell, D. Andrew Foley, Ryan J. Zeng, Yaotian Liu, Zheng-Wei Hosseinzadeh, Griffin Bildsten, Lars Riess, Adam G. Kirshner, Robert P. Marion, G.H. Camacho-Neves, Yssavo 

作者机构：Las Cumbres Observatory 6740 Cortona Dr Ste 102 GoletaCA93117-5575 United States Department of Physics University of California Santa BarbaraCA93106-9530 United States Department of Physics and Astronomy Rutgers The State University of New Jersey 136 Frelinghuysen Road PiscatawayNJ08854 United States School of Mathematics and Statistics The University of Sydney CamperdownNSW2006 Australia Centre for Translational Data Science University of Sydney DarlingtonNSW2008 Australia Department of Astronomy and Astrophysics University of California Santa CruzCA92064 United States  Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects CAS Kunming650216 China University of Chinese Academy of Science Beijing100012 China Center for Astronomical Mega-Science CAS Beijing100012 China Center for Astrophysics - Harvard and Smithsonian 60 Garden Street CambridgeMA02138-1516 United States Kavli Institute for Theoretical Physics University of California Santa BarbaraCA93106 United States Space Telescope Science Institute 3700 San Martin Drive BaltimoreMD21218 United States Department of Physics and Astronomy Johns Hopkins University BaltimoreMD21218 United States Gordon and Betty Moore Foundation 1661 Page Mill Road Palo AltoCA94304 United States University of Texas at Austin 1 University Station C1400 AustinTX78712-0259 United States 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2021年

核心收录：

主　　题：Supernovae 

摘      要：Type Iax supernovae represent the largest class of peculiar white-dwarf supernovae. The type Iax SN 2012Z in NGC 1309 is the only white dwarf supernova with a detected progenitor system in pre-explosion observations. Deep Hubble Space Telescope images taken before SN 2012Z show a luminous, blue source that we have interpreted as a helium-star companion (donor) to the exploding white dwarf. We present here late-time HST observations taken ∼1400 days after the explosion to test this model. We find the SN light curve can empirically be fit by an exponential decay model in magnitude units. The fitted asymptotic brightness is within 10% of our latest measurements and approximately twice the brightness of the pre-explosion source. The decline of the light curve is too slow to be powered by 56Co or 57Co decay: if radioactive decay is the dominate power source, it must be from longer half-life species like 55Fe. Interaction with circumstellar material may contribute to the light curve, as may shock heating of the companion star. Companion-star models underpredict the observed flux in the optical, producing most of their flux in the UV at these epochs. A radioactively-heated bound remnant, left after only a partial disruption of the white dwarf, is also capable of producing the observed excess late-time flux. Our analysis suggests that the total ejecta + remnant mass is consistent with the Chandrasekhar mass for a range of type Iax supernovae. Copyright © 2021, The Authors. All rights reserved.