skip to main content


Title: PTF11kx: A Type Ia Supernova with Hydrogen Emission Persisting after 3.5 Years

The optical transient PTF11kx exhibited both the characteristic spectral features of Type Ia supernovae (SNe Ia) and the signature of ejecta interacting with circumstellar material (CSM) containing hydrogen, indicating the presence of a nondegenerate companion. In this paper, we present an optical spectrum at 1342 days after peak from Keck Observatory, in which the broad component of Hα emission persists with a similar profile as in early-time observations. We also present Spitzer IRAC detections obtained 1237 and 1818 days after peak, and an upper limit from Hubble Space Telescope ultraviolet imaging at 2133 days. We interpret our late-time observations in the context of published results—and reinterpret the early-time observations—in order to constrain the CSM's physical parameters and to compare to theoretical predictions for recurrent-nova systems. We find that the CSM's radial extent may be several times the distance between the star and the CSM's inner edge, and that the CSM column density may be two orders of magnitude lower than previous estimates. We show that the Hα luminosity decline is similar to other SNe with CSM interaction and demonstrate how our infrared photometry is evidence for newly formed, collisionally heated dust. We create a model for PTF11kx's late-time CSM interactionmore » and find that X-ray reprocessing by photoionization and recombination cannot reproduce the observed Hα luminosity, suggesting that the X-rays are thermalized and that Hα radiates from collisional excitation. In conclusion, we discuss the implications of our results regarding the progenitor scenario and the geometric properties of the CSM for the PTF11kx system.« less
ORCiD logo [1] ; ORCiD logo [2] ; ORCiD logo [3] ; ORCiD logo [2] ;  [4] ; ORCiD logo [5] ; ORCiD logo [4]
  1. Univ. of Washington, Seattle, WA (United States); Univ. of California, Berkeley, CA (United States)
  2. Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  3. Space Telescope Science Inst., Baltimore, MD (United States)
  4. Univ. of California, Berkeley, CA (United States)
  5. Univ. of Texas, Austin, TX (United States)
Publication Date:
Grant/Contract Number:
AC02-05CH11231; NAS5-26555; AST-1211916; AST-1302771
Accepted Manuscript
Journal Name:
The Astrophysical Journal (Online)
Additional Journal Information:
Journal Name: The Astrophysical Journal (Online); Journal Volume: 843; Journal Issue: 2; Journal ID: ISSN 1538-4357
Institute of Physics (IOP)
Research Org:
Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE; National Aeronautic and Space Administration (NASA); National Science Foundation (NSF)
Country of Publication:
United States
OSTI Identifier: