Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published February 10, 2019 | Published + Submitted
Journal Article Open

Long-term Evolution and Appearance of Type Iax Postgenitor Stars


Type Iax supernovae may arise from failed explosions of white dwarfs (WDs) that leave behind a bound remnant (i.e., a "postgenitor" star) that could be identified in wide field surveys. To understand their observational signatures, we simulate these WD postgenitors from shortly after explosion until they move back down the WD cooling track, and we consider several possible WD masses and explosion energies. To predict the peculiar surface abundances of the WD postgenitors, our models take into account gravitational settling and radiative levitation. We find that radiative levitation is significant at temperatures above a mass-dependent critical temperature, typically in the range T_(eff) ≈ (50–100) × 10^3 K, significantly increasing surface abundances of iron group elements. Due to enhanced iron group opacity compared to normal WDs, the postgenitor peak luminosity and cooling timescale depend sensitively on mass, with more massive WDs becoming brighter but cooling much faster. We discuss our results in light of recently discovered hypervelocity WDs with peculiar surface compositions, finding that our low-mass postgenitor models match many of their observational characteristics. Finally, we explore the effects of thermohaline diffusion, tentatively finding that it strongly suppresses abundance enhancements created by radiative levitation, but more realistic modeling is required to reach a firm conclusion.

Additional Information

© 2019 The American Astronomical Society. Received 2018 October 31; revised 2018 December 27; accepted 2018 December 28; published 2019 February 7. We thank Ken Shen, Evan Bauer, and Lars Bildsten for useful discussions, and we thank the referee for a very constructive and thorough report. This work was supported by the Heising-Simons Foundation through grant #2017-274. Support for this work was provided by NASA through Hubble Fellowship grant #HST-HF2-51382.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. This research made use of NASA's Astrophysics Data System. R.J.F. is supported in part by NSF grant AST-1518052, the Gordon & Betty Moore Foundation, and by a fellowship from the David and Lucile Packard Foundation. Software: MESA, py_mesa_reader, numpy, scipy, matplotlib.

Attached Files

Submitted - 1812.08793.pdf

Published - Zhang_2019_ApJ_872_29.pdf


Files (2.9 MB)
Name Size Download all
1.6 MB Preview Download
1.2 MB Preview Download

Additional details

August 19, 2023
August 19, 2023