Abstract
Recently, Cheng et al. identified a number of massive white dwarfs (WD) that appear to have an additional heat source providing a luminosity near ≈10−3 L☉ for multiple Gyr [S. Cheng, J. D. Cummings, and B. Ménard, Astrophys. J. 886, 100 (2019)]. In this paper we explore heating from electron capture and pycnonuclear reactions. We also explore heating from dark matter annihilation. WD stars appear to be too small to capture enough dark matter for this to be important. Finally, if dark matter condenses to very high densities inside a WD this could ignite nuclear reactions. We calculate the enhanced central density of a WD in the gravitational potential of a very dense dark matter core. While this might start a supernova, it seems unlikely to provide modest heating for a long time. We conclude that electron capture, pycnonuclear, and dark matter reactions are unlikely to provide significant heating in the massive WD that Cheng considers.
| Original language | English |
|---|---|
| Article number | 083031 |
| Journal | Physical Review D |
| Volume | 102 |
| Issue number | 8 |
| DOIs | |
| State | Published - 27 Oct 2020 |
| Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2020 American Physical Society.
Funding
We thank Ed Brown, Matt Caplan, and Brendan Reed for very helpful comments. This work is supported in part by United States Department of Energy Office of Science, Office of Nuclear Physics Grants No. DE-FG02-87ER40365 and No. DE-SC0018083.
| Funders | Funder number |
|---|---|
| Office of Nuclear Physics | DE-SC0018083, DE-FG02-87ER40365 |
| United States Department of Energy Office of Science |