White Dwarfs in Dwarf Spheroidal Galaxies: A New Class of Compact-Dark-Matter Detectors

TL;DR

This paper proposes that Ca-rich gap transients, a type of faint supernovae, could be caused by dark matter interactions, specifically primordial black holes, inducing explosions in white dwarfs within dwarf spheroidal galaxies.

Contribution

It introduces a novel hypothesis linking dark matter interactions with specific supernovae events in dwarf galaxies, suggesting primordial black holes as potential triggers.

Findings

Ca-rich gap transients are spatially correlated with dwarf spheroidal galaxies.

Dark matter interactions could induce thermonuclear explosions in white dwarfs.

Primordial black holes with masses above 10^{21} grams are plausible candidates.

Abstract

Recent surveys have discovered a population of faint supernovae, known as Ca-rich gap transients, inferred to originate from explosive ignitions of white dwarfs. In addition to their unique spectra and luminosities, these supernovae have an unusual spatial distribution and are predominantly found at large distances from their presumed host galaxies. We show that the locations of Ca-rich gap transients are well matched to the distribution of dwarf spheroidal galaxies surrounding large galaxies, in accordance with a scenario where dark matter interactions induce thermonuclear explosions among low-mass white dwarfs that may be otherwise difficult to ignite with standard stellar or binary evolution mechanisms. A plausible candidate to explain the observed event rate are primordial black holes with masses above $10^{21}$ grams.