Dark Matter Triggers of Supernovae (1505.04444v1)

Abstract: The transit of primordial black holes through a white dwarf causes localized heating around the trajectory of the black hole through dynamical friction. For sufficiently massive black holes, this heat can initiate runaway thermonuclear fusion causing the white dwarf to explode as a supernova. The shape of the observed distribution of white dwarfs with masses up to $1.25 M_{\odot}$ rules out primordial black holes with masses $\sim 10^{19}$ gm - $10^{20}$ gm as a dominant constituent of the local dark matter density. Black holes with masses as large as $10^{24}$ gm will be excluded if recent observations by the NuStar collaboration of a population of white dwarfs near the galactic center are confirmed. Black holes in the mass range $10^{20}$ gm - $10^{22}$ gm are also constrained by the observed supernova rate, though these bounds are subject to astrophysical uncertainties. These bounds can be further strengthened through measurements of white dwarf binaries in gravitational wave observatories. The mechanism proposed in this paper can constrain a variety of other dark matter scenarios such as Q balls, annihilation/collision of large composite states of dark matter and models of dark matter where the accretion of dark matter leads to the formation of compact cores within the star. White dwarfs, with their astronomical lifetimes and sizes, can thus act as large space-time volume detectors enabling a unique probe of the properties of dark matter, especially of dark matter candidates that have low number density. This mechanism also raises the intriguing possibility that a class of supernova may be triggered through rare events induced by dark matter rather than the conventional mechanism of accreting white dwarfs that explode upon reaching the Chandrasekhar mass.

• The paper introduces a theoretical framework showing that primordial black holes transiting white dwarfs can trigger supernova explosions through localized heating.
• The study uses observations of white dwarf populations to constrain PBH mass ranges, particularly ruling out significant dark matter contributions from masses around 10^19 gm to 10^20 gm.
• The analysis implies that PBH-induced events could influence type 1a supernova rates, offering new insights into dark matter properties and stellar evolution.

Dark Matter Triggers of Supernovae: A Novel Approach

The paper "Dark Matter Triggers of Supernovae" by Graham, Rajendran, and Varela presents a compelling theoretical framework that explores the potential role of dark matter, specifically primordial black holes (PBHs), in triggering supernova explosions. This research challenges conventional mechanisms of type 1a supernovae, typically attributed to accreting white dwarfs reaching the Chandrasekhar limit. Instead, it proposes that localized heating induced by PBHs transiting through white dwarfs could cause thermonuclear runaway reactions leading to the explosion of the star, offering unique insights into dark matter properties.

Key Findings

1. Primordial Black Holes as Triggers: The authors demonstrate that the passage of PBHs through white dwarfs can generate sufficient heat through dynamical friction. For PBHs of certain mass ranges (specifically $10^{19}$ gm to $10^{24}$ gm), this heating can initiate runaway fusion reactions within white dwarfs, causing them to explode. Notably, PBHs with masses around $10^{19}$ gm are constrained by existing white dwarf distributions, while heavier PBHs face constraints under high dark matter density conditions near the galactic center.
2. Constraints on PBHs: Observations of heavy white dwarfs, such as RX J0648.0Ð4418, suggest that PBHs in the mass range of $10^{19}$ gm to $10^{20}$ gm cannot be a significant dark matter component. Moreover, if a denser population of white dwarfs near the galactic center is confirmed, heavier PBHs (up to $10^{24}$ gm) could also be ruled out.
3. Impact on Supernova Rates: The paper explores the contribution of PBH-induced supernovae to observed type 1a supernova rates. PBHs with masses between $10^{20}$ gm and $10^{22}$ gm potentially contribute significantly to this rate, although uncertainties in white dwarf population distributions render this exclusion less robust.

Implications and Future Research Directions

• Novel Constraints on Dark Matter Models: By considering interactions between PBHs and white dwarfs, the paper provides novel constraints on dark matter scenarios beyond the typical scope of WIMP and axion studies. This includes models where dark matter particles accumulate in stars to form compact cores, potentially leading to explosions.
• Potential Supernova Classification: The mechanism suggests that some supernovae may result from dark matter interactions rather than traditional stellar processes. This leads to potential correlations between supernova rates and local dark matter densities, indicating a new classification of supernovae.
• Gravitational Wave Observations: The detection of white dwarf binaries in high dark matter density regions, such as the galactic center, through gravitational wave observatories like AGIS or LISA could confirm or refute the proposed constraints, enhancing our understanding of dark matter's role in stellar evolution.
• Further Studies on Dark Matter Accretion: The proposed mechanism invites further investigation into various dark matter scenarios, including Q-balls and composite states of dark matter, which could similarly influence stellar phenomena.

In summary, the research by Graham and colleagues offers a novel perspective on the interplay between dark matter and stellar dynamics, providing both constraints on PBH dark matter models and potential explanations for anomalous supernova observations. Continued investigations in this domain could yield significant advancements in our understanding of both dark matter properties and fundamental astrophysical processes.