Compact Remnant Mass Function: Dependence on the Explosion Mechanism and Metallicity (1110.1726v1)

Abstract: The mass distribution of neutron stars and stellar-mass black holes provides vital clues into the nature of stellar core collapse and the physical engine responsible for supernova explosions. Using recent advances in our understanding of supernova engines, we derive mass distributions of stellar compact remnants. We provide analytical prescriptions for compact object masses for major population synthesis codes. In an accompanying paper, Belczynski et al., we demonstrate that these qualitatively new results for compact objects can explain the observed gap in the remnant mass distribution between ~2-5 solar masses and that they place strong constraints on the nature of the supernova engine. Here, we show that advanced gravitational radiation detectors (like LIGO/VIRGO or the Einstein Telescope) will be able to further test the supernova explosion engine models once double black hole inspirals are detected.

Insights into Compact Remnant Mass Functions

The paper, "Compact Remnant Mass Function: Dependence on the Explosion Mechanism and Metallicity," addresses pivotal aspects of stellar evolution, particularly focusing on the mass distribution of neutron stars (NSs) and black holes (BHs) formed after core-collapse supernovae. The mass distributions of these compact objects are not only influenced by their progenitor masses but are also directly dependent on the explosion mechanism and the metallicity of the progenitor stars.

The paper presents a detailed exploration into the mass distribution resulting from different supernova explosion mechanisms, namely rapid and delayed explosions. Both mechanisms exhibit distinct energy distributions and resultant compact object mass functions. The rapid mechanism is characterized by prompt explosions post-bounce, resulting in strong supernova energy outputs when successful, whereas the delayed mechanism leans on the SASI-induced convection, often resulting in a more significant spectrum of explosion energies.

Key numerical findings of this investigation include the impact of metallicity on the stellar mass loss and, consequently, the remnant mass. At lower metallicities, stars undergo reduced mass loss, creating more massive BHs. The authors utilized the progenitor models from Woosley et al. to project the remnant mass distributions, highlighting a metal-dependent continuation onto heavier remnants. They also provide detailed analytic prescriptions for determining compact remnants in major population synthesis models.

An intriguing aspect discussed in the paper is the gap in observed BH masses between approximately 2 to 5 M$_\odot$. This research provides theoretical backing for such a gap, notably through the rapid explosion mechanism. This is attributed to the sensitivity of remnant masses to the convection structure and fallback dynamics during star collapse. Therefore, understanding how this mass gap emerges is fundamental to deciphering the underlying physics of core-collapse processes.

The paper meticulously bridges theoretical insights with observational phenomena. It suggests that forthcoming gravitational wave detections could offer further validation and constraints on supernova models, particularly highlighting the detection of BH-BH inspirals by facilities like LIGO/VIRGO and the future Einstein Telescope. The distribution of chirp masses from merging BH systems is particularly compelling, reflecting the underlying explosion mechanism.

In terms of the broader context, the paper implies significant ramifications for stellar evolution and the role of metallicity and explosion dynamics in shaping the compact object landscape. The venture into exploring various explosion mechanisms also enriches the theoretical modeling approaches used in understanding supernova energetics and the consequent remnant feedback.

Overall, the results showcased in this paper serve as a robust framework for both theorists understanding supernova processes and observational astronomers in validating these models through cosmic remnant populations. The collaboration of diverse methodologies and consideration of multiple astrophysical parameters sets a comprehensive standard for future extensions in the field. Further exploration into the intricacies of explosion mechanism variance and their empirical counterparts can shed light on the mysterious complexities of stellar deaths and compact object formation.