The mass spectrum of compact remnants from the parsec stellar evolution tracks

Abstract

The mass spectrum of stellar-mass black holes (BHs) is highly uncertain. Dynamical mass measurements are available only for few (∼ 10) BHs in X-ray binaries, while theoretical models strongly depend on the hydrodynamics of supernova (SN) explosions and on the evolution of massive stars. In this paper, we present and discuss the mass spectrum of compact remnants that we obtained with SEVN, a new public populationsynthesis code, which couples the PARSEC stellar evolution tracks with up-to-date recipes for SN explosion (depending on the Carbon-Oxygen mass of the progenitor, on the compactness of the stellar core at pre-SN stage, and on a recent two-parameter criterion based on the dimensionless entropy per nucleon at pre-SN stage). SEVN can be used both as a stand-alone code and in combination with direct-summation N-body codes (Starlab, HiGPUs). The PARSEC stellar evolution tracks currently implemented in SEVN predict significantly larger values of the Carbon-Oxygen core mass with respect to previous models. For most of the SN recipes we adopt, this implies substantially larger BH masses at low metallicity ( 2 × 10 −3 ), than other populationsynthesis codes. The maximum BH mass found with SEVN is ∼ 25, 60 and 130 M at metallicity Z = 2 × 10 −2 , 2 × 10 −3 and 2 × 10 −4 , respectively. Mass loss by stellar winds plays a major role in determining the mass of BHs for very massive stars ( 90 M ), while the remnant mass spectrum depends mostly on the adopted SN recipe for lower progenitor masses. We discuss the implications of our results for the transition between NS and BH mass, and for the expected number of massive BHs (with mass > 25 M ) as a function of metallicity.

Supernovae from Massive Stars

“…This result is in agreement with other studies, like, e.g. [53]. On the contrary, models with initial masses lower than ∼ 60 M ⊙ , at all metallicities, can easily produce black holes with the typical masses associated to GW151226.…”

Dissipative Evolution of Unequal-mass Binary–single Interactions and Its Relevance to Gravitational-wave Detections

“…We speculate that this could represent the dynamical environment of an early collapse associated with the formation of a dense stellar system, such as a GC (e.g. Mapelli et al 2013;Mapelli & Zampieri 2014;Ziosi et al 2014;Spera et al 2015;Kimpson et al 2016). For this scenario we study the cumulative number of BBH mergers forming through the GW inspiral channel, N Iij , relative to that of the post-interaction binary merger channel, N Mij , as a function of time τ = t − t 0 .…”

Blossoms from black hole seeds: properties and early growth regulated by supernova feedback

“…They found that they shed most of their mass via winds and are expected to end their lives as BHs less massive than ∼ 150 M . At low metallicity, instead, mass loss due to winds is much reduced, thus increasing the mass of the final remnant (Heger et al 2003;Vink 2008;Mapelli, Colpi & Zampieri 2009;Belczynski et al 2010;Mapelli et al 2013;Spera, Mapelli & Bressan 2015). A BH seed of 10 3 M can be formed in this "nuclear cluster" scenario (Omukai, Schneider & Haiman 2008;Devecchi & Volonteri 2009;Regan & Haehnelt 2009;Katz, Sijacki & Haehnelt 2015).…”