Near-Critical Gravitational Collapse and the Initial Mass Function of Primordial Black Holes

ABSTRACT We show that it is not possible to determine the final mass Mfin of a red supergiant (RSG) at the pre-supernova (SN) stage from its luminosity L and effective temperature Teff alone. Using a grid of stellar models, we demonstrate that for a given value of L and Teff, an RSG can have a range of Mfin as wide as 3 to 45 M⊙. While the probability distribution within these limits is not flat, any individual determination of Mfin for an RSG will be degenerate. This makes it difficult to determine its evolutionary history and to map Mfin to an initial mass. Single stars produce a narrower range that is difficult to accurately determine without making strong assumptions about mass-loss, convection, and rotation. Binaries would produce a wider range of RSG Mfin. However, the final Helium core mass $M_{\operatorname{He-core}}$ is well determined by the final luminosity and we find $\log (M_{\operatorname{He-core}}/\mathrm{M}_{\odot }) = 0.659 \log (L/\mathrm{L}_{\odot }) -2.630$. Using this relationship, we derive $M_{\operatorname{He-core}}$ for directly imaged SN progenitors and one failed SN candidate. The value of Mfin for stripped star progenitors of SNe IIb is better constrained by L and Teff due to the dependence of Teff on the envelope mass Menv for Menv ≲ 1 M⊙. Given the initial mass function, our results apply to the majority of progenitors of core-collapse SNe, failed SNe, and direct-collapse black holes.

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Planck stars

International Journal of Modern Physics D ◽

10.1142/s0218271814420267 ◽

2014 ◽

Vol 23 (12) ◽

pp. 1442026 ◽

Cited By ~ 116

Author(s):

Carlo Rovelli ◽

Francesca Vidotto

Keyword(s):

Black Holes ◽

Quantum Gravity ◽

Gravitational Collapse ◽

Proper Time ◽

Time Dilation ◽

Initial Mass ◽

Primordial Black Holes ◽

Planck Mass ◽

Gravity Effects

Quantum-gravitational pressure can stop gravitational collapse and cause a bounce. We observe that: (i) due to the huge time dilation, the process can last micro-seconds in local proper time and billions of years observed from the outside; (ii) the bounce volume can be much larger than planckian, because the onset of quantum-gravity effects is governed by density, not size; (iii) the emerging object can then be bigger than planckian by a factor (m/mP)n, where m is the initial mass, mP is the Planck mass, and n positive; (iv) the interior of an evaporating hole can keep memory of the initial mass, providing an independent scale for the physics of the final explosion. If so, primordial black holes could produce a detectable signal of quantum gravitational origin, which we estimate, under some hypotheses, around the wavelength 10-14 cm.

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On the Mass Distribution of Stellar-Mass Black Holes

Open Astronomy ◽

10.1515/astro-2017-0190 ◽

2014 ◽

Vol 23 (3-4) ◽

pp. 267-271

Author(s):

O. Yu. Malkov

Keyword(s):

Black Holes ◽

Black Hole ◽

Mass Distribution ◽

Mass Function ◽

Stellar Mass ◽

Initial Mass Function ◽

Initial Mass ◽

Mass Relation ◽

Massive Star Evolution ◽

Remnant Mass

AbstractThe observational stellar-mass black hole mass distribution exhibits a maximum at about 8 M⊙. It can be explained via the details of the massive star evolution, supernova explosions, or consequent black hole evolution. We propose another explanation, connected with an underestimated influence of the relation between the initial stellar mass and the compact remnant mass. We show that an unimodal observational mass distribution of black holes can be produced by a power-law initial mass function and a monotonic “remnant mass versus initial mass” relation.

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