scholarly journals NUCLEOSYNTHESIS CONSTRAINTS ON THE NEUTRON STAR-BLACK HOLE MERGER RATE

2014 ◽  
Vol 795 (1) ◽  
pp. L9 ◽  
Author(s):  
A. Bauswein ◽  
R. Ardevol Pulpillo ◽  
H.-T. Janka ◽  
S. Goriely
Keyword(s):  
2017 ◽  
Vol 26 (01n02) ◽  
pp. 1740015 ◽  
Author(s):  
Chang-Hwan Lee

With H. A. Bethe, G. E. Brown worked on the merger rate of neutron star binaries for the gravitational wave detection. Their prediction has to be modified significantly due to the observations of [Formula: see text] neutron stars and the detection of gravitational waves. There still, however, remains a possibility that neutron star-low mass black hole binaries are significant sources of gravitational waves for the ground-based detectors. In this paper, I review the evolution of neutron star binaries with super-Eddington accretion and discuss the future prospect.


2019 ◽  
Vol 490 (4) ◽  
pp. 4991-5001 ◽  
Author(s):  
Giacomo Fragione ◽  
Abraham Loeb

ABSTRACT Observations of black hole–neutron star (BH–NS) mergers via gravitational waves (GWs) are of great interest for their electromagnetic counterparts, such as short gamma-ray bursts, and could provide crucial information on the nature of BHs and the NS crust and magnetosphere. While no event has been confirmed, a recent possible detection of a BH–NS merger event by the LIGO–Virgo collaboration has attracted a lot of attention to these sources. In this second paper of the series, we follow-up our study of the dynamical evolution of triples composed of an inner BH–NS binary. In particular, we examine how the progenitor metallicity affects the characteristics of the BH–NS mergers in triples. We determine the distributions of masses, orbital parameters, and merger times, as a function of the progenitor metallicity and initial triple orbital distributions, and show that the typical eccentricity in the LIGO band is ∼10−2–10−1. We derive a merger rate range of ΓBH–NS = 1.9 × 10−4–22 Gpc−3 yr−1, consistent the LIGO–Virgo upper limit. Finally, we study the expected spin–orbit misalignments of merging BH–NS binaries from this channel, and find that typically the effective spin distribution is peaked at χeff ∼ 0 with significant tails.


2011 ◽  
Vol 742 (1) ◽  
pp. L2 ◽  
Author(s):  
Krzysztof Belczynski ◽  
Tomasz Bulik ◽  
Charles Bailyn

Author(s):  
Filippo Santoliquido ◽  
Michela Mapelli ◽  
Nicola Giacobbo ◽  
Yann Bouffanais ◽  
M Celeste Artale

Abstract We evaluate the redshift distribution of binary black hole (BBH), black hole – neutron star binary (BHNS) and binary neutron star (BNS) mergers, exploring the main sources of uncertainty: star formation rate (SFR) density, metallicity evolution, common envelope, mass transfer via Roche lobe overflow, natal kicks, core-collapse supernova model and initial mass function. Among binary evolution processes, uncertainties on common envelope ejection have a major impact: the local merger rate density of BNSs varies from ∼103 to ∼20 Gpc−3 yr−1 if we change the common envelope efficiency parameter from αCE = 7 to 0.5, while the local merger rates of BBHs and BHNSs vary by a factor of ∼2 − 3. The BBH merger rate changes by one order of magnitude, when 1σ uncertainties on metallicity evolution are taken into account. In contrast, the BNS merger rate is almost insensitive to metallicity. Hence, BNSs are the ideal test bed to put constraints on uncertain binary evolution processes, such as common envelope and natal kicks. Only models assuming values of αCE ≳ 2 and moderately low natal kicks (depending on the ejected mass and the SN mechanism), result in a local BNS merger rate density within the 90% credible interval inferred from the second gravitational-wave transient catalogue.


2021 ◽  
Vol 502 (1) ◽  
pp. L72-L78
Author(s):  
K Mohamed ◽  
E Sonbas ◽  
K S Dhuga ◽  
E Göğüş ◽  
A Tuncer ◽  
...  

ABSTRACT Similar to black hole X-ray binary transients, hysteresis-like state transitions are also seen in some neutron-star X-ray binaries. Using a method based on wavelets and light curves constructed from archival Rossi X-ray Timing Explorer observations, we extract a minimal timescale over the complete range of transitions for 4U 1608-52 during the 2002 and 2007 outbursts and the 1999 and 2000 outbursts for Aql X-1. We present evidence for a strong positive correlation between this minimal timescale and a similar timescale extracted from the corresponding power spectra of these sources.


2021 ◽  
Vol 103 (6) ◽  
Author(s):  
Francois Foucart ◽  
Alexander Chernoglazov ◽  
Michael Boyle ◽  
Tanja Hinderer ◽  
Max Miller ◽  
...  

Physics ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 372-378
Author(s):  
Viktor D. Stasenko ◽  
Alexander A. Kirillov

In this paper, the merger rate of black holes in a cluster of primordial black holes (PBHs) is investigated. The clusters have characteristics close to those of typical globular star clusters. A cluster that has a wide mass spectrum ranging from 10−2 to 10M⊙ (Solar mass) and contains a massive central black hole of the mass M•=103M⊙ is considered. It is shown that in the process of the evolution of cluster, the merger rate changed significantly, and by now, the PBH clusters have passed the stage of active merging of the black holes inside them.


Author(s):  
R Pattnaik ◽  
K Sharma ◽  
K Alabarta ◽  
D Altamirano ◽  
M Chakraborty ◽  
...  

Abstract Low Mass X-ray binaries (LMXBs) are binary systems where one of the components is either a black hole or a neutron star and the other is a less massive star. It is challenging to unambiguously determine whether a LMXB hosts a black hole or a neutron star. In the last few decades, multiple observational works have tried, with different levels of success, to address this problem. In this paper, we explore the use of machine learning to tackle this observational challenge. We train a random forest classifier to identify the type of compact object using the energy spectrum in the energy range 5-25 keV obtained from the Rossi X-ray Timing Explorer archive. We report an average accuracy of 87±13% in classifying the spectra of LMXB sources. We further use the trained model for predicting the classes for LMXB systems with unknown or ambiguous classification. With the ever-increasing volume of astronomical data in the X-ray domain from present and upcoming missions (e.g., SWIFT, XMM-Newton, XARM, ATHENA, NICER), such methods can be extremely useful for faster and robust classification of X-ray sources and can also be deployed as part of the data reduction pipeline.


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