A5032450649- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Geophysics and Gravity Measurements
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- High-pressure geophysics and materials
- Geophysics and Sensor Technology
- Astrophysics and Cosmic Phenomena
- Seismic Waves and Analysis
- Radio Astronomy Observations and Technology
- Advanced Frequency and Time Standards
- Atomic and Subatomic Physics Research
- Astronomical Observations and Instrumentation
- Stellar, planetary, and galactic studies
- Statistical and numerical algorithms
- Cold Atom Physics and Bose-Einstein Condensates
- Superconducting Materials and Applications
- Magnetic confinement fusion research
- Computational Physics and Python Applications
- Black Holes and Theoretical Physics
- Seismology and Earthquake Studies
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Inertial Sensor and Navigation
- Dark Matter and Cosmic Phenomena
Polish Academy of Sciences
2000-2024
University of Warsaw
2010-2024
Astronomical Observatory
2010-2024
Nicolaus Copernicus Astronomical Center
2003-2024
HUN-REN Institute for Nuclear Research
2024
HUN-REN Wigner Research Centre for Physics
2024
Istituto Nazionale di Fisica Nucleare, Sezione di Napoli
2023
University of Zielona Góra
2012-2021
European Gravitational Observatory
2019
Institute of Astronomy
2009-2016
Abstract In this first of a series papers, we utilize results for around 2000 star cluster models simulated using the mocca code evolution (Survey Database I) to determine astrophysical properties and local merger rate densities coalescing binary black holes (BBHs) originating from globular clusters (GCs). We extracted information all BBHs that escape subsequently merge within Hubble time along with are retained in our GC inside via gravitational wave emission. By obtaining substantial...
We performed a detailed analysis of the detectability wide range gravitational waves derived from core-collapse supernova simulations using gravitational-wave detector noise scaled to sensitivity upcoming fourth and fifth observing runs Advanced LIGO, Virgo, KAGRA. use coherent WaveBurst algorithm, which was used in previous search for supernovae. As makes minimal assumptions on morphology signal, it can play an important role first detection event Milky Way. predict that signals...
We present the results from a search for gravitational-wave transients associated with core-collapse supernovae observed optically within 30 Mpc during third observing run of Advanced LIGO and Virgo. No gravitational wave supernova has been identified. then report detection efficiency variety possible emissions. For neutrino-driven explosions, distance at which we reach 50% is up to 8.9 kpc, while more energetic magnetorotationally driven explosions are detectable larger distances. The...
A highly accurate, multidomain spectral code is used in order to construct sequences of general relativistic, differentially rotating neutron stars axisymmetry and stationarity. For bodies with a spheroidal topology homogeneous or an N= 1 polytropic equation state, we investigate the solution space corresponding broad ranges degree differential rotation stellar densities. In particular, starting from static spherical configurations, analyse changes surface shapes as rate increased....
Using the StarTrack binary population synthesis code we model of double neutron stars in Galaxy. We include a detailed treatment spin evolution each pulsar due to processes such as spin-down and spin-up during accretion events well magnetic field decay. also spatial distribution by including their natal kicks subsequent propagation Galactic gravitational potential. This synthetic is compared observed sample taking into account selection effects detection radio band, determine most likely...
Abstract We study the main astrophysical properties of differentially rotating neutron stars described as stationary and axisymmetric configurations a moderately stiff <?CDATA ${\rm{\Gamma }}=2$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi mathvariant="normal">Γ</mml:mi> <mml:mo>=</mml:mo> <mml:mn>2</mml:mn> </mml:math> polytropic fluid. The high level accuracy stability our relativistic multidomain pseudo-spectral code enables us to explore whole...
Knowing the value of maximum mass a differentially rotating relativistic star is key step towards understanding signals to be expected from merger binary neutron stars, one most awaited alternative sources gravitational waves after black holes. In this paper, we study effects differential rotation and equation state on stars modelled as polytropes with various adiabatic indices. Calculations are performed using highly accurate numerical code, based multidomain spectral method. We thoroughly...
ABSTRACT In this work, we investigate properties of intermediate-mass black holes (IMBHs) that escape from star clusters due to dynamical interactions. The studied models were simulated as part the preliminary second survey carried out using MOCCA code (MOCCA-SURVEY Database II), which is based on Monte Carlo N-body method and does not include gravitational wave recoil kick prescriptions binary hole merger product. We have found IMBHs are more likely be formed ejected in where both initial...
We present calculations of quasi-equilibrium sequences irrotational binary neutron stars based on realistic equations state (EOS) for the whole star interior. Three nuclear EOSs various softness and different microscopic models have been joined with a recent EOS crust, giving in this way three neutron-star Computations are performed within Isenberg-Wilson-Mathews approximation to general relativity. For all evolutionary sequences, innermost stable circular orbit (ISCO) is found be given by...
The current gravitational wave detectors have reached their operational sensitivity and are nearing detection of compact object binaries. In the coming years, we expect that Advanced LIGO/VIRGO will start taking data. At same time, there plans for third generation ground-based such as Einstein Telescope, space DECIGO. We discuss eccentricity distribution inspiral binaries during they phase. analyze expected distributions eccentricities at three frequencies characteristic future detectors:...
We present analytical formulae for the orbital and epicyclic frequencies in orbits around Maclaurin spheroids Newtonian gravity. The Laplace equation gravitational potential implies that frequency squared is arithmetic mean of squares frequencies, |$\omega _r^2 + \omega _z^2 = 2\Omega _{\rm o}^2$|. radial has a maximum at radius |$r=\sqrt{2}ae$| spheroid ellipticities |$e>1/\sqrt{2}$|, while e 0.834 583 18 it vanishes stellar equator (at r a). For still larger innermost stable circular...
We present the first relativistic calculations of final phase inspiral a binary system consisting two stars built predominantely strange quark matter (strange stars). study precoalescing stage within Isenberg-Wilson-Mathews approximation general relativity using multidomain spectral method. A hydrodynamical treatment is performed under assumption that flow either rigidly rotating or irrotational, taking into account finite density at stellar surface -- distinctive feature with respect to...
Kilohertz quasi periodic oscillations (QPOs) can be used as a probe of the inner regions accretion disks in compact stars and hence also properties central object. Most models kHz QPOs involve epicyclic frequencies to explain their origin. We compute nearly circular orbits around rotating strange quark stars. The MIT bag model is equation state matter, uniformly stellar configurations are computed full general relativity. vertical frequency related nodal precession rate inclined very...
We show that in the limit of low masses (M<0.1M solar), orbital and rotational frequencies exact relativistic numerical models rotating, axially symmetric, quark stars coincide with those for Maclaurin spheroids. In particular, when eccentricity spheroid exceeds a critical value (e>0.83458318), circular orbits equatorial plane are unstable range radii outside stellar surface. The frequency marginally stable orbit, all other orbits, around spheroids goes to zero e=1. Maximum accreting...
We perform some numerical study of the secular triaxial instability rigidly rotating homogeneous fluid bodies in general relativity. In Newtonian limit, this arises at bifurcation point between Maclaurin and Jacobi sequences. It can be driven astrophysical systems by viscous dissipation. locate onset along several constant baryon mass sequences uniformly axisymmetric for compaction parameter $M/R = 0-0.275$. find that relativity weakens like bar mode instability, but stabilizing effect is...
We study the viscosity driven bar mode (Jacobi-like) instability of rapidly rotating quark matter stars (strange stars) in general relativity. A triaxial, "bar shaped" compact star could be an efficient source continuous wave gravitational radiation frequency range forthcoming interferometric detectors. locate secular point along several constant baryon mass sequences uniformly strange described by MIT bag model. Contrary to neutron stars, with (the ratio rotational kinetic energy absolute...
We present calculations of the final phase inspiral irrotational strange star binaries. Two types equation state at zero temperature are used - MIT bag model and Dey et al. 1998 quark matter. study precoalescence stage within Isenberg-Wilson-Mathews approximation General Relativity using a multidomain spectral method. The gravitational-radiation driven evolution binary system is approximated by sequence quasi-equilibrium configurations fixed baryon number with decreasing separation. find...
Abstract Summary of the long term data taking, related to one proposed next generation ground-based gravitational detector’s location is presented here. Results seismic and infrasound noise, electromagnetic attenuation cosmic muon radiation measurements are reported in underground Matra Gravitational Geophysical Laboratory near Gyöngyösoroszi, Hungary. The collected more than two years evaluated from point view Einstein Telescope, a third wave observatory. Applying our results for site...
We present the results from a search for gravitational-wave transients associated with core-collapse supernovae observed optically within 30 Mpc during third observing run of Advanced LIGO and Virgo. No gravitational wave supernova has been identified. then report detection efficiency variety possible emissions. For neutrino-driven explosions, distance at which we reach 50% is up to 8.9 kpc, while more energetic magnetorotationally-driven explosions are detectable larger distances. The...
We present our study of stability differentially rotating, axisymmetric neutron stars described by a polytropic equation state with Γ = 2.We focus on quasi-toroidal solutions degree differential rotation A 1.Our results show that for wide range parameters hypermassive, are dynamically stable against quasi-radial perturbations, which may have implications newly born and binary mergers.
Accretion powered pulsars exhibit a variety of lightcurves. In this paper we propose to classify the observed lightcurves as single or double pulsed. We analyze 89 accretion and assign them these classes. present three datasets: first in which classification can be easily done, second for is more difficult not certain, third were unable pulsar because lack published data. simple model angles between magnetic rotation axis β, line sight θ are random, show that it inconsistent with also angle...