scholarly journals A Detailed Analysis of GW190521 with Phenomenological Waveform Models

2022 ◽  
Vol 924 (2) ◽  
pp. 79
Author(s):  
Héctor Estellés ◽  
Sascha Husa ◽  
Marta Colleoni ◽  
Maite Mateu-Lucena ◽  
Maria de Lluc Planas ◽  
...  
Keyword(s):  
Statistical Significance ◽  
Domain Model ◽  
High Mass ◽  
Fourth Generation ◽  
Fast Time ◽  
Mass Ratio ◽  
Intermediate Mass ◽  
Binary Black Hole ◽  
The Family ◽  
Wave Event

Abstract In this paper we present an extensive analysis of the GW190521 gravitational wave event with the current (fourth) generation of phenomenological waveform models for binary black hole coalescences. GW190521 stands out from other events since only a few wave cycles are observable. This leads to a number of challenges, one being that such short signals are prone to not resolving approximate waveform degeneracies, which may result in multimodal posterior distributions. The family of waveform models we use includes a new fast time-domain model (IMRPhenomTPHM), which allows us to extensively test different priors and robustness with respect to variations in the waveform model, including the content of spherical harmonic modes. We clarify some issues raised in a recent paper, Nitz & Capano, associated with possible support for a high-mass-ratio source, but confirm their finding of a multimodal posterior distribution, albeit with important differences in the statistical significance of the peaks. In particular, we find that the support for both masses being outside the pair instability supernova mass gap, and the support for an intermediate-mass-ratio binary are drastically reduced with respect to what Nitz & Capano found. We also provide updated probabilities for associating GW190521 to the potential electromagnetic counterpart from the Zwicky Transient Facility (ZTF) Graham et al.

A ROBUST TEST OF GENERAL RELATIVITY IN SPACE

2007 ◽  
Vol 16 (12a) ◽  
pp. 2319-2324 ◽  
Author(s):  
JAMES GRABER
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Quadrupole Moment ◽  
Binary Systems ◽  
High Mass ◽  
Uniqueness Theorems ◽  
Mass Ratio ◽  
Intermediate Mass ◽  
Robust Test

LISA may make it possible to test the black-hole uniqueness theorems of general relativity, also called the no-hair theorems, by Ryan's method of detecting the quadrupole moment of a black hole using high-mass-ratio inspirals. This test can be performed more robustly by observing inspirals in earlier stages, where the simplifications used in making inspiral predictions by the perturbative and post-Newtonian methods are more nearly correct. Current concepts for future missions such as DECIGO and BBO would allow even more stringent tests by this same method. Recently discovered evidence supports the existence of intermediate-mass black holes (IMBHs). Inspirals of binary systems with one IMBH and one stellar-mass black hole would fall into the frequency band of proposed maximum sensitivity for DECIGO and BBO. This would enable us to perform the Ryan test more precisely and more robustly. We explain why tests based on observations earlier in the inspiral are more robust and provide preliminary estimates of possible optimal future observations.

scholarly journals Massively Parallel Simulations of Binary Black Hole Intermediate-Mass-Ratio Inspirals

2019 ◽  
Vol 41 (2) ◽  
pp. C97-C138 ◽  
Author(s):  
Milinda Fernando ◽  
David Neilsen ◽  
Hyun Lim ◽  
Eric Hirschmann ◽  
Hari Sundar
Keyword(s):  
Black Hole ◽  
Massively Parallel ◽  
Mass Ratio ◽  
Intermediate Mass ◽  
Parallel Simulations ◽  
Binary Black Hole

scholarly journals Hunting for intermediate-mass black holes in globular clusters: an astrometric study of NGC 6441

2021 ◽  
Vol 503 (1) ◽  
pp. 1490-1506
Author(s):  
Maximilian Häberle ◽  
Mattia Libralato ◽  
Andrea Bellini ◽  
Laura L Watkins ◽  
Jörg-Uwe Pott ◽  
...  
Keyword(s):  
Globular Clusters ◽  
Velocity Dispersion ◽  
Angular Resolution ◽  
Hubble Space Telescope ◽  
High Mass ◽  
High Angular Resolution ◽  
Stellar Kinematics ◽  
Intermediate Mass ◽  
The Core ◽  
Large Telescopes

ABSTRACT We present an astrometric study of the proper motions (PMs) in the core of the globular cluster NGC 6441. The core of this cluster has a high density and observations with current instrumentation are very challenging. We combine ground-based, high-angular-resolution NACO@VLT images with Hubble Space Telescope ACS/HRC data and measure PMs with a temporal baseline of 15 yr for about 1400 stars in the centremost 15 arcsec of the cluster. We reach a PM precision of ∼30 µas yr−1 for bright, well-measured stars. Our results for the velocity dispersion are in good agreement with other studies and extend already existing analyses of the stellar kinematics of NGC 6441 to its centremost region never probed before. In the innermost arcsecond of the cluster, we measure a velocity dispersion of (19.1 ± 2.0) km s−1 for evolved stars. Because of its high mass, NGC 6441 is a promising candidate for harbouring an intermediate-mass black hole (IMBH). We combine our measurements with additional data from the literature and compute dynamical models of the cluster. We find an upper limit of $M_{\rm IMBH} \lt 1.32 \times 10^4\, \textrm{M}_\odot$ but we can neither confirm nor rule out its presence. We also refine the dynamical distance of the cluster to $12.74^{+0.16}_{-0.15}$ kpc. Although the hunt for an IMBH in NGC 6441 is not yet concluded, our results show how future observations with extremely large telescopes will benefit from the long temporal baseline offered by existing high-angular-resolution data.

scholarly journals Dark Matter: An Efficient Catalyst for Intermediate-mass-ratio-inspiral Events

2019 ◽  
Vol 874 (1) ◽  
pp. 34 ◽  
Author(s):  
Xiao-Jun Yue ◽  
Wen-Biao Han ◽  
Xian Chen
Keyword(s):  
Dark Matter ◽  
Mass Ratio ◽  
Intermediate Mass ◽  
Efficient Catalyst

scholarly journals Probing gas disc physics with LISA: simulations of an intermediate mass ratio inspiral in an accretion disc

2019 ◽  
Vol 486 (2) ◽  
pp. 2754-2765 ◽  
Author(s):  
A M Derdzinski ◽  
D D’Orazio ◽  
P Duffell ◽  
Z Haiman ◽  
A MacFadyen
Keyword(s):  
Small Deviation ◽  
Compact Object ◽  
Accretion Disc ◽  
Mass Ratio ◽  
Intermediate Mass ◽  
Laser Interferometer Space Antenna ◽  
Total Phase ◽  
Accretion Rates ◽  
Hydrodynamical Simulations ◽  
And Migration

Abstract The coalescence of a compact object with a $10^{4}\hbox{--}10^{7}\, {\rm M_\odot }$ supermassive black hole (SMBH) produces mHz gravitational waves (GWs) detectable by the future Laser Interferometer Space Antenna (LISA). If such an inspiral occurs in the accretion disc of an active galactic nucleus (AGN), the gas torques imprint a small deviation in the GW waveform. Here, we present two-dimensional hydrodynamical simulations with the moving-mesh code disco of a BH inspiraling at the GW rate in a binary system with a mass ratio q = M2/M1 = 10−3, embedded in an accretion disc. We assume a locally isothermal equation of state for the gas (with Mach number $\mathcal {M}=20$) and implement a standard α-prescription for its viscosity (with α = 0.03). We find disc torques on the binary that are weaker than in previous semi-analytic toy models, and are in the opposite direction: the gas disc slows down, rather than speeds up the inspiral. We compute the resulting deviations in the GW waveform, which scale linearly with the mass of the disc. The SNR of these deviations accumulates mostly at high frequencies, and becomes detectable in a 5 yr LISA observation if the total phase shift exceeds a few radians. We find that this occurs if the disc surface density exceeds $\Sigma _0 \gtrsim 10^{2-3}\rm g\, cm^{-2}$, as may be the case in thin discs with near-Eddington accretion rates. Since the characteristic imprint on the GW signal is strongly dependent on disc parameters, a LISA detection of an intermediate mass ratio inspiral would probe the physics of AGN discs and migration.

The Numerical Simulation of Two-Degrees-of-Freedom Vortex-Induced Vibrations of Circular Cylinder with High Mass-Ratio

2013 ◽  
Vol 284-287 ◽  
pp. 557-561
Author(s):  
Jie Li Fan ◽  
Wei Ping Huang
Keyword(s):  
Circular Cylinder ◽  
Drag Force ◽  
Frequency Ratio ◽  
Lift Force ◽  
Degrees Of Freedom ◽  
Cross Flow ◽  
High Mass ◽  
Mass Ratio ◽  
Main Frequency ◽  
Line Amplitude

The two-degrees-of-freedom VIV of the circular cylinder with high mass-ratio is numerically simulated with the software ANSYS/CFX. The VIV characteristic is analyzed in the different conditions (Ur=3, 5, 6, 8, 10). When Ur is 5, 6, 8 and 10, the conclusion which is different from the cylinder with low mass-ratio can be obtained. When Ur is 3, the frequency of in-line VIV is twice of that of cross-flow VIV which is equal to the frequency ratio between drag force and lift force, and the in-line amplitude is much smaller than the cross-flow amplitude. The motion trace is the crescent. When Ur is 5 and 6, the frequency ratio between the drag force and lift force is still 2, but the main frequency of in-line VIV is mainly the same as that of cross-flow VIV and the secondary frequency of in-line VIV is equal to the frequency of the drag force. The in-line amplitude is still very small compared with the cross-flow amplitude. When Ur is up to 8 and 10, the frequency of in-line VIV is the same as the main frequency of cross-flow VIV which is close to the inherent frequency of the cylinder and is different from the frequency of drag force or lift force. But the secondary frequency of cross-flow VIV is equal to the frequency of the lift force. The amplitude ratio of the VIV between in-line and cross-flow direction is about 0.5. When Ur is 5, 6, 8 and 10, the motion trace is mainly the oval.

scholarly journals Prospects for Detection of Gravitational Waves from Intermediate-Mass-Ratio Inspirals

2007 ◽  
Vol 99 (20) ◽  
Author(s):  
Duncan A. Brown ◽  
Jeandrew Brink ◽  
Hua Fang ◽  
Jonathan R. Gair ◽  
Chao Li ◽  
...  
Keyword(s):  
Gravitational Waves ◽  
Mass Ratio ◽  
Intermediate Mass

scholarly journals Maciej Ziemierski, Testamenty krakowskiej rodziny Królików z XVII w.

2020 ◽  
Vol 26 ◽  
pp. 11-41
Author(s):  
Maciej Ziemierski
Keyword(s):  
18Th Century ◽  
Family Members ◽  
17Th Century ◽  
16Th Century ◽  
Fourth Generation ◽  
Third Generation ◽  
The Third ◽  
The Family ◽  
The Town ◽  
Distinguished Member

17th century testaments of the Królik family from Krakow The article is dedicated to the Królik family from Krakow, who lived in the town from the late 16th century until the first years of the 18th century. The family members initially worked as tailors, later reinforcing the group of Krakow merchants in the third generation (Maciej Królik). Wojciech Królik – from the fourth generation – was a miner in Olkusz. The text omits the most distinguished member of the family, Wojciech’s oldest brother, the Krakow councillor Mikołaj Królik, whose figure has been covered in a separate work. The work shows the complicated religious relations in the family of non-Catholics, initially highly engaged in the life of the Krakow Congregation, but whose members gradually converted from Evangelism to Catholicism. As a result, Wojciech Królik and his siblings became Catholics. This work is complemented by four testaments of family members, with the first, Jakub Królik’s, being written in 1626 and the last one, Wojciech Królik’s, written in 1691.

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