scholarly journals How can LISA probe a population of GW190425-like binary neutron stars in the Milky Way?

2021 ◽  
Author(s):  
Valeriya Korol ◽  
Mohammadtaher Safarzadeh
Keyword(s):  
Mass Distribution ◽  
Total Mass ◽  
Scientific Collaboration ◽  
Milky Way ◽  
Binary Neutron Star ◽  
Laser Interferometer Space Antenna ◽  
Orbital Periods ◽  
Merger Rate ◽  
Prime Target ◽  
Better Than

Abstract The nature of GW190425, a presumed binary neutron star (BNS) merger detected by the LIGO/Virgo Scientific Collaboration (LVC) with a total mass of $3.4^{+0.3}_{-0.1}$ M⊙, remains a mystery. With such a large total mass, GW190425 stands at five standard deviations away from the total mass distribution of Galactic BNSs of 2.66 ± 0.12 M⊙. LVC suggested that this system could be a BNS formed from a fast-merging channel rendering its non-detection at radio wavelengths due to selection effects. BNSs with orbital periods less than a few hours – progenitors of LIGO/Virgo mergers – are prime target candidates for the future Laser Interferometer Space Antenna (LISA). If GW190425-like binaries exist in the Milky Way, LISA will detect them within the volume of our Galaxy and will measure their chirp masses to better than 10 per cent for those binaries with gravitational wave frequencies larger than 2 mHz. This work explores how we can probe a population of Galactic GW190425-like BNSs with LISA and investigate their origin. We assume that the Milky Way’s BNS population consists of two distinct sub-populations: a fraction w1 that follows the observed Galactic BNS chirp mass distribution and w2 that resembles chirp mass of GW190425. We show that LISA’s accuracy on recovering the fraction of GW190425-like binaries depends on the BNS merger rate. For the merger rates reported in the literature, 21 − 212 Myr−1, the error on the recovered fractions varies between ∼30 − 5 per cent.

scholarly journals The Mass Distribution of the Milky Way Deduced from Globular Cluster Dynamics

1996 ◽  
Vol 169 ◽  
pp. 697-702 ◽  
Author(s):  
B. Dauphole ◽  
J. Colin ◽  
M. Geffert ◽  
M. Odenkirchen ◽  
H.-J. Tucholke
Keyword(s):  
Spatial Distribution ◽  
Mass Distribution ◽  
Globular Cluster ◽  
Total Mass ◽  
Globular Clusters ◽  
Large Scale ◽  
Milky Way ◽  
Proper Motions ◽  
Orbital Parameters ◽  
Galactic Potential

We present here a new analytical Galactic potential. We used the constraint of galactic globular cluster dynamics compared to their spatial distribution. This was done with the help of the globular clusters' proper motions. The result for the clusters dynamics show a better agreement between orbital parameters and statistical distribution of the studied globular clusters than in previous published potentials. The globular cluster dynamics constrain the mass distribution on a large scale, until 40 kpc from the centre. In this model, the total mass for the Milky Way is 7.9 1011 M⊙.

scholarly journals Finding binary black holes in the Milky Way with LISA

2020 ◽  
Vol 494 (1) ◽  
pp. L75-L80 ◽  
Author(s):  
Alberto Sesana ◽  
Astrid Lamberts ◽  
Antoine Petiteau
Keyword(s):  
White Dwarf ◽  
Milky Way ◽  
Laser Interferometer ◽  
Mass Measurement ◽  
Binary Black Holes ◽  
Binary Black Hole ◽  
Laser Interferometer Space Antenna ◽  
Wave Emission ◽  
Binary Evolution ◽  
Merger Rate

ABSTRACT We determine the main properties of the Galactic binary black hole (BBH) population detectable by Laser Interferometer Space Antenna (LISA) and strategies to distinguish them from the much more numerous white dwarf binaries. We simulate BBH populations based on cosmological simulations of Milky Way-like galaxies and binary evolution models. We then determine their gravitational wave emission as observed by LISA and build mock catalogues. According to our model, LISA will detect ≈4 (6) BBHs assuming 4 (10) yr of operations. Those figures grow to ≈6 (9) when models are re-normalized to the inferred LIGO/Virgo merger rates. Largely independent on mass and distance, sources emitting at f > 0.5 mHz – 40 per cent (70 per  cent) of the detections – have a measurable frequency drift, which allows a good enough chirp mass measurement to separate them from the much lighter white dwarf and neutron star binaries. Most of the remaining, lower frequency, sources should be identifiable by their lack of electromagnetic (EM) counterpart within ≈100 pc. These results are robust with respect to the current uncertainties of the BBH merger rate as measured by LIGO/Virgo as well as the global mass spectrum of the binaries. Based on the LIGO/Virgo merger rate, we determine that there is a 94 per  cent chance that LISA finds at least one of these systems within 4 yr, which will allow us to pinpoint the conditions where they were formed and possibly find unique EM signatures.

scholarly journals On the formation of GW190814

2020 ◽  
Vol 500 (2) ◽  
pp. 1817-1832
Author(s):  
Wenbin Lu ◽  
Paz Beniamini ◽  
Clément Bonnerot
Keyword(s):  
Stellar Evolution ◽  
Total Mass ◽  
High Probability ◽  
Milky Way ◽  
Semimajor Axis ◽  
Triple Systems ◽  
Binary Neutron Star ◽  
Mass Gap ◽  
Low Metallicity ◽  
The Universe

ABSTRACT The LIGO–Virgo collaboration recently reported a puzzling event, GW190814, with component masses of 23 and 2.6 M⊙. Motivated by the relatively small rate of such a coalescence (1–$23\rm \, Gpc^{-3}\, yr^{-1}$) and the fact that the mass of the secondary is close to the total mass of known binary neutron star (bNS) systems, we propose that GW190814 was a second-generation merger from a hierarchical triple system; i.e. the remnant from the bNS coalescence was able to merge again with the 23 M⊙ black hole (BH) tertiary. We show that this occurs at a sufficiently high probability provided that the semimajor axis of the outer orbit is less than a few au at the time of bNS coalescence. It remains to be explored whether the conditions for the formation of such tight triple systems are commonly realized in the Universe, especially in low-metallicity (≲0.1 Z⊙) environments. Our model provides a number of predictions. (1) The spin of the secondary in GW190814-like systems is 0.6–0.7. (2) The component mass distribution from a large sample of LIGO sources should have a narrow peak between 2.5 and ∼3.5 M⊙, whereas the range between ∼3.5 and ∼5 M⊙ stays empty (provided that stellar evolution does not generate such BHs in the ‘mass gap’). (3) About 90 per cent (10 per cent) of GW190814-like events have an eccentricity of e ≳ 2 × 10−3 (≳0.1) near gravitational wave frequency of $10\,$ mHz. (4) A significant fraction (${\gtrsim}10\, \rm {per\, cent}$) of bNS mergers should have signatures of a massive tertiary at a distance of a few au in the gravitational waveform. (5) There are 105 undetected radio-quiet bNS systems with a massive BH tertiary in the Milky Way.

scholarly journals THE MASS DISTRIBUTION AND ASSEMBLY OF THE MILKY WAY FROM THE PROPERTIES OF THE MAGELLANIC CLOUDS

2011 ◽  
Vol 743 (1) ◽  
pp. 40 ◽  
Author(s):  
Michael T. Busha ◽  
Philip J. Marshall ◽  
Risa H. Wechsler ◽  
Anatoly Klypin ◽  
Joel Primack
Keyword(s):  
Mass Distribution ◽  
Milky Way ◽  
Magellanic Clouds

scholarly journals Mass determination of the 1:3:5 near-resonant planets transiting GJ 9827 (K2-135)

2018 ◽  
Vol 618 ◽  
pp. A116 ◽  
Author(s):  
J. Prieto-Arranz ◽  
E. Palle ◽  
D. Gandolfi ◽  
O. Barragán ◽  
E. W. Guenther ◽  
...  
Keyword(s):  
Planetary System ◽  
Initial Conditions ◽  
Dynamical Evolution ◽  
Space Mission ◽  
Mass Determination ◽  
Velocity Measurements ◽  
Orbital Periods ◽  
The Masses ◽  
Better Than

Context. Multiplanet systems are excellent laboratories to test planet formation models as all planets are formed under the same initial conditions. In this context, systems transiting bright stars can play a key role, since planetary masses, radii, and bulk densities can be measured. Aims. GJ 9827 (K2-135) has recently been found to host a tightly packed system consisting of three transiting small planets whose orbital periods of 1.2, 3.6, and 6.2 days are near the 1:3:5 ratio. GJ 9827 hosts the nearest planetary system (~30 pc) detected by NASA’s Kepler or K2 space mission. Its brightness (V = 10.35 mag) makes the star an ideal target for detailed studies of the properties of its planets. Methods. Combining the K2 photometry with high-precision radial-velocity measurements gathered with the FIES, HARPS, and HARPS-N spectrographs we revised the system parameters and derive the masses of the three planets. Results. We find that GJ 9827 b has a mass of Mb = 3.69−0.46+0.48 M⊕ and a radius of Rb = 1.58−0.13+0.14 R⊕, yielding a mean density of ρb = 5.11−1.27+1.74 g cm−3. GJ 9827 c has a mass of Mc = 1.45−0.57+0.58 M⊕, radius of Rc = 1.24−0.11+0.11 R⊕, and a mean density of ρc = 4.13−1.77+2.31 g cm−3. For GJ 9827 d, we derive Md = 1.45−0.57+0.58 M⊕, Rd = 1.24−0.11+0.11 R⊕, and ρd = 1.51−0.53+0.71 g cm−3. Conclusions. GJ 9827 is one of the few known transiting planetary systems for which the masses of all planets have been determined with a precision better than 30%. This system is particularly interesting because all three planets are close to the limit between super-Earths and sub-Neptunes. The planetary bulk compositions are compatible with a scenario where all three planets formed with similar core and atmosphere compositions, and we speculate that while GJ 9827 b and GJ 9827 c lost their atmospheric envelopes, GJ 9827 d maintained its primordial atmosphere, owing to the much lower stellarirradiation. This makes GJ 9827 one of the very few systems where the dynamical evolution and the atmosphericescape can be studied in detail for all planets, helping us to understand how compact systems form and evolve.

scholarly journals Bondgraph modelling and simulation of the dynamic behaviour of above-knee prostheses

1987 ◽  
Vol 11 (2) ◽  
pp. 65-70 ◽  
Author(s):  
P. G. Van De Veen ◽  
W. Van Der Tempel ◽  
J. De Vreiss
Keyword(s):  
Mathematical Model ◽  
Computer Simulation ◽  
Mass Distribution ◽  
Total Mass ◽  
Dynamic Behaviour ◽  
Step Length ◽  
Swing Phase ◽  
Knee Prostheses ◽  
Prosthetic Foot ◽  
Walking Velocity

A mathematical model was used to investigate the dynamic behaviour of an above-knee (AK) prosthesis in the swing phase and to analyse the influence of mass and mass distribution on the maximal stump load and the required energy. The model consists of a bondgraph model of the prosthesis and a “walking” model which predicts the walking velocity, step length and the femoral trajectory. Equipment was developed to measure the inertial properties of the components of the prosthesis. Through computer simulation, stickdiagrams of the swing phase and graphs of the variation with time of the hip and stump forces were obtained. It was found that for a normal AK prosthesis with a knee-lock mechanism the axial stump load is greatest at the beginning and at the end of the swing phase. At a walking velocity of 5 km/hr the maximum axial stump load amounts to 2.1 times the static weight of the prosthesis. The maximum axial stump force appeared to be almost directly proportional to the total mass of the prosthesis but independent of the mass distribution. The required energy also increased with the mass of the prosthesis but is' dependent on mass distribution. Because of their comparable weights the influence of the shoe is almost equal to the influence of the prosthetic foot. Thus lightweight shoes should be used with lightweight prosthetic feet in order to add to their advantages.

The Mass Distribution of the Milky Way Deduced from Globular Cluster Dynamics

1996 ◽  
pp. 697-702 ◽  
Author(s):  
B. Dauphole ◽  
J. Colin ◽  
M. Geffert ◽  
M. Odenkirchen ◽  
H.-J. Tucholke
Keyword(s):  
Mass Distribution ◽  
Globular Cluster ◽  
Milky Way

scholarly journals The effect of the Magellanic Clouds on the mass distribution in the galaxy

1991 ◽  
Vol 148 ◽  
pp. 487-488
Author(s):  
G. X. Song
Keyword(s):  
Mass Distribution ◽  
Milky Way ◽  
Galactic Disk ◽  
Initial Position ◽  
Tidal Effect ◽  
Magellanic Clouds ◽  
The Galaxy

The disk of the Milky Way suffered from the tidal effect as the Magellanic Clouds were passing by. Numerical stimulations were performed to study the evolution of the mass distribution in this disk. These simulations were run with the galactic disk initially flat, and different sets of the initial position and velocity of the Magellanic Clouds were considered. One of the most conspicuous observational facts is the warp of the disk of the Milky Way. Results show that the characteristics of this warp are related to the orbit of the Magellanic Clouds.

Microstructure, Mass and Chemical Analysis with 8 to 44 Angstrom X-Radiation

1958 ◽  
Vol 2 ◽  
pp. 117-155 ◽  
Author(s):  
Burton L. Henke
Keyword(s):  
High Resolution ◽  
Chemical Analysis ◽  
Mass Distribution ◽  
Total Mass ◽  
Biological Research ◽  
Chemical Information ◽  
Analysis Method ◽  
X Ray

AbstractThe requirement of ultrasoft x-radiation (10 to 100A) for high resolution microradiographic analysis is established. Optimum methods are described for obtaining structure, mass distribution and mass-chemical information for microscopic sample regions as small as a few square microns and for total mass as small as a few micro-micrograms. The details of the techniques and of the instrumentation which are used in high resolution microradiographic analysis are presented.There has been a considerable amount of work reported on low magnification microradiography (up to 100 diameters) using conventional x-ray wavelengths.Relatively little work has been done in high resolution microradiography and with ultra soft x-radiation. Nearly all which has been reported has been in application to biological research where the need for such an analysis method seems to be greatest at this time. Outstanding among this work has been that of Engstrom and his co-workers.Much of the material which is presented in the present paper is intended as a supplement to that presented in the works of Engstrom and Lindstrom and with an emphasis upon the quantitative aspects of microradiographic analysis, using ultrasoft x-radiation.

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