Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userMeasurement of Hubble constant with stellar-mass binary black holes
47
0
0.0
(
0
)
Authors
Atsushi Nishizawa
Ask ChatGPT about the research
No Arabic abstract
The direct detections of gravitational waves (GW) from merging binary black holes (BBH) by aLIGO have brought us a new opportunity to utilize BBH for a measurement of the Hubble constant. In this paper, we point out that there exists a small number of BBH that gives significantly small sky localization volume so that a host galaxy is uniquely identified. Then a redshift of a BBH is obtained from a spectroscopic follow-up observation of the host galaxy. Using these redshift-identified BBH, we show that the Hubble constant is measured at a level of precision better than 1% with advanced detectors like aLIGO at design sensitivity. Since a GW observation is completely independent of other astrophysical means, this qualitatively new probe will help resolve a well-known value discrepancy problem on the Hubble constant from cosmological measurements and local measurements.
rate research
Read More
The LIGO and Virgo detectors have recently directly observed gravitational waves from several mergers of pairs of stellar-mass black holes, as well as from one merging pair of neutron stars. These observations raise the hope that compact object mergers could be used as a probe of stellar and binary evolution, and perhaps of stellar dynamics. This colloquium-style article summarizes the existing observations, describes theoretical predictions for formation channels of merging stellar-mass black-hole binaries along with their rates and observable properties, and presents some of the prospects for gravitational-wave astronomy.
In large and complicated stellar systems like galaxies it is difficult to predict the number and characteristics of a black hole population. Such populations may be modelled as an aggregation of homogeneous (i.e. having uniform star formation history and the same initial chemical composition) stellar populations. Using realistic evolutionary models we predict the abundances and properties of black holes formed from binaries in these environments. We show that the black hole population will be dominated by single black holes originating from binary disruptions and stellar mergers. Furthermore, we discuss how black hole populations are influenced by such factors as initial parameters, metallicity, initial mass function, and natal kick models. As an example application of our results, we estimate that about 26 microlensing events to happen every year in the direction of the Galactic Bulge due to black holes in a survey like OGLE-IV. Our results may be used to perform in-depth studies related to realistic black hole populations, e.g. observational predictions for space survey missions like Gaia, or Einstein Probe. We prepared a publicly available database with the raw data from our simulations to be used for more in-depth studies.
The possibility that primordial black hole binary mergers of stellar mass can explain the signals detected by the gravitational-wave interferometers has attracted much attention. In this scenario, primordial black holes can comprise only part of the entire dark matter, say, of order 0.1 %. This implies that most of the dark matter is accounted for by a different component, such as Weakly Interacting Massive Particles. We point out that in this situation, very compact dark matter minihalos, composed of the dominant component of the dark matter, are likely to be formed abundantly in the early Universe, with their formation redshift and abundance depending on primordial non-Gaussianity. They may be detected in future experiments via pulsar observations.
We study the prospect of using TianQin to detect stellar-mass binary black holes (SBBHs). We estimate the expected detection number as well as the precision of parameter estimation on SBBH inspirals, using five different population models. We note TianQin can possibly detect a few SBBH inspirals with signal to noise ratios greater than 12; lowering the threshold and combining multiple detectors can both boost the detection number. The source parameters can be recovered with good precision for most events above the detection threshold. For example, the precision of the merger time most likely occurs near 1s, making it possible to guide the detection of the ground-based detectors, the precision of the eccentricity $e_0$ most likely occurs near $10^{-4}$, making it possible to distinguish the formation channels, and the precision of the mass parameter is better than $10^{-6}$ in general and most likely occurs near $10^{-7}$. We note, in particular, that for a typical merger event, the error volume is likely to be small enough to contain only the host galaxy, which could greatly help in the study of gravitational wave cosmology and relevant studies through the multimessenger observation.
The Zwicky Transient Facility (ZTF) reported the event ZTF19abanrhr as a candidate electromagnetic (EM) counterpart at a redshift $z=0.438$ to the gravitational wave (GW) emission from the binary black hole merger GW190521. Assuming that ZTF19abanrhr is the {it bona fide} EM counterpart to GW190521, and using the GW luminosity distance estimate from three different waveforms NRSur7dq4, SEOBNRv4PHM, and IMRPhenomPv3HM, we report a measurement of the Hubble constant $H_0= 50.4_{-19.5}^{+28.1}$ km/s/Mpc, $ 62.2_{-19.7}^{+29.5}$ km/s/Mpc, and $ 43.1_{-11.4}^{+24.6}$ km/s/Mpc (median along with $68%$ credible interval) respectively after marginalizing over matter density $Omega_m$ (or dark energy equation of state $w_0$) assuming the flat LCDM (or wCDM) model. Combining our results with the binary neutron star event GW170817 with its redshift measurement alone, as well as with its inclination angle inferred from Very Large Baseline Interferometry (VLBI), we find $H_0= 67.6_{-4.2}^{+4.3}$ km/s/Mpc, $Omega_m= 0.47_{-0.27}^{+0.34}$, and $w_0= -1.17_{-0.57}^{+0.68}$ (median along with $68%$ credible interval) providing the most stringent measurement on $H_0$ and the first estimation on $Omega_m$ and $w_0$ from bright standard siren. In the future, $1.3%$ measurement of $H_0=68$ km/s/Mpc and $28%$ measurement of $w_0=-1$ is possible from about $200$ GW190521-like sources.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
