Showing papers by "Ilya Mandel published in 2007"
TL;DR: In this paper, a review of the current state of knowledge and an outline of some of the outstanding questions that still need to be addressed is provided, based on discussions at a workshop hosted by the Albert Einstein Institute in Golm, Germany.
Abstract: Black hole binaries with extreme (gtrsim104:1) or intermediate (~102–104:1) mass ratios are among the most interesting gravitational wave sources that are expected to be detected by the proposed laser interferometer space antenna (LISA). These sources have the potential to tell us much about astrophysics, but are also of unique importance for testing aspects of the general theory of relativity in the strong field regime. Here we discuss these sources from the perspectives of astrophysics, data analysis and applications to testing general relativity, providing both a description of the current state of knowledge and an outline of some of the outstanding questions that still need to be addressed. This review grew out of discussions at a workshop in September 2006 hosted by the Albert Einstein Institute in Golm, Germany.
425 citations
TL;DR: In this article, a review of the current state of knowledge and an outline of some of the outstanding questions that still need to be addressed is presented. But the review is limited to binary sources with extreme mass ratios (10^4:1$) or intermediate mass ratios.
Abstract: Black hole binaries with extreme ($\gtrsim 10^4:1$) or intermediate ($\sim 10^2-10^4:1$) mass ratios are among the most interesting gravitational wave sources that are expected to be detected by the proposed Laser Interferometer Space Antenna. These sources have the potential to tell us much about astrophysics, but are also of unique importance for testing aspects of the general theory of relativity in the strong field regime. Here we discuss these sources from the perspectives of astrophysics, data analysis, and applications to testing general relativity, providing both a description of the current state of knowledge and an outline of some of the outstanding questions that still need to be addressed. This review grew out of discussions at a workshop in September 2006 hosted by the Albert Einstein Institute in Golm, Germany.
87 citations
TL;DR: It is suggested that the evolutions of the waves' three fundamental frequencies and of the complex amplitudes of their spectral components encode (in principle) details of the central body's metric, the energy and angular momentum exchange between the centralBody and the orbit, and the time-evolving orbital elements.
Abstract: We explore prospects for detecting gravitational waves from stellar-mass compact objects spiraling into intermediate mass black holes (BHs) M~50M[sun] to 350M[sun]) with ground-based observatories. We estimate a rate for such intermediate-mass-ratio inspirals of <~1–30 yr^-1 in Advanced LIGO. We show that if the central body is not a BH but its metric is stationary, axisymmetric, reflection symmetric and asymptotically flat, then the waves will likely be triperiodic, as for a BH. We suggest that the evolutions of the waves' three fundamental frequencies and of the complex amplitudes of their spectral components encode (in principle) details of the central body's metric, the energy and angular momentum exchange between the central body and the orbit, and the time-evolving orbital elements. We estimate that advanced ground-based detectors can constrain central body deviations from a BH with interesting accuracy.
83 citations
TL;DR: In this paper, the authors used Markov chain Monte Carlo methods to estimate the parameters of a binary inspiral source with a spinning component and determined the accuracy of the parameter estimation, for simulated observations with ground-based gravitational-wave detectors.
Abstract: Inspiral signals from binary compact objects (black holes and neutron stars) are primary targets of the ongoing searches by ground-based gravitational-wave interferometers (LIGO, Virgo, GEO-600 and TAMA-300). We present parameter-estimation simulations for inspirals of black-hole--neutron-star binaries using Markov-chain Monte-Carlo methods. For the first time, we have both estimated the parameters of a binary inspiral source with a spinning component and determined the accuracy of the parameter estimation, for simulated observations with ground-based gravitational-wave detectors. We demonstrate that we can obtain the distance, sky position, and binary orientation at a higher accuracy than previously suggested in the literature. For an observation of an inspiral with sufficient spin and two or three detectors we find an accuracy in the determination of the sky position of typically a few tens of square degrees.
72 citations
Posted Content•
19 Mar 2007
TL;DR: In this paper, a review of the current state of knowledge and an outline of some of the outstanding questions that still need to be addressed is presented. But the review is limited to binary sources with extreme mass ratios (10^4:1$) or intermediate mass ratios.
Abstract: Black hole binaries with extreme ($\gtrsim 10^4:1$) or intermediate ($\sim 10^2-10^4:1$) mass ratios are among the most interesting gravitational wave sources that are expected to be detected by the proposed Laser Interferometer Space Antenna. These sources have the potential to tell us much about astrophysics, but are also of unique importance for testing aspects of the general theory of relativity in the strong field regime. Here we discuss these sources from the perspectives of astrophysics, data analysis, and applications to testing general relativity, providing both a description of the current state of knowledge and an outline of some of the outstanding questions that still need to be addressed. This review grew out of discussions at a workshop in September 2006 hosted by the Albert Einstein Institute in Golm, Germany.
47 citations
Goddard Space Flight Center1, University of Paris2, Albert Einstein Institution3, University of Texas at Brownsville4, University of Glasgow5, California Institute of Technology6, Carleton College7, Montana State University8, Pennsylvania State University9, Polish Academy of Sciences10, Weber State University11, University of Auckland12, University of Birmingham13, Northwestern University14, Ames Research Center15
TL;DR: The Mock LISA Data challenges have just been completed: nine challenges consisting of data sets containing simulated gravitational-wave signals produced either by galactic binaries or massive black hole binaries embedded in simulated LISA instrumental noise were released in June 2006 with deadline for submissions at the beginning of December 2006.
Abstract: The Mock LISA Data Challenges (MLDCs) have the dual purpose of fostering the development of LISA data analysis tools and capabilities, and demonstrating the technical readiness already achieved by the gravitational-wave community in distilling a rich science payoff from the LISA data output. The first round of MLDCs has just been completed: nine challenges consisting of data sets containing simulated gravitational-wave signals produced either by galactic binaries or massive black hole binaries embedded in simulated LISA instrumental noise were released in June 2006 with deadline for submission of results at the beginning of December 2006. Ten groups have participated in this first round of challenges. All of the challenges had at least one entry which successfully characterized the signal to better than 95% when assessed via a correlation with phasing ambiguities accounted for. Here, we describe the challenges, summarize the results and provide a first critical assessment of the entries.
39 citations
TL;DR: The first round of the Mock LISA Data Challenge (MLDC) as mentioned in this paper was held in 2006, with the goal of fostering the development of LISA data analysis tools and capabilities, and demonstrating the technical readiness already achieved by the gravitational-wave community in distilling a rich science payoff from the LISA dataset.
Abstract: The Mock LISA Data Challenges (MLDCs) have the dual purpose of fostering the development of LISA data analysis tools and capabilities, and demonstrating the technical readiness already achieved by the gravitational-wave community in distilling a rich science payoff from the LISA data output. The first round of MLDCs has just been completed: nine data sets containing simulated gravitational wave signals produced either by galactic binaries or massive black hole binaries embedded in simulated LISA instrumental noise were released in June 2006 with deadline for submission of results at the beginning of December 2006. Ten groups have participated in this first round of challenges. Here we describe the challenges, summarise the results, and provide a first critical assessment of the entries.
35 citations
TL;DR: In this paper, a three-stage data-analysis pipeline is designed to search for and measure the parameters of supermassive black-hole (SMBH) binaries in LISA data.
Abstract: Gravitational waves from the inspiral and coalescence of supermassive black-hole (SMBH) binaries with masses m1 ~ m2 ~ 10^6Modot are likely to be among the strongest sources for the Laser Interferometer Space Antenna (LISA). We describe a three-stage data-analysis pipeline designed to search for and measure the parameters of SMBH binaries in LISA data. The first stage uses a time–frequency track-search method to search for inspiral signals and provide a coarse estimate of the black-hole masses m1, m2 and the coalescence time of the binary tc. The second stage uses a sequence of matched-filter template banks, seeded by the first stage, to improve the measurement accuracy of the masses and coalescence time. Finally, a Markov chain Monte Carlo search is used to estimate all nine physical parameters of the binary (masses, coalescence time, distance, initial phase, sky position and orientation). Using results from the second stage substantially shortens the Markov chain burn-in time and allows us to determine the number of SMBH-binary signals in the data before starting parameter estimation. We demonstrate our analysis pipeline using simulated data from the first Mock LISA Data Challenge. We discuss our plan for improving this pipeline and the challenges that will be faced in real LISA data analysis.
32 citations
Journal Article•
TL;DR: In this paper, the authors analyzed four possible IMRI formation mechanisms: hardening of an NS-IMBH or stellar-mass black hole (BH) binary via three-body interactions, hardening via Kozai resonance in a hierarchical triple system, direct capture, and inspiral of a CO from a tidally captured main-sequence star.
Abstract: Gravitational waves (GWs) from the inspiral of a neutron star (NS) or stellar-mass black hole (BH) into an intermediate-mass black hole (IMBH) with mass M � 50 350 Mmay be detectable by the planned advanced generation of ground-based GWinterferometers Such intermediate mass ratio inspirals (IMRIs) are most likelyto be found in globular clusters We analyze four possible IMRI formation mechanisms: (1) hardening of an NS-IMBH or BH-IMBH binary via three-body interactions, (2) hardening via Kozai resonance in a hierarchical triple system, (3) direct capture, and (4) inspiral of a CO from a tidally captured main-sequence star; we also discuss tidal effects when the inspiraling object is an NS For each mechanism we predict the typical eccentricities of the resulting IMRIs We find that IMRIs will have largely circularized by the time they enter the sensitivity band of ground-based detec- tors Hardening of a binary via three-body interactions, which is likely to be the dominant mechanism for IMRI for- mation,yieldseccentricitiesunder10 � 4 whentheGWfrequencyreaches10HzEvenamongIMRIsformedviadirect captures, which can have the highest eccentricities, around 90% will circularize to eccentricities under 01 before the GW frequency reaches 10 Hz We estimate the rate of IMRI coalescences in globular clusters and the sensitivity of a network of three Advanced LIGO detectors to the resulting GWs We show that this detector network may see up to tens of IMRIs per year, although rates of one to a few per year may be more plausible We also estimate the loss in signal-to-noise ratio that will result from using circular IMRI templates for data analysis and find that, for the eccen- tricities we expect, this loss is negligible Subject headingg black hole physics — globular clusters: general — gravitational waves
18 citations
Albert Einstein Institution1, Goddard Space Flight Center2, University of Texas at Brownsville3, Montana State University4, California Institute of Technology5, Weber State University6, University of Birmingham7, Northwestern University8, University of Paris9, University of Southampton10, University of Wrocław11, University of Glasgow12, Syracuse University13, Carleton College14, Cardiff University15, University of Cambridge16, Polish Academy of Sciences17, University of Auckland18
TL;DR: The Mock LISA data challenges successfully demonstrated the recovery of signals from nonspinning supermassive-black-hole binaries with optimal SNRs between ~10 and 2000, from ~20 000 overlapping galactic white-dwarf binaries (among a realistically distributed population of 26 million), and from the extreme-mass-ratio inspirals of compact objects into central galactic black holes with optimalSNRs ~100.
Abstract: The Mock LISA Data Challenges are a program to demonstrate LISA data-analysis capabilities and to encourage their development. Each round of challenges consists of several data sets containing simulated instrument noise and gravitational-wave sources of undisclosed parameters. Participants are asked to analyze the data sets and report the maximum information about source parameters. The challenges are being released in rounds of increasing complexity and realism: in this proceeding we present the results of Challenge 2, issued in January 2007, which successfully demonstrated the recovery of signals from supermassive black-hole binaries, from ~20,000 overlapping Galactic white-dwarf binaries, and from the extreme-mass-ratio inspirals of compact objects into central galactic black holes.
14 citations
Posted Content•
TL;DR: In this paper, the probability distribution for the spin of a black hole following a series of minor mergers with isotropically distributed, non-spinning, inspiraling compact objects is computed.
Abstract: We compute the probability distribution for the spin of a black hole following a series of minor mergers with isotropically distributed, non-spinning, inspiraling compact objects. By solving the Fokker-Planck equation governing this stochastic process, we obtain accurate analytical fits for the evolution of the mean and standard deviation of the spin distribution in several parameter regimes. We complement these analytical fits with numerical Monte-Carlo simulations in situations when the Fokker-Planck analysis is not applicable. We find that a ~150 solar-mass intermediate-mass black hole that gained half of its mass through minor mergers with neutron stars will have dimensionless spin parameter chi=a/M~0.2 \pm 0.08. We estimate the effect of the spin of the central black hole on the detection range for intermediate-mass-ratio inspiral (IMRI) detections by Advanced LIGO and extreme-mass-ratio inspiral(EMRI) detections by LISA. We find that for realistic black hole spins, the inclination-averaged Advanced-LIGO IMRI detection range may be increased by up to 10% relative to the range for IMRIs into non-spinning intermediate-mass black holes. For LISA, we find that the detection range for EMRIs into 10^5 solar-mass massive black holes (MBHs) is not significantly affected by MBH spin, the range for EMRIs into 10^6 solar-mass MBHs is affected at the ~ 10% level, and EMRIs into maximally spinning 10^7 solar-mass MBHs are detectable to a distance ~25 times greater than EMRIs into non-spinning black holes. The resulting bias in favor of detecting EMRIs into rapidly spinning MBHs will play a role when extracting the MBH spin distribution from EMRI statistics.
TL;DR: In this paper, the Hierarchical Algorithm for Clusters and Ridges (HALG) was used to identify tracks in the time-frequency spectrogram corresponding to EMRI sources.
Abstract: Extreme-mass-ratio inspirals (EMRIs) of ~ 1-10 solar-mass compact objects into ~ million solar-mass massive black holes can serve as excellent probes of strong-field general relativity. The Laser Interferometer Space Antenna (LISA) is expected to detect gravitational wave signals from apprxomiately one hundred EMRIs per year, but the data analysis of EMRI signals poses a unique set of challenges due to their long duration and the extensive parameter space of possible signals. One possible approach is to carry out a search for EMRI tracks in the time-frequency domain. We have applied a time-frequency search to the data from the Mock LISA Data Challenge (MLDC) with promising results. Our analysis used the Hierarchical Algorithm for Clusters and Ridges to identify tracks in the time-frequency spectrogram corresponding to EMRI sources. We then estimated the EMRI source parameters from these tracks. In these proceedings, we discuss the results of this analysis of the MLDC round 1.3 data.
TL;DR: In this article, the authors predict the typical eccentricities of the resulting IMRIs in globular clusters, and estimate the loss in signal-to-noise ratio that will result from using circular IMRI templates for data analysis.
Abstract: Gravitational waves (GWs) from the inspiral of a neutron star (NS) or stellar-mass black hole (BH) into an intermediate-mass black hole (IMBH) with mass between ~50 and ~350 solar masses may be detectable by the planned advanced generation of ground-based GW interferometers. Such intermediate mass ratio inspirals (IMRIs) are most likely to be found in globular clusters. We analyze four possible IMRI formation mechanisms: (1) hardening of an NS-IMBH or BH-IMBH binary via three-body interactions, (2) hardening via Kozai resonance in a hierarchical triple system, (3) direct capture, and (4) inspiral of a compact object from a tidally captured main-sequence star; we also discuss tidal effects when the inspiraling object is an NS. For each mechanism we predict the typical eccentricities of the resulting IMRIs. We find that IMRIs will have largely circularized by the time they enter the sensitivity band of ground-based detectors. Hardening of a binary via three-body interactions, which is likely to be the dominant mechanism for IMRI formation, yields eccentricities under 10^-4 when the GW frequency reaches 10 Hz. Even among IMRIs formed via direct captures, which can have the highest eccentricities, around 90% will circularize to eccentricities under 0.1 before the GW frequency reaches 10 Hz. We estimate the rate of IMRI coalescences in globular clusters and the sensitivity of a network of three Advanced LIGO detectors to the resulting GWs. We show that this detector network may see up to tens of IMRIs per year, although rates of one to a few per year may be more plausible. We also estimate the loss in signal-to-noise ratio that will result from using circular IMRI templates for data analysis and find that, for the eccentricities we expect, this loss is negligible.
01 Jan 2007
TL;DR: In this paper, a non-spinning binary inspiral parameter estimation code was extended to extract the source parameters of spinning binary inspirals, based on a Markov chain Monte Carlo (MCMC) technique.
Abstract: Binary systems consisting of stellar-mass (∼ 1M⊙− 100M⊙) compact objects are amongst the most promising gravitational-wave sources for groundbased laser interferometers. If at least one of the binary members is a black hole, our current astrophysical understanding suggests that the black hole should be spinning at least moderately [1]. Spins strongly affect the gravitational waveforms by introducing phase and amplitude modulations, caused by the coupling of the angular momenta. For parameter estimation on an inspiral signal, it is therefore of vital importance to take into account the effects of spins. Building on a non-spinning binary inspiral parameter-estimation code [2], we have extended this code to extract the source parameters of spinning binary inspirals. The algorithm is based on a Markov-chain Monte-Carlo (MCMC) technique [3] to compute the posterior probability density functions (posterior PDFs) of the source parameters.
TL;DR: In this article, a three-stage data-analysis pipeline is designed to search for and measure the parameters of supermassive black-hole (SMBH) binaries in LISA data.
Abstract: Gravitational waves from the inspiral and coalescence of supermassive black-hole (SMBH) binaries with masses ~10^6 Msun are likely to be among the strongest sources for the Laser Interferometer Space Antenna (LISA). We describe a three-stage data-analysis pipeline designed to search for and measure the parameters of SMBH binaries in LISA data. The first stage uses a time-frequency track-search method to search for inspiral signals and provide a coarse estimate of the black-hole masses m_1, m_2 and of the coalescence time of the binary t_c. The second stage uses a sequence of matched-filter template banks, seeded by the first stage, to improve the measurement accuracy of the masses and coalescence time. Finally, a Markov Chain Monte Carlo search is used to estimate all nine physical parameters of the binary. Using results from the second stage substantially shortens the Markov Chain burn-in time and allows us to determine the number of SMBH-binary signals in the data before starting parameter estimation. We demonstrate our analysis pipeline using simulated data from the first LISA Mock Data Challenge. We discuss our plan for improving this pipeline and the challenges that will be faced in real LISA data analysis.