Showing papers by "Ilya Mandel published in 2018"
University of Warwick1, Astrophysics Research Institute2, University of Leicester3, University of Birmingham4, Monash University, Clayton campus5, University of Copenhagen6, Space Telescope Science Institute7, Spanish National Research Council8, Seoul National University9, University of Iceland10, INAF11, Stockholm University12, University of Amsterdam13, Weizmann Institute of Science14, Cardiff University15
TL;DR: In this paper, the authors present late-time optical detections and deep near-infrared limits on the emission from GW170817 at 110 days post-merger.
Abstract: The binary neutron star merger GW170817 was the first multi-messenger event observed in both gravitational and electromagnetic waves1,2. The electromagnetic signal began approximately two seconds post-merger with a weak, short burst of gamma rays3, which was followed over the next hours and days by the ultraviolet, optical and near-infrared emission from a radioactively powered kilonova4,5,6,7,8,9,10,11. Later, non-thermal rising X-ray and radio emission was observed12,13. The low luminosity of the gamma rays and the rising non-thermal flux from the source at late times could indicate that we are outside the opening angle of the beamed relativistic jet. Alternatively, the emission could be arising from a cocoon of material formed from the interaction between a jet and the merger ejecta13,14,15. Here we present late-time optical detections and deep near-infrared limits on the emission from GW170817 at 110 days post-merger. Our new observations are at odds with expectations of late-time emission from kilonova models, being too bright and blue16,17. Instead, the emission arises from the interaction between the relativistic ejecta of GW170817 and the interstellar medium. We show that this emission matches the expectations of a Gaussian-structured relativistic jet, which would have launched a high-luminosity, short gamma-ray burst to an aligned observer. However, other jet structure or cocoon models can also match current data—the future evolution of the afterglow will directly distinguish the origin of the emission.
246 citations
TL;DR: In this paper, the authors perform rapid population synthesis of massive binary stars and discuss model predictions, including DNS formation rates, mass distributions, and delay time distributions, varying assumptions and parameters of physical processes such as mass transfer stability criteria.
Abstract: Double neutron stars (DNSs) have been observed as Galactic radio pulsars, and the recent discovery of gravitational waves from the DNS merger GW170817 adds to the known DNS population. We perform rapid population synthesis of massive binary stars and discuss model predictions, including DNS formation rates, mass distributions, and delay time distributions. We vary assumptions and parameters of physical processes such as mass transfer stability criteria, supernova natal kick distributions, remnant mass prescriptions, and common-envelope energetics.We compute the likelihood of observing the orbital period-eccentricity distribution of the Galactic DNS population under each of our population synthesis models, allowing us to quantitatively compare the models.We find that mass transfer from a stripped post-heliumburning secondary (case BB) on to a neutron star is most likely dynamically stable. We also find that a natal kick distribution composed of both low (Maxwellian σ = 30 km s-1) and high (σ = 265 km s-1) components is preferred over a single high-kick component. We conclude that the observed DNS mass distribution can place strong constraints on model assumptions.
213 citations
TL;DR: In this paper, the authors consider isolated binary evolution and explore how accurately the physical model can be constrained with such observations by applying the Fisher information matrix to the merging black hole population simulated with the rapid binary-population synthesis code COMPAS.
Abstract: The properties of the population of merging binary black holes encode some of the uncertain physics underlying the evolution of massive stars in binaries. The binary black hole merger rate and chirp-mass distribution are being measured by ground-based gravitational-wave detectors. We consider isolated binary evolution, and explore how accurately the physical model can be constrained with such observations by applying the Fisher information matrix to the merging black hole population simulated with the rapid binary-population synthesis code COMPAS. We investigate variations in four COMPAS parameters: common-envelope efficiency, kick-velocity dispersion and mass-loss rates during the luminous blue variable, and Wolf–Rayet stellar-evolutionary phases. We find that ∼1000 observations would constrain these model parameters to a fractional accuracy of a few per cent. Given the empirically determined binary black hole merger rate, we can expect gravitational-wave observations alone to place strong constraints on the physics of stellar and binary evolution within a few years. Our approach can be extended to use other observational data sets; combining observations at different evolutionary stages will lead to a better understanding of stellar and binary physics.
133 citations
TL;DR: In this paper, the surface brightness fluctuation (SBF) distance to NGC4993 in the F110W and F160W passbands of the Wide Field Camera 3 Infrared Channel on the Hubble Space Telescope (HST) was derived.
Abstract: The joint detection of gravitational waves and electromagnetic radiation from the binary neutron star (BNS) merger GW170817 has provided unprecedented insight into a wide range of physical processes: heavy element synthesis via the $r$-process; the production of relativistic ejecta; the equation of state of neutron stars and the nature of the merger remnant; the binary coalescence timescale; and a measurement of the Hubble constant via the "standard siren" technique. In detail, all of these results depend on the distance to the host galaxy of the merger event, NGC4993. In this paper we measure the surface brightness fluctuation (SBF) distance to NGC4993 in the F110W and F160W passbands of the Wide Field Camera 3 Infrared Channel on the Hubble Space Telescope (HST). For the preferred F110W passband we derive a distance modulus of $m{-}M=33.05\pm0.08\pm0.10$ mag, or a linear distance $d=40.7\pm1.4\pm1.9$ Mpc (random and systematic errors, respectively); a virtually identical result is obtained from the F160W data. This is the most precise distance to NGC4993 available to date. Combining our distance measurement with the corrected recession velocity of NGC4993 implies a Hubble constant $H_0=71.9\pm 7.1$ \kmsmpc. A comparison of our result to the GW-inferred value of $H_0$ indicates a binary orbital inclination of $i\,{\gtrsim}\,137~\deg$. The SBF technique can be applied to early-type host galaxies of BNS mergers to ${\sim\,}100$ Mpc with HST and possibly as far as ${\sim\,}300$ Mpc with the James Webb Space Telescope, thereby helping to break the inherent distance-inclination degeneracy of the GW signals at distances where many future BNS mergers are likely to be detected.
128 citations
TL;DR: In this paper, the first detections of Advanced LIGO and Advanced VIRGO were made using the NASA/IPAC Extragalactic Database (NED) under contract with the National Aeronautics and Space Administration.
Abstract: This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. We acknowledge funding from INAF project: Gravitational Wave Astronomy with the first detections of Advanced LIGO and Advanced VIRGO experiments (PI: E. Brocato). M.C., G.R., and J.P.B. acknowledge partial support from the PRIN INAF-2014 >EXCALIBURS: EXtragalactic distance scale CALIBration Using first-Rank Standard candles> project (PI: G. Clementini). The Berger Time-Domain Group at Harvard is supported in part by the NSF through grant AST-1714498, and by NASA through grants NNX15AE50G and NNX16AC22G. N.R.T. acknowledges support from STFC consolidated grant ST/N000757/1. P.D.A. and S.C. acknowledge support from ASI grant I/004/11/3. J.H. was supported by a VILLUM FONDEN Investigator grant (project number 16599). I.M. acknowledges STFC for partial support. We thank the anonymous referee for a clear and unequivocal report.
118 citations
TL;DR: GPL is supported by a Science Technology and Facilities Council Grant (STFC) ST/N000757/1 as discussed by the authors, which has been used for the development of the PL project.
Abstract: GPL is supported by a Science Technology and Facilities Council Grant (STFC) ST/N000757/1. IM acknowledges partial support from the STFC. RL acknowledges support from the grant EMR/2016/007127 from Dept. of Science and Technology, India.
71 citations
TL;DR: In this article, the authors combine the gravitational-wave measurement of the effective distance to the binary neutron star merger GW170817, the redshift of its host galaxy NGC 4993, and the latest Hubble constant measurement from the Dark Energy Survey to constrain the inclination between the orbital angular momentum of the binary and the line of sight to 18° ± 8° (less than 28° at 90% confidence).
Abstract: We combine the gravitational-wave measurement of the effective distance to the binary neutron star merger GW170817, the redshift of its host galaxy NGC 4993, and the latest Hubble constant measurement from the Dark Energy Survey to constrain the inclination between the orbital angular momentum of the binary and the line of sight to 18° ± 8° (less than 28° at 90% confidence). This provides a complementary constraint on models of potential afterglow observations.
44 citations
TL;DR: In this paper, the astrophysical science case for a decihertz gravitational-wave mission is discussed, focusing on unique opportunities for scientific discovery in this frequency range, including probes of type IA supernova progenitors, mergers in the presence of third bodies, intermediate mass black holes, seeds of massive black holes and tracking the population of merging compact binaries.
Abstract: We discuss the astrophysical science case for a decihertz gravitational-wave mission. We focus on unique opportunities for scientific discovery in this frequency range, including probes of type IA supernova progenitors, mergers in the presence of third bodies, intermediate mass black holes, seeds of massive black holes, improved sky localization, and tracking the population of merging compact binaries.
36 citations
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TL;DR: 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 as discussed by the authors.
Abstract: 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.
33 citations
TL;DR: Adopting an improved approach, an ad hoc statistical method is used in their calculation of the stellar initial mass function and the power-law exponent of 2.05−0.13+0.14 is determined.
Abstract: Schneider et al (Reports, 5 January 2018, p. 69) used an ad hoc statistical method in their calculation of the stellar initial mass function. Adopting an improved approach, we reanalyze their data and determine a power-law exponent of [Formula: see text] Alternative assumptions regarding dataset completeness and the star formation history model can shift the inferred exponent to [Formula: see text] and [Formula: see text], respectively.
19 citations
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TL;DR: In this paper, the authors reanalyse the data and determine a power law exponent of $2.05 − 0.14 + 0.13 − 1.13− 0.17 − 0.
Abstract: Schneider et al. (Science, 2018) used an ad hoc statistical method in their calculation of the stellar initial mass function. Adopting an improved approach, we reanalyse their data and determine a power law exponent of $2.05_{-0.14}^{+0.13}$. Alternative assumptions regarding data set completeness and the star formation history model can shift the inferred exponent to $2.11_{-0.19}^{+0.17}$ and $2.15_{-0.13}^{+0.13}$, respectively.
TL;DR: In this article, a tool called saprEMo is proposed to predict the number of electromagnetic signals characterised by a specific light curve and spectrum, expected in a particular sky survey.
Abstract: The multi-wavelength detection of GW170817 has inaugurated multi-messenger astronomy The next step consists in interpreting observations coming from population of gravitational wave sources We introduce saprEMo, a tool aimed at predicting the number of electromagnetic signals characterised by a specific light curve and spectrum, expected in a particular sky survey By looking at past surveys, saprEMo allows us to constrain models of electromagnetic emission or event rates Applying saprEMo to proposed astronomical missions/observing campaigns provides a perspective on their scientific impact and tests the effect of adopting different observational strategies For our first case study, we adopt a model of spindown-powered X-ray emission predicted for a binary neutron star merger producing a long-lived neutron star We apply saprEMo on data collected by XMM-Newton and Chandra and during $10^4$ s of observations with the mission concept THESEUS We demonstrate that our emission model and binary neutron star merger rate imply the presence of some signals in the XMM-Newton catalogs We also show that the new class of X-ray transients found by Bauer et al in the Chandra Deep Field-South is marginally consistent with the expected rate Finally, by studying the mission concept THESEUS, we demonstrate the substantial impact of a much larger field of view in searches of X-ray transients
TL;DR: The optical afterglow of GRB 170817A was observed by the Hubble Space Telescope between February and August 2018, up to one year after the neutron star merger, GW170817 as discussed by the authors.
Abstract: We present observations of the optical afterglow of GRB\,170817A, made by the {\it Hubble Space Telescope}, between February and August 2018, up to one year after the neutron star merger, GW170817. The afterglow shows a rapid decline beyond $170$~days, and confirms the jet origin for the observed outflow, in contrast to more slowly declining expectations for `failed-jet' scenarios. We show here that the broadband (radio, optical, X-ray) afterglow is consistent with a structured outflow where an ultra-relativistic jet, with Lorentz factor $\Gamma\gtrsim100$, forms a narrow core ($\sim5^\circ$) and is surrounded by a wider angular component that extends to $\sim15^\circ$, which is itself relativistic ($\Gamma\gtrsim5$). For a two-component model of this structure, the late-time optical decline, where $F \propto t^{-\alpha}$, is $\alpha=2.20\pm0.18$, and for a Gaussian structure the decline is $\alpha=2.45\pm0.23$. We find the Gaussian model to be consistent with both the early $\sim10$ days and late $\gtrsim290$ days data. The agreement of the optical light curve with the evolution of the broadband spectral energy distribution and its continued decline indicates that the optical flux is arising primarily from the afterglow and not any underlying host system. This provides the deepest limits on any host stellar cluster, with a luminosity $\lesssim 4000 L_\odot~(M_{\rm F606W}\gtrsim-4.3)$.
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University of Warwick1, Astrophysics Research Institute2, University of Leicester3, Monash University, Clayton campus4, University of Birmingham5, University of Copenhagen6, Space Telescope Science Institute7, Spanish National Research Council8, Seoul National University9, University of Iceland10, INAF11, Stockholm University12, University of Amsterdam13, Weizmann Institute of Science14, Cardiff University15
TL;DR: In this paper, the authors present late-time optical detections and deep near-infrared limits on the emission from GW170817 at 110 days post-merger.
Abstract: The binary neutron star merger GW170817 was the first multi-messenger event observed in both gravitational and electromagnetic waves. The electromagnetic signal began approximately 2 seconds post-merger with a weak, short burst of gamma-rays, which was followed over the next hours and days by the ultraviolet, optical and near-infrared emission from a radioactively- powered kilonova. Later, non-thermal rising X-ray and radio emission was observed. The low luminosity of the gamma-rays and the rising non-thermal flux from the source at late times could indicate that we are outside the opening angle of the beamed relativistic jet. Alternatively, the emission could be arising from a cocoon of material formed from the interaction between a jet and the merger ejecta. Here we present late-time optical detections and deep near-infrared limits on the emission from GW170817 at 110 days post-merger. Our new observations are at odds with expectations of late-time emission from kilonova models, being too bright and blue. Instead, the emission arises from the interaction between the relativistic ejecta of GW170817 and the interstellar medium. We show that this emission matches the expectations of a Gaussian structured relativistic jet, which would have launched a high luminosity short GRB to an aligned observer. However, other jet structure or cocoon models can also match current data - the future evolution of the afterglow will directly distinguish the origin of the emission.