Finding the electromagnetic counterparts of cosmological standard sirens

Bence Kocsis, Z. Frei, Zoltán Haiman, Kristen Menou

Research output: Contribution to journalArticle

79 Citations (Scopus)

Abstract

The gravitational waves (GWs) emitted during the coalescence of supermassive black holes (SMBHs) in the mass range ∼104-10 7 M/(1 + z) will be detectable out to high redshifts with the future Laser Interferometer Space Antenna (LISA), The distance and direction to these "standard sirens" can be inferred directly from the GW signal, with a precision that depends on the masses, spins, and geometry of the merging system. In a given cosmology, the LISA-measured luminosity distance translates into a redshift shell. We calculate the size and shape of the corresponding three-dimensional error volume in which an electromagnetic counterpart to a LISA event could be found, taking into account errors in the background cosmology (as expected by the time LISA flies), weak gravitational lensing (de)magnification due to inhomogeneities along the line of sight, and potential source-peculiar velocities. Weak-lensing errors largely exceed other sources of uncertainties (by a factor of ∼7 for typical sources at z = 1). Under the plausible assumption that SMBH-SMBH mergers are accompanied by gas accretion leading to Eddington-limited quasar activity, we then compute the number of quasars that would be found in a typical three-dimensional LISA error volume, as a function of BH mass and event redshift. Low redshifts offer the best opportunities to identify quasar counterparts to cosmological standard sirens. For mergers of ∼4 × (105-107) M SMBHs, the LISA error volume will typically contain a single near-Eddington quasar at z ∼ 1. If SMBHs are spinning rapidly, the error volume is smaller and may contain a unique quasar out to redshift z ∼ 3. This will allow a straightforward test of the hypothesis that GW events are accompanied by bright quasar activity and, if the hypothesis proves correct, will guarantee the identification of a unique quasar counterpart to a LISA event, with a B-band luminosity of LB ∼ (1010-10 11) L. Robust counterpart identifications would allow unprecedented tests of the physics of SMBH accretion, such as precision measurements of the Eddington ratio. They would clarify the role of gas as a catalyst in SMBH coalescences and would also offer an alternative method to constrain cosmological parameters.

Original languageEnglish
Pages (from-to)27-37
Number of pages11
JournalAstrophysical Journal
Volume637
Issue number1 I
DOIs
Publication statusPublished - Jan 20 2006

Fingerprint

sirens
LISA (observatory)
interferometer
quasars
antenna
laser
electromagnetism
gravitational waves
cosmology
coalescence
merger
coalescing
accretion
luminosity
magnification
gases
gas
inhomogeneity
metal spinning
line of sight

Keywords

  • Cosmic microwave background
  • Cosmology: observations
  • Cosmology: theory
  • Galaxies: clusters: general
  • Large-scale structure of universe

ASJC Scopus subject areas

  • Space and Planetary Science
  • Nuclear and High Energy Physics

Cite this

Finding the electromagnetic counterparts of cosmological standard sirens. / Kocsis, Bence; Frei, Z.; Haiman, Zoltán; Menou, Kristen.

In: Astrophysical Journal, Vol. 637, No. 1 I, 20.01.2006, p. 27-37.

Research output: Contribution to journalArticle

Kocsis, Bence ; Frei, Z. ; Haiman, Zoltán ; Menou, Kristen. / Finding the electromagnetic counterparts of cosmological standard sirens. In: Astrophysical Journal. 2006 ; Vol. 637, No. 1 I. pp. 27-37.
@article{70ae7fc382074eb7ae1cf7fc022a0452,
title = "Finding the electromagnetic counterparts of cosmological standard sirens",
abstract = "The gravitational waves (GWs) emitted during the coalescence of supermassive black holes (SMBHs) in the mass range ∼104-10 7 M⊙/(1 + z) will be detectable out to high redshifts with the future Laser Interferometer Space Antenna (LISA), The distance and direction to these {"}standard sirens{"} can be inferred directly from the GW signal, with a precision that depends on the masses, spins, and geometry of the merging system. In a given cosmology, the LISA-measured luminosity distance translates into a redshift shell. We calculate the size and shape of the corresponding three-dimensional error volume in which an electromagnetic counterpart to a LISA event could be found, taking into account errors in the background cosmology (as expected by the time LISA flies), weak gravitational lensing (de)magnification due to inhomogeneities along the line of sight, and potential source-peculiar velocities. Weak-lensing errors largely exceed other sources of uncertainties (by a factor of ∼7 for typical sources at z = 1). Under the plausible assumption that SMBH-SMBH mergers are accompanied by gas accretion leading to Eddington-limited quasar activity, we then compute the number of quasars that would be found in a typical three-dimensional LISA error volume, as a function of BH mass and event redshift. Low redshifts offer the best opportunities to identify quasar counterparts to cosmological standard sirens. For mergers of ∼4 × (105-107) M ⊙ SMBHs, the LISA error volume will typically contain a single near-Eddington quasar at z ∼ 1. If SMBHs are spinning rapidly, the error volume is smaller and may contain a unique quasar out to redshift z ∼ 3. This will allow a straightforward test of the hypothesis that GW events are accompanied by bright quasar activity and, if the hypothesis proves correct, will guarantee the identification of a unique quasar counterpart to a LISA event, with a B-band luminosity of LB ∼ (1010-10 11) L⊙. Robust counterpart identifications would allow unprecedented tests of the physics of SMBH accretion, such as precision measurements of the Eddington ratio. They would clarify the role of gas as a catalyst in SMBH coalescences and would also offer an alternative method to constrain cosmological parameters.",
keywords = "Cosmic microwave background, Cosmology: observations, Cosmology: theory, Galaxies: clusters: general, Large-scale structure of universe",
author = "Bence Kocsis and Z. Frei and Zolt{\'a}n Haiman and Kristen Menou",
year = "2006",
month = "1",
day = "20",
doi = "10.1086/498236",
language = "English",
volume = "637",
pages = "27--37",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "1 I",

}

TY - JOUR

T1 - Finding the electromagnetic counterparts of cosmological standard sirens

AU - Kocsis, Bence

AU - Frei, Z.

AU - Haiman, Zoltán

AU - Menou, Kristen

PY - 2006/1/20

Y1 - 2006/1/20

N2 - The gravitational waves (GWs) emitted during the coalescence of supermassive black holes (SMBHs) in the mass range ∼104-10 7 M⊙/(1 + z) will be detectable out to high redshifts with the future Laser Interferometer Space Antenna (LISA), The distance and direction to these "standard sirens" can be inferred directly from the GW signal, with a precision that depends on the masses, spins, and geometry of the merging system. In a given cosmology, the LISA-measured luminosity distance translates into a redshift shell. We calculate the size and shape of the corresponding three-dimensional error volume in which an electromagnetic counterpart to a LISA event could be found, taking into account errors in the background cosmology (as expected by the time LISA flies), weak gravitational lensing (de)magnification due to inhomogeneities along the line of sight, and potential source-peculiar velocities. Weak-lensing errors largely exceed other sources of uncertainties (by a factor of ∼7 for typical sources at z = 1). Under the plausible assumption that SMBH-SMBH mergers are accompanied by gas accretion leading to Eddington-limited quasar activity, we then compute the number of quasars that would be found in a typical three-dimensional LISA error volume, as a function of BH mass and event redshift. Low redshifts offer the best opportunities to identify quasar counterparts to cosmological standard sirens. For mergers of ∼4 × (105-107) M ⊙ SMBHs, the LISA error volume will typically contain a single near-Eddington quasar at z ∼ 1. If SMBHs are spinning rapidly, the error volume is smaller and may contain a unique quasar out to redshift z ∼ 3. This will allow a straightforward test of the hypothesis that GW events are accompanied by bright quasar activity and, if the hypothesis proves correct, will guarantee the identification of a unique quasar counterpart to a LISA event, with a B-band luminosity of LB ∼ (1010-10 11) L⊙. Robust counterpart identifications would allow unprecedented tests of the physics of SMBH accretion, such as precision measurements of the Eddington ratio. They would clarify the role of gas as a catalyst in SMBH coalescences and would also offer an alternative method to constrain cosmological parameters.

AB - The gravitational waves (GWs) emitted during the coalescence of supermassive black holes (SMBHs) in the mass range ∼104-10 7 M⊙/(1 + z) will be detectable out to high redshifts with the future Laser Interferometer Space Antenna (LISA), The distance and direction to these "standard sirens" can be inferred directly from the GW signal, with a precision that depends on the masses, spins, and geometry of the merging system. In a given cosmology, the LISA-measured luminosity distance translates into a redshift shell. We calculate the size and shape of the corresponding three-dimensional error volume in which an electromagnetic counterpart to a LISA event could be found, taking into account errors in the background cosmology (as expected by the time LISA flies), weak gravitational lensing (de)magnification due to inhomogeneities along the line of sight, and potential source-peculiar velocities. Weak-lensing errors largely exceed other sources of uncertainties (by a factor of ∼7 for typical sources at z = 1). Under the plausible assumption that SMBH-SMBH mergers are accompanied by gas accretion leading to Eddington-limited quasar activity, we then compute the number of quasars that would be found in a typical three-dimensional LISA error volume, as a function of BH mass and event redshift. Low redshifts offer the best opportunities to identify quasar counterparts to cosmological standard sirens. For mergers of ∼4 × (105-107) M ⊙ SMBHs, the LISA error volume will typically contain a single near-Eddington quasar at z ∼ 1. If SMBHs are spinning rapidly, the error volume is smaller and may contain a unique quasar out to redshift z ∼ 3. This will allow a straightforward test of the hypothesis that GW events are accompanied by bright quasar activity and, if the hypothesis proves correct, will guarantee the identification of a unique quasar counterpart to a LISA event, with a B-band luminosity of LB ∼ (1010-10 11) L⊙. Robust counterpart identifications would allow unprecedented tests of the physics of SMBH accretion, such as precision measurements of the Eddington ratio. They would clarify the role of gas as a catalyst in SMBH coalescences and would also offer an alternative method to constrain cosmological parameters.

KW - Cosmic microwave background

KW - Cosmology: observations

KW - Cosmology: theory

KW - Galaxies: clusters: general

KW - Large-scale structure of universe

UR - http://www.scopus.com/inward/record.url?scp=33644553470&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33644553470&partnerID=8YFLogxK

U2 - 10.1086/498236

DO - 10.1086/498236

M3 - Article

AN - SCOPUS:33644553470

VL - 637

SP - 27

EP - 37

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1 I

ER -