Detecting the gravitational redshift of cluster gas

Tom Broadhurst, Evan Scannapieco

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

We examine the gravitational redshift of radiation emitted from within the potential of a cluster. Spectral lines from the intracluster medium (ICM) are redshifted in proportion to the emission-weighted mean potential along the line of sight, amounting to ≈50 km s-1 at a radius of 100 kpc h-1, for a cluster dispersion of 1200 km s-1. We show that the relative redshifts of different ionization states of metals in the ICM provide a unique probe of the three-dimensional matter distribution. An examination of the reported peculiar velocities of cD galaxies in well-studied Abell clusters reveals that they are typically redshifted by an average of ∼200 km s-1. This can be achieved by gravity with the addition of a steep central potential associated with the cD galaxy. Note that, in general, gravitational redshifts cause a small overestimate of the recessional velocities of clusters by an average of ∼20 km s-1.

Original languageEnglish (US)
JournalAstrophysical Journal
Volume533
Issue number2 PART 2
StatePublished - Apr 20 2000
Externally publishedYes

Fingerprint

gases
gas
ionization
probe
gravity
galaxies
metal
line of sight
line spectra
proportion
examination
gravitation
radii
probes
causes
radiation
metals
distribution

Keywords

  • Cosmology: observations
  • Galaxies: clusters: general
  • Techniques: spectroscopic
  • X-rays: galaxies

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Detecting the gravitational redshift of cluster gas. / Broadhurst, Tom; Scannapieco, Evan.

In: Astrophysical Journal, Vol. 533, No. 2 PART 2, 20.04.2000.

Research output: Contribution to journalArticle

@article{238fbdb525a84dffa8ea718f9799b7da,
title = "Detecting the gravitational redshift of cluster gas",
abstract = "We examine the gravitational redshift of radiation emitted from within the potential of a cluster. Spectral lines from the intracluster medium (ICM) are redshifted in proportion to the emission-weighted mean potential along the line of sight, amounting to ≈50 km s-1 at a radius of 100 kpc h-1, for a cluster dispersion of 1200 km s-1. We show that the relative redshifts of different ionization states of metals in the ICM provide a unique probe of the three-dimensional matter distribution. An examination of the reported peculiar velocities of cD galaxies in well-studied Abell clusters reveals that they are typically redshifted by an average of ∼200 km s-1. This can be achieved by gravity with the addition of a steep central potential associated with the cD galaxy. Note that, in general, gravitational redshifts cause a small overestimate of the recessional velocities of clusters by an average of ∼20 km s-1.",
keywords = "Cosmology: observations, Galaxies: clusters: general, Techniques: spectroscopic, X-rays: galaxies",
author = "Tom Broadhurst and Evan Scannapieco",
year = "2000",
month = "4",
day = "20",
language = "English (US)",
volume = "533",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "2 PART 2",

}

TY - JOUR

T1 - Detecting the gravitational redshift of cluster gas

AU - Broadhurst, Tom

AU - Scannapieco, Evan

PY - 2000/4/20

Y1 - 2000/4/20

N2 - We examine the gravitational redshift of radiation emitted from within the potential of a cluster. Spectral lines from the intracluster medium (ICM) are redshifted in proportion to the emission-weighted mean potential along the line of sight, amounting to ≈50 km s-1 at a radius of 100 kpc h-1, for a cluster dispersion of 1200 km s-1. We show that the relative redshifts of different ionization states of metals in the ICM provide a unique probe of the three-dimensional matter distribution. An examination of the reported peculiar velocities of cD galaxies in well-studied Abell clusters reveals that they are typically redshifted by an average of ∼200 km s-1. This can be achieved by gravity with the addition of a steep central potential associated with the cD galaxy. Note that, in general, gravitational redshifts cause a small overestimate of the recessional velocities of clusters by an average of ∼20 km s-1.

AB - We examine the gravitational redshift of radiation emitted from within the potential of a cluster. Spectral lines from the intracluster medium (ICM) are redshifted in proportion to the emission-weighted mean potential along the line of sight, amounting to ≈50 km s-1 at a radius of 100 kpc h-1, for a cluster dispersion of 1200 km s-1. We show that the relative redshifts of different ionization states of metals in the ICM provide a unique probe of the three-dimensional matter distribution. An examination of the reported peculiar velocities of cD galaxies in well-studied Abell clusters reveals that they are typically redshifted by an average of ∼200 km s-1. This can be achieved by gravity with the addition of a steep central potential associated with the cD galaxy. Note that, in general, gravitational redshifts cause a small overestimate of the recessional velocities of clusters by an average of ∼20 km s-1.

KW - Cosmology: observations

KW - Galaxies: clusters: general

KW - Techniques: spectroscopic

KW - X-rays: galaxies

UR - http://www.scopus.com/inward/record.url?scp=0034689824&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034689824&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0034689824

VL - 533

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2 PART 2

ER -