Query : 2008A&A...482L..29W

2008A&A...482L..29W - Astronomy and Astrophysics, volume 482, L29-33 (2008/5-2)

Detection of hot gas in the filament connecting the clusters of galaxies Abell 222 and Abell 223.


Abstract (from CDS):

About half of the baryons in the local Universe are invisible and - according to simulations - their dominant fraction resides in filaments connecting clusters of galaxies in the form of low density gas with temperatures in the range of 105<T<107K. This warm-hot intergalactic medium has never been detected indisputably using X-ray observations. We aim to probe the low gas densities expected in the large-scale structure filaments by observing a filament connecting the massive clusters of galaxies A 222 and A 223 (z=0.21), which has a favorable orientation approximately along our line-of-sight. This filament has been previously detected using weak lensing data and as an over-density of colour-selected galaxies. We analyse X-ray images and spectra obtained from a deep observation (144 ks) of A 222/223 with XMM-Newton. We present observational evidence of X-ray emission from the filament connecting the two clusters. We detect the filament in the wavelet-decomposed soft-band (0.5-2.0keV) X-ray image with a 5σ significance. Following the emission down to the 3σ significance level, the observed filament is ≃1.2Mpc wide. The temperature of the gas associated with the filament, determined from the spectra, is kT=0.91±0.25keV, and its emission measure corresponds to a baryon density of (3.4±1.3)x10–5(l/15Mpc)–1/2cm–3, where l is the length of the filament along the line-of-sight. This density corresponds to a baryon over-density of ρ/<ρC≥∼150. The properties of the gas in the filament are consistent with results of simulations of the densest and hottest parts of the warm-hot intergalactic medium.

Abstract Copyright:

Journal keyword(s): cosmology: large-scale structure of Universe - X-rays: galaxies: clusters - galaxies: clusters: individual: Abell 222 - galaxies: clusters: individual: Abell 223

Simbad objects: 5

goto Full paper

goto View the references in ADS

Number of rows : 5
N Identifier Otype ICRS (J2000)
ICRS (J2000)
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2023
1 ACO 222 ClG 01 37 27.4 -12 58 45           ~ 133 1
2 ACO 223 ClG 01 37 55.9 -12 49 11           ~ 118 1
3 Mrk 421 BLL 11 04 27.3140835504 +38 12 31.798495872   13.50 12.90 8.31   ~ 2575 1
4 NAME Virgo Cluster ClG 12 26 32.1 +12 43 24           ~ 6421 0
5 ACO 1656 ClG 12 59 48.7 +27 58 50           ~ 4629 2

To bookmark this query, right click on this link: simbad:objects in 2008A&A...482L..29W and select 'bookmark this link' or equivalent in the popup menu


© Université de Strasbourg/CNRS

    • Contact