Evidence for line-of-sight structure in a comparison of X-ray and optical observations of the high-redshift cluster RCS 043938-2904.7
We present new Chandra observations of a high-redshift (z - 1) galaxy cluster discovered in the Red-Sequence Cluster Survey (RCS): RCS 043938-2904.7. X-ray luminosity measurements and mass estimates are consistent with L X-TX and MÎ´-TX relationships obtained from low-redshift data. Assuming a single cluster, X-ray mass estimates are a factor of âˆ¼ 10-100 below the red-sequence optical richness mass estimate. Optical spectroscopy reveals that this cluster comprises two components, which are close enough to perhaps be physically associated. We present simple modeling of this two-component system, which then yields an X-ray mass and optical richness consistent with expectations from statistical samples of lower redshift clusters. An unexpectedly high gas mass fraction is measured assuming a single cluster, which independently supports this interpretation. Additional observations will be necessary to confirm the excess gas mass fraction and to constrain the mass distribution. Â© 2008. The American Astronomical Society. All rights reserved.
|Título según WOS:||Evidence for line-of-sight structure in a comparison of X-ray and optical observations of the high-redshift cluster RCS 043938-2904.7|
|Título según SCOPUS:||Evidence for line-of-sight structure in a comparison of X-ray and optical observations of the high-redshift cluster RCS 043938-2904.7|
|Título de la Revista:||ASTROPHYSICAL JOURNAL|
|Editorial:||IOP PUBLISHING LTD|
|Fecha de publicación:||2008|
|Página de inicio:||293|