2002/02/19 by Caleb Scharf, Caleb A. Scharf · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Cluster (spacecraft) #Emission spectrum #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Galaxy groups and clusters #Order (exchange) #Redshift #Spectral line #astro-ph
paper · pdf · doi:10.1086/340338
9 pages, 4 postscript figures, uses AASTEX, accepted ApJ
arxiv created 2002/02/19 · openalex publication_date 2002/06/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
In this short paper I present the results of a calculation that seeks the maximum, or optimal, signal-to-noise energy band for galaxy group or cluster X-ray emission detected by the Chandra and XMM-Newton observatories. Using a background spectrum derived from observations and a grid of models, I show that the "classical" 0.5-2 keV band is indeed close to optimal for clusters with gas temperatures greater than 2 keV and redshifts z < 1. For cooler systems, however, this band is generally far from optimal. Sub-keV plasmas can suffer 20%-60% signal-to-noise loss, compared to an optimal band, and worse for z > 0. The implication is that current and forthcoming surveys should be carefully constructed in order to minimize bias against the low-mass, low-temperature end of the cluster/group population.