Using X ray images to detect substructure in a sample of 40 Abell clusters

Details Using X ray images to detect substructure in a sample of 40 Abell clusters Using X ray images to detect substructure in a sample of 40 Abell clusters

Jan 1993

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993egte.conf..285m&link_type=abstract

In NASA. Ames Research Center, The Evolution of Galaxies and Their Environment p 285-286 (SEE N93-26706 10-90)

Astronomy and Astrophysics

Astronomy

3

Brightness Distribution, Galactic Clusters, Galactic Structure, X Ray Astronomy, X Rays, Center Of Mass, Density Distribution, Emissivity, Heao 2, Substructures

Scientific paper

Using a method for constraining the dynamical state of a galaxy cluster by examining the moments of its x-ray surface brightness distribution, we determine the statistics of cluster substructure for a sample of 40 Abell clusters. Using x-ray observations from the Einstein Observatory Imaging Proportional Counter (IPC), we measure the first moment M1(r), the ellipsoidal orientation angle theta2(r), and the axial ratio eta(r) at several different radii in the cluster. We determine the effects of systematics such as x-ray point source emission, telescope vignetting, Poisson noise, and characteristics of the IPC by measuring the same parameters on an ensemble of simulated cluster images. Due to the small band-pass of the IPC, the ICM emissivity is nearly independent of temperature so the intensity at each point in the IPC images is simply proportional to the emission measure calculated along the line of sight through the cluster (e.g. Fabricant et al. 1980). Therefore, barring a change superposition of two x-ray emitting clusters, a significant variation in the image centroid M1(r) as a function of radius indicates that the center of mass of the intra-cluster medium (ICM) varies with radius. We argue that such a configuration (essentially an m = 1 component in the ICM density distribution) is a non-equilibrium component; it results from an off-center subclump or a recent merger in the ICM.

Affiliated with

Also associated with

No associations

Rating

Using X ray images to detect substructure in a sample of 40 Abell clusters does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Using X ray images to detect substructure in a sample of 40 Abell clusters, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Using X ray images to detect substructure in a sample of 40 Abell clusters will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1260129