Home What is ACCEPT Entropy? Cluster Primer Authors Reduction Code  

Cluster: MACS J1931.8-2634
ObsID: 3282

Page Navigation Links
Cluster Core Image Cooling Time Profile Density Profile
Entropy Profile Gravitating Mass Profile Light Curve
Metal abundance profile Pressure Profile SDSS/DSS Image
Spectral Analysis Surface Brightness Profile Temperature Profile
Wide-Field Image

Col. (1) Exposure time; col. (2) right ascension of cluster center; col. (3) declination of cluster center; col. (4) Galactic absorbing column density, NH; col. (5) redshift; col. (6) maximum radius from cluster center, Rmax; col. (7) minimum counts used per TX annulus; col. (8) average cluster temperature; col. (9) average cluster metal abundance; and col. (10) bolometric luminosity;
Exp
Time
R.A. Decl. NH z Rmax Min. cts. TX Abund. Lbol
ksec hr:min:sec deg:min:sec 1020 cm-2 --- pixels counts keV Solar 1044 ergs/s
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
13.6 19:31:49.656 -26:34:33.99 9.13 0.3520 670 2500 7.50 0.20 23.400

Click here to download a master table of profiles for this cluster.
All images generated using SAOImage DS9, developed by the Smithsonian Astrophysical Observatory.

Smoothed and binnd wide-field Chandra X-ray image of cluster
3282 MACS J1931.8-2634
A gaussian smoothing kernel with size 2 was applied to the flare-cleaned, level-2 events file binned with a factor of 8 to produce this image. Point sources have not been excluded and no exposure correction has been applied to this image.

Smoothed and binned Chandra X-ray image of the cluster "core"
3282 MACS J1931.8-2634
Same as the wide-field image above but the binning factor used here was 2.

SDSS/DSS footprint overlaid on cluster core
3282 MACS J1931.8-2634
The SDSS/DSS footprint (white box) is centered on the cluster core.

Digitized Sky Survey (DSS) image of cluster core
3282 MACS J1931.8-2634
Image taken from Digitized Sky Survey (DSS)

Background light curve
3282 light curve
To check for contamination from background flares or periods of excessively high background, light curve analysis was performed using Maxim Markevitch's contributed CIAO script lc_clean.sl. Periods with count rates >= 3sigma and/or a factor >= 1.2 of the mean background level of the observation were removed from the GTI file.

Surface brightness profile
3282 surface brightness profile
We began by extracting surface brightness profiles from the 0.7-2.0 keV energy range using concentric annular bins of size 5" (~10 ACIS pixels) originating from the X-ray center. To remove the effects of vignetting and exposure time fluctuations we corrected each surface brightness profile by an observation specific normalized radial exposure profile.

Annuli used for generating temperature profile
3282 temperature bins
Each annulus is centered at RA: 19:31:49.656, Decl: -26:34:33.99 and contains 2500 counts. Links to an image of each spectrum and the corresponding best-fit MeKaL model (solid-line) are provided below the image.

Links to images of spectra
Annulus 1 Annulus 2 Annulus 3 Annulus 4

Temperature profile
3282 temperature profile
The temperature profile corresponding to the image and annuli shown above. Uncertainties are 90% confidence.

Metal abundance profile
3282 abundance profile
The abundance profile corresponding to the image and annuli shown above. Uncertainties are 90% confidence.

Density profile
3282 density profile
Electron gas density profile derived from deprojecting the surface brightness with spectral information.

Pressure profile
3282 pressure profile
Electron gas pressure profile derived from the density and temperature profiles.

Entropy profile
3282 entropy profile
Entropy profile derived from density and temperature as K=Tne-2/3. The dashed line is the best-fit for the model K(r) = K0+K100(r/100 kpc)α with fit values:
K0 = 14.56 ± 3.56 keV cm2
K100 = 87.52 ± 9.22 keV cm2
α = 1.27 ± 0.11.
The dashed-dotted line is the best-fit for the model K=K100(r/100 kpc)α.

Conduction suppresion profile
3282 fc profile
Conduction suppression factor, fc profile derived from the entropy profile assuming Spitzer conduction.

Cooling time profile
3282 cooling profile
Gas cooling time profile using the formulation tcool=(3/2 nkT)/(nenpΛ(T,Z)) for isochoric cooling. The dashed horizontal line represents the age of the Universe at the redshift of the cluster.

Gravitating mass profile
3282 grav mass profile
Gravitating mass profile derived from assuming hydrostatic equilibrium and differentiating the log-space electron density profile with a piecewise method. The d(ln T)/dr term has been assumed to be negligible (a terrible assumption). **CAUTION** THIS WAS NOT THE FOCUS OF OUR WORK, USE AT YOUR OWN RISK!


Main Page Top of Page

Email the PI/webmaster: Kenneth W. Cavagnolo
This page was last updated: 2009-11-09 11:31:35 AM
Click map below to see locations of last 100 visitors
Click to zoom in on my visitor map!
Create your free world visitor maps
Unique hits to this page:
Hit Counter

Valid HTML 4.01 Transitional Level A conformance icon, W3C-WAI Web Content Accessibility Guidelines 1.0 Valid CSS! [Valid RSS]


Department of Physics and Astronomy Michigan State University
© Copyright 2009 Michigan State University Board of Trustees. East Lansing MI 48824
MSU is an affirmative-action, equal-opportunity employer.

Kiva - loans that change lives
Our research group proudly supports the microlending efforts of the non-profit organization Kiva.

© Copyright 2007-2009 Kenneth W. Cavagnolo
Except where explicitly stated, all rights are reserved and
content should not be copied, adapted, redistributed, or
otherwise used without the prior written permission of Kenneth
W. Cavagnolo. Any unauthorized publication, copying, hiring,
lending or reproduction is strictly prohibited and constitutes a
breach of copyright.