J/ApJ/611/821 A2125 in X-ray (Wang+, 2004)
X-raying A2125: a large-scale hierarchical complex of galaxies and hot gas.
Wang Q.D., Owen F., Ledlow M.
<Astrophys. J., 611, 821-834 (2004)>
=2004ApJ...611..821W 2004ApJ...611..821W
ADC_Keywords: Clusters, galaxy ; X-ray sources
Mission_Name: Chandra
Keywords: cosmology: observations - galaxies: clusters: individual (A2125) -
galaxies: evolution - galaxies: general - X-rays: galaxies -
X-rays: galaxies: clusters
Abstract:
We present an 82ks Chandra ACIS-I observation of a large-scale
hierarchical complex, which consists of various clusters/groups of
galaxies and low surface brightness X-ray emission at z=0.247. This
high-resolution Chandra observation allows us for the first time to
separate unambiguously the X-ray contributions from discrete sources
and large-scale diffuse hot gas. We detect 99 X-ray sources in a
17{arcmin}x17{arcmin} field.
Description:
The Chandra observation of A2125 (obs. ID 2207) was taken on 2001
August 24, for an exposure of 81.6ks. The instrument ACIS-I was at
the focal plane of the telescope and in the "VERY FAINT" mode.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 98 99 Chandra Source List
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See also:
B/chandra : The Chandra Archive Log (CXC, 2002-)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- [WOL2004] Sequential running number
5- 23 A19 --- CXOU CXOU designation (JHHMMSS.ss+DDMMSS.s)
26- 28 F3.1 arcsec e_pos Position uncertainty (1σ)
31- 35 F5.1 --- logP False detection probability (1)
38- 42 F5.2 ct/ks CR On-axis (exposure-corrected) source count
rate in the 0.5-8keV band
45- 48 F4.2 ct/ks e_CR Uncertainty in CR
51- 55 F5.2 --- HR ? Hardness ratio, HR=(H-S)/(H+S) (2)
58- 61 F4.2 --- e_HR ? Uncertainty in HR
63- 67 F5.2 --- HR1 ? Hardness ratio 1, HR1=(S2-S1)/S (2)
70- 73 F4.2 --- e_HR1 ? Uncertainty in HR1
76- 80 F5.2 --- HR2 ? Hardness ratio 2, HR2=(H2-H1)/H (2)
83- 86 F4.2 --- e_HR2 ? Uncertainty in HR2
89- 98 A10 --- Note Band of detection and correspondance (3)
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Note (1): The false detection probability P that the detected number
of counts may result from the Poisson fluctuation of the local
background within the detection aperture [log(P) smaller than
-20.0 is set to -20.0].
Note (2): The hardness ratios defined as HR=(H-S)/(H+S), HR1=(S2-S1)/S, and
HR2=(H2-H1)/H, where the net source count rates are:
S1 in the 0.5-1keV band,
S2 in the 1-2keV band,
H1 in the 2-4keV, and
H2 in the 4-8keV band,
and S=S1+S2 and H=H1+H2.
The hardness ratios are calculated only for sources with individual
signal-to-noise ratios greater than 4 in the broad band (B=S+H), and
only the values with uncertainties less than 0.2 are included.
Note (3): The labels "B," "S," or "H" mark the band in which a source is
detected (broad-band B=S=H, Soft or Hard); the detection with the most
accurate position, as adopted in CXOU, is marked first. The label "r"
and "o" denote the identification as the A2125 complex member galaxies
in radio and optical.
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History:
From electronic version of the journal
(End) Marianne Brouty [CDS] 06-Apr-2005