J/ApJ/598/969 Chandra X-ray sources in NGC 3556 (Wang+, 2003)
Chandra observation of the edge-on galaxy NGC 3556 (M108):
violent galactic disk-halo interaction revealed.
Wang Q.D., Chaves T., Irwin J.A.
<Astrophys. J., 598, 969-981 (2003)>
=2003ApJ...598..969W 2003ApJ...598..969W
ADC_Keywords: X-ray sources
Keywords: galaxies: general - galaxies: individual (NGC 3556) -
galaxies: spiral - X-rays: general
Abstract:
We present a 60ks Chandra ACIS-S observation of the isolated edge-on
spiral galaxy NGC 3556, together with a multiwavelength analysis of
various discrete X-ray sources and diffuse X-ray features.
Description:
Our Chandra observation of NGC 3556 (observation ID 2025) was taken
between 2001 September 8 and 9 for an exposure of 60ks. The instrument
ACIS-S was at the focal plane of the telescope.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 86 83 Chandra Source List
--------------------------------------------------------------------------------
See also:
B/chandra : The Chandra Archive Log (CXC, 2002)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- [WCI2003] Sequential number of the source
4- 22 A19 --- CXOU CXOU Name (JHHMMSS.SS+DDMMSS.s, J2000)
24- 26 F3.1 arcsec ePos Position uncertainty
28- 32 F5.1 --- logP False detection probability (1)
34- 38 F5.2 ct/ks CR On-axis (exposure-corrected) source count rate
in the 0.3-7keV band.
40- 43 F4.2 ct/ks e_CR rms uncertainty on CR
45- 49 F5.2 --- HR ? Hardness ratio, HR=(H-S)/(H+S) (2)
51- 54 F4.2 --- e_HR ? rms uncertainty on HR
56- 60 F5.2 --- HR1 ? Hardness ratio 1, HR1=(S2-S1)/S (2)
62- 65 F4.2 --- e_HR1 ? rms uncertainty on HR1
67- 71 F5.2 --- HR2 ? Hardness ratio 2, HR2=(H2-H1)/H (2)
73- 76 F4.2 --- e_HR2 ? rms uncertainty on HR2
78 A1 --- Band [BSH] Band in which a source is detected with
the most accurate position (2)
--------------------------------------------------------------------------------
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 (logP←20.0 is set to -20.0).
Note (2): Hardness ratios are defined by:
S1 = net source count rates in the 0.3-0.7keV band
S2 = net source count rates in the 0.7-1.5keV band
H1 = net source count rates in the 1.5-3keV band
H2 = net source count rates in the 3-7keV band
S = S1+S2, H = H1+H2, B = S+H
The hardness ratios are calculated only for sources with individual
S/Ns greater than 4 in the broad band (B=S+H), and only the values
with uncertainties less than 0.2 are included
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) James Marcout, Patricia Vannier [CDS] 23-Jan-2004