J/ApJ/669/765 Chandra X-ray sources in LALA Cetus field (Wang+, 2007)
Chandra X-ray sources in the LALA Cetus field.
Wang J.X., Zheng Z.Y., Malhotra S., Finkelstein S.L., Rhoads J.E.,
Norman C.A., Heckman T.M.
<Astrophys. J., 669, 765-775 (2007)>
=2007ApJ...669..765W 2007ApJ...669..765W
ADC_Keywords: X-ray sources ; Surveys ; Magnitudes
Keywords: catalogs - galaxies: active - galaxies: high-redshift -
X-rays: diffuse background - X-rays: galaxies
Abstract:
The 174ks Chandra Advanced CCD Imaging Spectrometer exposure of the
Large Area Lyman Alpha Survey (LALA) Cetus field is the second of the
two deep Chandra images on LALA fields. In this paper we present the
Chandra X-ray sources detected in the Cetus field, along with an
analysis of X-ray source counts, stacked X-ray spectrum, and optical
identifications. A total of 188 X-ray sources were detected: 174 in
the 0.5-7.0keV band, 154 in the 0.5-2.0keV band, and 113 in the
2.0-7.0keV band. The X-ray source counts were derived and compared
with LALA field (172ks exposure).
Description:
A total of 176ks of Chandra ACIS exposure on the LALA Cetus field was
obtained in very faint (VFAINT) mode, composed of two individual
observations. The first observation, with 160.4ks exposure, was taken
on UT 2002 June 13-14 (Chandra ObsID 4129). The second observation,
with 15.4ks exposure, was taken 1 day later (UT 2002 June 15, ObsID
4402).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 162 188 Chandra sources in LALA Cetus field
--------------------------------------------------------------------------------
See also:
B/chandra : The Chandra Archive Log (CXC, 1999-)
J/AJ/127/213 : LALA Bootes field X-ray source catalog (Wang+, 2004)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- [WZM2007] Sequential number
5- 22 A18 --- CXOLALA2 CXOLALA2 designation (JHHMMSS.s+DDMMSS.s)
23 A1 --- m_CXOLALA2 [X] Multiplicity index on CXOLALA2
24- 25 I2 h RAh Right ascension (J2000) (1)
27- 28 I2 min RAm Right ascension (J2000) (1)
30- 33 F4.1 s RAs Right ascension (J2000) (1)
35 A1 --- DE- Declination sign (J2000) (1)
36- 37 I2 deg DEd Declination (J2000) (1)
39- 40 I2 arcmin DEm Declination (J2000) (1)
42- 45 F4.1 arcsec DEs Declination (J2000) (1)
47- 50 F4.2 arcsec ePos 3σ uncertainties of the centroid
positions directly given by WAVDETECT
52- 56 F5.1 ct Tcts Total band (0.5-10keV) net counts
58- 61 F4.1 ct E_Tcts Error on Tcts (upper limit)
63- 66 F4.1 ct e_Tcts Error on Tcts (lower limit)
68- 72 F5.1 ct Scts Soft band (0.5-2keV) net counts
74- 77 F4.1 ct E_Scts Error on Scts (upper limit)
79- 82 F4.1 ct e_Scts Error on Scts (lower limit)
84- 88 F5.1 ct Hcts Hard band (2-10keV) net counts
90- 93 F4.1 ct E_Hcts Error on Hcts (upper limit)
95- 98 F4.1 ct e_Hcts Error on HCts (lower limit)
100-102 A3 --- Det [TSH ] Band detections (2)
104-108 F5.2 --- HR Hardness ratio (HR=(H-S)/(H+S)) (3)
110-113 F4.2 --- E_HR Error on HR (upper limit)
115-118 F4.2 --- e_HR Error on HR (lower limit)
120-124 F5.2 aW/m2 S0.5-10 Flux density in total band (0.5-10keV) (4)
126 A1 --- l_S0.5-2 Limit flag on S0.5-2
127-131 F5.2 aW/m2 S0.5-2 Flux density in soft band (0.5-2keV) (4)
133 A1 --- l_S2-10 Limit flag on S2-10
134-138 F5.2 aW/m2 S2-10 Flux density in hard band (2-10keV) (4)
140-143 F4.1 arcsec oRA ?=- Offset in right ascension of the detected
optical counterpart (RAO-RAX)
145-148 F4.1 arcsec oDE ?=- Offset in declination of the detected
optical counterpart (DEO-DEX)
150 A1 --- l_r'mag Limit flag on r
151-155 F5.2 mag r'mag ? r'-band AUTO magnitude from SExtractor (5)
157-160 F4.2 mag e_r'mag ? rms uncertainty on r'mag
162 A1 --- n_r'mag Note on r'mag (6)
--------------------------------------------------------------------------------
Note (1): Whenever available, source coordinates derived in the soft-band
image, which has the best spatial resolution among the three bands,
are presented. For sources not detected in the soft band, total (with
a higher priority) or hard-band positions are used as substitutions.
Note (2): Multiple letters are used for sources detected in more
than one band, where bands are:
T = source detected in total band
S = source detected in soft band
H = source detected in hard band
Note (3): Here we calculate the hardness ratios with a Bayesian approach
which models the detected counts as a Poisson distribution and can
give reliable error bars for both low and high count sources.
Note (4): Galactic-absorption-corrected, NH=2.2x1020cm-2.
In 10-15erg/cm2/s = 10-18W/m2
Note (5): Kron-like elliptical aperture magnitudes, Bertin & Arnouts
(1996A&AS..117..393B 1996A&AS..117..393B). For sources which are not detected in r' band,
5σ upper limits of the magnitudes are given when available.
Note (6): Notes as follows:
b = Sources with the searching circles seriously overlapped by nearby
bright sources and no optical counterparts can be visually
identified. Reliable upper limits on their r'-band magnitudes
are thus not available
c = Sources with optical counterparts visually identified. SExtractor
failed to detect these counterparts due to dilution of nearby
bright sources. For these counterparts, their r'-band magnitudes
are measured within a 1.5" radius circle.
d = Two Sources which are not covered by the MMT r'-band image
e = Sources with two counterparts identified within the searching
circles. Here we only present the one which is closer to the
center of the circles
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 17-Jan-2010