J/PASJ/53/445 ASCA Deep survey in Lockman Hole Field (Ishisaki+, 2001)
ASCA Deep survey in the Lockman Hole Field
Ishisaki Y., Ueda Y., Yamashita A., Ohashi T., Lehmann I., Hasinger G.
<Publ. Astron. Soc. Jap., 53, 445 (2001)>
=2001PASJ...53..445I 2001PASJ...53..445I
ADC_Keywords: X-ray sources ; Active gal. nuclei
Mission_Name: ASCA
Keywords: galaxies: active - surveys - X-rays: galaxies - X-rays: general
Abstract:
We present the results of deep observations of the Lockman Hole field
with the ASCA SIS, covering 926arcmin2 in the 1-7keV energy range,
with a sensitivity 3-5 times deeper than the previous ASCA larger area
surveys. Utilizing the results of the ROSAT Ultra Deep survey, we have
detected 32, 25, and 15 sources in the 1-7, 1-2, and 2-7keV bands, and
only 4, 4, and 1 sources remain unidentified, respectively. The
average hardness of the sources detected in the 1-7keV band with
fluxes of between 10-14 and 10-13erg/cm2/s corresponds to a
photon index of 1.65±0.10. Type-2 AGNs show significantly harder
spectra than type-1s, which can be explained by absorption column
densities of NH∼1022-23cm^-2 at the source redshifts. Fifteen
sources are detected in the hard-band (2-7keV), consisting of six
type-1 AGNs, six type-2 AGNs, one star, one cluster of galaxies, and
one unidentified source. Type-2 AGNs make up a major part of hard
X-ray populations in the 2-7keV band at a flux level of
3x10-14erg/cm2/s (2-7 keV). The redshift distributions of type-1
and type-2 AGNs suggest a lack of high luminosity (optically-defined)
type-2 AGNs with intrinsic NH<1023cm^-2, n the redshift range
z∼1-2 and/or with intrinsic luminosities larger than 3x1044erg/s
(2-10keV at source frame).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 109 50 ASCA properties of the X-ray sources in the
Lockman Hole Field
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See also:
J/A+A/371/833 : ROSAT Ultra Deep Survey (Lehmann+, 2001)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- [IUY2001] Sequential number
3- 4 A2 --- n_[IUY2001] [* ] **: variable source
6- 12 F7.3 deg RAdeg Right ascension (J2000)
14- 20 F7.3 deg DEdeg Declination (J2000)
22- 26 F5.3 --- z ? Redshift
27- 28 A2 --- n_z [+ ] ++: Photometric redshift from Lehmann
et al., 2001, Cat. J/A+A/371/833)
30- 33 A4 --- Class Classification (1)
35- 45 A11 --- OthClass Classification from other works (2)
48 A1 --- l_F1-7keV Limit flag on F1-7keV
49- 53 F5.3 10-16W/m2 F1-7keV X-flux at 1-7keV, in 10-13erg/s/cm2 (3)
55- 58 F4.2 10-16W/m2 e_F1-7keV ? rms uncertainty on F1-7keV
60 A1 --- l_F1-2keV Limit flag on F1-2keV
61- 65 F5.3 10-16W/m2 F1-2keV X-flux at 1-2keV, in 10-13erg/s/cm2 (3)
67- 71 F5.3 10-16W/m2 e_F1-2keV ? rms uncertainty on F1-2keV
73 A1 --- l_F2-7keV Limit flag on F2-7keV
74- 78 F5.3 10-16W/m2 F2-7keV X-flux at 2-7keV, in 10-13erg/s/cm2 (3)
80- 83 F4.2 10-16W/m2 e_F2-7keV ? rms uncertainty on F2-7keV
85- 88 F4.1 --- SF1-7keV Detection significance for 1-7keV band (4)
89 A1 --- --- [/]
90- 93 F4.1 --- SF1-2keV Detection significance for 1-2keV band (4)
94 A1 --- --- [/]
95- 98 F4.1 --- SF2-7keV Detection significance for 2-7keV band (4)
100-104 F5.2 --- HR Hardness ratio (5)
106-109 F4.2 --- e_HR rms uncertainty on HR
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Note (1): Classification:
AGN1: AGNs with ID class a-c in Schmidt et al. (1998A&A...329..495S 1998A&A...329..495S)
and Lehmann et al. (2000A&A...354...35L 2000A&A...354...35L)
AGN2: AGNs with ID class d and e in Schmidt et al. (1998A&A...329..495S 1998A&A...329..495S)
and Lehmann et al. (2000A&A...354...35L 2000A&A...354...35L)
CLUS: Cluster
GAL: Galaxy
GRP:
STAR: Star
UnID: Unidentified
Note (2):
PSPC-NNN : Classification given in table 4 of Hasinger et al.
(1998A&A...329..482H 1998A&A...329..482H)
HRI-NNN : Classification given in table 3 of Lehmann et al.
(2001, Cat. J/A+A/371/833)
ASCA-NNN : ASCA classification
Note (3):
X-ray flux is calculated from a counting rate in the corresponding
energy band,assuming a power-law spectrum with Γ=1.7 with no
intrinsic absorption. Errors or upper limits are 1σ.
Note (4): Detection significances for 1-7/1-2/2-7keV bands, defined as
(best fit count rate)/(its 1σ statistical error).
Note (5): Hardness ratio, calculated as (H-S)/(H+S) where H and S
represent the SIS vignetting-corrected count rate in the 2-7keV and
1-2keV bands, respectively. Errors are 1σ.
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History:
From electronic version of the journal
(End) James Marcout, Patricia Bauer [CDS] 28-Sep-2001