J/ApJS/162/304 ROSAT NEP X-ray source catalog (Henry+, 2006)
The ROSAT North Ecliptic Pole survey: the X-ray catalog.
Henry J.P., Mullis C.R., Voges W., Bohringer H., Briel U.G., Gioia I.M.,
Huchra J.P.
<Astrophys. J. Suppl. Ser., 162, 304-328 (2006)>
=2006ApJS..162..304H 2006ApJS..162..304H
ADC_Keywords: X-ray sources ; Surveys
Keywords: galaxies: active - galaxies: clusters: general - surveys -
X-rays: galaxies: clusters - X-rays: general - X-rays: stars
Abstract:
The sky around the North Ecliptic Pole (NEP), at 18:00:00+66:33:39,
has the deepest exposure of the entire ROSAT All-Sky Survey (RASS,
Cat. IX/10). The NEP is an undistinguished region of moderate
Galactic latitude, b=29.8°, and hence suitable for compiling
statistical samples of both Galactic and extragalactic objects. We
have made such a compilation in the 80.6°2 region surrounding
the NEP. Our sample fully exploits the properties of the RASS, since
the only criteria for inclusion are source position and significance,
and it yields the deepest large solid angle contiguous sample of X-ray
sources to date. We find 442 unique sources above a flux limit
∼2x10-14ergs/cm2/s in the 0.5-2.0keV band. In this paper we
present the X-ray properties of these sources as determined from the
RASS. These include positions, fluxes, spectral information in the
form of hardness ratios, and angular sizes. Since we have performed a
comprehensive optical identification program we also present the
average X-ray properties of classes of objects typical of the X-ray
sky at these flux levels. We discuss the use of the RASS to find
clusters of galaxies based on their X-ray properties alone.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 146 443 ROSAT NEP X-ray source catalog
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See also:
J/ApJS/149/29 : ROSAT NEP optical identifications (Gioia+, 2003)
VIII/28 : Bell Laboratories H I Survey (Stark+ 1992)
J/ApJ/617/192 : ROSAT AGN Catalog in North Ecliptic Pole (Mullis+, 2004)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- RX ROSAT-NEP source name (JHHMM.m+DDMM)
13- 16 I4 --- [GHM2003] The NEP source number (see J/ApJS/149/29)
18- 19 I2 h RAh Hour of Right Ascension (J2000)
21- 22 I2 min RAm Minute of Right Ascension (J2000)
24- 27 F4.1 s RAs Second of Right Ascension (J2000)
29 A1 --- DE- Sign of the Declination (J2000)
30- 31 I2 deg DEd Degree of Declination (J2000)
33- 34 I2 arcmin DEm Arcminute of Declination (J2000)
36- 37 I2 arcsec DEs Arcsecond of Declination (J2000)
39- 44 F6.4 ct/s CRate Net (0.1-2.4keV) count rate (1)
46- 51 F6.4 ct/s e_CRate The 1σ error in CRate
53- 57 I5 s ExpTime Equivalent on-axis exposure time
59- 62 F4.2 10+20/cm2 NH ? Hydrogen column density (2)
64- 68 F5.2 --- HR1 Hardness ratio 1 (3)
70- 73 F4.2 --- e_HR1 The 1σ error in HR1
75- 79 F5.2 --- HR2 Hardness ratio 2 (3)
81- 84 F4.2 --- e_HR2 The 1σ error in HR2
86- 88 I3 arcsec Ext Sigma of the source extent (4)
90- 92 I3 --- Ext-L Difference in likelihood (5)
94- 96 I3 --- Exist ?=999 Existence likelihood from Maximum
likelihood analysis (6)
98-100 I3 --- Map Existence likelihood from MDETECT
analysis (7)
102-108 F7.2 10-17W/m2 Flux ? Total observed 0.5-2keV unabsorbed flux
in units of 10-14erg/s/cm2
110-117 F8.4 10+37W Lum ? Total rest 0.5-2keV luminosity (8)
119-128 A10 --- Class Optical identification class (9)
130-135 F6.4 --- z ? Spectroscopic redshift
137-140 F4.1 --- Param ? Unabsorbed spectrum parameter,
temperature in keV or photon index (10)
142-146 F5.3 --- SC ? Size correction (10)
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Note (1): within a circular aperture of 5' radius,
except for RX J1834.1+7057 where the radius is 6.5'. The rate is
corrected for vignetting, that is it is larger than the net counts
divided by the time the source was in the PSPC field of view.
Note (2): From Elvis, Lockman, & Fassnacht (1994ApJS...95..413E 1994ApJS...95..413E)
supplemented by Stark et al. (1992, Cat. VIII/28). The column
densities were linearly interpolated among the four pixels of the
relevant map nearest to the X-ray position.
Note (3): HR1 compares the 0.52-2.01keV band to the 0.11-0.41keV band
(PHA channels 52-201 and 11-41, respectively) while HR2 uses the
0.91-2.01keV and 0.52-0.90keV bands (PHA channels 91-201 and 52-90,
respectively). The ratios are calculated dividing the harder minus the
softer band net counts by the harder plus the softer band net counts.
Negative net counts resulting from background subtraction have been
set to zero, yielding hardness ratios between -1 and +1.
Note (4): Approximating it by a Gaussian, measured as described in Section 2.1.
Note (5): Between the best fitting extended and point source models of the
source surface brightness, measured as described in Section 2.1
Note (6): In the 0.1-2.4keV band (PHA channels 11-235). The value has been
set to 999 if it exceeds that value.
Note (7): In the band for which the source has the highest MDETECT
existence likelihood. The value has been set to 999 if it
exceeds that value.
Note (8): In units of 1044erg/s.
Assuming a cosmology with H0=70km/s/Mpc, Ωm0=0.3 and
Ω{Lambda0}=0.7. The spectra assumed are thermal with kT=107K
for galactic objects and that given in Param for galaxy groups and
clusters. The spectra assumed are power laws with photon indices 2 for
extragalactic point sources. Absorption for extragalactic objects is
parameterized by the Hydrogen column density NH.
Note (9): Optical identification class, defined as follows:
STAR = stellar;
CL = galaxy group or cluster;
AGN1/AGN2 = AGN based on the equivalent width of the emission lines
and broadness of the permitted emission lines as defined in Gioia
et al. (2003, Cat. J/ApJS/149/29);
BL = BL Lac;
PN = Planetary Nebula
GAL = Possible interacting galaxy.
Note (10): These quantities vary for groups and clusters
but the unabsorbed spectra and size corrections are the same for all
galactic objects and for all extragalactic point sources, as described
in sections 2.3 and 2.4 respectively. In particular, the unabsorbed
spectrum for all galactic sources is a Raymond-Smith thermal plasma
model with solar abundances and a temperature of 107K (0.9keV).
For all extragalactic point sources the spectrum is a power law with
photon index 2. The size correction is 1.0498 for all point sources.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 03-Jan-2007