ROSNEPAGN - ROSAT North Ecliptic Pole Survey Active Galactic Nuclei Catalog
The ROSAT North Ecliptic Pole (NEP) Survey of Active Galactic
Nuclei (AGN) Catalog is an X-ray flux-limited sample of 219 AGN discovered
in the contiguous 80.7 square degrees region of the ROSAT North Ecliptic Pole
(NEP) Survey (Gioia et al. 2003, ApJS, 149, 29; CDS Cat. <J/ApJS/149/29>).
This catalog features complete optical identifications and spectroscopic
redshifts. The median redshift, X-ray flux, and X-ray luminosity are z = 0.41,
fx = 1.1 x 10^-13 erg/cm^2/s, and Lx = 9.2 x 10^43 h70^-2 erg/s (0.5 - 2.0
keV), respectively. Unobscured Type 1 AGN are the dominant constituents (90%)
of this soft X-ray-selected sample of AGN.
This catalog sample includes several notable revisions relative to previous
versions of the catalog (Mullis 2001, Ph. D. thesis, U. Hawaii; Gioia et al.
2003, ApJS, 149, 29, available in HEASARC Browse as the ROSNEPOID table).
Firstly, the AGN fluxes and luminosities previously reported were
overestimated by approximately 20% on average as a result of an error in
the conversion of X-ray count rate to flux. Secondly, the sample has grown
by 1 because of the reclassification of one of the X-ray sources
(RX J1824.7+6509). Finally, in the present study the authors have adopted
the presently favored "concordance" cosmology in computing the X-ray
luminosities. The revised and updated catalog with corrected properties
presented here should be the reference point for any future work with
the ROSAT NEP AGN sample.
Spatial correlation function of X-ray-selected active galactic nuclei.
Mullis C.R., Henry J.P., Gioia I.M., Bohringer H., Briel U.G., Voges W.,
<Astrophys. J., 617, 192-208 (2004)>
This table was created by the HEASARC in August 2005 based on
CDS table J/ApJ/617/192/table1.dat.
The source name as given in the published paper, formed using
the prefix 'RX J' (for ROSAT X-ray source, Julian 2000 position), and the
X-ray centroid position truncated to 0.1 minutes of time in RA and 1 arcmin
This parameter is a flag which is set to 'a' for the source
'RX J1824.7+6509' (NEP 5500), which was formerly classified as a stellar
X-ray source based on the literature. However, more recent work has
convincingly demonstrated that this source is a type 1 AGN at a redshift
z = 0.303 (e.g., Engels et al. 1998, A&AS, 128, 507 = CDS Cat.
The ROSAT NEP internal catalog identification number.
The Right Ascension, in fixed J2000 sexagesimal format, of the
The Declination, in fixed J2000 sexagesimal format, of the
The Right Ascension of the associated optical object in the
selected equinox. This was given in J2000 coordinates and to a precision
of 0.1 seconds of time in the original catalog.
The Declination of the associated optical object in the selected
equinox. This was given in J2000 coordinates and to a precision of 1
arcsecond in the original catalog.
The Galactic Longitude of the associated optical object.
The Galactic Latitude of the associated optical object.
The column density of Galactic hydrogen, in atoms cm^-2,
from Elvis et al. (1994, ApJS, 95, 413), with supplements from
Stark et al. (1992, ApJS, 79, 77).
The count rate in the 0.1 - 2.4 keV energy band, in
counts per second (ct/s), measured within a circular photometric aperture
of 5 arcminutes radius.
The 1-sigma uncertainty in the count rate
in the 0.1 - 2.4 keV energy band, in ct/s, based on a maximum-likelihood
The unabsorbed flux in the 0.5 - 2.0 keV energy band, in
erg/s/cm^2. The authors have derived the flux from the count rate assuming
that the source has a power-law spectrum with a photon index Gamma of 2, and
with absorption fixed at the Galactic value for the source position. This
total flux accounts for the small fraction of point source flux falling
outside the photometry aperture and reflects the size correction applied
to the detect flux. For point sources such as AGN, this flux correction
factor is constant and equal to 1.0369.
The rest-frame, K-Corrected 0.5 - 2.0 keV luminosity, in erg/s.
Note that the K-correction for a power-law spectrum is (1+z)^(Gamma-2),
and is thus unity for Gamma = 2 (adopted cosmology: H_0 =70 h70 km/s/Mpc,
Omega_M = 0.3, and Omega_Lambda = 0.7).
The spectroscopically measured redshift (typical uncertainty
The AGN classification based on the equivalent width of the
emission lines and the broadness of the permitted lines (1 = type 1, 2
= Type 2).
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