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## ASCAEGCLUS - ASCA Elliptical Galaxies and Galaxy Clusters Catalog |
HEASARC Archive |

For this project, the authors utilized all of the ASCA data of elliptical
galaxies and clusters of galaxies. Several clusters were observed more than
once, and they chose the observation with the longest exposure. The total
number of objects that the authors identified as elliptical galaxies and
clusters was 313, and these are listed in this table. Some of the objects
could not be utilized for deriving various correlations, due to either having
an unknown redshift (17 objects), an insignificant detection (13 objects
listed below), or contamination of the environmental X-ray emission, such as
cluster emission around non-cD elliptical galaxies (10 objects: NGC 4472, NGC
4406, NGC 4374, NGC 1404, NGC 499, NGC 6034, NGC 2865, NGC 4291, CL 2236-04
and RX J1031.6-2607). Thus, the authors analyzed the ASCA data for 292
objects, among which were ~ 50 elliptical galaxies and galaxy groups. In this
study, the authors assumed the Hubble constant to be 50 h_{50} km s^{-1}
Mpc^{-1} and q_{0} to be 0.

Table 1 of the reference paper (reproduced below) lists the 13 clusters for which only 90% confidence level upper limits to the flux in the observer's frame are available:

Name Flux (0.5 - 2 keV) Upper Limit (erg/s/cm^{2}) NGC 5018 9.8 x 10^{14}GHO 1322+3114 1.3 x 10^{13}J1888.16CL 5.9 x 10^{14}CL 0317+1521 4.5 x 10^{14}MS 1512.4+3647 1.0 x 10^{12}PRG 38 6.9 x 10^{14}SCGG 205 6.9 x 10^{14}RGH 101 9.1 x 10^{14}3C 184 8.5 x 10^{14}RX J1756.5+6512 1.6 x 10^{13}3C 324 5.4 x 10^{14}PDCS 01 2.8 x 10^{14}MS 0147.8-3941 5.0 x 10^{14}

ASCA compilation of X-ray properties of hot gas in elliptical galaxies and galaxy clusters: two breaks in the temperature dependences. Fukazawa Y., Makishima K., Ohashi T. <Publ. Astron. Soc. Jap., 56, 965-1009 (2004)> =2004PASJ...56..965F

**Name**

The name of the object (elliptical galaxy or cluster of galaxies).

**Sequence_Number**

The ASCA observation sequence identifier.

**Redshift_Flag**

For 17 objects flagged by a value of 'E', no redshift was
available and the authors
had to estimate a value. Among the 17 objects without an available redshift,
the Fe-K line was clearly detected in 3 clusters, and the authors obtained the
redshift by fitting the spectra with the redshift parameter as a free
parameter. For the remaining objects, they estimated the redshifts from the
luminosity-temperature relation of Edge and Stewart (1991, MNRAS, 252, 414),
L_{X} = 1.0E43(kT /keV)^{2.79} erg s^{-1} (2-10 keV).

**Redshift**

The redshift z of the object.

**Time**

The date/time of the start of the ASCA observation.

**End_Time**

The date/time of the end of the ASCA observation.

**RA**

The Right Ascension of the ASCA pointing at the object in the selected
equinox. This was given in J2000.0 decimal degrees to a precision of 0.001
degrees (3.6") in the original table.

**Dec**

The Declination of the ASCA pointing at the object in the selected
equinox. This was given in J2000.0 decimal degrees to a precision of 0.001
degrees (3.6") in the original table.

**LII**

The Galactic Longitude of the ASCA pointing at the object.

**BII**

The Galactic Latitude of the ASCA pointing at the object.

**Exposure**

The exposure time of the ASCA observation, in seconds

**Count_Rate**

The X-ray count rate of the object, in ct s^{-1} 1GIS^{-1}.

**Center_DetX**

The x-coordinate of the center of the integration region
for the spectra of the object, in units of DETX channels.

**Center_DetY**

The y-coordinate of the center of the integration region
for the spectra of the object, in units of DETY channels.

**Int_Inner_Radius**

The inner radius of the integration region for the spectra
of the object, in units of DETX/DETY channels.

**Int_Outer_Radius**

The outer radius of the integration region for the spectra
of the object, in units of DETX/DETY channels.

**NH**

The adopted Galactic column density towards the object, in H atoms
cm^{-2}, taken from Stark et al. (1992, ApJS, 79, 77).

**Spectral_Fit_Flag**

This flag parameter indicates a note on the spectral
fitting as follows:

1 = result from fitting only the GIS spectrum 2 = result from simultaneous fitting the GIS and SIS spectra

**kT_Limit**

This limit parameter is set to '<' if the corresponding parameter
value is an upper limit rather than an actual value.

**kT**

The inferred ICM temperature kT, in keV, from fitting the observed
spectrum with a MEKAL plasma model with the Galactic column density
towards the object. For objects with kT < 1.5 keV, the authors added
a bremsstrahlung component to reproduce the emission from low-mass X-ray
binaries in elliptical galaxies.

**kT_Error**

The 90% confidence uncertainty in kT, in keV.

**Abundance_Limit**

This limit parameter is set to '<' if the corresponding
parameter value is an upper limit rather than an actual value.

**Abundance**

The inferred metal abundance of the MEKAL plasma, relative to
the solar metallicity of Anders and Grevesse (1989, GCA, 53, 197).

**Abundance_Error**

The 90% confidence uncertainty in the inferred metal
abundance of the MEKAL plasma.

**Thermal_Fraction**

The fraction of observed flux due to the thermal MEKAL
component inferred from the spectral fitting. The remaining flux is due
to a bremsstrahlung component which was added for the low-temperature (kT < 1.5
keV) objects in order to reproduce the emission from low-mass X-ray
binaries in elliptical galaxies

**Radial_Flag**

The meaning of this parameter is somewhat unclear to the HEASARC. The
reference paper states that a flagged value for this parameter ('A' is used
in this version) means that for this object the redshift was assumed in the
radial fitting. It thus would seem to be similar to the redshift_flag
parameter (q.v.): in fact, of the 17 objects with the redshift_flag set, 16
also have the radial_flag set, while, conversely, of the 25 objects which
have the radial_flag set, 16 of them have the redshift_flag set.

**Beta_1**

The beta_{1} parameter value for the object's electron density dependence on
radius, as inferred from the spatial fitting using a single-beta model. The
authors represented the ICM density distribution with a standard single-beta
model for all objects, as discussed in Section 3.5 of the reference paper.

**Beta_1_Neg_Err**

The lower (negative) 90% confidence error in the
corresponding parameter value.

**Beta_1_Pos_Err**

The upper (positive) 90% confidence error in the
corresponding parameter value.

**Core_Radius**

The core radius a_{1}, in arcminutes, as inferred from the
spatial fitting of the object's X-ray emission using a single-beta model.
See Section 3.5 of the reference paper for more details

**Core_Radius_Neg_Err**

The lower (negative) 90% confidence error in the
corresponding parameter value.

**Core_Radius_Pos_Err**

The upper (positive) 90% confidence error in the
corresponding parameter value, in the same units as the latter.

**Core_Radius_Kpc**

The linear distance corresponding to the core radius a_{1},
in (h_{50})^{-1} kpc, for the single-beta model fit.

**Ne**

The central value of the electron density n_{(0,1)}, in (h_{50})^{0.5}
cm^{-3}, as inferred from the
spatial fitting of the object's X-ray emission using a single-beta model.
See Section 3.5 of the reference paper for more details.

**Ne_Neg_Err**

The lower (negative) 90% confidence error in the corresponding
parameter value, in the same units as the latter.

**Ne_Pos_Err**

The upper (positive) 90% confidence error in the corresponding
parameter value, in the same units as the latter.

**Total_Mass**

The total mass within R_{limit}, in (h_{50})^{-1} solar masses, as inferred from
the spatial fitting of the object's X-ray emission using a single-beta model,
where R_{limit} (called detect_radius in this table) is the radius outside of
which the ICM density is assumed to be zero. The authors determined R_{limit}
by increasing its value until the radial-fitting chi-squared value did not
significantly improve.

**Gas_Mass**

The gas mass within R_{limit}, in (h_{50})^{-2.5} solar masses, as inferred from
the spatial fitting of the object's X-ray emission using a single-beta model,
where R_{limit} (called detect_radius in this table) is the radius outside of
which the ICM density is assumed to be zero. The authors determined R_{limit}
by increasing its value until the radial-fitting chi-squared value did not
significantly improve.

**Gas_Mass_Neg_Err**

The lower (negative) 90% confidence error in the
corresponding parameter value, in the same units as the latter.

**Gas_Mass_Pos_Err**

The upper (positive) 90% confidence error in the
corresponding parameter value, in the same units as the latter.

**Detect_Radius_Limit**

This limit parameter is set to '>=' if the
corresponding parameter value might be a lower limit rather than an actual
value.

**Detect_Radius_Mpc**

The R_{limit} parameter, in (h_{50})^{-1} Mpc. This is the radius outside of
which the ICM density is assumed to be zero, or, equivalently, the maximum
radius out to which the ASCA GIS can detect X-ray emission. The authors
determined its value by increasing it until the radial-fitting chi-squared
value did not significantly improve.

**Detect_Radius**

The R_{limit} parameter, in arcminutes. This is the
radius outside of which the ICM density is assumed to be zero, or,
equivalently, the maximum radius out to which the ASCA GIS can detect X-ray
emission. The authors determined its value by increasing it until the
radial-fitting chi-squared value did not significantly improve.

**Flm_Flag**

The meaning of this parameter is somewhat unclear to the HEASARC. The
reference paper states that a flagged value for this parameter ('A' is used
in this version) means that for this object the redshift was assumed in the
flux, central surface brightness and luminosity calculation. It thus would
seem to be similar to the redshift_flag parameter (q.v.): in fact, of the 17
objects with the redshift_flag set, 16 also have the flm_flag set, while,
conversely, all 16 objects which have the flm_flag set also have the
redshift_flag set.

**Flux**

The observed X-ray flux of the object in the 0.5 - 10 keV band in the
observer's frame, in erg s^{-1} cm^{-2}, obtained by integrating the simulated
emission spectra of the best-fit single-beta model within the best-fit
R_{limit} value.

**Central_SB**

The central surface brightness of the object in the 0.5 - 10 keV
band in the observer's frame, in erg s^{-1} cm^{-2} arcmin^{-2}.

**Central_SB_Neg_Err**

The lower (negative) 90% confidence error in the
corresponding parameter value, in the same units as the latter.

**Central_SB_Pos_Err**

The upper (positive) 90% confidence error in the
corresponding parameter value, in the same units as the latter.

**Lx_Tot**

The bolometric X-ray luminosity of the object in the rest frame, in
h_{50}^{-2} erg s^{-1}, defined as the emissivity of the single-beta plasma model
in the 0.001 - 200 keV band in the rest frame.

**Lx_Tot_Neg_Err**

The lower (negative) 90% confidence error in the
corresponding parameter value, in the same units as the latter.

**Lx_Tot_Pos_Err**

The upper (positive) 90% confidence error in the
corresponding parameter value, in the same units as the latter.

**Lx_Fraction**

The fraction of the bolometric luminosity of the object
for the single-beta plasma model that is emitted in the 0.5 - 10 keV band.

**Lx_Tot_Inner_Limit**

This limit parameter is set to '<' if the corresponding
parameter value is an upper limit rather than an actual value.

**Lx_Tot_Inner**

The bolometric X-ray luminosity in the rest frame, L_{X2}, in
h_{50}^{-2} erg s^{-1}, defined as the emissivity of the inner component in the
double-beta plasma model for the emission from the object
in the 0.001 - 200 keV band in the rest frame.

**Lx_Tot_Inner_Neg_Err**

The lower (negative) 90% confidence error in the
corresponding parameter value, in the same units as the latter.

**Lx_Tot_Inner_Pos_Err**

The upper (positive) 90% confidence error in the
corresponding parameter value, in the same units as the latter.

**Lx_Tot_Outer**

The bolometric X-ray luminosity in the rest frame, L_{X1}, in h_{50}^{-2} erg
s^{-1}, defined as the emissivity of the outer component in the double-beta
plasma model for the emission from the object in the 0.001 - 200 keV band in
the rest frame.

**Lx_Tot_Outer_Neg_Err**

The lower (negative) 90% confidence error in the
corresponding parameter value, in the same units as the latter.

**Lx_Tot_Outer_Pos_Err**

The upper (positive) 90% confidence error in the
corresponding parameter value, in the same units as the latter.

**DB_Beta_1**

The beta_{1} parameter value for the object's electron density dependence on
radius, as inferred from the spatial fitting using a double-beta model, in
which the core radius a_2_and beta value beta_{2} of the second, small-scale
component are fixed at 10 (h_{50})^{-1} kpc and 0.7, respectively. This
additional component is often required to fit poor clusters. 57 such clusters
were fit using the double-beta model, the details of which are discussed in
Section 3.5 of the reference paper.

**DB_Beta_1_Neg_Err**

The lower (negative) 90% confidence error in the
corresponding parameter value.

**DB_Beta_1_Pos_Err**

The upper (positive) 90% confidence error in the
corresponding parameter value.

**DB_Core_Radius**

The core radius a_{1}, in arcminutes, as inferred from the
spatial fitting of the object's X-ray emission using a double-beta model,
in which the core radius a_2_and beta value beta_{2} of the second, small-scale
component are fixed at 10 (h_{50})^{-1} kpc and 0.7, respectively.
See Section 3.5 of the reference paper for more details.

**DB_Core_Radius_Neg_Err**

The lower (negative) 90% confidence error in the
corresponding parameter value, in the same units as the latter.

**DB_Core_Radius_Pos_Err**

The upper (positive) 90% confidence error in the
corresponding parameter value, in the same units as the latter.

**DB_Core_Radius_Kpc**

The linear distance corresponding to the core radius
a_{1}, in (h_{50})^{-1} kpc, for the double-beta model fit.

**DB_Alt_Core_Radius_Kpc**

The linear distance corresponding to the core radius
in an alternate double-beta model in which the authors assumed beta_{1} = 0.6
for the outer beta-model component.

**DB_Inner_Ne**

The central value of the electron density for the
inner component n_{(0,2)}, in (h_{50})^{0.5} cm^{-3}, as inferred from the
spatial fitting of the object's X-ray emission using a double-beta model.
See Section 3.5 of the reference paper for more details.

**DB_Inner_Ne_Neg_Err**

The lower (negative) 90% confidence error in the
corresponding parameter value, in the same units as the latter.

**DB_Inner_Ne_Pos_Err**

The upper (positive) 90% confidence error in the
corresponding parameter value, in the same units as the latter.

**DB_Outer_Ne**

The central value of the electron density for the
outer component n_{(0,1)}, in (h_{50})^{0.5} cm^{-3}, as inferred from the
spatial fitting of the object's X-ray emission using a double-beta model.
See Section 3.5 of the reference paper for more details.

**DB_Outer_Ne_Neg_Err**

The lower (negative) 90% confidence error in the
corresponding parameter value, in the same units as the latter.

**DB_Outer_Ne_Pos_Err**

The upper (positive) 90% confidence error in the ]
corresponding parameter value, in the same units as the latter.

**DB_Alt_Outer_Ne**

The central value of the electron density n_{(0,1)} for the outer component
n_{0,1}, in (h_{50})^{0.5} cm^{-3}, as inferred from the spatial fitting of the
object's X-ray emission using an alternate double-beta model in which beta_{1}
= 0.6 is assumed for the outer component. See Section 3.5 of the reference
paper for more details.

**DB_Gas_Mass**

The gas mass within R_{limit}, in (h_{50})^{-2.5} solar masses, as inferred from
the spatial fitting of the object's X-ray emission using a double-beta model,
where R_{limit} (called detect_radius in this table) is the radius outside of
which the ICM density is assumed to be zero. The authors determined R_{limit}
by increasing its value until the radial-fitting chi-squared value did not
significantly improve.

**DB_Gas_Mass_Neg_Err**

The lower (negative) 90% confidence error in the
corresponding parameter value, in the same units as the latter.

**DB_Gas_Mass_Pos_Err**

The upper (positive) 90% confidence error in the
corresponding parameter value, in the same units as the latter.

**DB_Alt_Gas_Mass**

The gas mass within R_{limit}, in (h_{50})^{-2.5} solar masses, as inferred from
the spatial fitting of the object's X-ray emission using an alternate
double-beta model in which beta_{1} = 0.6 for the outer beta-model component,
where R_{limit} (called detect_radius in this table) is the radius outside of
which the ICM density is assumed to be zero. The authors determined R_{limit}
by increasing its value until the radial-fitting chi-squared value did not
significantly improve.