NGC1399CXO - NGC 1399 Chandra X-Ray Source Catalog

Overview

This table contains results from a wide-field study of the globular cluster (GC)/low-mass X-ray binary (LMXB) connection in the giant elliptical NGC 1399. The large field of view of the Advanced Camera for Surveys/WFC, combined with the high resolution of the Hubble Space Telescope and Chandra, allow the authors to constrain the LMXB formation scenarios in elliptical galaxies. They confirm that NGC 1399 has the highest LMXB fraction in GCs of all nearby elliptical galaxies studied so far, even though the exact value depends on galactocentric distance due to the interplay of a differential GC versus galaxy light distribution and the GC color dependence. In fact, LMXBs are preferentially hosted by bright, red GCs out to > 5 R_eff of the galaxy light. The finding that GCs hosting LMXBs follow the radial distribution of their parent GC population argues against the hypothesis that the external dynamical influence of the galaxy affects the LMXB formation in GCs. On the other hand, field-LMXBs closely match the host galaxy light, thus indicating that they are originally formed in situ and not inside GCs. The authors measure GC structural parameters, finding that the LMXB formation likelihood is influenced independently by mass, metallicity, and GC structural parameters. In particular, the GC central density plays a major role in predicting which GCs host accreting binaries. Finally, this analysis shows that LMXBs in GCs are marginally brighter than those in the field, and in particular the only color-confirmed GC with L_X > 10³⁹ erg/s shows no variability, which may indicate a superposition of multiple LMXBs in these systems.

The optical data were taken with the ACS on board the HST (GO-10129), in the F606W filter. A detailed description of the HST data and source catalogs are given in Puzia T.H. et al. 2011, in preparation.

The X-ray data were retrieved from the Chandra public archive (CXC). The authors selected observations 319 (ACIS-S; 2000 Jan 18) and 1472 (ACIS-I; 2003 May 26).

This table contains the list of 230 X-ray sources detected in the overlap region common to Chandra ACIS-I, Chandra ACIS-S and HST ACS observation (see Fig 1 of the reference paper). Details of the X-ray source detection methodology are given in Section 2.2 of the reference paper.

Catalog Bibcode

2011ApJ...736...90P

References

Probing the GC-LMXB connection in NGC 1399: a wide-field study with the
Hubble Space Telescope and Chandra.
    Paolillo M., Puzia T.H., Goudfrooij P., Zepf S.E., Maccarone T.J.,
    Kundu A., Fabbiano G., Angelini L.
   <Astrophys. J., 736, 90 (2011)>
   =2011ApJ...736...90P    (SIMBAD/NED BibCode)

Provenance

This table was created by the HEASARC in January 2013 based on the CDS Catalog J/ApJ/736/90 file table3.dat.

Parameters

Source_Number
A running X-ray source number in order of increasing J2000.0 Right Ascension.

Name
The CDS-style X-ray source designation, using the prefix '[PPG2011]' for Paolillo, Puzai, Goudfrooij 2011 and the source number (this was created by the HEASARC in anticipation of its recommendation by the CDS Dictionary of Nomenclature of Celestial Objects).

RA
The Right Ascension of the X-ray source in the selected equinox registered on the USNO-B1 reference frame. This was given in J2000.0 equatorial coordinates to a precision of 0.1 seconds of time in the original table. The final accuracy of the X-ray catalog is 0.33 arcseconds, with a maximum systematic offset of 0.6 arcseconds.

Dec
The Declination of the X-ray source in the selected equinox registered on the USNO-B1 reference frame. This was given in J2000.0 equatorial coordinates to a precision of 0.1 arcseconds in the original table. The final accuracy of the X-ray catalog is 0.33 arcseconds, with a maximum systematic offset of 0.6 arcseconds.

LII
The Galactic Longitude of the X-ray source.

BII
The Galactic Latitude of the X-ray source.

Counts
The total net 0.5 - 8 keV X-ray source counts.

Counts_Neg_Err
The lower uncertainty in the total net 0.5 - 8 keV X-ray source counts.

Counts_Pos_Err
The upper uncertainty in the total net 0.5 - 8 keV X-ray source counts.

Photon_Flux
The photon flux in the 0.5 - 8 keV band of the X-ray sources, in photons s^-1 cm^-2.

Photon_Flux_Error
The uncertainty in the photon flux in the 0.5 - 8 keV band of the X-ray sources, in photons s^-1 cm^-2.

Hardness_Ratio_1
The hardness ratio HR1 of the X-ray source computed from its photon fluxes in the 0.5 - 1.0 vs. 1.0 - 2.0 bands.

Hardness_Ratio_1_Error
The uncertainty in the hardness ratio HR1 of the X-ray source.

Hardness_Ratio_1_Flag
This flag parameter is set to 'i' to indicate that the uncertainty in HR1 is infinite.

Hardness_Ratio_2
The hardness ratio HR2 of the X-ray source computed from its photon fluxes in the 0.5 - 1.0 vs. 2.0 - 8.0 bands.

Hardness_Ratio_2_Error
The uncertainty in the hardness ratio HR2 of the X-ray source.

Hardness_Ratio_2_Flag
This flag parameter is set to 'i' to indicate that the uncertainty in HR2 is infinite.

Variability_Flag
This variability flag parameter is set based on either the K-S probability P > 95% or a flux difference > 3 sigma between the Chandra ObsIDs 319 and 1472, where 1 = variable and 0 = non-variable.

Offset
The angular separation between the X-ray source and the closest HST V-band counterpart, in arcseconds.

Vmag
The HST F606V-band magnitude of the nearest optical counterpart within 1 arcsecond (2.5 combined sigma) of the X-ray source.

Stellarity_Index
The SExtractor stellarity index flag value, where 0=Galaxy; 1=Star, of the nearest optical counterpart within 1 arcsecond (2.5 combined sigma) of the X-ray source.

T1_Mag
The ground-based Washington system T1-band magnitude of the nearest optical counterpart within 1 arcsecond (2.5 combined sigma) of the X-ray source.

Ct1_Color
The ground-based Washington system (C-T1) color of the nearest optical counterpart within 1 arcsecond (2.5 combined sigma) of the X-ray source.

Zmag
The ACS z-band magnitude of the nearest optical counterpart within 1 arcsecond (2.5 combined sigma) of the X-ray source.

Gz_Color
The ACS (g-z) color index of the nearest optical counterpart within 1 arcsecond (2.5 combined sigma) of the X-ray source.

Contact Person

Questions regarding the NGC1399CXO database table can be addressed to the HEASARC Help Desk.

Page Author: Browse Software Development Team
Last Modified: Monday, 16-Sep-2024 17:31:41 EDT