NGC4365CXO - NGC 4365 Chandra LMXB Catalog

Overview

The authors used the Chandra X-Ray Observatory ACIS-S3 to image the X-ray-faint elliptical galaxy NGC 4365 and the lenticular galaxy NGC 4382. This table presents only the NGC 4365 results; however, the results for NGC 4382 are also available in a separate table. NGC 4365 was observed on 2001 June 23 with a live exposure of 40429 s. The observations resolved much of the X-ray emission into 99 sources for NGC 4365, most of which are low-mass X-ray binaries (LMXBs) associated with the galaxy. Within one effective radius of NGC 4365, about 45% of the counts were resolved into sources, 30% were attributed to unresolved LMXBs, and 25% were attributed to diffuse gas. The authors identified 18 out of the 37 X-ray sources in a central field in NGC 4365 with globular clusters.

The authors defined two hardness ratios: HR21 = (M - S)/(M + S) and HR31 = (H - S)/(H + S), where S, M, and H are the total counts in the soft (0.3 - 1 keV), medium (1 - 2 keV), and hard (2 - 10 keV) bands, respectively.

Catalog Bibcode

2003ApJ...599..218S

References

Chandra observations of low-mass X-ray binaries and diffuse gas in the
early-type galaxies NGC 4365 and NGC 4382 (M85).
    Sivakoff G.R., Sarazin C.L., Irwin J.A.
   <Astrophys. J., 599, 218-236 (2003)>
   =2003ApJ...599..218S

Provenance

This table was created by the HEASARC in June 2018 based upon the CDS Catalog J/ApJ/599/218 file table1.dat.

Parameters

Source_Number
A unique sequential identification number for each X-ray source in the catalog, sorted in order of increasing J2000.0 Right Ascension.

Alt_Name
An alternative catalog-based source designation which uses "[SSI2003b] NGC 4365" as a prefix and the source_number.

Name
The name of the Chandra source using the "CXOU" prefix (for Chandra X-ray Observatory Unregistered source) and the J2000.0 coordinates of the source in the "JHHMMSS.ss+DDMMSS.s" format.

RA
The Right Ascension of the Chandra X-ray source in the selected equinox. This parameter was given in J2000.0 equatorial coordinates to a precision of 0.01 seconds of time in the original table. All listed positions include astrometry corrections based on optical/IR counterparts (see Sections 2 and 4.1 of the reference paper); the overall absolute astrometric errors are probably ~1" near the field center, with larger errors farther out.

Dec
The Declination of the Chandra X-ray source in the selected equinox. This parameter was given in J2000.0 equatorial coordinates to a precision of 0.1 arcseconds in the original table. All listed positions include astrometry corrections based on optical/IR counterparts (see Sections 2 and 4.1 of the reference paper); the overall absolute astrometric errors are probably ~1" near the field center, with larger errors farther out.

LII
The Galactic Longitude of the Chandra X-ray source.

BII
The Galactic Latitude of the Chandra X-ray source.

Radial_Distance
The projected radial distance of the Chandra X-ray source from the center of NGC 4365, in arcminutes (converted by the HEASARC from the arcsecond units used in the original table).

Count_Rate
The wavdetect count rate of the Chandra X-ray source in the 0.3-10 keV band, in counts per second. The fluxes were corrected for exposure and the instrument point-spread function (PSF).

Count_Rate_Error
The 1-sigma error in the wavdetect count rate of the Chandra X-ray source in the 0.3-10 keV band, in counts per second.

SNR
The signal-to-noise ratio (S/N) for the count rate of the Chandra X-ray source.

Lx
The X-ray luminosity of the Chandra source in the 0.3-10.0 keV band, in erg/s. To convert the source count rates into unabsorbed X-ray luminosities, the authors used the adopted Chandra X-ray spectrum (see Section 4.3, Table 3, row [3] of the reference paper) of the resolved sources to convert count rates into 0.3-10 keV fluxes. They then assumed each source was at the distance of NGC 4365, 20.4 Mpc, yielding a conversion factor of 4.08 x 10⁴¹ ergs/count. The X-ray luminosities range roughly from 1.1 x 10³⁸ to 2.3 x 10³⁹ ergs/s.

Hardness_Ratio21
The intrinsic hardness ratio HR21₀ of the Chandra X-ray source (see Overview above for more details).

Hardness_Ratio21_Pos_Err
The positive 1-sigma error in the intrinsic hardness ratio HR21₀ of the Chandra X-ray source (see Overview above for more details).

Hardness_Ratio21_Neg_Err
The negative 1-sigma error in the intrinsic hardness ratio HR21₀ of the Chandra X-ray source (see Overview above for more details).

Hardness_Ratio31
The intrinsic hardness ratio HR31₀ of the Chandra X-ray source (see Overview above for more details).

Hardness_Ratio31_Pos_Err
The positive 1-sigma error in the intrinsic hardness ratio HR31₀ of the Chandra X-ray.

Hardness_Ratio31_Neg_Err
The negative 1-sigma error in the intrinsic hardness ratio HR31₀ of the Chandra X-ray source (see Overview above for more details).

Source_Flags
This parameter contains comments concerning the specified Chandra X-ray source, coded as follows:

      a = Sources near the center may be confused with nearby sources, making
          their positions, fluxes, and extents uncertain.
      b = Source is noticeably more extended than PSF.
      c = Possible faint optical counterpart.
      d = Globular cluster is possible optical counterpart.
      e = Source may be variable.
      f = Source is at the edge of the S3 detector, and flux is uncertain as a
          result of large exposure correction.
      g = Identified with known AGN.

Contact Person

Questions regarding the NGC4365CXO database table can be addressed to the HEASARC Help Desk.

Page Author: Browse Software Development Team
Last Modified: Monday, 16-Sep-2024 17:32:01 EDT