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IC348CXO - IC 348 Chandra X-Ray Point Source Catalog

HEASARC
Archive

Overview

The authors have obtained a deep (53 ks) X-ray image of the very young stellar cluster IC 348 with the Advanced CCD Imaging Spectrometer on board the Chandra X-Ray Observatory. In this image with a sensitivity limit of ~ 1 x 10^28 ergs/s (more than 10 times deeper than their ROSAT images of IC 348), 215 X-ray sources were detected. While 115 of these sources can be identified with known cluster members, 58 X-ray sources are most likely new, still unidentified cluster members. About 80% of all known cluster members with masses between ~0.15 and 2 solar masses are visible as X-ray sources in the ACIS image. X-ray emission at levels of ~10^28 ergs/s was discovered from four of 13 known brown dwarfs and from three of 12 brown dwarf candidates in IC 348. X-ray emission was also detected from two deeply embedded objects, presumably class I protostars, south of the cluster center.

Optical and infrared counterparts have been identified for most of the X-ray sources. Some 40 X-ray sources do not have optical or IR counterparts, and are most likely background (probably extragalactic) objects. This number is consistent with the expected number of extragalactic background X-ray sources based on the observed log N - log S statistics from the deep X-ray counts in the Chandra Deep Field South.


Catalog Bibcodes

2001AJ....122..866P
2002AJ....123.1613P

References

Deep Chandra X-ray observatory imaging study of the
very young stellar cluster IC 348.
     Preibisch T., Zinnecker H.
    <Astron. J. 122, 866 (2001)>
    =2001AJ....122..866P
X-ray properties of the young stellar and substellar objects
in the IC 348 cluster: the Chandra view.
     Preibisch T., Zinnecker H.
    <Astron. J. 123, 1613 (2002)>
    =2002AJ....123.1613PP

Provenance

This table was created by the HEASARC in January 2007 based on the merger of CDS table J/AJ/122/866/table1.dat (Table 1 from Preibisch and Zinnecker 2001) with the electronic AJ table version of Table 1 from Preibisch and Zinnecker 2002.

Parameters

Source_Number
A sequential identification number for each X-ray source in this study, in order of increasing J2000 Right Ascension.

Alt_Name
An alternative designation for the X-ray source, using the CXOPZ prefix (Chandra X-ray Observatory, Preibisch & Zinnecker) registered by the authors and its source_number value.

RA
The Right Ascension of the X-ray source in the selected equinox. This parameter was given in J2000 coordinates and to a precision of 0.01 seconds of time in the originating table.

Dec
The Declination of the X-ray source in the selected equinox. This parameter was given in J2000 coordinates and to a precision of 0.1 arcseconds in the originating table. A small offset of 0.51" +/ 0.14" between the declinations in the X-ray and optical coordinate frames has been applied to the X-ray declinations listed in this table.

LII
The Galactic Longitude of the X-ray source.

BII
The Galactic Latitude of the X-ray source.

RA_Error
The X-ray source positional uncertainty in the Right Ascension direction, in arcseconds.

Dec_Error
The X-ray source positional uncertainty in the Declination direction, in arcseconds.

Count_Rate
The exposure-time-corrected X-ray source count rate in the 0.2 - 8.0 keV ACIS energy band, in counts per second.

Count_Rate_Error
The unceratinty in the X-ray source count rate, in counts per second.

Name
The preferred designation for the X-ray source, using the CXOPZ prefix (Chandra X-ray Observatory, Preibisch & Zinnecker) registered by the authors, followed by the 'J' and the usual numeric string format based on the J2000 position truncated to 0.1 seconds of time and 1 arcsecond of declination, e.g., 'CXOPZ J034346.9+321320'.

Optical_IR_ID
The identifications of the X-ray source with an optical and/or infrared counterpart from the catalogs of (i) Herbig (1998, ApJ, 497, 736) if the name begins with an 'H-' prefix, (ii) Luhman et al. (1998, ApJ, 508, 347) or Luhman (1999, ApJ, 525, 466) if the name begins with an 'L-' prefix, or (iii) Najita et al. (2000, ApJ, 541, 977) if the name begins with an 'N-' prefix. Stars known to be foreground or background objects are marked with 'FG' and 'BG', respectively. If no catalogued counterpart is known, the entry '2MASS' means that the X-ray source has a counterpart in the 2MASS point source catalog, while 'noCP' means that no optical or infrared counterpart could be found. Source CXOPZ-J034424.6+321349 is identified with a faint infrared source not included in the 2MASS catalog.

Spect_Type
The spectral type of the counterpart to the X-ray source.

Av
The visual extinction of the counterpart to the X-ray source, in magnitudes.

Av_Flag
This flag parameter for the visual extinction has the following values:

    'i' means that the value has been estimated from the near-infrared colors
    ':' means that, due to a lack of further information, an extinction of
        3.5 magnitudes has been assumed
  

Ew_Halpha
The equivalent width of the H-alpha emission line, in Angstroms. Negative values denote H-alpha absorption.

Kt_Plasma
The best-fit temperature found in a single-component model to the X-ray spectrum, or, if such a model did not yield an acceptable fit, the emission-weighted mean of the best-fit temperature values that were found in a 2-component model of the X-ray spectrum of the source, in keV.

Kt_Plasma_Error
The uncertainty in the derived characteristic plasma temperature inferred from X-ray spectral modeling, in keV.

Lx
The extinction-corrected, 0.2 - 10 keV band X-ray luminosity of the source, in erg/s, calculated based on the analysis of the X-ray spectra as described in Section 5 of Preibisch & Zinnecker (2002) and assuming a distance of 310 pc.

Lx_Error
The uncertainty in the X-ray luminosity of the source, in erg/s.

Class
The HEASARC Browse object classification, based on the spectral type of the counterpart when available.


Contact Person

Questions regarding the IC348CXO database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 8-Jan-2007