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J/AJ/122/866        X-ray sources in IC 348 from Chandra     (Preibisch+, 2001)
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
ADC_Keywords: Clusters, open ; X-ray sources

Mission_Name: Chandra

Keywords: open clusters and associations: individual (IC 348) - stars: coronae -
          stars: low-mass, brown dwarfs - stars: pre-main-sequence - X-rays

Abstract:
    We 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 our image with a sensitivity limit of
    ∼1x1028ergs/s (more than 10 times deeper than our ROSAT images of IC
    348), 215 X-ray sources are 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 2M☉ are visible as
    X-ray sources in our image. We discover X-ray emission at levels of
    ∼1028ergs/s from four of 13 known brown dwarfs and from three of 12
    brown dwarf candidates in IC 348. We also detect X-ray emission from
    two deeply embedded objects, presumably class I protostars, south of
    the cluster center. Description:

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table1.dat        51      215   ACIS X-ray Sources in IC 348
table2.dat       104       25   Brown dwarfs and brown dwarfs candidates in IC 348


See also:
   J/A+A/324/549 : Deep UVBRI photometry in IC 348 (Trullols+ 1997)


Byte-by-byte Description of file: table1.dat

   Bytes Format Units     Label     Explanations

   1-  3  I3    ---       CXOPZ     Source number
       6  I1    h         RAh       Right Ascension (J2000)
   8-  9  I2    min       RAm       Right Ascension (J2000)
  11- 15  F5.2  s         RAs       Right Ascension (J2000)
      17  A1    ---       DE-       Declination sign (J2000)
  18- 19  I2    deg       DEd       Declination (J2000)
  21- 22  I2    arcmin    DEm       Declination (J2000)
  24- 27  F4.1  arcsec    DEs       Declination (J2000)
  30- 33  F4.1  arcsec    e_RAs     Right Ascension position uncertainty
  35- 38  F4.1  arcsec    e_DEs     Declination position uncertainty
  41- 45  F5.2  ct/ks     CR        Count rate
  48- 51  F4.2  ct/ks     e_CR      Error in CR


Byte-by-byte Description of file: table2.dat

   Bytes Format Units     Label    Explanations

   1-  3  A3    ---       Origin   L99: Objects from Luhman, 1999ApJ...525..466L
                                   N00: Additional objects from Najita et al.,
                                         2000ApJ...541..977N
   5- 10  A6    ---       Object   Object identification (1)
  12- 17  A6    ---       SpType   Spectral type
  18- 20  F3.1  ---      e_SpType  ? Uncertainty on sub-type
  22- 24  A3    ---       Class    Classification (2)
  27- 31  F5.2  mag       AVmag    Absorption  in V band
      32  A1    ---       u_AVmag  Uncertainty flag on AVmag
  34- 39  F6.4  solLum    Lbol     Bolometric luminosity
  41- 42  A2    ---       l_Massl  [~< ] Limit flag on Massl
  43- 46  F4.2  solMass   Massl    Mass, lower limit  (3)
  49- 52  F4.2  solMass   Massu    ? Mass, upper limit (3)
      54  A1    ---       l_ACIS   Limit flag on ACIS
  55- 58  F4.1  ct        ACIS     Number of background-subtracted source
                                    counts detected in the ACIS image
  60- 62  F3.1  ---       e_ACIS   ? rms uncertainty on ACIS
      64  A1    ---       l_Lx     Limit flag on Lx
  65- 68  F4.1  10+21W    Lx       X-ray luminosity (4)
  70- 72  F3.1  10+21W    e_Lx     ? rms uncertainty on Lx
      74  A1    --- l_log(Lx/Lbol)  Limit flag on log(Lx/Lbol)
  75- 78  F4.1  ---  log(Lx/Lbol)  X-ray to bolometric luminosity ratio
  81- 82  I2    h         RAh      Right ascension (J2000)
  84- 85  I2    min       RAm      Right ascension (J2000)
  87- 91  F5.2  s         RAs      Right ascension (J2000)
      93  A1    ---       DE-      Declination sign (J2000)
  94- 95  I2    deg       DEd      Declination (J2000)
  97- 98  I2    arcmin    DEm      Declination (J2000)
 100-103  F4.1  arcsec    DEs      Declination (J2000)

Note (1): Luhman 1999: Cl* IC 348 LRL NNN in Simbad

Note (2): (BD) brown dwarf; (BDC) brown dwarf candidate.

Note (3): Range of the mass estimates given by the different models and
          temperature scales.
Note (4): Dereddened 0.2-8 keV-band X-ray luminosity based on the exposure
           time-corrected source count rate computed assuming a Raymond-Smith
           plasma spectrum with kT=1keV.


History:
    From electronic version of the journal
(End)                   Greg Schwarz [AAS],  Patricia Bauer [CDS]    10-Sep-2001