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J/A+AS/131/197      F, G and K stars BVRI photometry (Metanomski+ 1998)
F, G and K stars in the ROSAT all-sky survey. I. Photometry.
       Metanomski A.D.F., Pasquini L., Krautter J., Cutispoto G., Fleming T.A.
      <Astron. Astrophys. Suppl. Ser. 131, 197 (1998)>
      =1998A&AS..131..197M      (SIMBAD/NED BibCode)
ADC_Keywords: Radio sources ; Stars, late-type ; Photometry, UBVRI

Mission_Name: ROSAT

Keywords: stars: late-type - X-ray: stars - surveys


Abstract:
    We present accurate BV(RI)c photometry for a sample of F, G and K
    stars detected in selected areas of the ROSAT all-sky survey (RASS).
    We have used the photometry, in addition to low-resolution
    spectroscopy, to estimate spectral classifications, distances and
    X-ray luminosities. The log(LX/LV) in the sample lies below -2.
    Although the sample contains also nearby, inactive stars, it is
    dominated by active objects. The median X-ray luminosity in our sample
    is <LX≥29.88 and the mean value of the hardness ratios
    <HR1≥0.13±0.35. We compare the derived X-ray luminosity function
    with similar functions obtained from the serendipitous samples of the
    Einstein Observatory medium sensitivity survey (EMSS, Cat. IX/15)
    and EXOSAT (Cat. J/A+AS/115/41). Our
    sample is completely consistent with the EMSS sample of solar type
    stars, indicating that both our sources and the EMSS sources are
    representative of the high galactic latitude X-ray stellar population.
    We do not find extremely active stars (log(LX)≥32), as are found in
    the EMSS sample, and we argue that these objects are rare.

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table3.dat       195      107   Summary of X-ray and observational data as well
                                  as results for the studied sample
notes.dat         80       86   Individual notes


See also:
           IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1996)
           IX/15 : Einstein EMSS Survey (Gioia+ 1990, Stocke+ 1991)
   J/ApJS/99/701 : EMSS (Fleming+ 1995)
   J/A+AS/115/41 : UBV(RI) photometry of cool stars (Cutispoto+, 1996)


Byte-by-byte Description of file: table3.dat

   Bytes Format Units       Label     Explanations

   1- 15  A15   ---         RXJ       ROSAT name
      16  A1    ---         n_RXJ     [*] *: see note detailed in file notes.dat
  17- 18  I2    h           RAXh      X-ray source right ascension (J2000.0)
  20- 21  I2    min         RAXm      X-ray source right ascension (J2000.0)
  23- 26  F4.1  s           RAXs      X-ray source right ascension (J2000.0)
      28  A1    ---         DEX-      X-ray source declination sign
  29- 30  I2    deg         DEXd      X-ray source declination (J2000.0)
  32- 33  I2    arcmin      DEXm      X-ray source declination (J2000.0)
  35- 36  I2    arcsec      DEXs      X-ray source declination (J2000.0)
  38- 44  F7.5  ct/s        Counts    Count-rate for the X-ray source
  46- 52  F7.2  s           Texp      Total exposition time
  54- 58  F5.2  ---         HR1       ? Hardness Ratio 1 (1)
  60- 61  I2    h           RAh       Counterpart right ascension (J2000.0)
  63- 64  I2    min         RAm       Counterpart right ascension (J2000.0)
  66- 69  F4.1  s           RAs       Counterpart right ascension (J2000.0)
      71  A1    ---         DE-       Counterpart declination sign
  72- 73  I2    deg         DEd       Counterpart declination (J2000.0)
  75- 76  I2    arcmin      DEm       Counterpart declination (J2000.0)
  78- 79  I2    arcsec      DEs       Counterpart declination (J2000.0)
  81- 84  F4.1  arcsec      DX-C      Distance between X-ray and counterpart
                                       positions
  86- 94  A9    ---         SpType    Spectral type
  96- 98  A3    ---         n_SpType  Note on Spectral type for binaries (2)
 100-102  I3    pc          Dist      Distance of the star form the Sun
 104-106  I3    pc          E_Dist    ? Error in Distance (upper limit)
 108-109  I2    pc          e_Dist    ? Error in Distance (lower limit)
 111-115  F5.2  10-15W/m2   fX        X-ray flux
 117-120  F4.2  10-15W/m2   E_fX      Error in fX (upper limit)
 122-125  F4.2  10-15W/m2   e_fX      Error in fX (lower limit)
 127-133  F7.3  10+22W      LX        X-ray luminosity
 135-140  F6.2  10+22W      E_LX      Error in LX (upper limit)
 142-147  F6.2  10+22W      e_LX      Error in Lx (lower limit)
 149-162  A14   ---         Name      Counterpart name
 164-171  A8    ---         SpTypeO   Counterpart spectral type
 173-177  F5.2  mag         Vmag      Counterpart V magnitude
 179-183  F5.2  mag         B-V       Counterpart B-V colour index
 185-189  F5.2  mag         V-R       ? Counterpart V-R  colour index
 191-194  F4.2  mag         V-I       ? Counterpart V-I  colour index

Note (1): HR1 = (CR[ch52-201]-CR[ch11-41])/CR[ch11-240] where
                CD[cha-b] being the count-rate in the channels "a" to "b"Note (2): 1: the binarity/multiplicity obtained by the photometry was confirmed
Note (2): 1: the binarity/multiplicity obtained by the photometry was confirmed
              by the high-resolution spectra
          2: the binarity was determined for the high-resolution spectra
          3: the binarity is a visual one
          4: the binarity information was only obtained through the literature


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

   Bytes Format Units   Label     Explanations

   1- 15  A15   ---     RXJ       Source name
  17- 18  I2    ---     Ntot      Total number of lines for the RXJ object
  20- 21  I2    ---     Nline     Running line number in range [1,Ntot]
  23- 80  A58   ---     Note      Text of the note


History: Prepared via OCR at CDS
         An error was detected in the original publication and corrected.
         For RXJ 1413.7-0050, the position of the Counterpart (HD 124425) is
         14 13 40.6 -00 50 40 instead of 14 13 40.6 -00 05 40
(End)                                          Patricia Bauer [CDS]  31-Jul-1998