CDROM/AJ/V114/P1488     Globulars in M31 (Holland+ 1997)
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Deep HST V- and I-Band Observations of Two Globular Clusters in the Halo of M31
      Stephen Holland, Gregory G. Fahlman, and Harvey B. Richer
      <1997, AJ, 114, 1488>
      =1997AJ....114.1488H
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Abstract:
  We present deep (V =~ 27) V- and I-band stellar photometry of G302 and
  G312, two globular star clusters in the halo of M31. These data were
  obtained using the Hubble Space Telescope's Wide Field/Planetary
  Camera 2. We find iron abundances of [Fe/H] = -1.85 +/- 0.12 for G302
  and [Fe/H] = -0.56 +/- 0.03 for G312, consistent with spectroscopic
  measurements. The color-magnitude diagrams for each cluster show no
  evidence for an intermediate-aged population of stars, or a second
  parameter effect in the morphology of the horizontal branch. G302
  shows no evidence for a color gradient but the inner regions of G312
  are bluer than the outer regions.  G312 shows no evidence of
  ellipticity or an extended halo of stars. G302 has a projected
  ellipticity of epsilon = 0.195 +/- 0.012 with the projected major axis
  oriented towards the center of M31. G302 also shows evidence of an
  extended asymmetric stellar halo extending to at least twice the
  fitted Michie-King tidal radius. The amount of mass beyond the tidal
  radius of G302 is consistent with the stellar escape rates which have
  been predicted by N-body simulations of globular clusters in the
  Galactic tidal field. (c) 1997 American Astronomical Society.

File Summary:
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File Name    Lrecl    Records   Explanations
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table3.dat      64      13321   Stellar photometry for G302 and the surrounding
                                fields
table4.dat      64       3349   Stellar photometry for G312 and the surrounding
                                fields
table5.dat      70        626   Stellar photometry for G302
table6.dat      70        325   Stellar Photometry for G312
table3.tex      86      13364   AASTeX version of table3.dat
table4.tex      86       3392   AASTeX version of table4.dat
table5.tex     101        669   AASTeX version of table5.dat
table6.tex     101        368   AASTeX version of table6.dat
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Byte-by-byte Description of file: table3.dat table4.dat
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   Bytes Format  Units      Label      Explanations
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   1- 4   A4     ---        CCD        CCD the star was observed on
   5-10   I6     ---        ID        *Identification number
  11-18   F8.3   pix        X          X pixel coordinate
  19-26   F8.3   pix        Y          Y pixel coordinate
  27-33   F7.3   mag        V          V-band magnitude
  34-39   F6.3   mag        e_V        1-sigma uncertainty in V
  40-45   F6.3   ---        Chi_V      Value of the DAOPHOT Chi statistics for V
  46-52   F7.3   mag        I          I-band magnitude
  53-58   F6.3   mag        e_I        1-sigma uncertainty in I
  59-64   F6.3   ---        Chi_I      Value of the DAOPHOT Chi statistics for I
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Notes for file: table3.dat table4.dat
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ID:
  Identification numbers are only unique for stars on a given CCD.
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Byte-by-byte Description of file: table5.dat table6.dat
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   Bytes Format  Units      Label      Explanations
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   1- 4   A4     ---        CCD        CCD the star was observed on
   5-10   I6     ---        ID         Identification number
  11-18   F8.3   pix        X          X pixel coordinate
  19-26   F8.3   pix        Y          Y pixel coordinate
  27-32   F6.3   arcsec     r          Distance of star from cluster center
  33-39   F7.3   mag        V          V-band magnitude
  40-45   F6.3   mag        e_V        1-sigma uncertainty in V
  46-51   F6.3   ---        Chi_V      Value of the DAOPHOT Chi statistics for V
  52-58   F7.3   mag        I          I-band magnitude
  59-64   F6.3   mag        e_I        1-sigma uncertainty in I
  65-70   F6.3   ---        Chi_I      Value of the DAOPHOT Chi statistics for I
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(End)                                             Lee Brotzman [ADS] 04-Nov-1997