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J/A+A/282/436     Abundance gradients from disk PNs               (Maciel+ 1994)
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Abundance gradients from disk planetary nebulae: O, Ne, S, and Ar
     Maciel W.J., Koeppen J.
    <Astron. Astrophys. 282, 436 (1994)>
    =1994A&A...282..436M
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ADC_Keywords: Planetary nebulae ; Abundances
Keywords: planetary nebulae: general - stars: abundances -
          Galaxy: abundances - Galaxy: evolution

Abstract:
    A new determination of the radial abundance gradients of O/H, Ne/H,
    S/H, and Ar/H is made for disk planetary nebulae, (PN), that is, those
    objects of Peimbert types I, II, and III. On the basis of a sample
    containing 200 nebulae, it can be concluded that these gradients are
    generally similar, and of the same order of magnitude as the O/H
    gradient displayed by galactic HII regions. Some distance-independent
    correlations confirm the accuracy of the abundances and support the
    interpretation of the gradients in terms of chemical evolution models.
    The time evolution of the abundance gradients in the Milky Way is
    investigated, and their variation with the types of PN are compared
    with predictions of chemical evolution models.


File Summary:
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 FileName    Lrecl    Records    Explanations
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ReadMe          80          .    This file
table1.dat      58        201    Basic data for planetary nebulae
table2.dat      90        201    Abundance of disk planetary nebulae
refs.dat        79         45    References
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Byte-by-byte Description of file: table1.dat
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   Bytes Format  Units   Label    Explanations
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   1- 10  A10    ---     Name     Name of the planetary nebula
  12- 20  A9     ---     PK       Perek-Kohoutek designation
  23- 25  A3     ---     Type    *Peimbert type
  29- 32  F4.1   kpc     d        Heliocentric distance
  37- 47  A11    ---   r_d        references to distance (see file refs.dat)
  52- 56  F5.2   kpc     R        Projected distance to the Galactic Center
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Note on Type: classification introduced by Peimbert, 1978IAUS...76..215P;
   Type   I; He- and N-rich
   Type  II: intermediate population
   Type III: high-velocity
   Type  IV: halo (not studied here)
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Byte-by-byte Description of file: table2.dat
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   Bytes Format  Units   Label   Explanations
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   2- 11  A10    ---     Name    Name of the planetary nebula
  12- 15  F4.2   ---     O/H     ? Oxygen abundances with respect to H
  17- 30  A14    ---   r_O/H     ? references to O/H (see refs.dat)
  32- 35  F4.2   ---     Ne/H    ? Neon abundances with respect to H
  37- 50  A14    ---   r_Ne/H    ? references to Ne/H (see refs.dat)
  52- 55  F4.2   ---     S/H     ? Sulfur abundances with respect to H
  57- 70  A14    ---   r_S/H     ? references to S/H (see refs.dat)
  72- 75  F4.2   ---     Ar/H    ? Argon abundances with respect to H
  77- 91  A15    ---   r_Ar/H    ? references to Ar/H (see refs.dat)
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Byte-by-byte Description of file: refs.dat
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   Bytes Format Units   Label     Explanations
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   1-  8  A8    ---     Ref       Reference code used in the tables
  10- 28  A19   ---     Bibcode   The 19-digit bibcode
  30- 79  A50   ---     Text      Authors
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History:
  * 30-Jul-2001: File refs.dat with bibcodes added.
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(End)                                           Patricia Bauer [CDS] 29-Oct-1993