J/MNRAS/338/253      K extinction near the Galactic Centre        (Dutra+, 2003)
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Extinction within 10 degrees of the Galactic Centre using 2MASS
    Dutra C.M., Santiago B.X., Bica E.L.D., Barbuy B.
   <Mon. Not. R. Astron. Soc. 338, 253 (2003)>
   =2003MNRAS.338..253D
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ADC_Keywords: Interstellar medium ; Extinction ; Infrared sources
Keywords: The Galaxy - interstellar medium - extinction - dust

Description:
    We extract J and Ks magnitudes from the 2MASS Point Source Catalog
    for approximately 6 million stars with 8<Ks<13 in order to
    build an A_K_ extinction map within 10 degrees of the Galactic centre.
    The extinction was determined by fitting the upper giant branch of
    (Ks, J-Ks) colour-magnitude diagrams to a dereddened upper giant
    branch mean locus built from previously studied Bulge fields. The
    extinction values vary from A_K=0.05 in the edges of the map up to
    A_K=3.2 close to the Galactic centre.
    The resulting extinction map is given in the file 'extmap.dat'.

File Summary:
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 FileName   Lrecl  Records   Explanations
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ReadMe         80        .   This file
extmap.dat     30    32761   Extinction map (181 x 181 points)
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See also:
       B/2mass : The 2MASS database (IPAC/UMass, 2000)
       II/62   : Catalogue of Extinction Data (Neckel+, 1980)
       II/114  : UV Interstellar Extinction (Savage+ 1985)
 J/A+A/349/L69 : Interstellar extinction towards inner Galactic Bulge
                                                             (Schultheis+, 1999)
 J/A+A/359/347 : Reddening in open and globular clusters (Dutra+, 2000)
 J/A+A/383/631 : Catalogue of dust clouds in the Galaxy (Dutra+, 2002)

Byte-by-byte Description of file: extmap.dat
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   Bytes Format Units   Label   Explanations
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   1-  6  F6.3  deg     GLON    [-6/6] Galactic longitude of the cell centre
   9- 14  F6.3  deg     GLAT    [-6/6] Galactic latitude of the cell centre
  16- 22  F7.3  mag     AK      K band extinction
  25- 30  F6.3  mag   e_AK      Error in extinction determination
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Acknowledgements: Carlos Dutra <dutra@astro.iag.usp.br>

References:
  Dutra et al., Low-extinction windows in the inner Galactic Bulge,
                2002A&A...381..219D
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(End)                                          Patricia Bauer [CDS]  24-Sep-2002