A Warped Disk Model for M33 and the 21 Centimeter Line Width in Spiral Galaxies
Author(s) -
E. Corbelli,
Stephen E. Schneider
Publication year - 1997
Publication title -
the astrophysical journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.376
H-Index - 489
eISSN - 1538-4357
pISSN - 0004-637X
DOI - 10.1086/303849
Subject(s) - physics , astrophysics , spiral galaxy , galaxy , irregular galaxy , line (geometry) , image warping , interacting galaxy , lenticular galaxy , line of sight , barred spiral galaxy , astronomy , elliptical galaxy , geometry , mathematics , artificial intelligence , computer science
To determine the actual HI distribution and the velocity field in theoutermost disk of the spiral galaxy M33, a tilted-ring model is fitted to 21-cmline data taken with the Arecibo Telescope. Since M33 is one of the maincalibrators for the extragalactic distance scale derived through theTully-Fisher relation, the outer disk warping is of interest for a correctdetermination and deprojection of the galaxy's line width. Even though our bestmodel predicts small effects on the observed line width of M33, we show thatsimilar outer disk warping in galaxies oriented differently along our line ofsight could affect the widths considerably. Therefore there may be systematiceffects in the determination of the rotation velocities and dynamic masses ofspiral galaxies, whose exact value depends also on which method is used formeasuring the galaxy's total line width.Comment: 27 pages, ps files only, ApJ in pres
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