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Date and Time of the Query: 2019-08-17 T11:17:44 PDT
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For refcode 2012AJ....144...96I:
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2012AJ....144...96I The Shapes of the H I Velocity Profiles of the THINGS Galaxies Ianjamasimanana, R.; de Blok, W. J. G.; Walter, Fabian; Heald, George H. Abstract. We analyze the shapes of the H I velocity profiles of The H I Nearby Galaxy Survey to study the phase structure of the neutral interstellar medium and its relation to global galaxy properties. We use a method analogous to the stacking method sometimes used in high-redshift H I observations to construct high-signal-to-noise (S/N) profiles. We call these high-S/N profiles super profiles. We analyze and discuss possible systematics that may change the observed shapes of the super profiles. After quantifying these effects and selecting a subsample of unaffected galaxies, we find that the super profiles are best described by a narrow and a broad Gaussian component, which are evidence of the presence of the cold neutral medium and the warm neutral medium. The velocity dispersion of the narrow component ranges from ~3.4 to ~8.6 km s^-1^ with an average of 6.5 +/- 1.5 km s^-1^, whereas that of the broad component ranges from ~10.1 to ~24.3 km s^-1^ with an average of 16.8 +/- 4.3 km s^-1^. We find that the super profile parameters correlate with star formation indicators such as metallicity, far-UV-near-UV colors, and Halpha luminosities. The flux ratio between the narrow and broad components tends to be highest for high-metallicity, high-star-formation-rate galaxies. We show that the narrow component identified in the super profiles is associated with the presence of star formation, and possibly with molecular hydrogen. Key words: galaxies: dwarf, galaxies: fundamental parameters, galaxies: ISM, galaxies: spiral, ISM: kinematics and dynamics, radio lines: ISM
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