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Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

University of Louisville

2013

ISM: structure

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Quantified H I Morphology – Vii. Star Formation And Tidal Influence On Local Dwarf H I Morphology., Benne W. Holwerda, N. Pirzkal, W. J. G. De Blok, S. -L. Blyth Oct 2013

Quantified H I Morphology – Vii. Star Formation And Tidal Influence On Local Dwarf H I Morphology., Benne W. Holwerda, N. Pirzkal, W. J. G. De Blok, S. -L. Blyth

Faculty Scholarship

Scale-invariant morphology parameters applied to atomic hydrogen maps (H i) of galaxies can be used to quantify the effects of tidal interaction or star formation on the interstellar matter (ISM). Here we apply these parameters, concentration, asymmetry, smoothness, Gini, M20, and the GM parameter, to two public surveys of nearby dwarf galaxies, the Very Large Array-ANGST and Local Irregulars That Trace Luminosity Extremes-The H i Nearby Galaxy Survey, to explore whether tidal interaction or the ongoing or past star formation is a dominant force shaping the H i disc of these dwarfs. Previously, H i morphological criteria were identified for …


The Opacity Of Spiral Galaxy Disks : Ix. Dust And Gas Surface Densities., Benne W. Holwerda, R. J. Allen, W. J. G. De Blok, A. Bouchard, R. A. Gonzalez-Lopezlira, P. C. Van Der Kruit, A. Leroy Mar 2013

The Opacity Of Spiral Galaxy Disks : Ix. Dust And Gas Surface Densities., Benne W. Holwerda, R. J. Allen, W. J. G. De Blok, A. Bouchard, R. A. Gonzalez-Lopezlira, P. C. Van Der Kruit, A. Leroy

Faculty Scholarship

Our aim is to explore the relation between gas, atomic and molecular, and dust in spiral galaxies. Gas surface densities are from atomic hydrogen and CO line emission maps. To estimate the dust content, we use the disk opacity as inferred from the number of distant galaxies identified in twelve HST/WFPC2 fields of ten nearby spiral galaxies. The observed number of distant galaxies is calibrated for source confusion and crowding with artificial galaxy counts and here we verify our results with sub-mm surface brightnesses from archival Herschel-SPIRE data. We find that the opacity of the spiral disk does not correlate …