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Please use this identifier to cite or link to this item: http://hdl.handle.net/2289/8199
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dc.contributor.authorDas, Mousumi-
dc.contributor.authorIanjamasimanana, Roger-
dc.contributor.authorS. McGaugh, Stacy-
dc.contributor.authorSchombert, James-
dc.contributor.authorDwarakanath, K. S.-
dc.date.accessioned2024-01-30T04:32:20Z-
dc.date.available2024-01-30T04:32:20Z-
dc.date.issued2023-03-22-
dc.identifier.citationThe Astrophysical Journal Letters, 2023,Vol. 946:L8,p8en_US
dc.identifier.issn2041-8213 (Online)-
dc.identifier.urihttp://hdl.handle.net/2289/8199-
dc.descriptionOpen Accessen_US
dc.description.abstractWe derive the oblateness parameter q of the dark matter halo of a sample of gas-rich, face-on disk galaxies. We have assumed that the halos are triaxial in shape but their axes in the disk plane (a and b) are equal, so that q = c/a measures the halo flattening. We have used the H I velocity dispersion, derived from the stacked H I emission lines and the disk surface density, determined from theH I flux distribution, to determine the disk potential and the halo shape at the R25 and 1.5R25 radii. We have applied our model to 20 nearby galaxies, of which six are large disk galaxies with M(stellar) > 1010, eight have moderate stellar masses, and six are low-surface-brightness dwarf galaxies. Our most important result is that gas-rich galaxies that have M(gas)/M(baryons) > 0.5 have oblate halos (q < 0.55), whereas stellar-dominated galaxies have a range of q values from 0.21 ± 0.07 in NGC4190 to 1.27 ± 0.61 in NGC5194. Our results also suggest a positive correlation between the stellar mass and the halo oblateness q, which indicates that galaxies with massive stellar disks have a higher probability of having halos that are spherical or slightly prolate, whereas low-mass galaxies have oblate halos (q < 0.55).en_US
dc.language.isoenen_US
dc.publisherAmerican Astronomical Societyen_US
dc.relation.urihttps://ui.adsabs.harvard.edu/abs/2023ApJ...946L...8D/abstracten_US
dc.relation.urihttps://arxiv.org/abs/2303.05104en_US
dc.relation.urihttps://doi.org/10.3847/2041-8213/acc10een_US
dc.rights2023, The Author(s)en_US
dc.subjectGalaxy dark matter halos (1880)en_US
dc.subjectH I line emission (690)en_US
dc.subjectInterstellar line emission (844)en_US
dc.subjectGalaxy structure (622)en_US
dc.titleEstimating the Oblateness of Dark Matter Halos Using Neutral Hydrogen Velocity Dispersionen_US
dc.typeArticleen_US
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