Year: 2022
Type: article
Abstract: ABSTRACT Rotation curves of galaxies probe their total mass distributions, including dark matter. Dwarf galaxies are excellent systems to investigate the dark matter density distribution, as they tend to have larger fractions of dark matter compared to higher mass systems. The core-cusp problem describes the discrepancy found in the slope of the dark matter density profile in the centres of galaxies (β*) between observations of dwarf galaxies (shallower cores) and dark matter-only simulations (steeper cusps). We investigate β* in six nearby spiral dwarf galaxies for which high-resolution CO J = 1–0 data were obtained with ALMA (Atacama Large Millimeter/submillimeter Array). We derive rotation curves and decompose the mass profile of the dark matter using our CO rotation curves as a tracer of the total potential and 4.5 $\mu$m photometry to define the stellar mass distribution. We find 〈β*〉 = 0.6 with a standard deviation of ±0.1 among the galaxies in this sample, in agreement with previous measurements in this mass range. The galaxies studied are on the high stellar mass end of dwarf galaxies and have cuspier profiles than lower mass dwarfs, in agreement with other observations. When the same definition of the slope is used, we observe steeper slopes than predicted by the FIRE and NIHAO simulations. This may signal that these relatively massive dwarfs underwent stronger gas inflows towards their centres than predicted by these simulations, that these simulations overpredict the frequency of accretion or feedback events, or that a combination of these or other effects are at work.
Institutions: Institut Interdisciplinaire de l'Innovation, Marriott International (United States), University of Maryland, College Park, University of Arizona, National Radio Astronomy Observatory, Joint Space Science Institute, Flatiron Institute, Carnegie Institution for Science, Carnegie Observatories, University of South Florida, University of California, Berkeley, Ames Research Center
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, National Aeronautics and Space Administration, Gordon and Betty Moore Foundation, Pacific Institute for Research and Evaluation, Association of American Geographers, U.S. Nuclear Regulatory Commission, California Institute of Technology, Johns Hopkins University, University of Maryland, University of Hawai'i, Space Telescope Science Institute, National Radio Astronomy Observatory, University of Edinburgh, Queen's University Belfast, Durham University, European School of Oncology, National Science Council, Korea Astronomy and Space Science Institute, National Astronomical Observatory of Japan, Eötvös Loránd Tudományegyetem, Jet Propulsion Laboratory, Smithsonian Astrophysical Observatory, National Institutes of Natural Sciences, Los Alamos National Laboratory
Awards: G3998922605, A NEO SEARCH PROGRAM USING THE PAN-STARRS PS1 TELESCOPETHE GOAL OF THE PROPOSED RESEARCH IS TO USE T, The Inner Workings of Starbursts and Their Winds, G7528236897, Pan-STARRS1: Operations; Public Data Release; Education and Outreach, A Multiscale View of the Effects of Stellar Feedback in the Local Universe
OpenAlex ID: W4214926704