Year: 2019
Type: article
Abstract: ABSTRACT Our GMRT (Giant Metrewave Radio Telescope) H i observations of the ultra-diffuse galaxy (UDG) UGC 2162, projected ∼ 300 kpc from the centre of the M 77 group, reveal it to a have an extended H i disc ($R_{\rm H\,{\small I}}/R_{25}$ ∼ 3.3) with a moderate rotational velocity (Vrot ∼ 31 km s−1). This Vrotis in line with that of dwarf galaxies with similar H i mass. We estimate an Mdyn of ∼1.14 × 109 M⊙ within the galaxy’s $R_ \rm {H\,{\small I}}$ ∼ 5.2 kpc. Additionally, our estimates of M200 for the galaxy from NFW models are in the range of 5.0–8.8 × 1010 M⊙. Comparing UGC 2162 to samples of UDGs with H i detections show it to have amongst the smallest Re with its MH i/M* being distinctly higher and g – icolour slightly bluer than typical values in those samples. We also compared H i and dark matter (DM) halo properties of UGC 2162 with dwarf galaxies in the LITTLE THINGS sample and find its DM halo mass and profile are within the range expected for a dwarf galaxy. While we were unable to determine the origin of the galaxy’s present-day optical form from our study, its normal H i rotation velocity in relation to its H i mass, H i morphology, environment, and dwarf mass DM halo ruled out some of the proposed ultra-diffuse galaxy formation scenarios for this galaxy.
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, National Aeronautics and Space Administration, Alfred P. Sloan Foundation, California Institute of Technology, Higher Education Funding Council for England, Commonwealth Scientific and Industrial Research Organisation, Tata Institute of Fundamental Research, Federación Española de Enfermedades Raras, National Research Foundation of Korea, Max-Planck-Gesellschaft, Ministério da Ciência, Tecnologia e Ensino Superior, Jet Propulsion Laboratory, Fundação para a Ciência e a Tecnologia
Awards: G1221254527, How do galaxy cluster mergers impact the evolution of their late-type galaxies ?, G1483381719, G1690109813, G1819696421, G281706780, Sem título, G4108995148, G5389921940, G5454278309, G5899352458, G5999395293, G6193589897, Identificação dos Buracos Negros Supermassivos mais Jovens com ALMA, Instituto de Astrofísica e Ciências do Espaço, Instituto de Astrofísica e Ciências do Espaço, G8053767858
OpenAlex ID: W2957054864