H i observations of IC 10 with the DRAO synthesis telescope. Issue 3 (26th October 2019)

• Record Type: Journal Article
• Authors: Namumba, B; Carignan, C; Foster, T; Deg, N
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 490:Issue 3(2019)
• Page Start: 3365
• Page End: 3377
• Publication Date: 2019-10-26
• Subjects: techniques: interferometric -- ISM: kinematics and dynamics -- galaxies: dwarf -- galaxies: individual: IC 10 -- Local Group -- dark matter; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stz2737
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: H i observations of the nearby blue compact dwarf galaxy IC 10 obtained with the Dominion Radio Astrophysical Observatory synthesis telescope, for a total integration of ∼1000 h, are presented. We confirm the NW faint 21 cm H i emission feature discovered in Green Bank Telescope (GBT) observations. The H i feature has an H i mass of 4.7 × 10 5 M⊙, which is only ∼0.6 ${{\ \rm per\ cent}}$ of the total H i mass of the galaxy (7.8 × 10 7 M⊙ ). In the inner disc, the rotation curve of IC 10 rises steeply, then flattens until the last point where it rises again, with a maximum velocity of 30 km s −1 . Based on our mass models, the kinematics of the inner disc of IC 10 can be described without the need of a dark matter halo. However, this does not exclude the possible presence of dark matter on a larger scale. It is unlikely that the disturbed features seen in the outer H i disc of IC 10 are caused by an interaction with M 31. Features seen from our simulations are larger and at lower surface density than can be reached by current observations. The higher velocity dispersions seen in regions where several distinct H i features meet with the main core of IC 10 suggest that there is ongoing accretion.