Observation of HI around three satellite galaxies of the M31 with the FAST: Andromeda II, NGC 205, and NGC 185

Abstract

With the exceptional sensitivity of the Five-hundred-meter Aperture Spherical radio Telescope (FAST), we conducted observations of the neutral hydrogen (HI) in the circumgalactic medium of Andromeda's (M31) satellite galaxies, specifically Andromeda II, NGC 205, and NGC 185. Initially, three drift scans were executed for these satellites, with a detection limit of $4\times 10^{18}$ cm${}^{-2}$ ( approximately $1.88\times 10^3{M}_{\odot }$ of HI mass), followed by a more in-depth scan of a specific region. We discovered a C-shaped HI arc structure sharing a position and line-of-sight velocity similar to a stellar ring structure around Andromeda II, hinting at a potential connection with Andromeda II. In the context of NGC 205, we identified two mass concentrations in the northeast direction, which could be indicative of tidal streams resulting from the interaction between this galaxy and M31. These new lumps discovered could be very helpful in solving the missing interstellar medium (ISM) problem for NGC 205. Observations regarding NGC 185 are consistent with previous studies, and we did not detect any additional HI material around this galaxy. These observational results enhance our understanding of the evolution of these satellite galaxies and provide insight into their historical interactions with the galaxy M31.

arXiv comment9 pages, 7 figures, accepted by RAA

References in corpus (26)

• Dwarf Galaxies of the Local Group
• The observed properties of dwarf galaxies in and around the Local Group
• A giant stream of metal-rich stars in the halo of the galaxy M31
• The Faintest Dwarf Galaxies
• The Progenitors of Dwarf Spheroidal Galaxies
• HI in Local Group Dwarf Galaxies and Stripping by the Galactic Halo
• The Fundamental Performance of FAST with 19-beam Receiver at L Band
• Gas Rich Dwarf Spheroidals
• The Dearth of Neutral Hydrogen in Galactic Dwarf Spheroidal Galaxies
• The remnant of a merger between two dwarf galaxies in Andromeda II
• Stellar Kinematics of the Andromeda II Dwarf Spheroidal Galaxy
• Local Group Dwarf Elliptical Galaxies: I. Mapping the Dynamics of NGC 205 Beyond the Tidal Radius
• The tidal trail of NGC205?
• The internal dynamics of the Local Group dwarf elliptical galaxies NGC147, NGC185, and NGC205
• The star formation history of the Local Group dwarf elliptical galaxy NGC 185: II. Gradients in the stellar population
• The Evolved Stellar Content of NGC 147, NGC 185, and NGC 205
• Andromeda II as a merger remnant
• Morphological properties of galaxies in different Local Volume environments
• HiFAST: an HI data calibration and imaging pipeline for FAST
• Radio Continuum and Star Formation in CO-rich Early Type Galaxies
• Herschel and JCMT observations of the early-type dwarf galaxy NGC 205
• The structure of Andromeda II dwarf spheroidal galaxy
• Formation of Andromeda II via a gas-rich major merger and an interaction with M31
• Properties of a Molecular Cloud in NGC 185
• HiFAST : An HI Data Calibration and Imaging Pipeline for FAST II. Flux Density Calibration
• The interstellar medium in Andromeda's dwarf spheroidal galaxies: II. Multi-phase gas content and ISM conditions

Cited by in corpus (1)

• HiFAST: An HI Data Calibration and Imaging Pipeline for FAST III. Standing Wave Removal