The MeerKAT Fornax Survey II. The rapid removal of HI from dwarf galaxies in the Fornax cluster

Abstract

We present MeerKAT Fornax Survey atomic hydrogen (HI) observations of the dwarf galaxies located in the central ~2.5 x 4 deg${}^2$ of the Fornax galaxy cluster. The HI images presented in this work have a $3\sigma$ column density sensitivity between 2.7 and 50 x 10${}^{18}$ cm${}^{-2}$ over 25 km s${}^{-1}$ for spatial resolution between 4 and 1 kpc. We are able to detect an impressive MHI = 5 x 10${}^5$ Msun 3$\sigma$ point source with a line width of 50 km s${}^{-1}$ at a distance of 20 Mpc. We detect HI in 17 out of the 304 dwarfs in our field -- 14 out of the 36 late type dwarfs (LTDs), and 3 of the 268 early type dwarfs (ETDs). The HI-detected LTDs have likely just joined the cluster and are on their first infall as they are located at large clustocentric radii, with comparable MHI and mean stellar surface brightness at fixed luminosity as blue, star-forming LTDs in the field. The HI-detected ETDs have likely been in the cluster longer than the LTDs and acquired their HI through a recent merger or accretion from nearby HI. Eight of the HI-detected LTDs host irregular or asymmetric HI emission and disturbed or lopsided stellar emission. There are two clear cases of ram-pressure shaping the HI, with the LTDs displaying compressed HI on the side closest to the cluster centre and a one-sided, starless tail pointing away from the cluster centre. The HI-detected dwarfs avoid the most massive potentials, consistent with massive galaxies playing an active role in the removal of HI. We create a simple toy model to quantify the timescale of HI stripping in the cluster. We find that a MHI = 10${}^8$ Msun dwarf will be stripped in ~ 240 Myr. The model is consistent with our observations, where low mass LTDs are directly stripped of their HI from a single encounter and more massive LTDs can harbour a disturbed HI morphology due to longer times or multiple encounters being required to fully strip their HI.

Accepted in Astronomy & Astrophysics. 21 pages, 10 figures. Data available at the MeerKAT Fornax Survey website https://sites.google.com/inaf.it/meerkatfornaxsurvey

References in corpus (26)

• Ram Pressure Stripping in High-Density Environments
• The origin of dwarf ellipticals in the Virgo cluster
• FIGGS: Faint Irregular Galaxies GMRT Survey - Overview, observations and first results
• The Dawes Review 9: The role of cold gas stripping on the star formation quenching of satellite galaxies
• On the origin of the faint-end of the red sequence in high density environments
• The ACS Fornax Cluster Survey. I. Introduction to the Survey and Data Reduction Procedures
• The Dearth of Neutral Hydrogen in Galactic Dwarf Spheroidal Galaxies
• New HI scaling relations to probe the HI content of galaxies via global HI-deficiency maps
• Physical properties of SDSS satellite galaxies in projected phase-space
• The Fornax Deep Survey (FDS) with VST. VI. Optical properties of the dwarf galaxies in the Fornax cluster
• The Fornax Deep Survey with VST. VIII. Connecting the accretion history with the cluster density
• The Fornax Deep Survey (FDS) with the VST XI. The search for signs of preprocessing between the Fornax main cluster and Fornax A group
• A blind ATCA HI survey of the Fornax galaxy cluster: properties of the HI detections
• A MeerKAT view of pre-processing in the Fornax A group
• The SAMI -- Fornax Dwarfs Survey I: Sample, observations and the specific stellar angular momentum of dwarf elliptical galaxies
• The Fornax Deep Survey with VST. X. The assembly history of the bright galaxies and intra-group light in the Fornax A subgroup
• Tidal origin of NGC 1427A in the Fornax cluster
• CO($J$=1-0) mapping survey of 64 galaxies in the Fornax cluster with the ALMA Morita array
• The SAMI-Fornax Dwarfs Survey III: Evolution of [$\alpha$/Fe] in dwarfs, from Galaxy Clusters to the Local Group
• HI observations of the MATLAS dwarf and ultra-diffuse galaxies
• The Fornax3D project: The assembly history of massive early-type galaxies in the Fornax cluster from deep imaging and integral field spectroscopy
• A possible signature of the influence of tidal perturbations in dwarf galaxy scaling relations
• AlFoCS + F3D II: unexpectedly low gas-to-dust ratios in the Fornax galaxy cluster
• A tale of two tails: insights from simulations into the formation of the peculiar dwarf galaxy NGC 1427A
• Census of Gaseous Satellites around Local Spiral Galaxies
• HI in Virgo's "Red and Dead" Dwarf Ellipticals - A Tidal Tail and Central Star Formation

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• The MeerKAT Fornax Survey VI. The collapse of the galaxy HI Mass Function in Fornax
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• The MeerKAT Fornax Survey -- I. Survey description and first evidence of ram pressure in the Fornax galaxy cluster
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