On the accretion of a new group of galaxies on to Virgo: I. Internal kinematics of nine in-falling dEs. Issue 2 (20th July 2020)

• Record Type: Journal Article
• Authors: Bidaran, Bahar; Pasquali, Anna; Lisker, Thorsten; Coccato, Lodovico; Falcón-Barroso, Jesus; van de Ven, Glenn; Peletier, Reynier; Emsellem, Eric; Grebel, Eva K; La Barbera, Francesco; Janz, Joachim; Sybilska, Agnieszka; Vijayaraghavan, Rukmani; Gallagher, John; Gadotti, Dimitri A
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 497:Issue 2(2020)
• Page Start: 1904
• Page End: 1924
• Publication Date: 2020-07-20
• Subjects: galaxies: dwarf -- galaxies: evolution -- galaxies: interactions -- galaxies: kinematics and dynamics -- galaxies: structure; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/staa2097
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: Galaxy environment has been shown to play an important role in transforming late-type, star-forming galaxies to quiescent spheroids. This transformation is expected to be more severe for low-mass galaxies ($M \lt 10^{10}\, \mathrm{M}_\odot$ ) in dense galaxy groups and clusters, mostly due to the influence of their past host haloes (also known as pre-processing) and their present-day environments. For the first time, in this study, we investigate a sample of nine early-type dwarf galaxies (dEs) that were accreted as a likely bound group on to the Virgo galaxy cluster about 2–3 Gyr ago. Considering this special condition, these nine dEs may provide a test bed for distinguishing between the influence of the Virgo galaxy cluster and the effects of the previous host halo on their current properties. Specifically, we use VLT/MUSE integral-field unit spectra to derive their kinematics and specific angular momentum (λ R ) profiles. We observe a spread in the λ R profiles of our sample dEs, finding that the λ R profiles of half of them are as high as those of low-mass field galaxies. The remaining dEs exhibit λ R profiles as low as those of Virgo dEs that were likely accreted longer ago. Moreover, we detect nebular emission in one dE with a gas velocity offset suggesting ongoing gas stripping in Virgo. We suggest that the low-λ R dEs in our sample were processed by their previous host halo, prior to their infall to Virgo, and that the high-λ R dEs may be experiencing ram pressure stripping in Virgo.