2019MNRAS.486..504S -
Mon. Not. R. Astron. Soc., 486, 504-522 (2019/June-2)
A 5deg x 5deg deep H I survey of the M81 group.
SORGHO A., FOSTER T., CARIGNAN C. and CHEMIN L.
Abstract (from CDS):
A 25 deg^2 region, including the M81 complex (M81, M82, and NGC 3077), NGC 2976, and IC2574, was mapped during ∼3000 h with the DRAO synthesis telescope. With a physical resolution of ∼1 kpc, these observations allow us to probe a large region down to column density levels of ∼1×1018 cm–2 over 16 km s–1, mapping the extent of the H I arm connecting the system and NGC 2976, and resolving the H I clouds adjacent to the arm. The observations also reveal a few clouds located between the system and IC 2574, probably tidally stripped from a past interaction between the two systems. Given the regular velocity distribution in the H I envelope of the system, we attempt and derive an idealized large-scale rotation curve of the system. We observe a flat trend for the rotation velocity of the overall system from 20 kpc out to 80 kpc, well beyond the outskirts of the M81 disk, although with asymmetries like a wiggle at the vicinity of M82. This supports the assumption that intergalactic gas and galaxies in the system participate to a large-scale ordered rotation motion which is dominated by M81. Also, our H I analysis of the group further supports the hypothesis that the galaxies forming the system moved closer from afar, in agreement with numerical simulations.
Abstract Copyright:
© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society
Journal keyword(s):
galaxies: evolution - galaxies: groups - galaxies: individual: (M81, M82, NGC 3077, NGC 2976, IC 2574, Ho IX) - galaxies: ISM - galaxies: interactions - galaxies: kinematics and dynamics
Simbad objects:
31
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2019MNRAS.486..504S and select 'bookmark this link' or equivalent in the popup menu