Open AccessGaseous tidal debris found in the NGC 3783 group ★
Author(s) -
Kilborn Virginia A.,
Forbes Duncan A.,
Koribalski Bärbel S.,
Brough Sarah,
Kern Katie
Publication year - 2006
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2006.10697.x
Subject(s) - physics , astrophysics , galaxy , galaxy group , velocity dispersion , surface brightness , luminosity , astronomy , local group , dwarf galaxy , irregular galaxy , group (periodic table) , radio galaxy , interacting galaxy , quantum mechanics
We have conducted wide‐field H i mapping of a ∼5.5 × 5.5‐deg 2 region surrounding the NGC 3783 galaxy group, to an H i mass limit of ∼4 × 10 8 M ⊙ . The observations were made using the multibeam system on the Parkes 64‐m radiotelescope, as part of the Galaxy Evolution Multiwavelength Study. We find twelve H i detections in our Parkes data, four more than catalogued in H i Parkes All Sky Survey (HIPASS). We find two new group members, and discover an isolated region of H i gas with an H i mass of ∼4 × 10 8 M ⊙ , without a visible corresponding optical counterpart. We discuss the likelihood of this H i region being a low surface brightness galaxy, primordial gas, or a remnant of tidal debris. For the NGC 3783 group we derive a mean recession velocity of 2903 ± 26 km s −1 , and a velocity dispersion of 190 ± 24 km s −1 . The galaxy NGC 3783 is the nearest galaxy to the luminosity‐weighted centre of the group, and is at the group mean velocity. From the X‐ray and dynamical state of this galaxy group, this group appears to be in the early stages of its evolution.