MCG+07-20-052: Interacting dwarf pair in a group environment (2002.10076v1)

Abstract: We present an observational study of the interacting pair of dwarf galaxies, MCG+07-20-052, in the vicinity of Milky Way mass spiral galaxy NGC 2998. MCG+07-20-052 is located at a sky-projected distance of 105 kpc from NGC 2998 and the two have a relative line-of-sight velocity of 60 kms. We observed tidal tail-like extensions on both members (D1 and D2) of the interacting pair MCG+07-20-052. The interacting dwarf galaxies, D1 and D2, have B-band absolute magnitudes of $-$17.17 and $-$17.14 mag, respectively, and D2 is significantly bluer than D1. We obtained HI 21 cm line data of the NGC 2998 system using the Giant Metrewave Radio Telescope (GMRT) to get a more detailed view of the neutral hydrogen (HI) emission in the interacting dwarf galaxies and in the galaxy members of the NGC 2998 group. Evidence of a merger between the dwarf galaxies in the MCG+07-20-052 is also present in the HI kinematics and morphology where we find that the HI is mostly concentrated around D2, which also shows a higher level of star-forming activity and bluer $g-r$ color index compared to D1. In addition, we detect extended tenuous HI emission around another member galaxy, NGC 3006, located close to the MCG+07-20-052-pair at a sky-projected distance of 41 kpc. We compare here our results from the MCG+07-20-052 pair-NGC 2998 system with other known LMC-SMC-Milky Way type systems and discuss the possible origin of the dwarf-dwarf interaction.