UGC 4703 Interacting Pair Near the Isolated Spiral Galaxy NGC 2718: A Milky Way Magellanic Cloud Analog

摘要

We present an analysis of physical and morphological properties of an interacting pair of dwarf galaxies, UGC 4703, located in the vicinity of an isolated Milky Way (MW) type spiral galaxy NGC 2718. Based on the comparison of physical and morphological properties with that of the Large and Small Magellanic Clouds (LMC and SMC), we report that the UGC 4703 pair–NGC 2718 system is probably an LMC–SMC–MW analog. Located at a sky-projected distance of 81 kpc from NGC 2718, we find that UGC 4703 is clearly interacting with its nearby lower-mass companion UGC 4703B, forming a bridge of stellar stream between them. Total B-band luminosity of UGC 4703 and its companion is ?17.75 and ?16.25 mag, respectively. We obtained H I 21 cm line data of UGC 4703 using the GMRT to get a more detailed view of neutral hydrogen (H I) emission. The H I image revealed evidence of interaction between the dwarf galaxy pair but no extended emission, such as the Magellanic Stream. We also detected star-forming regions along the UGC 4703/4703B bridge with stellar mass exceeding 10~7 M_☉. While comparing the optical and H I morphology of the interacting dwarf pairs (UGC 4703–4703B and LMC– SMC), we discuss possible differences in interaction histories of these systems.