A coupling pair of dwarfs in Lynx

TL;DR

This paper reports the discovery of a unique binary dwarf galaxy system in Lynx, characterized by its low surface brightness and tidal stream appearance, detected via HI line observations, with detailed measurements of its properties.

Contribution

The study presents the first detection and detailed analysis of a binary dwarf galaxy pair with unusual features, including a high orbital mass-to-luminosity ratio and a tidal stream appearance.

Findings

Binary dwarf galaxy pair with low surface brightness features.

High orbital mass-to-luminosity ratio of 49.

Short crossing time of 0.22 Gyr.

Abstract

We report on discovery of unique binary system of dIr galaxies which looks like a low surface brightness tidal stream in the halo of another dwarf galaxy. Both the galaxies are detected in the HI line with the Giant Metrewave Radio Telescope (GMRT). The pair components have absolute blue magnitudes -16.0 and -13.2, heliocentric radial velocities 1799 and 1842 km/s, and hydrogen masses-to-luminosity ratios 0.4 and 1.6 in solar units, respectively. The binary system is characterized by a high orbital mass-to-luminosity ratio of 49 in solar units and a short crossing time of 0.22 Gyr.