New dwarf galaxy candidates in the sphere of influence of the Local Volume spiral galaxy NGC2683

Abstract

ABSTRACT We present initial results of a survey of host L* galaxies environments in the Local Volume ($D\lt 10\,$ Mpc) searching for satellite dwarf galaxy candidates using the wide-field Hyper Suprime-Cam imager on the 8 m Subaru Telescope. This paper presents complete results on NGC2683 ($M_{B_T,0}=-19.62$, $D=9.36\, \mathrm{ Mpc}$, $v_{\odot }=411\, \mathrm{ km\, s}^{-1}$), an isolated Sc spiral galaxy in the Leo Spur. At the distance of NGC2683, we image the complete volume out to projected radii of $380\, \mathrm{ kpc}$ using a hexagonal arrangement of 7 pointings. Direct inspection of the images is complete down to Mg ∼ −11 and has revealed four new satellite galaxy candidates, two of which have been independently discovered by other researchers. Assuming the distance of NGC2683, these candidates span luminosities −12 < Mg < −9 and effective radii 150 pc <re < 1100 pc and are found to be morphologically reminiscent of satellite galaxies in the Local Group. These four new candidates add to the eight already known. A principle component analysis of the 2D projected distribution of the 12 satellite galaxies of NGC2683 reveals a flattened projected disc of satellites, with axis ratio b/a = 0.23. This flattening in the 2D projected system of satellites is a 1 per cent outlier of simulated isotropic satellite systems but is mostly consistent with satellite distributions of comparable galaxy environments in the IllustrisTNG simulation. This indicates the possible presence of a satellite plane, which will need to be investigated with follow-up observations.