Open AccessWhen dwarf galaxies turn to be spiral?
Author(s) -
А. В. Засов,
А. В. Хоперсков,
Natalia A. Zaitseva,
С. С. Храпов
Publication year - 2022
Publication title -
astronomy at the epoch of multimessenger studies. proceedings of the vak-2021 conference, aug 23–28, 2021
Language(s) - English
Resource type - Conference proceedings
DOI - 10.51194/vak2021.2022.1.1.173
Subject(s) - physics , astrophysics , irregular galaxy , disc , spiral galaxy , elliptical galaxy , lenticular galaxy , dwarf galaxy , astronomy , galaxy
Spiral structure is rarely observed in dwarf galaxies because the formation of spiral arms requires special conditions. Weanalyze the sample of about 40 dS-galaxies found among the bright late-type galaxies with M B > −18 m and photometricdiameter D 25 < 12 kpc. These galaxies do not dier statistically from non-dS galaxies apart from the lower average gas (HI)fraction. To check the conditions of formation of spiral structure we carried out a series of direct N-body/hydrodynamicsimulations of dynamic evolution of low-mass stellar/gaseous discs varying the initial parameters of galaxies. We came toconclusion that the gravitational mechanism of formation of spiral structure is eective only for thin stellar/gaseous discs,non-typical for dwarf galaxies. The thicker stellar disc, the more gas is required for the spiral structure to form. The reducedgas content in most dS-galaxies may be a result of more ecient star formation in their relatively thin discs.