IDENTIFIKASI DAN STUDI GALAKSI KATAI YANG DEFISIT MATERI GELAP PADA KATALOG SPARC DAN LITTLE THINGS

• Main Author: Andriyani, Ririn
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/65171
• Institution: Institut Teknologi Bandung

Dwarf galaxies are smaller in size, luminosity, and surface brightness than normal galaxies. Due to their low mass, these galaxies are highly vulnerable to internal and external disturbances, which alter the evolution of the galaxy. The disturbances cause baryonic matter to leave the system more easily; therefore, dwarf galaxies are expected to be more dominant in dark matter than normal galaxies. However, recent observations discovered some dark matter deficient dwarf galaxies. This motivates studies to investigate other dwarf galaxies and look for possible explanations for the deficiency. The aim of this thesis is to examine dwarf galaxies in the SPARC (Spitzer Photometry and Accurate Rotation Curves) and LITTLE THINGS (Local Irregulars That Trace Luminosity Extremes, The HI Nearby Galaxy Survey) catalogs, to identify if any of them are dark matter deficient, and to explore some possible causes. For this identification, EAGLE (Evolution and Assembly of GaLaxies and their Environments) simulation galaxies were also used, and it is assumed that their conditions describe the expected conditions for the observed galaxies. Three dark matter deficient galaxies were identified: IC 1613, DDO 50, and UGC 7125. They are identified as outliers in the BTF relation, having galaxy formation efficiency higher than 20% and different rotation curves compared to the simulated galaxies. However, the dark matter deficiency in UGC 7125 is not conclusive enough, due to the distance uncertainty. On the contrary, the available literature for IC 1613 and DDO 50 do not show any sign that the dark matter deficiency in the two galaxies is due to distance uncertainties. The uncertainty in the inclination of IC 1613 has the potential to make the galaxy normal, but that is not the case for DDO 50 and UGC 7125. Based on the examination of the tidal radii of the siblings, no potential of stripping is indicated in the three galaxies. However, literature show an indication of gas disturbance in DDO 50 through ram pressure stripping by the hot gas in the galaxy cluster, and that the HI disk of UGC 7125 warps.