Tez Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Rijksuniversiteit Groningen, Faculty of Science and Engineering, Kapteyn Astronomical Institute, Hollanda
Tez Danışmanı: Reynier Peletier
Tezin Onay Tarihi: 2008
Tezin Dili: İngilizce
Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu
Özet:
We have presented optical and near-IR surface photometry for quiescent dwarf galaxies (dEs). For this purpose, we have obtained optical images from SDSS (Sloan Digital Sky Survey) and near-IR images (H & K bands) from Magpop-ITP (Multi-wavelength Analysis of Galaxy Populations- International Time Programme) training network. The Magpop-ITP research has an importance that is the first study of quiescent dwarf galaxies which includes a detailed investigation of field systems. The near-IR sample contains the high resolution images of 33 quiescent and 22 star-forming dwarf galaxies which are in the Virgo Cluster and in the field. However, we mostly focus on quiescent dwarf galaxies. By doing surface photometry we obtain optical and optical - near-IR colours and colour gradients. By analyzing these colours and colour gradients together with comparing the LICK/IDS spectroscopic line strength indices, we have extracted physical information about their metallicity and star formation history.
The major results from this research are;
• Star-forming and quiescent dwarf galaxies can be well seperated in optical vs. UV colour-magnitude diagrams and as well as colour-colour diagrams.
• We do not find any differences between field and cluster dwarf galaxies as a function of environment.
• By making a comparison to stellar populations models we find that the quiescent dwarfs have Sub-Solar or Solar metallicities. Their ages range between 4-10 Gyrs and therefore they are not expected to be primordial.
• Quiescent dwarfs (dEs) have similar colour gradients as giant ellipticals (Es) but less metal rich.