Bibcode
Vaduvescu, Ovidiu
Bibliographical reference
PhD Thesis, Proquest Dissertations And Theses 2006. Section 0267, Part 0606 233 pages; [Ph.D. dissertation].Canada: York University (Canada); 2006. Publication Number: AAT NR11637. Source: DAI-B 67/01, p. 316, Jul 2006</td>
Advertised on:
7
2006
Citations
0
Refereed citations
0
Description
Dwarf galaxies are the most common galaxies in the Universe. They are
systems believed to consist of matter in a near-primordial state, from
which giant galaxies probably form. As such, they are important probes
for studying matter in its near-primordial state.
In an effort to study the main physical and chemical properties of
dwarfs, the present thesis focuses upon the main physical properties of
dwarfs. Two classes of star forming dwarf galaxies are considered: dwarf
irregulars (dIs), and blue compact dwarfs (BCDs). A third class, dwarf
ellipticals (dEs), is studied based on its structural properties and
compared with dIs.
Possible evolutionary connections are addressed between dIs and BCDs. To
measure the luminosity, deep imaging in the near-infrared (NIR) is
considered. Compared with the visible, the NIR domain gives a better
gauge of the galaxy mass contained in the old stellar populations,
minimising the starburst contribution and also the effects of
extinction.
Two observing samples of star-forming dwarf galaxies are considered. The
first includes 34 dIs in the Local Volume closer than ˜ 5 Mpc. The
second sample includes 16 BCDs in the Virgo Cluster.
Overall, based on their structural and physical properties, closer links
emerge between dIs, BCDs, and dEs. Comparing their structural
properties, dIs and BCDs appear to share common origins, with the sech
component modeling all the NIR flux for dIs and most of the flux for
BCDs. On the fundamental plane, dIs and BCDs also show similar dynamical
properties. Thus, BCDs seem to be dIs observed in a bursting phase.
Taking into account their gas-to-mass fraction, BCDs cannot be
considered closed systems, their shifted position in respect to dIs
suggesting flows of gas such as infall of gas clouds. Comparing
structural properties, dEs lie in the fundamental plane of dIs,
suggesting an intimate link between the two systems, in the sense that
dEs could be consider the final outcome of dIs after all gas is removed
from the system. (Abstract shortened by UMI.)