Self-Consistent Cosmological Initial Conditions for the First Objects in the Early Universe
Formation of the first objects in the early universe
such as the Pop III stars is a semi-cosmological
problem due to the nature of the primordial gas.
A typical, reliable treatment of this problem is a
N-body/hydrodynamics simulation with cosmological
initial conditions for the dark matter component
(dissipationless) and the baryon component
(dissipationless). A reliable linear perturbation
analysis is prerequisite for constructing the initial
conditions in the early Universe.
There have been new developments in the linear
perturbation analysis recently, both in the large-
scale regime and small-scale regime. I will review
a recent development of the linear perturbation
analysis in the small-scale regime, and our own
attempt to create the most self-consistent
cosmological initial conditions which would be
suitable for the study of the formation of the
first objects in the early Universe.
Turmoil in Orion: The Nearest Massive Protostar
Massive star formation is a complicated process, so theories
describing it need to be tested closely against observations. The
Orion KL nebula, inside the Orion Nebular Cluster, is the nearest and
best-studied region that is thought to harbor a massive protostar.
Unfortunately, it exhibits great complexity and there is good
evidence that the gas has been influenced by some unusual dynamical
events in the last 1000 years. I review the observations of this
region and describe how a theoretical model of massive star formation
from turbulent massive gas cores is still very relevant to
understanding what is happening in Orion KL.
The Extraction of Baryonic Acoustic Oscillations
using the FITEX Method
The first step toward a determination of the equation
of the state of dark energy from HETDEX is an
of the baryonic acoustic oscillations (BAO) in the
matter power spectrum from the observed galaxy power
spectrum. A FIT-and-EXtraction (FITEX) method is an
efficient way for doing this. Following an initial
development of this method for the 1-dimensional
power spectrum, I extend it to include the
2-dimensional information in redshift space, which
will be useful for correcting non-linear redshift
space distortion effects and estimating a value of
the Hubble parameter from HETDEX.