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Full-Text Articles in Physics
Reflection And Reverberation In Neutron Star Low-Mass X-Ray Binaries, Benjamin Coughenour
Reflection And Reverberation In Neutron Star Low-Mass X-Ray Binaries, Benjamin Coughenour
Wayne State University Dissertations
Neutron star low-mass X-ray binaries (NS LMXBs) are systems which consist of a NS and a low-mass companion star. They are naturally variable on a variety of timescales, and are even classified by their X-ray spectral variability on the timescales of hours to days. The most luminous NS LMXB sources are known as ‘Z’ sources, because they trace out a characteristic ‘Z’ shape when plotted on a color-color or hardness-intensity diagram. The physical mechanisms causing this variability are not well understood. To try to address this, we model spectra taken from different positions on a hardness-intensity diagram of two Z …
An Automated System To Measure The Quantum Efficiency Of Ccds For Astronomy, Rebecca Ann Coles
An Automated System To Measure The Quantum Efficiency Of Ccds For Astronomy, Rebecca Ann Coles
Wayne State University Dissertations
We describe a system to measure the Quantum Efficiency in the wavelength range of 300nm to 1100nm of 40x40 mm n-channel CCD sensors for the construction of the 3.2 gigapixel LSST focal plane. The technique uses a series of instruments to create a very uniform flux of photons of controllable intensity in the wavelength range of interest across the face the sensor. This allows the absolute Quantum Efficiency to be measured with an accuracy in the 1% range. This system will be part of a production facility at Brookhaven National Lab for the basic component of the LSST camera.
Oscillator Strength Measurements In Singly-Ionized, Doubly-Ionized And Neutral Lanthanides And Transition Elements (Sm, Nd, Pr, Gd, Cu, And Fe) Using Laser-Induced Breakdown Spectroscopy., Caleb Ryder
Wayne State University Dissertations
Models for stellar nucleosynthesis, age determinations for stars in the Milky Way's galactic halo, and stellar chemical abundance determinations are dependent upon accurate atomic spectroscopic data to allow the correct interpretation of stellar absorption and emission spectra. It is well known that calculations of many astrophysically important atomic parameters are limited due to line blending, insufficient spectral resolution of some key spectral lines, and also the complicated electronic structure of the important heavy elements. Astrophysicists have therefore looked to laboratory astrophysics experiments to provide accurate atomic data to help resolve these limiting issues. In this dissertation, laser-induced breakdown spectroscopy (LIBS) …
The Core Collapse Supernova Rate In The Sdss-Ii Supernova Survey, Matthew Frederick Taylor
The Core Collapse Supernova Rate In The Sdss-Ii Supernova Survey, Matthew Frederick Taylor
Wayne State University Dissertations
The Sloan Digital Sky Survey II Supernova Survey (SDSS-II SN), though designed as a type Ia supernova search for cosmology, also discovered a large sample of core collapse supernovae (CCSN). I use the SDSS-II SN data to measure the volumetric CCSN rate in the redshift range (0.03 < z < 0.09), finding a volume-averaged rate of 0.98±0.18 ×10⊃−4⊃h⊂70⊂⊃3⊃yr⊃−1⊃Mpc⊃−3⊃. The CCSN luminosity function is also extracted from the data, and its implications on the cosmic star formation history are considered.