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Recent Articles in Astrophysics and Astronomy
An Event-By-Event Comparison Of Clustering Algorithms For Photon Detection In The Star Endcap Calorimeter, William J. Pochron 
Valparaiso University
An Event-By-Event Comparison Of Clustering Algorithms For Photon Detection In The Star Endcap Calorimeter, William J. Pochron
Celebration of Undergraduate Scholarship
The STAR detector at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory uses polarized proton collisions to determine the origin of the proton spin, using measurements such as neutral pion asymmetries. The Endcap Electromagnetic Calorimeter (EEMC) in the STAR detector is especially useful for detecting photons from π° decays at forward angles. This latter measurement is obtained from the Shower Maximum Detector (SMD) in the EEMC where narrow crossed scintillator strips measure the energy deposited in them and can be used to identify the location of the photon shower. The electromagnetic shower most often deposits energy in a ...
Generating A ‘Clean’ Pi0 Spectrum In Star, William J. Pochron Valparaiso University
Generating A ‘Clean’ Pi0 Spectrum In Star, William J. Pochron
Celebration of Undergraduate Scholarship
The STAR detector at Brookhaven National Laboratory’s Relativistic Heavy Ion Collider uses polarized proton collisions to investigate the origin of the proton spin, using measurements such as neutral pion (π0) asymmetries. STAR’s Endcap Electromagnetic Calorimeter (EEMC) is especially useful for detecting photons from π0 decays at forward-angle scattering from ≈15 to ≈40 degrees above the beam direction. We identify π0’s by constructing invariant mass spectra from these photons. Large background contributions are present in these spectra and distort the true value of the π0 invariant mass. By applying constraints (cuts) on parameters such as the opening angle ...
Testing The Klein-Nishina Model For Compton Scattering Of 0.662 Mev Photons With A Focus On Lower Scattering Angles, Joel Rogers Valparaiso University
Testing The Klein-Nishina Model For Compton Scattering Of 0.662 Mev Photons With A Focus On Lower Scattering Angles, Joel Rogers
Celebration of Undergraduate Scholarship
The Thomson and Klein-Nishina equations for obtaining the differential cross section by Compton scattering of photons from free electrons in aluminum will be tested using 0.662 MeV photons from a Cesium-137 source. A NaI detector will be used to count the number of photons scattering from the target as a function of the scattering angle. A previous experiment carried out by VU student Josh Vredevoogd showed good agreement with the Klein-Nishina theory for angles greater than 45 but discrepancies with angles less than 45 degrees. This experiment will concentrate on testing the Klein-Nishina theory at angles less than 45 ...
A Study Of Light Variability In Dying Stars, Hannah Rotter, Aaron Seider, Austin Bain Valparaiso University
A Study Of Light Variability In Dying Stars, Hannah Rotter, Aaron Seider, Austin Bain
Celebration of Undergraduate Scholarship
In this research project, we observed and analyzed the light variability in a class of dying stars that are in the stage between Red Giant and White Dwarf in the evolution of stars like the Sun. Our observations were carried out during the summer and fall of 2012 at the Valparaiso Observatory. Thirty-two of these objects were observed in total. We analyzed a subset of 18 of these and found that they all varied in visual brightness by 10-70 percent. Periods for the variability were found for 8 out of 18 objects, and they range from 27 to 125 days ...
Stability Of The Gains Of The Star Endcap Calorimeter From 2006 To 2011, Kayla Kutz Valparaiso University
Stability Of The Gains Of The Star Endcap Calorimeter From 2006 To 2011, Kayla Kutz
Celebration of Undergraduate Scholarship
The Solenoid Tracker at RHIC (STAR) experiment, based at Brookhaven National Laboratory's Relativistic Heavy Ion Collider (RHIC), uses polarized-proton collisions to investigate sea quark and gluon contributions to the fundamental proton property called “spin.” The STAR detector's Endcap Electromagnetic Calorimeter (EEMC) measures the energy of particles produced by those collisions using a lead-scintillator sampling calorimeter, consisting of several layers that include pre-shower, shower maximum, tower, and post-shower detectors. In these detectors, the energy gains, which convert a measured pulse into an energy deposition, have been determined using data taken from the years 2006, 2009, and 2011. Changes in ...
Neutral Pion Background Analysis At Star, Adam Clark Valparaiso University
Neutral Pion Background Analysis At Star, Adam Clark
Celebration of Undergraduate Scholarship
The STAR detector at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory takes measurements of polarized proton collisions which can then be used to extract cross sections and spin asymmetries. The Endcap Electromagnetic Calorimeter (EEMC) in STAR allows measurements of electromagnetic particles in the forward direction, 1 < η < 2. The EEMC will be used to determine the neutral pion (π0) cross section and the double longitudinal spin asymmetry (ALL) which gives us information about the gluon contribution to the proton’s spin. The π0 cross section is an important supporting measurement to verify our signal reconstruction and the background characterization for the π0 asymmetry. In order to measure the π0 cross section and asymmetry, the backgrounds must be well understood (such as those from photon conversions and reconstruction errors where one photon reconstructs as two clusters). Efforts toward the π0 cross section and asymmetry measurements and, specifically, those to understand π0 backgrounds are discussed.
A Study Of Two Newly-Discovered Eclipsing Binary Systems, Austin Bain Valparaiso University
A Study Of Two Newly-Discovered Eclipsing Binary Systems, Austin Bain
Celebration of Undergraduate Scholarship
I have observed three newly-discovered variable stars using the 16-inch telescope and CCD at the Valparaiso University Observatory. Of these three variables, two have been verified as binary star systems, where one of the stars passes in front of the other. The third is found to be a pulsating variable, which varies due to a change in its size and temperature. One of the goals of this project has been to further refine the periods of these three variables. From my new data and some previous observations at the Valparaiso University Observatory, I have been able to determine that the ...
Dispersion Of Radon-222 Gas In Air, Erin Beckmeyer Valparaiso University
Dispersion Of Radon-222 Gas In Air, Erin Beckmeyer
Celebration of Undergraduate Scholarship
Radon-222 is a heavy radioactive gas with a half-life of 3.8 days, often found in basements and other enclosed, underground spaces. It is produced by decaying deposits of uranium-238, and presents a significant health risk to those who encounter it in their homes and places of work. The only gas in the uranium decay chain, radon atoms work their way through layers of soil, usually to dissipate harmlessly into the atmosphere. In buildings, however, the gas accumulates and causes dangerous environmental radiation. Much work has been done to measure the transmission of the gas through water and solid materials ...
Galaxy Inclination And Surface Brightness, Jordan C. Rozum, Shane L. Larson 
Utah State University
Galaxy Inclination And Surface Brightness, Jordan C. Rozum, Shane L. Larson
Student Showcase
The distribution of spiral and bar galaxy inclination angles is expected to be uniform. However, analysis of several major galaxy catalogs shows this is not the case; galaxies oriented near edge-on are significantly more common in these catalogs. In an attempt to explain this discrepancy, we have developed a galaxy simulation code to compute the appearance of a spiral type galaxy as a function of its morphological parameters. We examine the dependence of observed brightness upon inclination angle by using smooth luminous mass density and interstellar medium (ISM) density distributions. The luminous mass component is integrated along a particular line ...
Quantifying Night Sky Fluctuations: Striving For A Multi-Messenger Astronomy, Rachel K. Nydegger, Shane L. Larson Ph.D. Utah State University
Quantifying Night Sky Fluctuations: Striving For A Multi-Messenger Astronomy, Rachel K. Nydegger, Shane L. Larson Ph.D.
Browse All Undergraduate research
With LIGO coming back online soon, astronomers are attempting to solve the problems involved with coupling gravitational observations with electromagnetic telescope observations. To do this, my project aims to create all-sky surveys to characterize natural variability to reduce "false-alarm" rates in detections of gravitational emissions.
Core Formation In Partially Ionized Magnetic Molecular Clouds, Nicole D. Bailey 
Western University
Core Formation In Partially Ionized Magnetic Molecular Clouds, Nicole D. Bailey
University of Western Ontario - Electronic Thesis and Dissertation Repository
Linear analysis of the formation of protostellar cores in planar magnetic interstellar clouds shows that molecular clouds exhibit a preferred length scale for collapse that depends on the mass-to-flux ratio and neutral-ion collision time within the cloud. This linear analysis can be used to investigate the formation of star forming clusters and the distribution of mass within star forming regions. By combining the results of the linear analysis with a realistic ionization profile for the cloud, we find that a molecular cloud may evolve through two fragmentation events in the evolution toward the formation of stars. Our model suggests that ...
A Variability Study Of The Typical Red Supergiant Antares A, Teznie J D Pugh Western University
A Variability Study Of The Typical Red Supergiant Antares A, Teznie J D Pugh
University of Western Ontario - Electronic Thesis and Dissertation Repository
Red giants and red supergiants have long been known to be variable. In the last 40 years many of the features of this variability have been associated with large convective cells. Unfortunately, due to the long timescales of these variations they are not well studied, with the exception of the bright M-class supergiant Betelgeuse (α Orionis, M2 Iab). Betelgeuse has been well studied both observationally and theoretically, and has many features that are well described by models of convection. It was these studies of Betelgeuse that provided the main motivation for this thesis. We ask if the dramatic motions seen ...
On The Spherical Symmetry Of Perfect-Fluid Stellar Models In General Relativity, Joshua M Brewer 
University of Tennessee, Knoxville
On The Spherical Symmetry Of Perfect-Fluid Stellar Models In General Relativity, Joshua M Brewer
Masters Theses
It is well known in Newtonian theory that static self-gravitating perfect fluids in a vacuum are necessarily spherically symmetric. The necessity of spherical symmetry of perfect-fluid static spacetimes with constant density in general relativity is shown.
Determining Stellar Velocity Dispersion In Active Galaxies: Is The [Oiii] Width A Valid Surrogate?, Kelsi Flatland 
California Polytechnic State University
Determining Stellar Velocity Dispersion In Active Galaxies: Is The [Oiii] Width A Valid Surrogate?, Kelsi Flatland
Physics
The tight empirical relation between the stellar velocity dispersion (sigma) of the bulge and the mass of the supermassive black hole (BH) at its center indicates a close connection between galactic evolution and BH growth. The evolution of this relation with cosmic time provides valuable clues to its origin. While the mass of the BH can be easily estimated using the Doppler broadening of the Hbeta emission line in type I active galactic nuclei (AGNs), measuring sigma simultaneously is challenging, since the nuclear emission outshines the host galaxy. Thus, it is highly desirable to find an alternative way to estimate ...
Astronomy / Galactic Structure - Rensselaer Polytechnic Institute, Kathryn M. Dunn 
Purdue University
Astronomy / Galactic Structure - Rensselaer Polytechnic Institute, Kathryn M. Dunn
Data Curation Profiles Directory
The researcher participates in large-scale astronomical survey projects, which are collaborative efforts of many institutions and individuals. Management of the raw and processed/calibrated data is handled by those projects, but data for specific research questions is handled by the researcher. The researcher would like to have a better way to share the data behind the figures in their published papers with other researchers. The effort involved in retrieving and documenting the data so it’s usable by others is a barrier to sharing the data. It would be easier to share data from publications if it could be deposited ...
The Neutron-Star Equation Of State And Gravitational Waves From Compact Binaries, Benjamin David Lackey 
University of Wisconsin Milwaukee
The Neutron-Star Equation Of State And Gravitational Waves From Compact Binaries, Benjamin David Lackey
Theses and Dissertations
The equation of state (EOS) of matter above nuclear density is currently uncertain by almost an order of magnitude. Fortunately, neutron stars (NS) provide an ideal laboratory for studying high density matter. In order to systematize the study of the EOS from NS observations, we introduce a parametrized high-density EOS that accurately fits theoretical candidate EOSs. We then determine the ability of several recent and near-future electromagnetic observations to constrain the parameter space of our EOS. Recent observations include measurements of masses, gravitational redshift, and spin period, and we find that high mass observations are the most useful at constraining ...
Modeling Spiral Galaxy Surface Luminosity To Explain Non-Uniform Inclination Distributions, Jordan C. Rozum, Shane L. Larson 
Utah State University
Modeling Spiral Galaxy Surface Luminosity To Explain Non-Uniform Inclination Distributions, Jordan C. Rozum, Shane L. Larson
Jordan Rozum
The distribution of spiral and bar galaxy inclination angles is expected to be uniform. However, analysis of several major galaxy catalogs shows this is not the case; galaxies oriented near edge-on are significantly more common in these catalogs. In an attempt to explain this discrepancy, we have developed a galaxy simulation code to compute the appearance of a spiral type galaxy as a function of its morphological parameters. We examine the dependence of observed brightness upon inclination angle by using smooth luminous mass density and ISM density distributions. The luminous component is integrated along a particular line of sight, thus ...
Galaxy Inclination And Surface Brightness, Jordan C. Rozum, Shane L. Larson Utah State University
Galaxy Inclination And Surface Brightness, Jordan C. Rozum, Shane L. Larson
Jordan Rozum
The distribution of spiral and bar galaxy inclination angles is expected to be uniform. However, analysis of several major galaxy catalogs shows this is not the case; galaxies oriented near edge-on are significantly more common in these catalogs. In an attempt to explain this discrepancy, we have developed a galaxy simulation code to compute the appearance of a spiral type galaxy as a function of its morphological parameters. We examine the dependence of observed brightness upon inclination angle by using smooth luminous mass density and interstellar medium (ISM) density distributions. The luminous mass component is integrated along a particular line ...
Characterizing Sky Variability For Multi-Messenger Astronomy, Rachel K. Nydegger, Katie Breivik, Shane L. Larson Ph.D. Utah State University
Characterizing Sky Variability For Multi-Messenger Astronomy, Rachel K. Nydegger, Katie Breivik, Shane L. Larson Ph.D.
Rachel Nydegger
Multi-messenger astronomy employs both electromagnetic and gravitational -wave detectors to paint a richer picture of celestial objects, providing more depth and information. The interferometers utilized for gravitational-wave observations receive input from very broad fields of view on the sky, typically a few square degrees. To have simultaneous electromagnetic observations (typically less than one square degree) requires innovative techniques for the telescopes to find the origin of radiation. One idea is to “tile” the view of the interferometer, using multiple telescopes to simultaneously point at different areas of the field to observe the source. One di"culty of this observing paradigm ...
Quantifying Night Sky Fluctuations: Striving For A Multi-Messenger Astronomy, Rachel K. Nydegger, Shane L. Larson Ph.D. Utah State University
Quantifying Night Sky Fluctuations: Striving For A Multi-Messenger Astronomy, Rachel K. Nydegger, Shane L. Larson Ph.D.
Rachel Nydegger
With LIGO coming back online soon, astronomers are attempting to solve the problems involved with coupling gravitational observations with electromagnetic telescope observations. To do this, my project aims to create all-sky surveys to characterize natural variability to reduce "false-alarm" rates in detections of gravitational emissions.
Popular Institutions
Popular Authors
Min Yun
University of Massachusetts - Amherst
N Katz
University of Massachusetts - Amherst
Shane Larson
Utah State University
QD Wang
University of Massachusetts - Amherst
MD Weinberg
University of Massachusetts - Amherst
D Calzetti
University of Massachusetts - Amherst
Christine Borgman
University of Massachusetts Medical School
Rachel Nydegger
Utah State University
Trevor Strickland
California Polytechnic State University
Ronald Snell
University of Massachusetts - Amherst
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