Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Stars, Interstellar Medium and the Galaxy (117)
- External Galaxies (56)
- Cosmology, Relativity, and Gravity (55)
- Physics (28)
- Physical Processes (24)
-
- Other Astrophysics and Astronomy (21)
- The Sun and the Solar System (14)
- Instrumentation (9)
- Atomic, Molecular and Optical Physics (4)
- Mathematics (4)
- Nuclear (4)
- Applied Mathematics (3)
- Computer Sciences (3)
- Engineering (3)
- Arts and Humanities (2)
- Chemistry (2)
- Condensed Matter Physics (2)
- Databases and Information Systems (2)
- Earth Sciences (2)
- Education (2)
- Materials Science and Engineering (2)
- Other Physics (2)
- Plasma and Beam Physics (2)
- Science and Mathematics Education (2)
- Social and Behavioral Sciences (2)
- Chemical Engineering (1)
- Computer Engineering (1)
- Cosmochemistry (1)
- Institution
-
- Dartmouth College (171)
- Tennessee State University (21)
- Case Western Reserve University (7)
- Embry-Riddle Aeronautical University (7)
- Clemson University (5)
-
- Old Dominion University (4)
- University of Kentucky (4)
- University of New Mexico (4)
- California Polytechnic State University, San Luis Obispo (3)
- DePauw University (3)
- Michigan Technological University (3)
- Technological University Dublin (3)
- University of Nevada, Las Vegas (3)
- University of Richmond (3)
- University of South Carolina (3)
- Bridgewater State University (2)
- Cal Poly Humboldt (2)
- Rollins College (2)
- Stephen F. Austin State University (2)
- University at Albany, State University of New York (2)
- University of Arkansas, Fayetteville (2)
- University of Louisville (2)
- University of Texas Rio Grande Valley (2)
- Utah State University (2)
- Washington University in St. Louis (2)
- Western Kentucky University (2)
- Air Force Institute of Technology (1)
- Andrews University (1)
- Central Washington University (1)
- Claremont Colleges (1)
- Publication Year
- Publication
-
- Dartmouth Scholarship (170)
- Information Systems and Engineering Management Research Publications (21)
- Publications (8)
- Faculty Scholarship (7)
- All Dissertations (4)
-
- Branch Mathematics and Statistics Faculty and Staff Publications (4)
- Physics Faculty Publications (4)
- Annual Student Research Poster Session (3)
- Dissertations, Master's Theses and Master's Reports (3)
- UNLV Theses, Dissertations, Professional Papers, and Capstones (3)
- Articles (2)
- College of Arts & Sciences Senior Theses (2)
- Colloquia and Seminars (2)
- Electronic Theses and Dissertations (2)
- Honors Program Theses (2)
- IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt (2)
- Journal of the South Carolina Academy of Science (2)
- Mahurin Honors College Capstone Experience/Thesis Projects (2)
- Physics and Astronomy Faculty Publications (2)
- STAR Program Research Presentations (2)
- Senior Honors Papers / Undergraduate Theses (2)
- Theses and Dissertations (2)
- Theses and Dissertations--Physics and Astronomy (2)
- 2024 REYES Proceedings (1)
- Applications and Applied Mathematics: An International Journal (AAM) (1)
- Dartmouth College Ph.D Dissertations (1)
- DePaul Discoveries (1)
- Department of Physics and Astronomy: Syllabi (1)
- Doctoral (1)
- Faculty & Staff Scholarship (1)
- Publication Type
- File Type
Articles 1 - 30 of 292
Full-Text Articles in Astrophysics and Astronomy
Numerical Modeling Of Multi-Scale Jet Feedback In Seyfert Galaxies, Julianne Goddard
Numerical Modeling Of Multi-Scale Jet Feedback In Seyfert Galaxies, Julianne Goddard
Theses and Dissertations--Physics and Astronomy
We present a suite of high-resolution cosmological zoom-in simulations investigating the impact of mechanical and thermal feedback from low-luminosity jets launched from supermassive black holes (SMBHs) on Seyfert galaxy evolution from early cosmic times to the present (z ≤ 10). Our models follow the formation of central galaxies within identical dark matter halos of logMhalo/M⊙ ∼ 11.8 at z = 0, seeded with ∼ 10^6M⊙ SMBHs at z ∼ 9.1 and z ∼ 3.7. Feedback from active galactic nuclei (AGN) is implemented in the form of bipolar jets launched along the SMBH spin axis, with jet powers spanning Ljet ∼ …
Shock-Wave Structure In A Monatomic Gas Mixture With Rydberg Atoms, Anna Markhotok
Shock-Wave Structure In A Monatomic Gas Mixture With Rydberg Atoms, Anna Markhotok
Physics Faculty Publications
The effect of atom size on the shock-wave structure in a binary monatomic gas mixture with Rydberg atoms has been investigated. The problem was solved numerically using the system of hydrodynamic equations in argon gas for the atom-size ratios between 2 and 100, T = 1500 K, and the density between 10¹⁷ and 10²⁰ m−³. It was found that the presence of larger-sized atoms in the mixture results in shock front splitting that is on the order of the mean free path for this component. The results could be of interest in supersonic plasma dynamics and in astrophysics, studying shock …
A Study On The Great Comet Of 2024: C/2023 A3 (Tsuchinshan–Atlas) Via Radio Interferometry, Jesse Bier, Nathan X. Roth
A Study On The Great Comet Of 2024: C/2023 A3 (Tsuchinshan–Atlas) Via Radio Interferometry, Jesse Bier, Nathan X. Roth
Undergraduate Research Symposium
Our solar system is approximately 4.5 billion years old. Comets are remnants of its formation, serving as time capsules to give us an understanding of its natal heritage. Revealing our own solar system’s history allows us to gain insights into other young stellar systems and the potential for life elsewhere. C/2023 A3 (Tsuchinshan–ATLAS) was a comet from the Oort cloud on its first and possibly only journey to the inner solar system. The comet grew in brightness until it was brighter than Venus on October 9th, 2024, making it temporarily brighter than Venus and one of the brightest …
Cosmic Duets: A Search For Binary Supermassive Black Holes In Merging Galaxies, Sagar Adhikari
Cosmic Duets: A Search For Binary Supermassive Black Holes In Merging Galaxies, Sagar Adhikari
All Dissertations
Galaxies are vast cosmic islands of stars, dust, and gas. They come in various shapes and sizes. They might look static for the timescales we are used to, but they are dynamic and collisional systems that can merge with other galaxies to make bigger galaxies. Most galaxies, including the Milky Way, host a central supermassive black hole (SMBH) with a mass greater than a million (sometimes a billion) times the mass of the Sun. When galaxies merge, their SMBHs form a binary system before ultimately merging. These cosmic duets are of great interest to astronomers and astrophysicists as they are …
The Heart Of The Crab: Analyzing The Vhe Emission From The Crab Pulsar, Adi Empie, Thao Nguyen, Avery Archer
The Heart Of The Crab: Analyzing The Vhe Emission From The Crab Pulsar, Adi Empie, Thao Nguyen, Avery Archer
Annual Student Research Poster Session
The Crab Nebula is one of the most studied astrophysical objects at very-high-energies (VHE) and is one of the brightest sources of VHE gamma-rays. The Crab Nebula is a pulsar wind nebula with the Crab pulsar providing the energy and particles to power the nebula. The gamma-ray emission from the nebula and pulsar are understood to come from relativistic particles but the processes that are responsible for accelerating these particles is not well understood. Studying the highest energy emission from the Crab Nebula can provide valuable insight into the underlying emission mechanisms at work. This project was intended to examine …
Discovering High-Redshift Bl Lacs And Localizing Grbs For Mev Missions, Yong Sheng
Discovering High-Redshift Bl Lacs And Localizing Grbs For Mev Missions, Yong Sheng
All Dissertations
Blazars are active galactic nuclei (AGNs) with their jets aligned towards Earth. Gamma-ray bursts (GRBs) can be classified into long and short types. Long GRBs are produced by the collapse of massive stars, while short GRBs are formed by binary mergers (neutron star - neutron star or neutron star - black hole mergers). Both objects are the key probes of extreme physics processes and cosmic evolution, providing us an unique window to understand the Universe. My research aims to measure the redshift of blazars and localize GRBs for proposed and upcoming gamma-ray telescopes. BL Lac objects (BL Lacs) are a …
Cross-Correlation Studies Of The Cosmological 21 Cm Signal And High-Redshift Galaxy Distributions, Simon Matin
Cross-Correlation Studies Of The Cosmological 21 Cm Signal And High-Redshift Galaxy Distributions, Simon Matin
UNLV Theses, Dissertations, Professional Papers, and Capstones
The Epoch of Reionization (EoR) marks a critical phase in cosmic history, during which time the first stars and galaxies ionized the surrounding neutral hydrogen gas. A powerful way to probe this period is by cross-correlating the 21 cm signal from neutral hydrogen with high-redshift galaxy distributions. In this study, we analyze the 21 cm-galaxy cross-power spectrum using simulated sky maps and explore its redshift evolution, revealing a transition from positive correlation at early times (high redshift) to anti-correlation at later stages of reionization (low redshift). Our results highlight the sensitivity of the cross-power spectrum to the evolving ionized structure …
In Search Of Extreme Extragalactic Energy: A Catalog Of Tev-Emitting Bl Lac Candidates From Erosita And Wise, Cassidy M. Metzger, Manel Errando, Andrea Gokus
In Search Of Extreme Extragalactic Energy: A Catalog Of Tev-Emitting Bl Lac Candidates From Erosita And Wise, Cassidy M. Metzger, Manel Errando, Andrea Gokus
Senior Honors Papers / Undergraduate Theses
Active galactic nuclei (AGN) are supermassive black holes that reside at galactic centers and are actively accreting matter. In approximately 10% of cases, AGN produce relativistic jets: collimated streams of particles that travel for thousands of light years and have been detected at TeV energies by ground-based gamma-ray observatories. However, the mechanisms that accelerate particles beyond the TeV scale are largely unknown. Currently, only 56 objects are confirmed to accelerate particles to these extreme energies. Here we provide a selection of over 150 sources that exhibit infrared (IR) and X-ray emission profiles similar to those of the 56 TeV sources. …
Computational Modeling Of Astrophysical Systems, Leleya Iris Stallard
Computational Modeling Of Astrophysical Systems, Leleya Iris Stallard
Spring Showcase for Research and Creative Inquiry
This research project focuses on the computational modeling of astrophysical systems using Femap with NX Nastran. The goal was to simulate and analyze the vibrational behavior and structural deformation of celestial bodies under different material compositions and collision conditions. Materials such as iron, granite, titanium, and models for white dwarf stars were used to investigate how varying physical properties affect the systems' dynamic responses. Both isotropic and anisotropic models were created to represent realistic astrophysical materials. Through static and modal analyses, the study explored how internal structure and material stiffness influence the reaction of celestial objects to applied forces and …
Josephson Junctions: Fabrication And Applications For The Axion Dark Matter Experiment, Jonah M. Sachs
Josephson Junctions: Fabrication And Applications For The Axion Dark Matter Experiment, Jonah M. Sachs
Senior Honors Papers / Undergraduate Theses
The observation of axions could revolutionize the world of physics. Through microwave frequency cavity readout of the photons associated with these axions, the ADMX project at WashU utilizes multiple different forms of the Josephson junction (JJ), a superconductive circuit element. The physics behind the JJ are essential to understanding its operation for resonant cavity readout in addition to parametric amplification. Parametric amplifiers produced using JJs can approach the signal-to-noise ratio set by quantum mechanics, and prove essential for the amplification chain used by the ADMX experiment for axionic detection. The limits of these amplifiers are set by the noise tuning …
Nonlinear Wave Dynamics In Asteroseismology With Application To Delta Scuti Stars, Mohammed Mourabit
Nonlinear Wave Dynamics In Asteroseismology With Application To Delta Scuti Stars, Mohammed Mourabit
Physics Dissertations - Archive
This thesis compiles the collection of works in nonlinear astroseismology and its implication to the δ Sct variable that we carried over the course of five years. With the advent of high-resolution space missions such as the Kepler and TESS telescopes, we were able to see significant progress in the field in recent years. Nonetheless the new technologies also brought an increasing number of observation that are seemingly contradictory to the linear theory of asteroseismology. In particular, we find the δ Sct variable, which eludes our models in terms of how varied we find they spectra for stars with very …
A Spectrum Of Light: Speculative Poetry Of Celestial Bodies And Astrophysics, Shannon Sosebee
A Spectrum Of Light: Speculative Poetry Of Celestial Bodies And Astrophysics, Shannon Sosebee
Electronic Theses and Dissertations
This is a collection of speculative poetry with a focus on celestial objects within our solar system and larger bodies outside of our solar system, some of which are only theorized to exist. The author finishes the collection with introspective works, laying bare vulnerabilities and insecurities.
Sunyaev-Zeldovich Effect In The Intra-Cluster Medium, Nathan Fronk
Sunyaev-Zeldovich Effect In The Intra-Cluster Medium, Nathan Fronk
Senior Seminars and Capstones
This paper covers the Sunyaev-Zeldovich effect, it’s derivation, and it’s applications in astronomy. The effect is a result of inverse Compton scattering in a cloud of hot charged particles, causing an increase in the temperature of the the cosmic microwave background radiation passing through the cloud. This change in temperature can be measured, and used to calculate the physical properties of the structure in question. This paper focuses on the a method used by Adam et al. (2017) to find a temperature map of the intra-cluster medium.
Unraveling The Physics Of Quasar Jets Using Hst Polarimetry, Devon Clautice
Unraveling The Physics Of Quasar Jets Using Hst Polarimetry, Devon Clautice
Theses and Dissertations
We present a multiwavelength study of three high-power FR II (quasar) jets -- 3C 273, PKS 0637-752, and 1150+497 -- with an emphasis on new high-quality Hubble Space Telescope (HST) optical polarimetry and Chandra X-ray Observatory imaging. Relativistic jets from active galactic nuclei transport energy and mass from the supermassive black hole’s accretion region out to Megaparsec-scale lobes, with effects that feedback into galaxy formation and cluster energetics. We build on recent work which has called into question our fundamental understanding of FR II jet physics, and suggest that highly-efficient particle acceleration must be taking place in situ …
Models Of Low Mass Stars As Physical Labratories, Emily M. Boudreaux
Models Of Low Mass Stars As Physical Labratories, Emily M. Boudreaux
Dartmouth College Ph.D Dissertations
Low mass stars account for approximately 70 percent of the stellar populations (Conroy & Van Dokkum, 2012); yet, due to their small sizes and cool temperatures they account for only a small fraction of the galaxies luminosity function (Laughlin et al., 1997). Moreover, due to the lack of laboratory conditions available to astronomy and astrophysics low mass stars can provide a rare controlled environment for calibrations of numerical models. Consequently, across multiple domains there has been significant interest in these key astronomical objects. In this thesis I present three projects which have further revealed properties of low mass stars and …
Analysis Of Neutron Star Structure And Equation Of State Using Computational Simulations, Sohila Sameh
Analysis Of Neutron Star Structure And Equation Of State Using Computational Simulations, Sohila Sameh
2024 REYES Proceedings
Understanding neutron star structures is crucial for advancing astrophysical research. This study explores the structure of neutron stars using advanced equations, including the Tolman-Oppenheimer-Volkoff (TOV) equations, and various equations of state (EoS). We investigate the mass-radius relationship, stability criteria, and cooling mechanisms. Key findings highlight the impact of relativistic corrections and rotational effects on neutron star properties. The results demonstrate how integrating these advanced equations enhances the understanding of neutron star behavior and stability. This research provides a comprehensive framework for analyzing neutron star structures, with implications for future astrophysical studies.
Decreasing Cross-Coupling In The Tianlai Radio Antenna Array, Nadia Marie Schwartz Bolef
Decreasing Cross-Coupling In The Tianlai Radio Antenna Array, Nadia Marie Schwartz Bolef
Scripps Senior Theses
The 21-cm line is the electromagnetic radiation spectral line created by the change in energy state of neutral hydrogen atoms. This signal can be used for intensity mapping, a method of mapping the large-scale structure of the universe at different redshifts. However, challenges are being faced in the designing and building of the radio antenna arrays used to detect the 21-cm line signal. Currently, cross-coupling between antenna feeds is introducing beam errors and correlated noise that could overpower the signal. One possible solution we are working on is to use a phased array of antenna feeds instead of dishes and …
Evolution Of Angular Momentum In Triaxial Dark Matter Halos, Tara C. Nester
Evolution Of Angular Momentum In Triaxial Dark Matter Halos, Tara C. Nester
Honors College Theses
Galactic halos are believed to form through both the early inflow of dark matter from the cosmic web and mergers over an extended period. At the same time, stellar disks are forming within this evolving halo. How a stellar disk responds to a changing halo is investigated in this study using live n-body disks embedded in an analytic triaxial potential. At triaxialities of a few percent, we find that while there are subtle perturbations in the disk, there is no significant change in the total disk angular momentum. However, between 5 and 10% triaxialities there is a sharp transition to …
Exploring The Hot And Gaseous Universe From Infrared To X-Ray, Chamani Gunasekera
Exploring The Hot And Gaseous Universe From Infrared To X-Ray, Chamani Gunasekera
Theses and Dissertations--Physics and Astronomy
Over 90% of baryonic matter in the universe exists as astrophysical plasmas. The gas
is often far from thermodynamic equilibrium, so numerical non-equilibrium spectral
synthesis simulations are used to understand observations. cloudy simulates vari-
ous physical conditions, providing spectra predictions. This thesis aims to meet the
challenge of new observatories like the JWST (James Webb Space Telescope) and
XRISM (X-Ray Imaging Spectroscopy Mission). These simulations are no better
than the underlying atomic and molecular database and the fourth chapter details
a long-needed update to an evolving database. The predicted spectra are strongly
affected by the composition of the gas, which …
Constructing The 4th Hawc Catalog Of Very-High-Energy Sources Using An Automated Likelihood Pipeline Search, Samuel J. Groetsch
Constructing The 4th Hawc Catalog Of Very-High-Energy Sources Using An Automated Likelihood Pipeline Search, Samuel J. Groetsch
Dissertations, Master's Theses and Master's Reports
In this thesis, I present an analysis pipeline that allows one to search for and identify sources of very-high-energy (VHE) γ-ray emission in sky maps created from data collected with the High Altitude Water-Cherenkov (HAWC) Observatory. The HAWC Observatory is located at about 4100 m elevation just below Pico de Orizaba, the highest mountain in Mexico also known as Citlaltepetl (from the Nahuatl words citlal(in) = star, and tepetl = mountain). The observatory is an array of several hundred detector stations that measure signals from particle showers, so-called extensive air showers (EAS), that are initiated in interactions of primary cosmic …
Temporal And Spectral Analysis Of 1es 2344+514 In Two Flaring States Observed By Veritas, Connor Poggemann
Temporal And Spectral Analysis Of 1es 2344+514 In Two Flaring States Observed By Veritas, Connor Poggemann
Physics
VERITAS observed the bright blazar 1ES 2344+514 during two flaring periods, one from Dec. 17 to Dec. 18, 2015 (MJD 57373-57374) with a peak flux of ~60% of the Crab and another from Nov. 28 to Dec. 3, 2021 (MJD 59546-59551) with a peak flux of ~20% of the Crab. This blazar, located at a redshift of z = 0.044, is classified as an extreme high-frequency-peaked BL Lacertae object (HBL). It is known to be variable, including several previous day-scale flares: Whipple on Dec. 20, 1995, VERITAS on Dec. 7, 2007, and MAGIC on Aug. 11, 2016. The VERITAS near-nightly …
Improving Inferences About Exoplanet Habitability, Risinie D. Perera, Kevin H. Knuth
Improving Inferences About Exoplanet Habitability, Risinie D. Perera, Kevin H. Knuth
Physics Faculty Scholarship
Assessing the habitability of exoplanets (planets orbiting other stars) is of great importance in deciding which planets warrant further careful study. Planets in the habitable zones of stars like our Sun are sufficiently far away from the star so that the light rays from the star can be assumed to be parallel, leading to straightforward analytic models for stellar illumination of the planet’s surface. However, for planets in the close-in habitable zones of dim red dwarf stars, such as the potentially habitable planet orbiting our nearest stellar neighbor, Proxima Centauri, the analytic illumination models based on the parallel ray approximation …
An Introduction To The Veritas Observatory, Alexander Bittle, Ian Kuhl, Jingze (Justin) Zhou, Avery Archer
An Introduction To The Veritas Observatory, Alexander Bittle, Ian Kuhl, Jingze (Justin) Zhou, Avery Archer
Annual Student Research Poster Session
Located at the base of Mount Hopkins, Arizona, at an elevation of approximately 4200 feet, the Very Energetic Radiation Imaging Telescope Array System (VERITAS) is a ground-based gamma ray observatory containing four Cherenkov telescopes designed to detect very high energy gamma rays with energies ranging from 100GeV to 10TeV using the Imaging Atmospheric Cherenkov Technique. In April 2007, VERITAS began successful operations with all four telescopes. As of today, over 15 years of data has been taken by the VERITAS array, stored in an archive of data, and used for a wide variety of research, publications, PhD theses, and conventions …
Analysis Of The Crab Nebula And Pulsar, Alexander Bittle, Ian Kuhl, Jingze (Justin) Zhou, Avery Archer
Analysis Of The Crab Nebula And Pulsar, Alexander Bittle, Ian Kuhl, Jingze (Justin) Zhou, Avery Archer
Annual Student Research Poster Session
Although the Crab Nebula is well understood, the Very Energetic Radiation Imaging Telescope Array System (VERITAS) still regularly observes the Crab's highest energy emissions. These emissions are used to calibrate the telescopes, further, document the system, and investigate the validity of physical models. Our research this summer is geared to analyze data from 2018-2022 to add to an ongoing research project investigating the long term variability of the Crab Nebula’s emission.
Identifying And Analyzing Multi-Star Systems Among Tess Planetary Candidates Using Gaia, Katie E. Bailey
Identifying And Analyzing Multi-Star Systems Among Tess Planetary Candidates Using Gaia, Katie E. Bailey
Electronic Theses and Dissertations
Exoplanets represent a young, rapidly advancing subfield of astrophysics where much is still unknown. It is therefore important to analyze trends among their parameters to learn more about these systems. More complexity is added to these systems with the presence of additional stellar companions. To study these complex systems, one can employ programming languages such as Python to parse databases such as those constructed by TESS and Gaia to bridge the gap between exoplanets and stellar companions. Data can then be analyzed for trends in these multi-star exoplanet systems and in juxtaposition to their single-star counterparts. This research was able …
The Loneliest Galaxies In The Universe: A Gama And Galaxy Zoo Study On Void Galaxy Morphology., Lori E. Porter
The Loneliest Galaxies In The Universe: A Gama And Galaxy Zoo Study On Void Galaxy Morphology., Lori E. Porter
College of Arts & Sciences Senior Theses
The large-scale structure (LSS) of the Universe is comprised of galaxy filaments, tendrils, and voids. The majority of the Universe’s volume is taken up by these voids, which exist as underdense, but not empty, regions. The galaxies found inside voids are void galaxies and expected to be some of the most isolated objects in the Universe. However, their standard morphology remains poorly studied. This study, using the Galaxy and Mass Assembly (GAMA) data and Galaxy Zoo survey, aims to remedy this. For completeness purposes, we use void galaxies identified by Alpaslan et al. (2014) with stellar masses (M*) of 10 …
Exploring The Dependence Of Bulges In Spiral Galaxies On Their Environment, William Jackson Clark
Exploring The Dependence Of Bulges In Spiral Galaxies On Their Environment, William Jackson Clark
Physics Theses & Dissertations
Recent research has shown a relationship between spiral galaxy satellite populations and the size of spiral bulges. The modern cosmological model of our universe (ΛCDM), does not predict this. Instead, ΛCMD predicts that only the total dynamical mass of a host galaxy should be correlated with satellite populations. We investigate this relationship in regimes other than satellites. In this study we compare the bulge to total mass ratios of spiral galaxies to the number of nearby galaxies within “n” Mpc. We use four papers from literature that calculate bulge to total mass ratios of 189 spiral galaxies using …
The Search For Heavily Obscured Active Galactic Nuclei In The Local Universe, Ross Silver
The Search For Heavily Obscured Active Galactic Nuclei In The Local Universe, Ross Silver
All Dissertations
Active galactic nuclei (AGN) are supermassive black holes (SMBHs) in the center of galaxies that accrete surrounding gas and emit across the entire electromagnetic spectrum. They are the most energetic persistent emitters in the Universe, capable of outshining their host galaxies despite their emission originating from a region smaller than our Solar System. AGN were some of the first sources discovered that helped teach us that there were galaxies outside of our own, and they proved the existence of black holes. Moreover, AGN can give us valuable insights into other branches of astrophysics. For example, they can be used to …
Optimal Method For Reconstructing Polychromatic Maps From Broadband Observations With An Aysmmetric Antenna Pattern, Brianna Cantrall, Emory F. Bunn, Solomon Quinn
Optimal Method For Reconstructing Polychromatic Maps From Broadband Observations With An Aysmmetric Antenna Pattern, Brianna Cantrall, Emory F. Bunn, Solomon Quinn
Honors Theses
Broadband time-ordered data obtained from telescopes with a wavelength-dependent, asymmetric beam pattern can be used to extract maps at multiple wavelengths from a single scan. This technique is especially useful when collecting data on cosmic phenomena such as the Cosmic Microwave Background (CMB) radiation, as it provides the ability to separate the CMB signal from foreground contaminants. We develop a method to determine the optimal linear combinations of wavelengths (“colors”) that can be reconstructed for a given telescope design and the number of colors that are measurable with high signal-to-noise ratio. The optimal colors are found as eigenvectors of a …
Measurement Of Near-Threshold Proton Branching Ratios In 31s Important For Novae, Sudarsan Balakrishnan
Measurement Of Near-Threshold Proton Branching Ratios In 31s Important For Novae, Sudarsan Balakrishnan
LSU Doctoral Dissertations
Classical novae are stellar explosions that contribute to the nucleosynthesis of isotopes on the proton-rich side of the valley of stability up to 40Ca. In ONe novae, the incompletely understood reaction rate of 30P(p,γ)31S is known to strongly influence the production rate of several stable isotopes such as 30Si, 31P, and 32,33,34S. A precise measurement of this reaction rate has several potential implications towards matching astrophysical observables to the physical composition of the nova site -- the observed elemental abundance ratios of O/S and S/Al have been suggested as useful `thermometers' to gauge …