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Full-Text Articles in Physical Sciences and Mathematics

The Loneliest Galaxies In The Universe: A Gama And Galaxy Zoo Study On Void Galaxy Morphology., Lori E. Porter May 2023

The Loneliest Galaxies In The Universe: A Gama And Galaxy Zoo Study On Void Galaxy Morphology., Lori E. Porter

College of Arts & Sciences Senior Honors 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 …


Table Of Contents Jan 2023

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.


Measurement Of Near-Threshold Proton Branching Ratios In 31s Important For Novae, Sudarsan Balakrishnan Jan 2023

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 …


Wallaby Pilot Survey: Hi Gas Kinematics Of Galaxy Pairs In Cluster Environment, Shin-Jeong Kim, Se-Heon Oh, Jing Wang, Lister Staveley-Smith, Bärbel S. Koribalski, Minsu Kim, Hye-Jin Park, Shinna Kim, Kristine Spekkens, Juan P. Madrid Jan 2023

Wallaby Pilot Survey: Hi Gas Kinematics Of Galaxy Pairs In Cluster Environment, Shin-Jeong Kim, Se-Heon Oh, Jing Wang, Lister Staveley-Smith, Bärbel S. Koribalski, Minsu Kim, Hye-Jin Park, Shinna Kim, Kristine Spekkens, Juan P. Madrid

Physics and Astronomy Faculty Publications and Presentations

We examine the HI gas kinematics of galaxy pairs in two clusters and a group using Australian Square Kilometre Array Pathfinder (ASKAP) WALLABY pilot survey observations. We compare the HI properties of galaxy pair candidates in the Hydra I and Norma clusters, and the NGC 4636 group, with those of non-paired control galaxies selected in the same fields. We perform HI profile decomposition of the sample galaxies using a tool, {\sc baygaud} which allows us to de-blend a line-of-sight velocity profile with an optimal number of Gaussian components. We construct HI super-profiles of the sample galaxies via stacking of their …


Multifrequency Scintillation In The Polar Caps, Tate Colby Dec 2022

Multifrequency Scintillation In The Polar Caps, Tate Colby

Doctoral Dissertations and Master's Theses

In the ionosphere, plasma density structures with scales sizes ranging from a few centimeters to hundreds of kilometers are capable of modifying the phase and amplitude of a radio signal in a rapid random manner in a process called scintillation. The Coherent Electromagnetic Radio Tomography (CERTO) and the Canadian High Arctic Ionospheric Network (CHAIN) are two different networks of scintillation receivers, each with a station in Resolute Bay, Canada. CERTO measures amplitude and phase signals in VHF and UHF while CHAIN measures amplitude and phase signals in the L-band. Through these measurements we can calculate the scintillation indexes, S_4 and …


Galaxy And Mass Assembly (Gama): The Dependence Of Star Formation On Surface Brightness In Low-Redshift Galaxies, S Phillipps, S Bellstedt, M N. Bremer, R De Propris, P A. James, S Casura, J Liske, B W. Holwerda Dec 2022

Galaxy And Mass Assembly (Gama): The Dependence Of Star Formation On Surface Brightness In Low-Redshift Galaxies, S Phillipps, S Bellstedt, M N. Bremer, R De Propris, P A. James, S Casura, J Liske, B W. Holwerda

Faculty Scholarship

The star-formation rate in galaxies is well known to correlate with stellar mass (the ‘star-forming main sequence’). Here, we extend this further to explore any additional dependence on galaxy surface brightness, a proxy for stellar mass surface density. We use a large sample of low-redshift (z ≤ 0.08) galaxies from the Galaxy And Mass Assembly survey which have both spectral energy distribution (SED) derived star-formation rates and photometric bulge-disc decompositions, the latter providing measures of disc surface brightness and disc masses. Using two samples, one of galaxies fitted by a single component with Sérsic index below 2 and one …


Dataset For Electronic And Optical Properties Of Y2o2s And Er Dopped Y2o2s Calculated Using Density Functional Theory And Simulated X-Ray Near Edge Spectra, N. Dimakis, Eric Baldemar Rodriguez Jr., Kofi Nketia Ackaah-Gyasi, Madhab Pokhrel Dec 2022

Dataset For Electronic And Optical Properties Of Y2o2s And Er Dopped Y2o2s Calculated Using Density Functional Theory And Simulated X-Ray Near Edge Spectra, N. Dimakis, Eric Baldemar Rodriguez Jr., Kofi Nketia Ackaah-Gyasi, Madhab Pokhrel

Physics and Astronomy Faculty Publications and Presentations

The computational data presented in this paper refer to the research article “Optical properties and simulated x-ray near edge spectra for Y2O2S and Er doped Y2O2S”. We present the data used to calculate the structural, electronic, and optical properties of the Y2O2S and its Er+3 doped counterparts at various concentrations using density functional theory (DFT) and simulated X-ray near edge (XANES) spectra. We report electronic information from DFT and DFT+U generated from the Vienna Ab initio Simulation Package (VASP) using PAW pseudopotentials. We also report VASP calculated optical properties for the host Y2O2S using the independent particle approximation (IPA), the …


Core-Collapse Supernova Simulations With Spectral Two-Moment Neutrino Transport, Ran Chu Dec 2022

Core-Collapse Supernova Simulations With Spectral Two-Moment Neutrino Transport, Ran Chu

Doctoral Dissertations

The primary focus of this dissertation is to develop a next-generation, state-of-the-art neutrino kinetics capability that will be used in the context of the next-generation, state-of-the-art core-collapse supernova (CCSN) simulation frameworks \thornado\ and \FLASH.\index{CCSN} \thornado\ is a \textbf{t}oolkit for \textbf{h}igh-\textbf{or}der \textbf{n}eutrino-r\textbf{ad}iation hydr\textbf{o}dynamics, which is a collection of modules that can be incorporated into a simulation code/framework, such as \FLASH, together with a nuclear equation of state (EOS)\index{EOS} library, such as the \WeakLib\ EOS tables. The first part of this work extends the \WeakLib\ code to compute neutrino interaction rates from~\cite{Bruenn_1985} and produce corresponding opacity tables.\index{Bruenn 1985} The processes of emission, …


Galaxy And Mass Assembly (Gama): Extended Intragroup Light In A Group At Z = 0.2 From Deep Hyper Suprime-Cam Images, Cristina Martínez-Lombilla, Sarah Brough, Mireia Montes, Roberto Baena-Gallé, Mohammad Akhlaghi, Raúl Infante-Sainz, Simon P. Driver, Benne W. Holwerda, Kevin A. Pimbblet, Aaron S G Robotham Nov 2022

Galaxy And Mass Assembly (Gama): Extended Intragroup Light In A Group At Z = 0.2 From Deep Hyper Suprime-Cam Images, Cristina Martínez-Lombilla, Sarah Brough, Mireia Montes, Roberto Baena-Gallé, Mohammad Akhlaghi, Raúl Infante-Sainz, Simon P. Driver, Benne W. Holwerda, Kevin A. Pimbblet, Aaron S G Robotham

Faculty Scholarship

We present a pilot study to assess the potential of Hyper Suprime-Cam Public Data Release 2 (HSC-PDR2) images for the analysis of extended faint structures within groups of galaxies. We examine the intragroup light (IGL) of the group 400138 (Mdyn = 1.3 ± 0.5 × 1013 M, z ∼ 0.2) from the Galaxy And Mass Assembly (GAMA) survey using Hyper Suprime-Cam Subaru Strategic Program Public Data Release 2 (HSC-SSP PDR2) images in g, r, and i bands. We present the most extended IGL measurement to date, reaching down to μglim=30.76" role="presentation" style="box-sizing: border-box; margin: 0px; …


Wallaby Pilot Survey: Hi Gas Kinematics Of Galaxy Pairs In Cluster Environment, Shin-Jeong Kim, Minsu Kim, Hye-Jin Park, Shinna Kim, Bigiel Frank, Helga Denes, Bi-Qing For, Peter Kamphuis, Se-Heon Oh, Benne Holwerda, Kristen Mcquinn, Juan Madrid, Ahmed Elagali, Gerhardt R. Meurer, Kristine Spekkens, Lister Staveley-Smith, Barbara Catinella, Nathan Deg, Karen Lee-Waddell, Jing Wang, Lourdes Verdes-Montenegro, Ivy Wong, Jonghwan Rhee Nov 2022

Wallaby Pilot Survey: Hi Gas Kinematics Of Galaxy Pairs In Cluster Environment, Shin-Jeong Kim, Minsu Kim, Hye-Jin Park, Shinna Kim, Bigiel Frank, Helga Denes, Bi-Qing For, Peter Kamphuis, Se-Heon Oh, Benne Holwerda, Kristen Mcquinn, Juan Madrid, Ahmed Elagali, Gerhardt R. Meurer, Kristine Spekkens, Lister Staveley-Smith, Barbara Catinella, Nathan Deg, Karen Lee-Waddell, Jing Wang, Lourdes Verdes-Montenegro, Ivy Wong, Jonghwan Rhee

Faculty Scholarship

We examine the H I gas kinematics of galaxy pairs in two clusters and a group using Australian Square Kilometre Array Pathfinder (ASKAP) WALLABY pilot survey observations. We compare the H I properties of galaxy pair candidates in the Hydra I and Norma clusters, and the NGC 4636 group, with those of non-paired control galaxies selected in the same fields. We perform H I profile decomposition of the sample galaxies using a tool, BAYGAUD which allows us to de-blend a line-of-sight velocity profile with an optimal number of Gaussian components. We construct H I super-profiles of the sample galaxies via …


Collation Model For Ljs 64: [Illustrations To Georg Von Peurbach's Novae Theoricae Planetarum]., Dot Porter Nov 2022

Collation Model For Ljs 64: [Illustrations To Georg Von Peurbach's Novae Theoricae Planetarum]., Dot Porter

Collation Models

Diagrams, many with moving parts, designed to accompany the work Theoricae novae planetarum by 15th-century Austrian astronomer Georg von Peurbach, who taught at the universities in Padua and Ferrara. The diagrams demonstrate increasingly complex planetary motion. An early 17th-century inscription on the first flyleaf refers to an edition of Peurbach published in Venice in 1616.


Collation Model For Ms. Codex 761: [Cosmographies]., Dot Porter Nov 2022

Collation Model For Ms. Codex 761: [Cosmographies]., Dot Porter

Collation Models

Four ancient Greek cosmographies in Latin translation: Plato's Timaeus translated and with a commentary by Calcidius, Aristotle's De mundo translated by Ioannes Argyropoulos, Philo's De incorruptione mundi probably translated by Lilius Tifernas, and Cleomedes's De mundo translated by Carolus Valgulius.


Characteristics Of Kelvin-Helmholtz Waves As Observed By The Mms From September 2015 To June 2017, Katariina Nykyri, Xuanye Ma, Rachel C. Rice Nov 2022

Characteristics Of Kelvin-Helmholtz Waves As Observed By The Mms From September 2015 To June 2017, Katariina Nykyri, Xuanye Ma, Rachel C. Rice

Publications

The Magnetospheric Multiscale (MMS) mission has presented a new opportunity to study the fine scale structures and phenomena of Earth’s magnetosphere, including cross scale processes associated with the Kelvin-Helmholtz Instability (KHI). We present an overview of 19 MMS observations of the KHI from September 2015 to June 2017. Unitless growth rates and unstable solid angles for each of the 19 events were calculated using 5 techniques to automatically detect plasma regions on either side of the magnetopause boundary. There was no apparent correlation between solar wind conditions during the KHI and its growth rate and unstable solid angle, though we …


Physics 516: Electromagnetic Phenomena (Spring 2023), Philip C. Nelson Nov 2022

Physics 516: Electromagnetic Phenomena (Spring 2023), Philip C. Nelson

Department of Physics Papers

These course notes are made publicly available in the hope that they will be useful. All reports of errata will be gratefully received. I will also be glad to hear from anyone who reads them, whether or not you find errors: pcn@upenn.edu.


Electromagnetism In Quark Matter At Intermediate Densities, Efrain J. Ferrer Nov 2022

Electromagnetism In Quark Matter At Intermediate Densities, Efrain J. Ferrer

Physics and Astronomy Faculty Publications and Presentations

Several anomalous electromagnetic effects that can take place in quark matter at low temperatures and intermediate densities will be discussed. The anomalous transport properties of the spatially inhomogeneous phase of quark matter known as the Magnetic Dual Chiral Density Wave (MDCDW) phase will be reviewed. Going beyond mean-field approximation, it will be shown how linearly polarized electromagnetic waves that penetrate the MDCDW medium mix with the phonon fluctuations to give rise to two hybridized modes of propagation called axion polaritons. Finally, some possible implications of these results for the astrophysics of neutron stars will be indicated.


All-Sky Search For Short Gravitational-Wave Bursts In The Third Advanced Ligo And Advanced Virgo Run, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales Nov 2022

All-Sky Search For Short Gravitational-Wave Bursts In The Third Advanced Ligo And Advanced Virgo Run, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales

Faculty Publications

After the detection of gravitational waves from compact binary coalescences, the search for transient gravitational-wave signals with less well-defined waveforms for which matched filtering is not well suited is one of the frontiers for gravitational-wave astronomy. Broadly classified into “short” ≲1  s and “long” ≳1  s duration signals, these signals are expected from a variety of astrophysical processes, including non-axisymmetric deformations in magnetars or eccentric binary black hole coalescences. In this work, we present a search for long-duration gravitational-wave transients from Advanced LIGO and Advanced Virgo’s third observing run from April 2019 to March 2020. For this search, we use …


Devils: Cosmic Evolution Of Sed-Derived Metallicities And Their Connection To Star Formation Histories, Jessica E. Thorne, Aaron S G Robotham, Sabine Bellstedt, Luke J M Davies, Robin H W Cook, Luca Cortese, Benne Holwerda, Steven Phillipps, Malgorzata Siudek Nov 2022

Devils: Cosmic Evolution Of Sed-Derived Metallicities And Their Connection To Star Formation Histories, Jessica E. Thorne, Aaron S G Robotham, Sabine Bellstedt, Luke J M Davies, Robin H W Cook, Luca Cortese, Benne Holwerda, Steven Phillipps, Malgorzata Siudek

Faculty Scholarship

Gas-phase metallicities of galaxies are typically measured through auroral or nebular emission lines, but metallicity also leaves an imprint on the overall spectral energy distribution (SED) of a galaxy and can be estimated through SED fitting. We use the PROSPECT SED fitting code with a flexible parametric star formation history and an evolving metallicity history to self-consistently measure metallicities, stellar mass, and other galaxy properties for 90 000 galaxies from the Deep Extragalactic VIsible Legacy Survey (DEVILS) and Galaxy and Mass Assembly (GAMA) survey. We use these to trace the evolution of the mass–metallicity relation (MZR) and show that the …


Wallaby Pre-Pilot And Pilot Survey: The Tully Fisher Relation In Eridanus, Hydra, Norma And Ngc4636 Fields, Helene Courtois, Alexandra Dupuy, Kristen Mcquinn, Lister Staveley-Smith, Danail Obreschkow, Edward Taylor, Benne Holwerda, Cullan Howlett, Frank Bigiel, Daniel Pomarede, Bi-Qing For, Tao Hong, Dane Kleiner, Thomas Jarrett, Ivy Wong, Jonghwan Rhee, Albert Bosma, Khaled Said, Tamara Davis, Igor Karachentsev, Matthew Colless, Renee Kraan-Korteweg, Nathan Deg, Kristine Spekkens, Karen Lee-Waddell, Jing Wang, Gerhardt R. Meurer Nov 2022

Wallaby Pre-Pilot And Pilot Survey: The Tully Fisher Relation In Eridanus, Hydra, Norma And Ngc4636 Fields, Helene Courtois, Alexandra Dupuy, Kristen Mcquinn, Lister Staveley-Smith, Danail Obreschkow, Edward Taylor, Benne Holwerda, Cullan Howlett, Frank Bigiel, Daniel Pomarede, Bi-Qing For, Tao Hong, Dane Kleiner, Thomas Jarrett, Ivy Wong, Jonghwan Rhee, Albert Bosma, Khaled Said, Tamara Davis, Igor Karachentsev, Matthew Colless, Renee Kraan-Korteweg, Nathan Deg, Kristine Spekkens, Karen Lee-Waddell, Jing Wang, Gerhardt R. Meurer

Faculty Scholarship

The WALLABY pilot survey has been conducted using the Australian SKA Pathfinder (ASKAP). The integrated 21-cm HI line spectra are formed in a very different manner compared to usual single-dish spectra Tully-Fisher measurements. It is thus extremely important to ensure that slight differences (e.g. biases due to missing flux) are quantified and understood in order to maximise the use of the large amount of data becoming available soon. This article is based on four fields for which the data are scientifically interesting by themselves. The pilot data discussed here consist of 614 galaxy spectra at a rest wavelength of 21cm. …


Collation Model For Ljs 361: [Astronomical And Astrological Tables]., Dot Porter Nov 2022

Collation Model For Ljs 361: [Astronomical And Astrological Tables]., Dot Porter

Collation Models

Opening and closing sections of astronomical and astrological tables on either side of a remnant of commentaries on gospel and epistle readings. The opening section (f. 2r-9r) includes tables for calculating the day of the week for any day from 1204 to 1512; the Sunday letter from 1204 to 1736; the golden letter from 1215 to 1728; movable feasts; time variation according to latitude and longitude; the conjunction of the sun and moon from January to September from 1327 to 1367; and the hours of day and night in any day of the year, as well as lists of human …


Iterative Time-Domain Method For Resolving Multiple Gravitational Wave Sources In Pulsar Timing Array Data, Yi Qian Qian, Soumya D. Mohanty, Yan Wang Nov 2022

Iterative Time-Domain Method For Resolving Multiple Gravitational Wave Sources In Pulsar Timing Array Data, Yi Qian Qian, Soumya D. Mohanty, Yan Wang

Physics and Astronomy Faculty Publications and Presentations

The sensitivity of ongoing searches for gravitational wave (GW) sources in the ultra-low-frequency regime (10(-9) Hz to 10(-7) Hz) using pulsar timing arrays (PTAs) will continue to increase in the future as more well-timed pulsars are added to the arrays. It is expected that next-generation radio telescopes, namely, the Five-Hundred-Meter Aperture Spherical Radio Telescope (FAST) and the Square Kilometer Array (SKA), will grow the number of well-timed pulsars to O(10(3)). The higher sensitivity will result in greater distance reach for GW sources, uncovering multiple resolvable GW sources in addition to an unresolved population. Data analysis techniques that can search for …


Galaxy And Mass Assembly: Galaxy Morphology In The Green Valley, Prominent Rings, And Looser Spiral Arms, Dominic Smith, Lutz Haberzettl, L E. Porter, Ren Porter-Temple, Christopher P A Henry, Benne Holwerda, Á R. López-Sánchez, Steven Phillipps, Alister W. Graham, Sarah Brough, Kevin A. Pimbblet, Jochen Liske, Lee S. Kelvin, Clayton D. Robertson, Wade Roemer, Michael Walmsley, David O’Ryan, Tobias Géron Nov 2022

Galaxy And Mass Assembly: Galaxy Morphology In The Green Valley, Prominent Rings, And Looser Spiral Arms, Dominic Smith, Lutz Haberzettl, L E. Porter, Ren Porter-Temple, Christopher P A Henry, Benne Holwerda, Á R. López-Sánchez, Steven Phillipps, Alister W. Graham, Sarah Brough, Kevin A. Pimbblet, Jochen Liske, Lee S. Kelvin, Clayton D. Robertson, Wade Roemer, Michael Walmsley, David O’Ryan, Tobias Géron

Faculty Scholarship

Galaxies broadly fall into two categories: star-forming (blue) galaxies and quiescent (red) galaxies. In between, one finds the less populated “green valley". Some of these galaxies are suspected to be in the process of ceasing their star-formation through a gradual exhaustion of gas supply or already dead and are experiencing a rejuvenation of star-formation through fuel injection. We use the Galaxy And Mass Assembly database and the Galaxy Zoo citizen science morphological estimates to compare the morphology of galaxies in the green valley against those in the red sequence and blue cloud. Our goal is to examine the structural differences …


The Spectro-Temporal Relationships Of Repeating Fast Radio Bursts, Mohammed Afif Chamma Oct 2022

The Spectro-Temporal Relationships Of Repeating Fast Radio Bursts, Mohammed Afif Chamma

Electronic Thesis and Dissertation Repository

Fast radio bursts (FRBs) are short and extremely energetic bursts of radiation detected from galaxies across the universe that occur thousands of times a day. Despite advances in instrumentation, it is difficult to explain the enormous implied energy reservoirs of FRBs, their emission mechanism and the existence of repeating and periodic sources. This thesis explores the spectro-temporal properties of repeating FRBs and details the discovery of several new relationships between them, providing valuable information on the nature of FRBs. By measuring the spectro-temporal properties of a sample of bursts from the repeating source FRB20121102A I show that the magnitude of …


How Do Galaxies Form Their Stars Over Cosmic Time?, Jed H. Mckinney Oct 2022

How Do Galaxies Form Their Stars Over Cosmic Time?, Jed H. Mckinney

Doctoral Dissertations

Galaxies in the past were forming more stars than those today, but the driving force behind this increase in activity remains uncertain. In this thesis I explore the origin of high star-formation rates today and in the past by studying the properties of gas and dust in the cold interstellar medium (ISM) of dusty galaxies over cosmic time. Critically, we do not yet understand how these galaxies could form so many stars. This work began with my discovery of unusual infrared (IR) emission line ratios in the class of dusty galaxies where most of the Universe’s stars were formed. To …


Hyperspectral Unmixing: A Theoretical Aspect And Applications To Crism Data Processing, Yuki Itoh Oct 2022

Hyperspectral Unmixing: A Theoretical Aspect And Applications To Crism Data Processing, Yuki Itoh

Doctoral Dissertations

Hyperspectral imaging has been deployed in earth and planetary remote sensing, and has contributed the development of new methods for monitoring the earth environment and new discoveries in planetary science. It has given scientists and engineers a new way to observe the surface of earth and planetary bodies by measuring the spectroscopic spectrum at a pixel scale.

Hyperspectal images require complex processing before practical use. One of the important goals of hyperspectral imaging is to obtain the images of reflectance spectrum. A raw image obtained by hyperspectral remote sensing usually undergoes conversion to a physical quantity representing the intensity of …


Deep Investigation Of Neutral Gas Origins (Dingo): Hi Stacking Experiments With Early Science Data, Jonghwan Rhee, Richard Dodson, Kristóf Rozgonyi, Sarah Brough, Benne Holwerda, Simon Driver, Attila Popping, Sambit Roychowdhury, Sabine Bellstedt, Michael J. I. Brown, Lister Staveley-Smith, Ivan Baldry, Angel Lopez-Sanchez, Martin Meyer, Elizabeth Mahony, Aaron Robotham, Andrew Hopkins, Karen Lee-Waddell Oct 2022

Deep Investigation Of Neutral Gas Origins (Dingo): Hi Stacking Experiments With Early Science Data, Jonghwan Rhee, Richard Dodson, Kristóf Rozgonyi, Sarah Brough, Benne Holwerda, Simon Driver, Attila Popping, Sambit Roychowdhury, Sabine Bellstedt, Michael J. I. Brown, Lister Staveley-Smith, Ivan Baldry, Angel Lopez-Sanchez, Martin Meyer, Elizabeth Mahony, Aaron Robotham, Andrew Hopkins, Karen Lee-Waddell

Faculty Scholarship

We present early science results from Deep Investigation of Neutral Gas Origins (DINGO), an H I survey using the Australian Square Kilometre Array Pathfinder (ASKAP). Using ASKAP subarrays available during its commissioning phase, DINGO early science data were taken over ∼60 deg2 of the Galaxy And Mass Assembly (GAMA) 23 h region with 35.5 h integration time. We make direct detections of six known and one new sources at z < 0.01. Using H I spectral stacking, we investigate the H I gas content of galaxies at 0.04 < z < 0.09 for different galaxy colours. The results show that galaxy morphology based on optical colour is strongly linked to H I gas properties. To examine environmental impacts on the H I gas content of galaxies, three subsamples are made based on the GAMA group catalogue. The average H I mass of group central galaxies is larger than those of satellite and isolated galaxies, but with a lower H I gas fraction. We derive a variety of H I scaling relations for physical properties of our sample, including stellar mass, stellar mass surface density, NUV − r colour, specific star formation rate, and halo mass. We find that the derived H I scaling relations are comparable to other published results, with consistent trends also observed to ∼0.5 dex lower limits in stellar mass and stellar surface density. The cosmic H I densities derived from our data are consistent with other published values at similar redshifts. DINGO early science highlights the power of H I spectral stacking techniques with ASKAP


Detectability Of Wormholes Through Various Methods, Jonathan W. Keathley Oct 2022

Detectability Of Wormholes Through Various Methods, Jonathan W. Keathley

PANDION: The Osprey Journal of Research and Ideas

There are three methods that can possibly detect wormholes: Negative Temperature, Hawking/ Phantom Radiation, and iron emission lines. This paper discusses whether or not any of these three methods are useful ways to detect wormholes with today’s technology and if so, which one is the best and which is the worst. As it turns out, all of these methods have their flaws and impracticalities. After looking through all the evidence and comparing it to what capabilities we have currently, there is clearly a best and worst method. The best method to detect possible wormhole candidates is through the detection …


Table Of Contents Oct 2022

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.


2022 Scas Annual Meeting Program And Bulletin Oct 2022

2022 Scas Annual Meeting Program And Bulletin

Journal of the South Carolina Academy of Science

No abstract provided.


Extended Duration Studies Of Energetic Particles In The Stratosphere, Ian Kuhl, Ashna Coondiah, Howard Brooks Oct 2022

Extended Duration Studies Of Energetic Particles In The Stratosphere, Ian Kuhl, Ashna Coondiah, Howard Brooks

Annual Student Research Poster Session

The Balloon Assisted Stratospheric Experiments (BASE) program aims to measure atmospheric muon concentration at the Pfotzer Maximum with Geiger Counters carried by weather balloons. The most intense radiation is found at the Pfotzer Maximum 18 - 22 km (11 - 13 mi) above ground level. During this summer, seven flights were conducted to attain maximum time in the Pfotzer Maximum using different strategies like underfilling and multiple balloon systems.


Galaxy And Mass Assembly (Gama): Probing Galaxy-Group Correlations In Redshift Space With The Halo Streaming Model, Qianjun Hang, John A. Peacock, Shadab Alam, Yan-Chuan Cai, Katarina Kraljic, Marcel Van Daalen, M Bilicki, Benne Holwerda, J Loveday Oct 2022

Galaxy And Mass Assembly (Gama): Probing Galaxy-Group Correlations In Redshift Space With The Halo Streaming Model, Qianjun Hang, John A. Peacock, Shadab Alam, Yan-Chuan Cai, Katarina Kraljic, Marcel Van Daalen, M Bilicki, Benne Holwerda, J Loveday

Faculty Scholarship

We have studied the galaxy-group cross-correlations in redshift space for the Galaxy And Mass Assembly (GAMA) Survey. We use a set of mock GAMA galaxy and group catalogues to develop and test a novel ‘halo streaming’ model for redshift-space distortions. This treats 2-halo correlations via the streaming model, plus an empirical 1-halo term derived from the mocks, allowing accurate modelling into the non-linear regime. In order to probe the robustness of the growth rate inferred from redshift-space distortions, we divide galaxies by colour, and divide groups according to their total stellar mass, calibrated to total mass via gravitational lensing. We …