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Articles 1 - 30 of 7539

Full-Text Articles in Physical Sciences and Mathematics

Sampling Candidate Reionization Galaxies Using Spectral Energy Distribution Fitting, Nicholas J. Velikonja, Michael Rutkowski May 2021

Sampling Candidate Reionization Galaxies Using Spectral Energy Distribution Fitting, Nicholas J. Velikonja, Michael Rutkowski

Macalester Journal of Physics and Astronomy

The process of reionization is one of the major pieces of galaxy evolution which remain to be un- derstood. With new observational tools like JWST on the horizon, imaging reionization-era galaxies will soon be possible. However, because the ionizing radiation is absorbed by the neutral hydrogen it ionizes, observers need some other parameter by which to identify those galaxies capable of reionizing. The search for ionizing emission via related parameters is well underway, and has come up with some tentative correlations, yet a consistent indicator or set of indicators remains to be discovered. New data in the Low-Redshift Lyman Continuum ...


Carrier Lifetime And Carrier Mobility Of Gaasn With Changing Nitrogen Concentration, Sun Gyu Park May 2021

Carrier Lifetime And Carrier Mobility Of Gaasn With Changing Nitrogen Concentration, Sun Gyu Park

Macalester Journal of Physics and Astronomy

In this work, we conducted Ultrafast Conductivity Measurements, using THz Spectroscopy to characterize the carrier mobility and the carrier lifetime of gallium arsenide nitride (GaAsN) thin films with a range of Nitrogen concentrations. The photoexcitation of semiconductor samples excites free charges by promoting electrons from the valence band to the conduction band. We then measure the change in conductivity by measuring the transmission of a THz electromagnetic pulse after photoexcitation and comparing with the signal that was measured without photoexcitation. The values of transmission are then converted into conductivity, from which we derive the carrier concentration and scattering time of ...


Renewing The Paradigm: Simulating The Miso Region Electrical Grid Using Renewable Energy Generation With Implementation Of Long-Term Hydrogen Storage, Jackson C. Henningfield May 2021

Renewing The Paradigm: Simulating The Miso Region Electrical Grid Using Renewable Energy Generation With Implementation Of Long-Term Hydrogen Storage, Jackson C. Henningfield

Macalester Journal of Physics and Astronomy

The current electrical grid regime is not optimized to include renewable sources of power generation such as wind and solar. Electrical storage, as of now, is primarily established through the short-term generation and demand-meeting consumption leaving much of the grid susceptible to inefficiencies and power loss during natural events that leave grids out of commission. Delineating a new type of long-term storage, a hydrogen fuel cell, would ensure a reliable source of power to the masses regardless of the physical and climatic geography. The MISO region provides a perfect case study to introduce the ideas of diverse energy generation and ...


Electrical Grid Energy Storage Using Hydrogen: A Feasibility Study, Elizabeth M. Curtiss May 2021

Electrical Grid Energy Storage Using Hydrogen: A Feasibility Study, Elizabeth M. Curtiss

Macalester Journal of Physics and Astronomy

In this project, we studied the possibility of implementing hydrogen as energy storage. With the focus being on decarbonizing the grid, we looked at studies that were powered by renewable sources. In addition to utilizing renewable sources, we decided to study electrolysis as a way to produce hydrogen. Electrolysis is the splitting of water to obtain hydrogen and oxygen, which is a carbon free technique. Pulling from two different papers, we were able to construct an equation that modeled the levelized cost of producing hydrogen. We also calculated the levelized cost of a fuel cell too, with hydrogen as fuel ...


Standard Non-Uniform Noise Dataset, Andres Imperial, John M. Edwards May 2021

Standard Non-Uniform Noise Dataset, Andres Imperial, John M. Edwards

Browse all Datasets

Fixed Pattern Noise Non-Uniformity Correction through K-Means Clustering

Fixed pattern noise removal from imagery by software correction is a practical approach compared to a physical hardware correction because it allows for correction post-capture of the imagery. Fixed pattern noise presents a unique challenge for de-noising techniques as the noise does not present itself where large number statistics are effective. Traditional noise removal techniques such as blurring or despeckling produce poor correction results because of a lack of noise identification. Other correction methods developed for fixed pattern noise can often present another problem of misidentification of noise. This problem can result ...


Chandra Grating Spectroscopy Of Embedded Wind Shock X-Ray Emission From O Stars Shows Low Plasma Temperatures And Significant Wind Absorption, David H. Cohen, V. Vaughn Parts, Graham M. Doskoch , '20, Jiaming Wang , '22, V. Petit, M. A. Leutenegger, M. Gagné May 2021

Chandra Grating Spectroscopy Of Embedded Wind Shock X-Ray Emission From O Stars Shows Low Plasma Temperatures And Significant Wind Absorption, David H. Cohen, V. Vaughn Parts, Graham M. Doskoch , '20, Jiaming Wang , '22, V. Petit, M. A. Leutenegger, M. Gagné

Physics & Astronomy Faculty Works

We present a uniform analysis of six examples of embedded wind shock (EWS) O star X-ray sources observed at high resolution with the Chandra grating spectrometers. By modelling both the hot plasma emission and the continuum absorption of the soft X-rays by the cool, partially ionized bulk of the wind we derive the temperature distribution of the shock-heated plasma and the wind mass-loss rate of each star. We find a similar temperature distribution for each star’s hot wind plasma, consistent with a power-law differential emission measure, dlogEMdlogT⁠, with a slope a little steeper than −2, up to temperatures of ...


Distant Stars Become Future Homes: The Close Relationship Of Interstellar Between Hard Science-Fiction And Spectacle, Gabriel Davis May 2021

Distant Stars Become Future Homes: The Close Relationship Of Interstellar Between Hard Science-Fiction And Spectacle, Gabriel Davis

Undergraduate Honors Theses

Hard Science-fiction shares a close relationship with the element of spectacle. This is especially apparent in Christopher Nolan’s Interstellar (2014), a film based in realistic science and emotional appeal. Nolan makes use of creating a team comprised of creative minds with different backgrounds. This includes theoretical physicist Kip Thorne, co-writer Jonathan Nolan, and composer Hans Zimmer. Together, the four develop a film that focuses on three main facets of science: time dilation, black holes, and dimensions. Incorporating these elements based in the historical world gives Interstellar its classification as hard science-fiction, a genre based more solidly in realistic science ...


Spectroscopic Analysis Of Potential Astromolecules Via Quantum Chemical Quartic Force Fields, Mason Gardner May 2021

Spectroscopic Analysis Of Potential Astromolecules Via Quantum Chemical Quartic Force Fields, Mason Gardner

Honors Theses

Astrochemistry has been substantially aided by computational techniques, particularly through the use of Quartic Force Field (QFF) analysis. Several methods have proven useful at correlating computed spectroscopic data with experimental observations. The F12-TZ QFF correlated well with experimental data for silicon oxide compounds, particularly those potentially involved in development from rocky bodies to planetary masses [27]. Compared to argon matrix experimental data, the vibrational frequencies for the molecules SiO2, SiO3, Si2O3, and Si2O4 become less accurate as the complexity of the molecules increases but should still be predictive of infrared characteristics of silicon oxides as they form clusters in space ...


The James Webb Space Telescope And Scientific Progress, Robert Astle Apr 2021

The James Webb Space Telescope And Scientific Progress, Robert Astle

Quest

Independent Research Paper

Research in progress for PHYS 2425: University Physics I

Faculty Mentor: Raji Kannampuzha, Ph.D.

The following paper represents research work done by students in University Physics 2425, the first half of a two-semester introductory course in physics. It is a calculus- based physics course, intended primarily for physics, chemistry, math, and engineering majors. Students are introduced to the concept of academic research by learning to ask research-focused questions and then use the library resources to pursue outside research to find answers. For this assignment, students are asked to investigate a physical science, biological science, or technology ...


287— The X-Ray Afterglows Of Short Gamma-Ray Bursts, Sarah Popp Apr 2021

287— The X-Ray Afterglows Of Short Gamma-Ray Bursts, Sarah Popp

GREAT Day

Light curves of the X-ray afterglow from 81 short gamma-ray bursts, from 2005 to 2018, were obtained from the Swift/XRT catalog. The light curves were fit with single power-law and double-power law models using the emcee library in Python and sorted into three groups: bursts well fit by a single power-law, bursts well fit by a double power-law, and bursts not well fit by either. Filters were applied to each category to identify bursts with a steep decay or a plateau. Once these unusual bursts were identified, their properties (duration, flux, fluence, and hardness) were compared to those of ...


029— Calculating Gravitational Waves In A Black Hole Binary System, Nami Nishimura Apr 2021

029— Calculating Gravitational Waves In A Black Hole Binary System, Nami Nishimura

GREAT Day

Our ultimate goal is to compute the gravitational waves in an extreme mass-ratio binary system. Since gravitational perturbations are difficult to calculate, we model the compact object as a point carrying a scalar charge q and moving around a spinning black holes.

In this project, we take advantage of symmetry under rotation around the spin axis in order to separate φ variables and leverage the periodicity of the source to separate t variable with a Fourier series. The remaining differential equations will be solved numerically with an appropriate discretization considering a grid of points in r-θ plane


382— Wiyn Open Cluster Study: Ubvri Photometry Of Ngc 2204, Kylie Snyder, Dante Scarazzini Apr 2021

382— Wiyn Open Cluster Study: Ubvri Photometry Of Ngc 2204, Kylie Snyder, Dante Scarazzini

GREAT Day

The purpose of this project was to study the open star cluster NGC2204 using images taken at Kitt Peak National Observatory using the WIYN 0.9m telescope. These images were analyzed photometrically with the intention of determining the reddening, metallicity, age, and distance modulus of the star cluster. Each image was analyzed using software that determined the point spread function and applied that function to determine the magnitude of each star in that image. These magnitudes were taken for each filter, UBVRI, and then combined and averaged to create a single catalog. Standard stars, taken on the same night, were ...


Phenomenology Of Fermion Production During Axion Inflation, Michael Roberts Apr 2021

Phenomenology Of Fermion Production During Axion Inflation, Michael Roberts

Doctoral Dissertations

We study the production of fermions through a derivative coupling to an axion inflaton and the effects of the produced fermions on the scalar and tensor metric perturbations. We show how such a coupling can arise naturally from supergravity with an axion-like field driving large-field inflation and small instanton-like corrections. We present analytic results for the scalar and tensor power spectra, and estimate the amplitude of the non-Gaussianties in the equilateral regime. The scalar spectrum is found to have a red-tilted spectral index, small non-Gaussianities, and can be dominant over the vacuum contribution. In contrast, the tensor power spectrum from ...


Formation Of Supermassive Black Holes In The Early Universe, Arpan Das Apr 2021

Formation Of Supermassive Black Holes In The Early Universe, Arpan Das

Electronic Thesis and Dissertation Repository

The aim of the work presented in this thesis is to understand the formation and growth of the seeds of the supermassive black holes in early universe. Supermassive black holes (SMBH) with masses larger than 108MSun have been observed when the Universe was only 800 Myr old. The formation and accretion history of the seeds of these supermassive black holes are a matter of debate. We consider the scenario of massive seed black hole formation which allows gas to directly collapse into a black hole (DCBH) of similar mass. Considering this scenario, we show that the mass ...


Ast 101: Introductory Astronomy, Cuny School Of Professional Studies Apr 2021

Ast 101: Introductory Astronomy, Cuny School Of Professional Studies

Open Educational Resources

An exploration of our solar system’s creation and the planets in our solar system using the latest scientific information, recent probe data, and new discoveries in the science of extra-solar planetary astronomy. This course is based in part upon materials developed by the American Museum of Natural History and is used with permission by the School of Professional Studies for this course.


A Hot Mini-Neptune In The Radius Valley Orbiting Solar Analogue Hd 110113, H. P. Osborn, D. J. Armstrong, V. Adibekyan, K. A. Collins, E. Delgado-Mena, S. B. Howell, C. Hellier, G. W. King, J. Lillo-Box, L. D. Nielsen, J. F. Otegi, N. C. Santos, C. Ziegler, D. R. Anderson, C. Briceño, C. Burke, D. Bayliss, D. Barrado, E. M. Bryant, D. J. A. Brown, S. C. C. Barros, F. Bouchy, D. A. Caldwell, D. M. Conti, R. F. Díaz, D. Dragomir, M. Deleuil, O. D. S. Demangeon, C. Dorn, T. Daylan, P. Figueira, R. Helled, S. Hoyer, J. M. Jenkins, Eric L.N. Jensen, D. W. Latham, N. Law, D. R. Louie, A. W. Mann, A. Osborn, D. L. Pollacco, D. R. Rodriguez, B. V. Rackham, G. Ricker, N. J. Scott, S. G. Sousa, S. Seager, K. G. Stassun, J. C. Smith, P. Strøm, S. Udry, J. Villaseñor, R. Vanderspek, R. West, P. J. Wheatley, J. N. Winn Apr 2021

A Hot Mini-Neptune In The Radius Valley Orbiting Solar Analogue Hd 110113, H. P. Osborn, D. J. Armstrong, V. Adibekyan, K. A. Collins, E. Delgado-Mena, S. B. Howell, C. Hellier, G. W. King, J. Lillo-Box, L. D. Nielsen, J. F. Otegi, N. C. Santos, C. Ziegler, D. R. Anderson, C. Briceño, C. Burke, D. Bayliss, D. Barrado, E. M. Bryant, D. J. A. Brown, S. C. C. Barros, F. Bouchy, D. A. Caldwell, D. M. Conti, R. F. Díaz, D. Dragomir, M. Deleuil, O. D. S. Demangeon, C. Dorn, T. Daylan, P. Figueira, R. Helled, S. Hoyer, J. M. Jenkins, Eric L.N. Jensen, D. W. Latham, N. Law, D. R. Louie, A. W. Mann, A. Osborn, D. L. Pollacco, D. R. Rodriguez, B. V. Rackham, G. Ricker, N. J. Scott, S. G. Sousa, S. Seager, K. G. Stassun, J. C. Smith, P. Strøm, S. Udry, J. Villaseñor, R. Vanderspek, R. West, P. J. Wheatley, J. N. Winn

Physics & Astronomy Faculty Works

We report the discovery of HD 110113 b (TESS object of interest-755.01), a transiting mini-Neptune exoplanet on a 2.5-d orbit around the solar-analogue HD 110113 (Teff = 5730 K). Using TESS photometry and High Accuracy Radial velocity Planet Searcher (HARPS) radial velocities gathered by the NCORES program, we find that HD 110113 b has a radius of 2.05 ± 0.12  R⊕ and a mass of 4.55 ± 0.62  M⊕. The resulting density of 2.90+0.75−0.59  g cm−3 is significantly lower than would be expected from a pure-rock world; therefore HD 110113 b ...


Tic 168789840: A Sextuply Eclipsing Sextuple Star System, B. P. Powell, V. B. Kostov, S. A. Rappaport, T. Borkovits, P. Zasche, A. Tokovinin, E. Kruse, D. W. Latham, B. T. Montet, Eric L.N. Jensen, R. Jayaraman, K. A. Collins, M. Mašek, C. Hellier, P. Evans, T.-G. Tan, J. E. Schlieder, G. Torres, A. P. Smale, A. H. Friedman, T. Barclay, R. Gagliano, E. V. Quintana, T. L. Jacobs, E. A. Gilbert, M. H. Kristiansen, K. D. Colón, D. M. Lacourse, G. Olmschenk, M. Omohundro, J. D. Schnittman, H. M. Schwengeler, R. K. Barry, I. A. Terentev, P. Boyd, A. R. Schmitt, S. M. Quinn, A. Vanderburg, E. Palle, J. Armstrong, G. R. Ricker, R. Vanderspek, S. Seager, J. N. Winn, J. M. Jenkins, D. A. Caldwell, B. Wohler, B. Shiao, C. J. Burke, T. Daylan, J. Villaseñor Apr 2021

Tic 168789840: A Sextuply Eclipsing Sextuple Star System, B. P. Powell, V. B. Kostov, S. A. Rappaport, T. Borkovits, P. Zasche, A. Tokovinin, E. Kruse, D. W. Latham, B. T. Montet, Eric L.N. Jensen, R. Jayaraman, K. A. Collins, M. Mašek, C. Hellier, P. Evans, T.-G. Tan, J. E. Schlieder, G. Torres, A. P. Smale, A. H. Friedman, T. Barclay, R. Gagliano, E. V. Quintana, T. L. Jacobs, E. A. Gilbert, M. H. Kristiansen, K. D. Colón, D. M. Lacourse, G. Olmschenk, M. Omohundro, J. D. Schnittman, H. M. Schwengeler, R. K. Barry, I. A. Terentev, P. Boyd, A. R. Schmitt, S. M. Quinn, A. Vanderburg, E. Palle, J. Armstrong, G. R. Ricker, R. Vanderspek, S. Seager, J. N. Winn, J. M. Jenkins, D. A. Caldwell, B. Wohler, B. Shiao, C. J. Burke, T. Daylan, J. Villaseñor

Physics & Astronomy Faculty Works

We report the discovery of a sextuply eclipsing sextuple star system from TESS data, TIC 168789840, also known as TYC 7037-89-1, the first known sextuple system consisting of three eclipsing binaries. The target was observed in Sectors 4 and 5 during Cycle 1, with lightcurves extracted from TESS Full Frame Image data. It was also previously observed by the WASP survey and ASAS-SN. The system consists of three gravitationally bound eclipsing binaries in a hierarchical structure of an inner quadruple system with an outer binary subsystem. Follow-up observations from several different observatories were conducted as a means of determining additional ...


Precise Transit And Radial-Velocity Characterization Of A Resonant Pair: The Warm Jupiter Toi-216c And Eccentric Warm Neptune Toi-216b, R. I. Dawson, C. X. Huang, R. Brahm, K. A. Collins, M. J. Hobson, A. Jordán, J. Dong, J. Korth, T. Trifonov, L. Abe, A. Agabi, I. Bruni, R. P. Butler, M. Barbieri, K. I. Collins, D. M. Conti, J. D. Crane, N. Crouzet, G. Dransfield, P. Evans, N. Espinoza, T. Gan, T. Guillot, T. Henning, J. J. Lissauer, Eric L. N. Jensen, W. M. Sainte, D. Mékarnia, G. Myers, S. Nandakumar, H. M. Relles, P. Sarkis, P. Torres, S. Shectman, F.-X. Schmider, A. Shporer, C. Stockdale, J. Teske, A. H. M. J. Triaud, S. X. Wang, C. Ziegler, G. Ricker, R. Vanderspek, D. W. Latham, S. Seager, J. Winn, J. M. Jenkins, L. G. Bouma, J. A. Burt, D. Charbonneau, A. M. Levine, S. Mcdermott, B. Mclean, M. E. Rose, A. Vanderburg, B. Wohler Apr 2021

Precise Transit And Radial-Velocity Characterization Of A Resonant Pair: The Warm Jupiter Toi-216c And Eccentric Warm Neptune Toi-216b, R. I. Dawson, C. X. Huang, R. Brahm, K. A. Collins, M. J. Hobson, A. Jordán, J. Dong, J. Korth, T. Trifonov, L. Abe, A. Agabi, I. Bruni, R. P. Butler, M. Barbieri, K. I. Collins, D. M. Conti, J. D. Crane, N. Crouzet, G. Dransfield, P. Evans, N. Espinoza, T. Gan, T. Guillot, T. Henning, J. J. Lissauer, Eric L. N. Jensen, W. M. Sainte, D. Mékarnia, G. Myers, S. Nandakumar, H. M. Relles, P. Sarkis, P. Torres, S. Shectman, F.-X. Schmider, A. Shporer, C. Stockdale, J. Teske, A. H. M. J. Triaud, S. X. Wang, C. Ziegler, G. Ricker, R. Vanderspek, D. W. Latham, S. Seager, J. Winn, J. M. Jenkins, L. G. Bouma, J. A. Burt, D. Charbonneau, A. M. Levine, S. Mcdermott, B. Mclean, M. E. Rose, A. Vanderburg, B. Wohler

Physics & Astronomy Faculty Works

TOI-216 hosts a pair of warm, large exoplanets discovered by the TESS mission. These planets were found to be in or near the 2:1 resonance, and both of them exhibit transit timing variations (TTVs). Precise characterization of the planets' masses and radii, orbital properties, and resonant behavior can test theories for the origins of planets orbiting close to their stars. Previous characterization of the system using the first six sectors of TESS data suffered from a degeneracy between planet mass and orbital eccentricity. Radial-velocity measurements using HARPS, FEROS, and the Planet Finder Spectrograph break that degeneracy, and an expanded ...


Tess Delivers Five New Hot Giant Planets Orbiting Bright Stars From The Full-Frame Images, J. E. Rodriguez, S. N. Quinn, G. Zhou, A. Vanderburg, L. D. Nielsen, R. A. Wittenmyer, R. Brahm, P. A. Reed, C. X. Huang, S. Vach, D. R. Ciardi, R. J. Oelkers, K. G. Stassun, C. Hellier, B. S. Gaudi, J. D. Eastman, K. A. Collins, A. Bieryla, S. Christian, D. W. Latham, I. Carleo, D. J. Wright, E. Matthews, E. J. Gonzales, C. Ziegler, C. D. Dressing, S. B. Howell, T.-G. Tan, J. Wittrock, P. Plavchan, K. K. Mcleod, D. Baker, G. Wang, D. J. Radford, R. P. Schwarz, M. Esposito, G. R. Ricker, R. K. Vanderspek, S. Seager, J. N. Winn, J. M. Jenkins, B. Addison, D. R. Anderosn, T. Barclay, T. G. Beatty, P. Berlind, F. Bouchy, M. Bowen, B. P. Bowler, C. E. Brasseur, C. Briceño, D. A. Caldwell, M. L. Calkins, S. Cartwright, P. Chaturvedi, G. Chaverot, S. Chimaladinne, J. L. Christiansen, K. I. Collins, I. J. M. Crossfield, K. Eastridge, N. Espinoza, G. A. Esquerdo, D. L. Felix, T. Fenske, W. Fong, T. Gan, S. Giacalone, H. Gill, L. Gordon, A. Granados, N. Grieves, E. W. Guenther, N. Guerrero, T. Henning, C. E. Henze, K. Hesse, M. J. Hobson, J. Horner, D. J. James, Eric L. N. Jensen, M. Jimenez, A. Jordán, S. R. Kane, J. Kielkopf, K. Kim, R. B. Kuhn, N. Latouf, N. M. Law, A. M. Levine, M. B. Lund, A. W. Mann, S. Mao, R. A. Matson, M. W. Mengel, J. Mink, P. Newman, T. O’Dwyer, J. Okumura, E. Palle, J. Pepper, E. V. Quintana, P. Sarkis, A. B. Savel, J. E. Schlieder, C. Schnaible, A. Shporer, R. Sefako, J. V. Seidel, R. J. Siverd, B. Skinner, M. Stalport, D. J. Stevens, C. Stibbards, C. G. Tinney, R. G. West, D. A. Yahalomi, H. Zhang Apr 2021

Tess Delivers Five New Hot Giant Planets Orbiting Bright Stars From The Full-Frame Images, J. E. Rodriguez, S. N. Quinn, G. Zhou, A. Vanderburg, L. D. Nielsen, R. A. Wittenmyer, R. Brahm, P. A. Reed, C. X. Huang, S. Vach, D. R. Ciardi, R. J. Oelkers, K. G. Stassun, C. Hellier, B. S. Gaudi, J. D. Eastman, K. A. Collins, A. Bieryla, S. Christian, D. W. Latham, I. Carleo, D. J. Wright, E. Matthews, E. J. Gonzales, C. Ziegler, C. D. Dressing, S. B. Howell, T.-G. Tan, J. Wittrock, P. Plavchan, K. K. Mcleod, D. Baker, G. Wang, D. J. Radford, R. P. Schwarz, M. Esposito, G. R. Ricker, R. K. Vanderspek, S. Seager, J. N. Winn, J. M. Jenkins, B. Addison, D. R. Anderosn, T. Barclay, T. G. Beatty, P. Berlind, F. Bouchy, M. Bowen, B. P. Bowler, C. E. Brasseur, C. Briceño, D. A. Caldwell, M. L. Calkins, S. Cartwright, P. Chaturvedi, G. Chaverot, S. Chimaladinne, J. L. Christiansen, K. I. Collins, I. J. M. Crossfield, K. Eastridge, N. Espinoza, G. A. Esquerdo, D. L. Felix, T. Fenske, W. Fong, T. Gan, S. Giacalone, H. Gill, L. Gordon, A. Granados, N. Grieves, E. W. Guenther, N. Guerrero, T. Henning, C. E. Henze, K. Hesse, M. J. Hobson, J. Horner, D. J. James, Eric L. N. Jensen, M. Jimenez, A. Jordán, S. R. Kane, J. Kielkopf, K. Kim, R. B. Kuhn, N. Latouf, N. M. Law, A. M. Levine, M. B. Lund, A. W. Mann, S. Mao, R. A. Matson, M. W. Mengel, J. Mink, P. Newman, T. O’Dwyer, J. Okumura, E. Palle, J. Pepper, E. V. Quintana, P. Sarkis, A. B. Savel, J. E. Schlieder, C. Schnaible, A. Shporer, R. Sefako, J. V. Seidel, R. J. Siverd, B. Skinner, M. Stalport, D. J. Stevens, C. Stibbards, C. G. Tinney, R. G. West, D. A. Yahalomi, H. Zhang

Physics & Astronomy Faculty Works

We present the discovery and characterization of five hot and warm Jupiters—TOI-628 b (TIC 281408474; HD 288842), TOI-640 b (TIC 147977348), TOI-1333 b (TIC 395171208, BD+47 3521A), TOI-1478 b (TIC 409794137), and TOI-1601 b (TIC 139375960)—based on data from NASA's Transiting Exoplanet Survey Satellite (TESS). The five planets were identified from the full-frame images and were confirmed through a series of photometric and spectroscopic follow-up observations by the TESS Follow-up Observing Program Working Group. The planets are all Jovian size (RP = 1.01–1.77 RJ) and have masses that range from 0.85 to 6 ...


Comparing Dust In Other Galaxies To Dust In Our Galaxy, Fatima Elkhatib Apr 2021

Comparing Dust In Other Galaxies To Dust In Our Galaxy, Fatima Elkhatib

Senior Theses

Interstellar dust in galaxies has a profound effect on the galaxies’ light output and apparent properties as well as on the physical processes connected to star formation. Therefore, to understand the true properties of the galaxies around us, it is important to understand the dust in those galaxies and compare it to the dust in our galaxy. To do this, we study the effects of dust on background quasars by analyzing interstellar reddening and extinction. It has been shown that many quasars look redder and dimmer than the average quasar when observing them from Earth, due to the dust in ...


Determining The Origins Of Helix Glitches In Ligo’S H1 Detector, Kara Shepard Mar 2021

Determining The Origins Of Helix Glitches In Ligo’S H1 Detector, Kara Shepard

Honors Scholars & Undergraduate Research Poster Symposium Programs

The LIGO detectors are ultra-sensitive, making them susceptible to glitches from the noise that can block gravitational wave signals. In order to reduce the number of glitches that occur in the detector, the cause of the glitches must be found. I am researching the Helix glitch to try and determine its origin. This is accomplished by studying the times at which the glitch occurred in the detector and then looking for factors that may have caused a glitch to happen around the same time, to see if there are any correlations.


All-Sky Search In Early O3 Ligo Data For Continuous Gravitational-Wave Signals From Unknown Neutron Stars In Binary Systems, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, K. E. Ramirez, W. H. Wang Mar 2021

All-Sky Search In Early O3 Ligo Data For Continuous Gravitational-Wave Signals From Unknown Neutron Stars In Binary Systems, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, K. E. Ramirez, W. H. Wang

Physics and Astronomy Faculty Publications and Presentations

Rapidly spinning neutron stars are promising sources of continuous gravitational waves. Detecting such a signal would allow probing of the physical properties of matter under extreme conditions. A significant fraction of the known pulsar population belongs to binary systems. Searching for unknown neutron stars in binary systems requires specialized algorithms to address unknown orbital frequency modulations. We present a search for continuous gravitational waves emitted by neutron stars in binary systems in early data from the third observing run of the Advanced LIGO and Advanced Virgo detectors using the semicoherent, GPU-accelerated, BinarySkyHough pipeline. The search analyzes the most sensitive frequency ...


Identifying, Analyzing, And Using Discriminatory Variables For Classification Of Neutrino Signal And Background Noise In Multivariate Analysis In The Askaryan Radio Array Experiment, Jesse Osborn Mar 2021

Identifying, Analyzing, And Using Discriminatory Variables For Classification Of Neutrino Signal And Background Noise In Multivariate Analysis In The Askaryan Radio Array Experiment, Jesse Osborn

Honors Theses, University of Nebraska-Lincoln

The Askaryan Radio Array Experiment, located near the South Pole, works to pinpoint specific instances of neutrinos from outside the solar system interacting with nucleons inside the Antarctic ice, emitting radio waves. I have taken data from the ARA stations which is presumed to be background noise and compared it to simulated data meant to look like a neutrino signal. I developed a suite of variables for discrimination between the two data sets, using a computer algorithm to generate a single output variable which can be used to distinguish noise events from signal events. I maximized this discrimination process for ...


A Gravitational-Wave Measurement Of The Hubble Constant Following The Second Observing Run Of Advanced Ligo And Virgo, B. P. Abbott, R. Abbott, T. D. Abbott, S. Abraham, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, K. E. Ramirez, Satzhan Sitmukhambetov, Robert Stone, D. Tuyenbayev, W. H. Wang, Adam Zadrozny Mar 2021

A Gravitational-Wave Measurement Of The Hubble Constant Following The Second Observing Run Of Advanced Ligo And Virgo, B. P. Abbott, R. Abbott, T. D. Abbott, S. Abraham, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, K. E. Ramirez, Satzhan Sitmukhambetov, Robert Stone, D. Tuyenbayev, W. H. Wang, Adam Zadrozny

Physics and Astronomy Faculty Publications and Presentations

This paper presents the gravitational-wave measurement of the Hubble constant (H0) using the detections from the first and second observing runs of the Advanced LIGO and Virgo detector network. The presence of the transient electromagnetic counterpart of the binary neutron star GW170817 led to the first standard-siren measurement of H0. Here we additionally use binary black hole detections in conjunction with galaxy catalogs and report a joint measurement. Our updated measurement is H0 = - 69+8 16 km s−1 Mpc−1 (68.3% of the highest density posterior interval with a flat-in-log prior) which is an improvement by a factor ...


A Nearby Transiting Rocky Exoplanet That Is Suitable For Atmospheric Investigation, T. Trifonov, J. A. Caballero, J. C. Morales, A. Seifahrt, I. Ribas, A. Reiners, J. L. Bean, R. Luque, H. Parviainen, E. Pallé, S. Stock, M. Zechmeister, P. J. Amado, G. Anglada-Escudé, M. Azzaro, T. Barclay, V. J. S. Béjar, P. Bluhm, N. Casasayas-Barris, C. Cifuentes, K. A. Collins, K. I. Collins, M. Cortés-Contreras, J. De Leon, S. Dreizler, C. D. Dressing, E. Esparza-Borges, N. Espinoza, M. Fausnaugh, A. Fukui, A. P. Hatzes, C. Hellier, T. Henning, C. E. Henze, E. Herrero, S. V. Jeffers, J. M. Jenkins, Eric L.N. Jensen, A. Kaminski, D. Kasper, D. Kossakowski, M. Kürster, M. Lafarga, D. W. Latham, A. W. Mann, K. Molaverdikhani, D. Montes, B. T. Montet, F. Murgas, N. Narita, M. Oshagh, V. M. Passegger, D. Pollacco, S. N. Quinn, A. Quirrenbach, G. R. Ricker, C. Rodríguez López, J. Sanz-Forcada, R. P. Schwarz, A. Schweitzer, S. Seager, A. Shporer, M. Stangret, J. Stürmer, T. G. Tan, P. Tenenbaum, J. D. Twicken, R. Vanderspek, J. N. Winn Mar 2021

A Nearby Transiting Rocky Exoplanet That Is Suitable For Atmospheric Investigation, T. Trifonov, J. A. Caballero, J. C. Morales, A. Seifahrt, I. Ribas, A. Reiners, J. L. Bean, R. Luque, H. Parviainen, E. Pallé, S. Stock, M. Zechmeister, P. J. Amado, G. Anglada-Escudé, M. Azzaro, T. Barclay, V. J. S. Béjar, P. Bluhm, N. Casasayas-Barris, C. Cifuentes, K. A. Collins, K. I. Collins, M. Cortés-Contreras, J. De Leon, S. Dreizler, C. D. Dressing, E. Esparza-Borges, N. Espinoza, M. Fausnaugh, A. Fukui, A. P. Hatzes, C. Hellier, T. Henning, C. E. Henze, E. Herrero, S. V. Jeffers, J. M. Jenkins, Eric L.N. Jensen, A. Kaminski, D. Kasper, D. Kossakowski, M. Kürster, M. Lafarga, D. W. Latham, A. W. Mann, K. Molaverdikhani, D. Montes, B. T. Montet, F. Murgas, N. Narita, M. Oshagh, V. M. Passegger, D. Pollacco, S. N. Quinn, A. Quirrenbach, G. R. Ricker, C. Rodríguez López, J. Sanz-Forcada, R. P. Schwarz, A. Schweitzer, S. Seager, A. Shporer, M. Stangret, J. Stürmer, T. G. Tan, P. Tenenbaum, J. D. Twicken, R. Vanderspek, J. N. Winn

Physics & Astronomy Faculty Works

Spectroscopy of transiting exoplanets can be used to investigate their atmospheric properties and habitability. Combining radial velocity (RV) and transit data provides additional information on exoplanet physical properties. We detect a transiting rocky planet with an orbital period of 1.467 days around the nearby red dwarf star Gliese 486. The planet Gliese 486 b is 2.81 Earth masses and 1.31 Earth radii, with uncertainties of 5%, as determined from RV data and photometric light curves. The host star is at a distance of ~8.1 parsecs, has a J-band magnitude of ~7.2, and is observable from ...


Redefining Nietzsche’S Greatest Weight Into Contemporary Cosmology, Christian E. Coffinet-Crean Mar 2021

Redefining Nietzsche’S Greatest Weight Into Contemporary Cosmology, Christian E. Coffinet-Crean

Scholarly Horizons: University of Minnesota, Morris Undergraduate Journal

Friedrich Nietzsche’s theory of eternal recurrence and it’s cosmological value has been discredited and cast aside because of the lack of scientific backing the original theory had. In this essay, Nietzche’s eternal recurrence will be observed and analyzed through some of his major works and defended from outside criticism. Furthermore, Roger Penrose’s Conformal Cyclic Cosmology and Jean-Paul Luminet’s research are used in support for eternal recurrence as a cosmological theory. Luminet’s research of cosmic background radiation concludes that the universe has an odd but finite shape. Penrose’s research theorizes a sort of repeating ...


How And Why Mars Lost Its Water, Sana Akhter, Andre Beikircher Feb 2021

How And Why Mars Lost Its Water, Sana Akhter, Andre Beikircher

2021 Honors Council of the Illinois Region

The topic of this paper is to investigate how and why Mars lost its water. It is important to study the loss of water on Mars because it can give us a better understanding of how Mars once looked, if life were possible, and how it could have changed so drastically to what it is now. The paper aims to address which factors led to Mars losing its water and how long ago this happened. Using our data, we will predict how quickly Mars’ core cooled, when its magnetic field weakened, and when the water was lost. We learned that ...


Quasinormal Modes And Their Overtones At The Common Horizon In A Binary Black Hole Merger, Pierre Mourier, Xisco Jimenez Forteza, Daniel Pook-Kolb, Dadri Krishnan, Erik Schnetter Feb 2021

Quasinormal Modes And Their Overtones At The Common Horizon In A Binary Black Hole Merger, Pierre Mourier, Xisco Jimenez Forteza, Daniel Pook-Kolb, Dadri Krishnan, Erik Schnetter

Faculty Publications

It is expected that all astrophysical black holes in equilibrium are well described by the Kerr solution. Moreover, any black hole far away from equilibrium, such as one initially formed in a compact binary merger or by the collapse of a massive star, will eventually reach a final equilibrium Kerr state. At sufficiently late times in this process of reaching equilibrium, we expect that the black hole is modeled as a perturbation around the final state. The emitted gravitational waves will then be damped sinusoids with frequencies and damping times given by the quasinormal mode spectrum of the final Kerr ...


Extending The Frequency Reach Of Pulsar Timing Array Based Gravitational Wave Search Without High Cadence Observations, Yan Wang, Soumya Mohanty, Zhoujian Cao Feb 2021

Extending The Frequency Reach Of Pulsar Timing Array Based Gravitational Wave Search Without High Cadence Observations, Yan Wang, Soumya Mohanty, Zhoujian Cao

Physics and Astronomy Faculty Publications and Presentations

Gravitational wave (GW) searches using pulsar timing arrays (PTAs) are assumed to be limited by the typical average observational cadence of 1/(2 weeks) for a single pulsar to GW frequencies . 4 × 10−7 Hz. We show that this assumption is incorrect and that a PTA can detect signals with much higher frequencies, which are preserved in the data due to aliasing, by exploiting asynchronous observations from multiple pulsars. This allows an observation strategy that is scalable to future large-scale PTAs containing O(103) pulsars, enabled by the Five-hundred meter Aperture Spherical Telescope and the Square Kilometer Array, without requiring ...


Scalable, Cost-Efficient Synthesis And Properties Optimization Of Magnetoelectric Cobalt Ferrite/Barium Titanate Composites, Farnaz Safi Samghabadi, Long Chang, Mohammad Khodadadi, Karen S. Martirosyan, Dmitri Litvinov Feb 2021

Scalable, Cost-Efficient Synthesis And Properties Optimization Of Magnetoelectric Cobalt Ferrite/Barium Titanate Composites, Farnaz Safi Samghabadi, Long Chang, Mohammad Khodadadi, Karen S. Martirosyan, Dmitri Litvinov

Physics and Astronomy Faculty Publications and Presentations

Cobalt ferrite (CoFe2O4)/barium titanate (BaTiO3) particulate composites exhibiting high magnetoelectric coefficients were synthesized from low-cost commercial precursors using mechanical ball milling followed by high-temperature annealing. CoFe2O4 (20 nm–50 nm) and either cubic or tetragonal BaTiO3 nanoparticle powders were used for the synthesis. It was found that utilizing a 50nm cubic BaTiO3 powder as a precursor results in a composite with a magnetoelectric coupling coefficient value as high as 4.3 mV/Oe cm, which is comparable to those of chemically synthesized core–shell CoFe2O4–BaTiO3 nanoparticles. The microstructure of these composites is dramatically different from the composite synthesized ...