Astrophysics and Astronomy Commons^™

Hd 126516: A Triple System Containing A Short-Period Eclipsing Binary, Francis C. Fekel, Gregory W. Henry, James R. Sowell

Information Systems and Engineering Management Research Publications

From numerous radial velocities as well as Johnson B and V differential photoelectric photometry, we have determined the orbital elements and other properties of the single-lined triple system HD 126516. This system consists of a narrow-lined F5 V star and an unseen M dwarf companion in a 2.1241 day circular orbit. The small, low-mass secondary produces detectable eclipses of the primary, and that pair has been given the variable star name V349 Vir. Variations of the center-of-mass velocity of this short-period system have an orbital period of 702.7 days or 1.92 yr and an eccentricity of 0.36. The third star …

Automated Morgan Keenan Classification Of Observed Stellar Spectra Collected By The Sloan Digital Sky Survey Using A Single Classifier, Michael J. Brice, Răzvan Andonie

All Faculty Scholarship for the College of the Sciences

The classification of stellar spectra is a fundamental task in stellar astrophysics. Stellar spectra from the Sloan Digital Sky Survey are applied to standard classification methods, k-nearest neighbors and random forest, to automatically classify the spectra. Stellar spectra are high dimensional data and the dimensionality is reduced using astronomical knowledge because classifiers work in low dimensional space. These methods are utilized to classify the stellar spectra into a complete Morgan Keenan classification (spectral and luminosity) using a single classifier. The motion of stars (radial velocity) causes machine-learning complications through the feature matrix when classifying stellar spectra. Due to the nature …

Synchrotron Self-Compton Emission From External Shocks As The Origin Of The Sub-Tev Emission In Grb 180720b And Grb 190114c, Xiang-Yu Wang, Ruo-Yu Liu, Hai-Ming Zhang, Shao-Qiang Xi, Bing Zhang

Physics & Astronomy Faculty Research

Recently, very high-energy photons above 100 GeV were reported to be detected from GRB 190114C and GRB 180720B at, respectively, 100–1000 s and 10 hr after the burst. We model the available broadband data of both GRBs with the synchrotron plus synchrotron self-Compton (SSC) emission of the afterglow shocks. We find that the sub-TeV emission of GRB 180720B can be interpreted as the SSC emission from afterglow shocks expanding in a constant-density circumburst medium. The SSC emission of GRB 190114C dominates over the synchrotron component from GeV energies at ~100 s, which can explain the possible hard spectrum of the …

"Double-Tracking" Characteristics Of The Spectral Evolution Of Grb 131231a: Synchrotron Origin?, Liang Li, Jin-Jun Geng, Yan-Zhi Meng, Xue-Feng Wu, Yong-Feng Huang, Yu Wang, Rahim Moradi, Lucas Uhm, Bing Zhang

Physics & Astronomy Faculty Research

The characteristics of the spectral evolution of the prompt emission of gamma-ray bursts (GRBs), which are closely related to the radiation mechanism (synchrotron or photosphere), are still an unsolved subject. Here, by performing the detailed time-resolved spectral fitting of GRB 131231A, which has a very bright and well-defined single pulse, some interesting spectral evolution features have been found. (i) Both the low-energy spectral index α and the peak energy E p exhibit the "flux-tracking" pattern ("double-tracking" characteristics). (ii) The parameter relations, i.e., F (the energy flux)-α, F–E p, and E p–α, along with the analogous Yonetoku E p–L γ,iso relation …

An Ideal Testbed For Planet-Disk Interaction: Two Giant Protoplanets In Resonance Shaping The Pds 70 Protoplanetary Disk, Jaehan Bae, Zhaohuan Zhu, Clément Baruteau, Myriam Benisty, Cornelis P. Dullemong, Stefano Facchini, Andrea Isella, Miriam Keppler, Laura M. Pérez, Richard Teague

Physics & Astronomy Faculty Research

While numerical simulations have been playing a key role in the studies of planet–disk interaction, testing numerical results against observations has been limited so far. With the two directly imaged protoplanets embedded in its circumstellar disk, PDS 70 offers an ideal testbed for planet–disk interaction studies. Using two-dimensional hydrodynamic simulations we show that the observed features can be well explained with the two planets in formation, providing strong evidence that previously proposed theories of planet–disk interaction are in action, including resonant migration, particle trapping, size segregation, and filtration. Our simulations suggest that the two planets are likely in 2:1 mean …

Radial Velocity Discovery Of An Eccentric Jovian World Orbiting At 18 Au, Sarah Blunt, Michael Endl, Lauren M. Weiss, William D. Cochran, Andrew W. Howard, Phillip J. Macqueen, Benjamin J. Fulton, Gregory W. Henry, Marshall C. Johnson, Molly R. Kosiarek, Kellen D. Lawson, Bruce Macintosh, Sean M. Mills, Eric L. Nielsen, Erik A. Petigura, Glenn Schneider, Andrew Vanderburg, John P. Wisniewski, Robert A. Wittenmyer, Erik Brugamyer, Caroline Caldwell, Anita L. Cochran, Artie P. Hatzes, Lea A. Hirsch, Howard Isaacson, Paul Robertson, Arpita Roy, Zili Shen

Information Systems and Engineering Management Research Publications

Based on two decades of radial velocity (RV) observations using Keck/High Resolution Echelle Spectrometer (HIRES) and McDonald/Tull, and more recent observations using the Automated Planet Finder, we found that the nearby star HR 5183 (HD 120066) hosts a 3 minimum mass planet with an orbital period of yr. The orbit is highly eccentric (e ≃ 0.84), shuttling the planet from within the orbit of Jupiter to beyond the orbit of Neptune. Our careful survey design enabled high cadence observations before, during, and after the planet's periastron passage, yielding precise orbital parameter constraints. We searched for stellar or planetary companions …

Diagnosing 0.1–10 Au Scale Morphology Of The Fu Ori Disk Using Alma And Vlti/Gravity, Hauyu Baobab Liu, Antoine Merand, Joel D. Green, Sebastian Perez, Antonio S. Hales, Yao-Lun Yang, Michael M. Dunham, Yasuhiro Hasegawa, Thomas Henning, Roberto Galvin-Madrid, Agnes Kospal, Michihiro Takami, Eduardo I. Vorobyov, Zhaohuan Zhu

Physics & Astronomy Faculty Research

We report new Atacama Large Millimeter/submillimeter Array Band 3 (86–100 GHz; ~80 mas angular resolution) and Band 4 (146–160 GHz; ~50 mas angular resolution) observations of the dust continuum emission toward the archetypal and ongoing accretion burst young stellar object FU Ori, which simultaneously covered its companion, FU Ori S. In addition, we present near-infrared (2–2.45 μm) observations of FU Ori taken with the General Relativity Analysis via VLT InTerferometrY (GRAVITY; ~1 mas angular resolution) instrument on the Very Large Telescope Interferometer (VLTI). We find that the emission in both FU Ori and FU Ori S at (sub)millimeter and near-infrared …

First Measurement Of Neutrino Oscillation Parameters Using Neutrinos And Antineutrinos By Nova, M. A. Acero, P. Adamson, L. Aliaga, T. Alion, V. Allakhverdian, S. Altakarli, N. Anfimov, A. Antoshkin, A. Aurisano, A. Back, C. Backhouse, M. Baird, N. Balashov, P. Baldi, B. A. Bambah, S. Bashar, K. Bays, S. Bending, R. Bernstein, V. Bhatnagar, Roberto Petti, Et. Al.

Faculty Publications

The NOvA experiment has seen a 4.4σ signal of ⊽ _e appearance in a 2 GeV⊽_μ beam at a distance of 810 km. Using 12.33×10²⁰ protons on target delivered to the Fermilab NuMI neutrino beamline, the experiment recorded 27 ⊽_μ→⊽_e candidates with a background of 10.3 and 102⊽_μ→⊽_μ candidates. This new antineutrino data are combined with neutrino data to measure the parameters |Δm ² ₃₂ | = 2.48 ^+0.11 _-0.06 x 10 ^-3 eV² / c⁴ and sin² θ₂₃ in the ranges …

The Frb 121102 Host Is Atypical Among Nearby Fast Radio Bursts, Ye Li, Bing Zhang, Kentaro Nagamine, Jingjing Shi

Physics & Astronomy Faculty Research

We search for host galaxy candidates of nearby fast radio bursts (FRBs), FRB 180729.J1316+55, FRB 171020, FRB 171213, FRB 180810.J1159+83, and FRB 180814.J0422+73 (the second repeating FRB). We compare the absolute magnitudes and the expected host dispersion measure DMhost of these candidates with that of the first repeating FRB, FRB 121102, as well as those of long gamma-ray bursts (LGRBs) and superluminous supernovae (SLSNe), the proposed progenitor systems of FRB 121102. We find that while the FRB 121102 host is consistent with those of LGRBs and SLSNe, the nearby FRB host candidates, at least for FRB 180729.J1316+55, FRB 171020, and …

The Best Studied Crab In Astronomy: Searching For Variability In Vhe Emission From The Crab Nebula, Christina Bourantas, Kate Cowger, Avery Archer

Annual Student Research Poster Session

The Crab Nebula is the remnant of a powerful stellar explosion first observed in 1054 AD and has been extremely well studied for decades. previous very high energy (VHE); GeV) studies have observed no variability in the nebula flux making the Crab a standard reference tool for gamma-ray telescopes. As part of the VERITAS (Very Energetic Radiation Imaging Telescope Array System) collaboration, we continue monitoring the nebula’s flux to understand the VERITAS telescopes and physical processes occurring within the nebula. We are analyzing over 80 hours of data from 2017 and 2018 from VERITAS Collaboration, developing and adding to a …

Search For Eccentric Binary Black Hole Mergers With Advanced Ligo And Advanced Virgo During Their First And Second Observing Runs, B. P. Abbott, R. Abbott, T. D. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Wenhui Wang

Physics & Astronomy Faculty Publications

When formed through dynamical interactions, stellar-mass binary black holes (BBHs) may retain eccentric orbits (e > 0.1 at 10 Hz) detectable by ground-based gravitational-wave detectors. Eccentricity can therefore be used to differentiate dynamically formed binaries from isolated BBH mergers. Current template-based gravitational-wave searches do not use waveform models associated with eccentric orbits, rendering the search less efficient for eccentric binary systems. Here we present the results of a search for BBH mergers that inspiral in eccentric orbits using data from the first and second observing runs (O1 and O2) of Advanced LIGO and Advanced Virgo. We carried out the search …

Asymmetries In Adaptive Optics Point Spread Functions, Alexander Madurowicz, Bruce Macintosh, Jeffrey Chilcote, Marshall Perrin, Lisa Poyneer, Laurent Pueyo, Jean Baptiste Ruffio, Vanessa P. Bailey, Travis Barman, Joanna Bulger, Tara Cotten, Robert J. De Rosa, Rene Doyon, Gaspard Duchêne, Thomas M. Esposito, Michael P. Fitzgerald, Katherine B. Follette, Benjamin L. Gerard, Stephen J. Goodsell, James R. Graham, Alexandra Z. Greenbaum, Pascale Hibon, Li Wei Hung, Patrick Ingraham, Paul Kalas, Quinn Konopacky, Jérôme Maire, Franck Marchis, Mark S. Marley, Christian Marois, Stanimir Metchev, Maxwell A. Millar-Blanchaer, Kimberly Ward-Duong

Astronomy: Faculty Publications

An explanation for the origin of asymmetry along the preferential axis of the point spread function (PSF) of an AO system is developed. When phase errors from high-altitude turbulence scintillate due to Fresnel propagation, wavefront amplitude errors may be spatially offset from residual phase errors. These correlated errors appear as asymmetry in the image plane under the Fraunhofer condition. In an analytic model with an open-loop AO system, the strength of the asymmetry is calculated for a single mode of phase aberration, which generalizes to two dimensions under a Fourier decomposition of the complex illumination. Other parameters included are the …

Effects Of Solvent Used For Fabrication On Drug Loading And Release Kinetics Of Electrosprayed Temozolomide-Loaded Plga Microparticles For The Treatment Of Glioblastoma, Daniel A. Rodriguez De Anda, Nareg Ohannesian, Karen S. Martirosyan, Sue Anne Chew

Physics & Astronomy Faculty Publications

Glioblastoma multiforme (GBM) is the most common and invasive form of malignant brain tumors and despite advances in surgery, radiotherapy, and chemotherapy, the survival of patients with GBM still remains poor. Temozolomide (TMZ) is the chemotherapy drug that is most commonly given orally after surgical resection of these tumors. In this study, the effects of solvents (i.e., dichloromethane and acetonitrile) used for the fabrication of electrosprayed TMZ-loaded poly(lactic-co-glycolic acid) (PLGA) on drug loading, loading efficiency, drug release kinetics, surface morphology, and particle size were investigated. The results from this study demonstrated that by using a larger volume of a solvent …

Descriptive Astronomy I: The Solar System (Csu), Rosa Williams, Kimberly Shaw

Physics and Astronomy Grants Collections

This Grants Collection for Descriptive Astronomy I was created under a Round Thirteen ALG Textbook Transformation Grant.

Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process.

Each collection contains the following materials:

• Linked Syllabus
• Initial Proposal
• Final Report

Byu’S Connection To The Development Of Optical Memory: Innovation Takes Multiple Disciplines, Dan Broadbent

Faculty Publications

Optical memory technology is a way to store information using lasers and is used in videodiscs, CDs, DVDs, Blu-rays, M-Discs, etc. This technology was developed in Torrance, California in the 1970s by a team lead by Kent D. Broadbent, who graduated from BYU with a degree in Physics in 1949.

This display showcases the technology and those involved in its development.

Estimating The Angular Power Spectrum Of The Gravitational-Wave Background In The Presence Of Shot Noise, Alexander C. Jenkins, Joseph D. Romano, Mairi Sakellariadou

Physics & Astronomy Faculty Publications

There has been much recent interest in studying anisotropies in the astrophysical gravitational-wave (GW) background, as these could provide us with interesting new information about galaxy clustering and large-scale structure. However, this information is obscured by shot noise, caused by the finite number of GW sources that contribute to the background at any given time. We develop a new method for estimating the angular spectrum of anisotropies, based on the principle of combining statistically-independent data segments. We show that this gives an unbiased estimate of the true, astrophysical spectrum, removing the offset due to shot noise power, and that …

Light Pollution, Radio Interference, And Space Debris: Threats And Opportunities In The 2020s, Jeffrey Hall, Lori Allen, Douglas Arion, John Barentine, Daniel Caton, Harvey Liszt, James D. Lowenthal, Dan Mckenna, Ashley Pipkin, Patrick Seitzer, Constance Walker

Astronomy: Faculty Publications

In this white paper, we will outline threats to astronomy in the areas of light pollution, radio interference, and space debris, and we will specify key principles and policy points that the AAS and other advocates can use in mitigating these threats.

Relativistic Astronomy. Iii. Test Of Special Relativity Via Doppler Effect, Yuan-Pei Yang, Jin-Peng Zhu, Bing Zhang

Physics & Astronomy Faculty Research

The "Breakthrough Starshot" program is planning to send transrelativistic probes to travel to nearby stellar systems within decades. Because the probe velocity is designed to be a good fraction of the light speed, Zhang & Li recently proposed that these transrelativistic probes can be used to study astronomical objects and to test special relativity. In this work, we propose some methods to test special relativity and constrain photon mass using the Doppler effect with the images and spectral features of astronomical objects as observed in the transrelativistic probes. We introduce more general theories to set up the framework of testing …

Search For Intermediate Mass Black Hole Binaries In The First And Second Observing Runs Of The Advanced Ligo And Virgo Network, Tiffany Summerscales, Ligo Scientific Collaboration And The Virgo Collaboration

Faculty Publications

Gravitational-wave astronomy has been firmly established with the detection of gravitational waves from the merger of ten stellar-mass binary black holes and a neutron star binary. This paper reports on the all-sky search for gravitational waves from intermediate mass black hole binaries in the first and second observing runs of the Advanced LIGO and Virgo network. The search uses three independent algorithms: two based on matched filtering of the data with waveform templates of gravitational-wave signals from compact binaries, and a third, model-independent algorithm that employs no signal model for the incoming signal. No intermediate mass black hole binary event …

Search For Eccentric Binary Black Hole Mergers With Advanced Ligo And Advanced Virgo During Their First And Second Observing Runs, Tiffany Summerscales, Ligo Scientific Collaboration And The Virgo Collaboration

Faculty Publications

When formed through dynamical interactions, stellar-mass binary black holes (BBHs) may retain eccentric orbits (e > 0.1 at 10 Hz) detectable by ground-based gravitational-wave detectors. Eccentricity can therefore be used to differentiate dynamically formed binaries from isolated BBH mergers. Current template-based gravitational-wave searches do not use waveform models associated with eccentric orbits, rendering the search less efficient for eccentric binary systems. Here we present the results of a search for BBH mergers that inspiral in eccentric orbits using data from the first and second observing runs (O1 and O2) of Advanced LIGO and Advanced Virgo. We carried out the search …

A Global View Of The Inner Accretion And Ejection Flow Around Super Massive Black Holes, Margherita Giustini, Daniel Proga

Physics & Astronomy Faculty Research

Context. Understanding the physics and geometry of accretion and ejection around super massive black holes (SMBHs) is important to understand the evolution of active galactic nuclei (AGN) and therefore of the large scale structures of the Universe. Aims. We aim at providing a simple, coherent, and global view of the sub-parsec accretion and ejection flow in AGN with varying Eddington ratio, ṁ, and black hole mass, MBH. Methods. We made use of theoretical insights, results of numerical simulations, as well as UV and X-ray observations to review the inner regions of AGN by including different accretion and ejection modes, with …

Polar Alignment Of A Protoplanetary Disc Around An Eccentric Binary – Iii. Effect Of Disc Mass, Rebecca G. Martin, Stephen H. Lubow

Physics & Astronomy Faculty Research

An initially sufficiently misaligned low-mass protoplanetary disc around an eccentric binary undergoes damped nodal oscillations of tilt angle and longitude of ascending node. Dissipation causes evolution towards a stationary state of polar alignment in which the disc lies perpendicular to the binary orbital plane with angular momentum aligned to the eccentricity vector of the binary. We use hydrodynamic simulations and analytical methods to investigate how the mass of the disc affects this process. The simulations suggest that a disc with non-zero mass settles into a stationary state in the frame of the binary, the generalized polar state, at somewhat lower …

The Radial Distribution Of Dust Particles In The Hl Tau Disk From Alma And Vla Observations, Carlos Carrasco-Gonzalez, Anibal Sierra, Mario Flock, Zhaohuan Zhu, Thomas Henning, Claire Chandler, Roberto Galvan-Madrid, Enrique Macias, Guillem Anglada, Hendrik Linz, Mayra Osorio, Luis F. Rodriguez, Leonardo Testi, Jose M. Torrelles, Laura Perez, Yao Liu

Physics & Astronomy Faculty Research

Understanding planet formation requires one to discern how dust grows in protoplanetary disks. An important parameter to measure in disks is the maximum dust grain size present. This is usually estimated through measurements of the dust opacity at different millimeter wavelengths assuming optically thin emission and dust opacity dominated by absorption. However, Atacama Large Millimeter/submillimeter Array (ALMA) observations have shown that these assumptions might not be correct in the case of protoplanetary disks, leading to overestimation of particle sizes and to underestimation of the disk's mass. Here, we present an analysis of high-quality ALMA and Very Large Array images of …

The Degree Of Alignment Between Circumbinary Disks And Their Binary Hosts, I. Czekala, E. Chiang, S. M. Andrews, Eric L.N. Jensen, G. Torres, D. J. Wilner, K. G. Stassun, B. Macintosh

Physics & Astronomy Faculty Works

All four circumbinary (CB) protoplanetary disks orbiting short-period (P < 20 days) double-lined spectroscopic binaries (SB2s)—a group that includes UZ Tau E, for which we present new Atacama Large Millimeter/Submillimeter Array data—exhibit sky-plane inclinations i _disk that match, to within a few degrees, the sky-plane inclinations i_★ of their stellar hosts. Although for these systems the true mutual inclinations θ between disk and binary cannot be directly measured because relative nodal angles are unknown, the near coincidence of i _disk and i_★ suggests that θ is small for these most compact of systems. We confirm this hypothesis using a hierarchical Bayesian analysis, showing that 68% of CB disks around short-period SB2s have θ < 30. Near coplanarity of CB disks implies near coplanarity of CB planets discovered by Kepler, which in turn implies that the occurrence …

Method For Approximating Field-Line Curves Using Ionospheric Observations Of Energy-Variable Electron Beams Launched From Satellites, Jake M. Willard, Jay R. Johnson, Jesse M. Snelling, Andrew T. Powis, Igor D, Kaganovich, Ennio R. Sanchez

Faculty Publications

Using electron beam accelerators attached to satellites in Earth orbit, it may be possible to measure arc length and curvature of field-lines in the inner magnetosphere if the accelerator is designed with the capability to vary the beam energy. In combination with additional information, these measurements would be very useful in modeling the magnetic field of the inner magnetosphere. For this purpose, a three step data assimilation modeling approach is discussed. The first step in the procedure would be to use prior information to obtain an initial forecast of the inner magnetosphere. Then, a family of curves would be defined …

Gamma-Ray Bursts Induced By Turbulent Reconnection, A. Lazarian, Bing Zhang, Siyao Xu

Physics & Astronomy Faculty Research

We revisit the Internal-Collision-induced MAgnetic Reconnection and Turbulence model of gamma-ray bursts (GRBs) in view of the advances made in understanding of both relativistic magnetic turbulence and relativistic turbulent magnetic reconnection. We identify the kink instability as the most natural way of changing the magnetic configuration to release the magnetic free energy through magnetic reconnection, as well as driving turbulence that enables fast turbulent reconnection. We show that this double role of the kink instability is important for explaining the prompt emission of GRBs. Our study confirms the critical role that turbulence plays in boosting reconnection efficiency in GRBs and …

Polarized X-Ray Sources For Calibration Of The Ixpe X-Ray Telescopes, Samantha Johnson, Wayne Baumgartner

Von Braun Symposium Student Posters

No abstract provided.

Wavelength Calibration Of The Full-Sun Ultraviolet Rocket Spectrometer (Furst), Nicolas Donders, Amy Winebarger, Charles Kankelborg, Genevieve Vigil, Ken Kobayashi, Laurel Rachmeler, Gary Zank

Von Braun Symposium Student Posters

No abstract provided.

The Design And Testing Of A Gamma-Neutron Spectrometer For The Helen Project, Everett Cavanaugh, Christopher Helmerich, Sean Widmier, Sarah Dangelo

Von Braun Symposium Student Posters

No abstract provided.

A Near Horizon Extreme Binary Black Hole Geometry, Jacob Ciafre, Maria J. Rodriguez

All Physics Faculty Presentations

A new solution of four-dimensional vacuum General Relativity is presented. It describes the near horizon region of the extreme (maximally spinning) binary black hole system with two identical extreme Kerr black holes held in equilibrium by a massless strut. This is the first example of a non-supersymmetric, near horizon extreme binary black hole geometry of two uncharged black holes. The black holes are co-rotating, their relative distance is fixed, and the solution is uniquely specified by the mass. Asymptotically, the geometry corresponds to the near horizon extreme Kerr (NHEK) black hole. The binary extreme system has finite entropy.