Charged Compact Binary Coalescence Signal And Electromagnetic Counterpart Of Plunging Black Hole–Neutron Star Mergers, 2019 University of Nevada, Las Vegas
Charged Compact Binary Coalescence Signal And Electromagnetic Counterpart Of Plunging Black Hole–Neutron Star Mergers, Bing Zhang
Physics & Astronomy Faculty Research
If at least one of the members of a compact binary coalescence is charged, the inspiral of the two members would generate a Poynting flux with an increasing power, giving rise to a brief electromagnetic counterpart temporally associated with the chirp signal of the merger (with possibly a small temporal offset), which we term as the charged compact binary coalescence (cCBC) signal. We develop a general theory of cCBC for any mass and amount of charge for each member. Neutron stars (NSs), as spinning magnets, are guaranteed to be charged, so the cCBC signal should accompany all NS mergers. The …
Coordinated Uv And X-Ray Spectroscopic Observations Of The O-Type Giant Ξ Per: The Connection Between X-Rays And Large-Scale Wind Structure, 2019 Space Science Institute
Coordinated Uv And X-Ray Spectroscopic Observations Of The O-Type Giant Ξ Per: The Connection Between X-Rays And Large-Scale Wind Structure, Derek Massa, Lidi Oskinova, Raman Prinja, Richard Ignace
ETSU Faculty Works
We present new, contemporaneous Hubble Space Telescope STIS and XMM-Newton observations of the O7 III(n)((f)) star ξ Per. We supplement the new data with archival IUE spectra, to analyze the variability of the wind lines and X-ray flux of ξ Per. The variable wind of this star is known to have a 2.086-day periodicity. We use a simple, heuristic spot model that fits the low-velocity (near-surface) IUE wind line variability very well, to demonstrate that the low-velocity absorption in the new STIS spectra of N iv λ1718 and Si iv λ1402 vary with the same 2.086-day period. It …
Book Review: Exoplanets : Hidden Worlds And The Quest For Extraterrestrial Life, 2019 Embry-Riddle Aeronautical University
Book Review: Exoplanets : Hidden Worlds And The Quest For Extraterrestrial Life, T. D. Oswalt
Publications
This document is Dr. Oswalt’s review of Exoplanets : Hidden Worlds and the Quest for Extraterrestrial Life. Harvard, 2018. 254p bibl index, 9780674976900 $24.95, 9780674988897
Long-Term Spot Monitoring Of The Young Solar Analogue V889 Herculis, 2019 University of Helsinki
Long-Term Spot Monitoring Of The Young Solar Analogue V889 Herculis, Teemu Willamo, Thomas Hackman, Jyri J. Lehtinen, Maarit J. Käpylä, Ilya Ilyin, Gregory W. Henry, Lauri Jetsu, Oleg Kochukhov, Nikolai Piskunov
Information Systems and Engineering Management Research Publications
Context. Starspots are important manifestations of stellar magnetic activity. By studying their behaviour in young solar analogues, we can unravel the properties of their magnetic cycles. This gives crucial information of the underlying dynamo process. Comparisons with the solar cycle enable us to infer knowledge about how the solar dynamo has evolved during the Sun’s lifetime.
Aims. Here we study the correlation between photometric brightness variations, spottedness, and mean temperature in V889 Her, a young solar analogue. Our data covers 18 years of spectroscopic and 25 years of photometric observations.
Methods. We use Doppler imaging to derive …
Infrared Spectroscopy Of Symbiotic Stars. Xii. The Neutron Star Syxb System 4u 1700+24 = V934 Herculis, 2019 National Optical Astronomy Observatory
Infrared Spectroscopy Of Symbiotic Stars. Xii. The Neutron Star Syxb System 4u 1700+24 = V934 Herculis, Kenneth H. Hinkle, Francis C. Fekel, Richard Joyce, Joanna Mikołajewska, Cezary Gałan, Thomas Lebzelter
Information Systems and Engineering Management Research Publications
The X-ray symbiotic (SyXB) V934 Her = 4U 1700+24 is an M giant–neutron star (NS) binary system. Employing optical and infrared radial velocities spanning 29 yr combined with the extensive velocities in the literature, we compute the spectroscopic orbit of the M giant in that system. We determine an orbital period of 4391 days, or 12.0 yr, the longest for any SyXB and far longer than the 404 day orbit commonly cited for this system in the literature. In addition to the 12.0 yr orbital period, we find a shorter period of 420 days, similar to the one previously found. …
Astronomy For Educators, 2019 University of Arkansas, Fayetteville
Astronomy For Educators, Daniel E. Barth
Open Educational Resources
Astronomy for Educators provides new and accomplished K-12 instructors with concepts and projects for low-cost, high-impact STEM classroom instruction that is built around the National Academies National Research Council's K-12 Framework for Science Education.
Gemini, 2019 Parkland College
Gemini, Michael Dalton
Natural Sciences Student Research Presentations
This poster for the Natural Sciences Poster Session at Parkland College features the constellation Gemini, including a calculation of the change in rise time to determine the length of a year, determining the life span of the major stars in the constellation, identifying Messier objects within the region as well as the mythology behind the name of the constellation.
The Polarization Mode Of The Auroral Radio Emission From The Early-Type Star Hd 142301, 2019 University Potsdam
The Polarization Mode Of The Auroral Radio Emission From The Early-Type Star Hd 142301, P. Leto, C. Trigilio, Lidi M. Oskinova, Richard Ignace, C. S. Buemi, G. Umana, F. Cavallaro, A. Ingallinera, F. Bufano, N. M. Phillips, C. Agliozzo, L. Cerrigone, H. Todt, S. Riggi, F. Leone
ETSU Faculty Works
We report the detection of the auroral radio emission from the early-type magnetic star HD 142301. New VLA observations of HD 142301 detected highly polarized amplified emission occurring at fixed stellar orientations. The coherent emission mechanism responsible for the stellar auroral radio emission amplifies the radiation within a narrow beam, making the star where this phenomenon occurs similar to a radio lighthouse. The elementary emission process responsible for the auroral radiation mainly amplifies one of the two magneto-ionic modes of the electromagnetic wave. This explains why the auroral pulses are highly circularly polarized. The auroral radio emission of HD 142301 …
Lower Atmosphere And Pressure Evolution On Pluto From Ground-Based Stellar Occultations, 1988-2016, 2019 L'Observatoire de Paris
Lower Atmosphere And Pressure Evolution On Pluto From Ground-Based Stellar Occultations, 1988-2016, E. Meza, B. Sicardy, M. Assafin, J. L. Ortiz
University Faculty Publications and Creative Works
Context. The tenuous nitrogen (N2) atmosphere on Pluto undergoes strong seasonal effects due to high obliquity and orbital eccentricity, and has recently (July 2015) been observed by the New Horizons spacecraft. Aims. The main goals of this study are (i) to construct a well calibrated record of the seasonal evolution of surface pressure on Pluto and (ii) to constrain the structure of the lower atmosphere using a central flash observed in 2015. Methods. Eleven stellar occultations by Pluto observed between 2002 and 2016 are used to retrieve atmospheric profiles (density, pressure, temperature) between altitude levels of ∼5 and ∼380 km …
Determination Of Multi-Messenger Signals From Matter Outflows Of Merger Systems, 2019 UNH Department of Physics
Determination Of Multi-Messenger Signals From Matter Outflows Of Merger Systems, Ronny Nguyen
Honors Theses and Capstones
In 2017, LIGO detected gravitational waves from GW170817. This presented for the first time, gravitational waves originating from a neutron star - neutron star merger. Studies of neutron star mergers are significant because the multi-messenger signals in the form of gravitational waves and electromagnetic waves can inform us on the nuclear physics of neutron stars and the creation of heavy elements in the universe. Matter is ejected in the merging process and forms the outflow which provides a neutron-rich environment for rapid neutron capture (r-process) to occur leading to the nucleosynthesis of heavy elements. What we detect on Earth are …
The Discovery Of A Lifetime: Gravitational-Waves, 2019 Nebraska College Preparatory Academy
The Discovery Of A Lifetime: Gravitational-Waves, Maria I Dominguez Barraza
Nebraska College Preparatory Academy: Senior Capstone Projects
This presentation offers an insight to one of the biggest discoveries made in science. The discovery of gravitational-waves had been a long journey to achieve for physicists and scientist. Now gravitational-waves are helping scientists study the universe in a more efficient way never seen before. The discovery of gravitational-waves is a sign that a new era of astronomy and physics is about to open doors for many scientists and astrophysicists.
● Gravitational-waves are energycarrying waves propagating through a gravitational field, produced when a massive body is accelerated or otherwise disturbed. ● Gravitational-waves prove the existence of Black Holes. ● Laser …
Unh Observatory Exoplanet Transit Depth Limit, 2019 University of New Hampshire, Durham
Unh Observatory Exoplanet Transit Depth Limit, Nicholas R. Larose
Honors Theses and Capstones
Using the University of New Hampshire Observatory, we performed multiple exoplanet transits observations on a variety of systems. Of these transits, those performed with ideal weather conditions were chosen to do extensive analysis on. The transit chosen for initial analysis was HAT-P-56b. We then used Z-Score values, along with the average mean and standard deviation collected from multiple transits to determine a minimum possible transit depth of 7.4 +/- 0.6 mmag. This value will allow UNH to access exoplanet transit observation and / or confirm potential exoplanets, thus making the UNH Observatory more research capable. A follow up threshold transit …
Charged Particle Filter For Entrance Of Imap-Lo, 2019 University of New Hampshire
Charged Particle Filter For Entrance Of Imap-Lo, Daniel Abel
Honors Theses and Capstones
No abstract provided.
High-Speed Distributed Data Process Of Photometric Astronomical Data, 2019 Technological University Dublin
High-Speed Distributed Data Process Of Photometric Astronomical Data, Paul Doyle
Other
Since the 1970s the CCD has been the principle method of measuring flux to calculate the apparent magnitude of celestial objects within astronomical photometry. Each CCD image must be digitally cleaned and calibrated prior to its use. As data archives increase in size to Petabytes, the data processing challenge requires image processing techniques to continue to exceed the rate of data capture.
This paper describes NIMBUS, a rapidly scalable, failure resilient distributed network architecture capable of processing CCD image data at a rate of hundreds of Terabytes per day. NIMBUS is implemented using a decentralized web queue to control the …
The Pre-Roche Lobe Overflow Evolution Of Massive Close Binary Stars: A Study Of Rotation, Wind Enhanced Mass-Loss, And The Bi-Stability Jump, 2019 Minnesota State University, Mankato
The Pre-Roche Lobe Overflow Evolution Of Massive Close Binary Stars: A Study Of Rotation, Wind Enhanced Mass-Loss, And The Bi-Stability Jump, Thomas C. Gehrman Jr.
All Graduate Theses, Dissertations, and Other Capstone Projects
Massive stars have the ability to enrich their environment with heavy elements and influence star formation in galaxies. Some massive stars exist in binary systems with short orbital periods. These are called massive close binaries. It is important to understand the evolution of massive close binary systems to gain insight about galaxy evolution. Massive stars above 20 solar masses experience a bi-stability jump where there is a sudden increase in mass-loss rate in their winds. There is ongoing research in this field, but the study of the bi-stability jump and its effects on massive close binary star properties has not …
The Impact Of Hii Regions On The Interstellar Medium Of Our Galaxy, 2019 West Virginia University
The Impact Of Hii Regions On The Interstellar Medium Of Our Galaxy, Matteo Luisi
Graduate Theses, Dissertations, and Problem Reports
The interstellar medium (ISM) of our Galaxy contains low-density diffuse ionized gas known as the warm ionized medium (WIM). O- and B-type stars emit large amounts of ionizing radiation and it is believed that a fraction of this radiation escapes from their fully ionized HII regions and into the ISM where it is responsible for maintaining the ionization of the WIM. Here we aim to better understand how the radiation produced by OB stars is able to leak from the HII regions, how the radiation field changes during this process, and how the radiation affects the ambient ISM. Using Green …
A Few Calculations Of Receding Moon From Spherical Kinetic Dynamics, Receding Planetary Orbits, And The Quantization Of Celestial Motions, 2019 University of New Mexico
A Few Calculations Of Receding Moon From Spherical Kinetic Dynamics, Receding Planetary Orbits, And The Quantization Of Celestial Motions, Florentin Smarandache, Victor Christianto, Robert Neil Boyd
Branch Mathematics and Statistics Faculty and Staff Publications
The present article discusses some interesting phenomena including the Lense-Thirring type anomalous precession, using a known spherical kinetic dynamics approach. Other implications include a plausible revised version of the celestial quantization equation described by Nottale and Rubcic & Rubcic. If the proposition described herein corresponds to the facts, then this kinetic dynamics interpretation of ‘frame-dragging’ effect could be viewed as a step to unification between GTR-type phenomena and QM. Further observation to verify or refute this conjecture is recommended, plausibly using LAGEOS type satellites.
On The New Concept Creatio Ex-Rotatione, 2019 University of New Mexico
On The New Concept Creatio Ex-Rotatione, Florentin Smarandache, Victor Christianto
Branch Mathematics and Statistics Faculty and Staff Publications
It is known that the Big Bang theory was based on the concept of creation ex nihilo, after ancient Greek philosophers. In this paper, we discuss the concept of creatio ex nihilo, as well as two other approaches - Intelligent Design and Emergence Theory. We argue that beside the above three approaches, a new concept called creatio ex-rotatione offers a resolution to the long standing disputes between beginning and eternity of the Universe. We agree with Vaas: [h]ow a conceptual and perhaps physical solution of the temporal aspect of Immanuel Kant’s “first antinomy of pure reason” is possible, i.e., how …
Classification Of Stars From Redshifted Stellar Spectra Utilizing Machine Learning, 2019 Central Washington University
Classification Of Stars From Redshifted Stellar Spectra Utilizing Machine Learning, Michael J. Brice
All Master's Theses
The classification of stellar spectra is a fundamental task in stellar astrophysics. There have been many explorations into the automated classification of stellar spectra but few that involve the Sloan Digital Sky Survey (SDSS). Stellar spectra from the SDSS are applied to standard classification methods such as K-Nearest Neighbors, Random Forest, and Support Vector Machine to automatically classify the spectra. Stellar spectra are high dimensional data and the dimensionality is reduced using standard Feature Selection methods such as Chi-Squared and Fisher score and with domain-specific astronomical knowledge because classifiers work in low dimensional space. These methods are utilized to classify …
Electron Model Based On Helmholtz’S Electron Vortex Theory & Kolmogorov’S Theory Of Turbulence, 2019 University of New Mexico
Electron Model Based On Helmholtz’S Electron Vortex Theory & Kolmogorov’S Theory Of Turbulence, Florentin Smarandache, Victor Christianto, Robert Neil Boyd
Branch Mathematics and Statistics Faculty and Staff Publications
In this paper, we explore a new electron model based on Helmholtz’s electron vortex and Kolmogorov theory of turbulence. We also discuss a new model of origination of charge and matter.