Search For Continuous Gravitational Waves From Neutron Stars In Globular Cluster Ngc 6544,
2017
The University of Texas Rio Grande Valley
Search For Continuous Gravitational Waves From Neutron Stars In Globular Cluster Ngc 6544, B. P. Abbott, R. Abbott, T. D. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov
Physics & Astronomy Faculty Publications
We describe a directed search for continuous gravitational waves in data from the sixth initial LIGO science run. The target was the nearby globular cluster NGC 6544 at a distance of ≈2.7 kpc. The search covered a broad band of frequencies along with first and second frequency derivatives for a fixed sky position. The search coherently integrated data from the two LIGO interferometers over a time span of 9.2 days using the matched-filtering F-statistic. We found no gravitational-wave signals and set 95% confidence upper limits as stringent as 6.0×10-25 on intrinsic strain and 8.5×10-6 on fiducial ellipticity. These values beat …
Fermi-Lat Daily Monitoring Observations Of The Microquasar Cygnus X-1,
2017
Georgia College and State University
Fermi-Lat Daily Monitoring Observations Of The Microquasar Cygnus X-1, Austin P. Waldron, Stephen R. Hood, Arash Bodaghee
Georgia College Student Research Events
Detection of gamma-ray emission from microquasars is important for understanding particle acceleration in the jet, and for constraining leptonic/hadronic emission models. We present a continuation of a 1-d likelihood analysis on gamma-ray observations by Fermi-LAT (0.1-10 GeV) of the accreting black hole candidate Cygnus X-1. Combining this gamma-ray data with available X-ray monitoring data from Swift and MAXI allowed us to reveal over a dozen days (in 2008-2016) during which Cyg X-1 displayed low-significance (3-4 sigma) excesses, many of which were contemporaneous with apparent transitions in the X-rays.
Prospecting For Iron In The Galactic Supernova Remnant W49b,
2017
Morehead State University
Prospecting For Iron In The Galactic Supernova Remnant W49b, Eddi Akers, Taylor Ray, Thomas G. Pannuti
Celebration of Student Scholarship Poster Sessions Archive
No abstract provided.
Psr B1509-58: When The Galaxy Has A Question,
2017
Morehead State University
Psr B1509-58: When The Galaxy Has A Question, Brandy Anderson, Austin Howard, Maggie Quesinberry, Thomas G. Pannuti, Jeannie Justice
Celebration of Student Scholarship Poster Sessions Archive
No abstract provided.
Rice, Laban Lacy, 1870-1973 (Mss 605),
2017
Western Kentucky University
Rice, Laban Lacy, 1870-1973 (Mss 605), Manuscripts & Folklife Archives
Manuscript Collection Finding Aids
Finding aid only for Manuscripts Collection 605. Correspondence, writings, photographs, clippings, and papers of Laban Lacy Rice, a Webster, County, Kentucky native, educator, author, lecturer, poet, and president of Cumberland University, Lebanon, Tennessee. Includes his scientific writing, principally on astronomy, relativity and cosmology, as well as fiction, poetry, and autobiographical writing. Also includes some correspondence and papers relating to his brother, poet and dramatist Cale Young Rice, and sister-in-law, author Alice Hegan Rice.
Detection Of Supermassive Black Holes In Two Virgo Ultracompact Dwarf Galaxies,
2017
University of Utah
Detection Of Supermassive Black Holes In Two Virgo Ultracompact Dwarf Galaxies, Christopher Ahn, Anil Seth, Mark Den Brok, Jay Strader, Holger Baumgardt, Remco Van Den Bosch, Igor Chilingarian, Matthias Frank, Michael Hilker, Richard Mcdermid, Steffen Mieske, Aaron Romanowsky, Lee Spitler, Jean Brodie, Nadine Neumayer, Jonelle Walsh
Faculty Publications
No abstract provided.
Physoon: High Altitude Radiation Detection,
2017
University of Alabama in Huntsville
Physoon: High Altitude Radiation Detection, Everett Cavanaugh, Christopher Helmerich, T. Jemison, J. Kim, Jennifer Miller, Elena Pradhan, Sean Widmier, Cory Wolfe
Research Horizons Day Posters
No abstract provided.
Radial And Longitudinal Extent Of Sep Radiation Environment: Modeling Gradual Sep Events With Ipath,
2017
University of Alabama in Huntsville
Radial And Longitudinal Extent Of Sep Radiation Environment: Modeling Gradual Sep Events With Ipath, Junxiang Hu, Gang Li, Xianzhi Ao, Olga Verkhoglyadova
Research Horizons Day Posters
No abstract provided.
Multiple Phase Transitions In An Agent-Based Evolutionary Model With Neutral Fitness,
2017
University of Missouri-St. Louis
Multiple Phase Transitions In An Agent-Based Evolutionary Model With Neutral Fitness, Sonya Bahar, Dawn King, Adam Scott
Physics Faculty Works
Null models are crucial for understanding evolutionary processes such as speciation and adaptive radiation. We analyse an agent-based null model, considering a case without selection—neutral evolution—in which organisms are defined only by phenotype. Universal dynamics has previously been demonstrated in a related model on a neutral fitness landscape, showing that this system belongs to the directed percolation (DP) universality class. The traditional null condition of neutral fitness (where fitness is defined as the number of offspring each organism produces) is extended here to include equal probability of death among organisms. We identify two types of phase transition: (i) a non-equilibrium …
Effects Of Waveform Model Systematics On The Interpretation Of Gw150914,
2017
The University of Texas Rio Grande Valley
Effects Of Waveform Model Systematics On The Interpretation Of Gw150914, B. P. Abbott, T. D. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano
Physics & Astronomy Faculty Publications
Parameter estimates of GW150914 were obtained using Bayesian inference, based on three semi-analytic waveform models for binary black hole coalescences. These waveform models differ from each other in their treatment of black hole spins, and all three models make some simplifying assumptions, notably to neglect sub-dominant waveform harmonic modes and orbital eccentricity. Furthermore, while the models are calibrated to agree with waveforms obtained by full numerical solutions of Einstein's equations, any such calibration is accurate only to some non-zero tolerance and is limited by the accuracy of the underlying phenomenology, availability, quality, and parameter-space coverage of numerical simulations. This paper …
Pulsar Timing Array Based Search For Supermassive Black Hole Binaries In The Square Kilometer Array Era,
2017
The University of Texas Rio Grande Valley
Pulsar Timing Array Based Search For Supermassive Black Hole Binaries In The Square Kilometer Array Era, Yan Wang, Soumya D. Mohanty
Physics & Astronomy Faculty Publications
The advent of next generation radio telescope facilities, such as the Square Kilometer Array (SKA), will usher in an era where a pulsar timing array (PTA) based search for gravitational waves (GWs) will be able to use hundreds of well timed millisecond pulsars rather than the few dozens in existing PTAs. A realistic assessment of the performance of such an extremely large PTA must take into account the data analysis challenge posed by an exponential increase in the parameter space volume due to the large number of so-called pulsar phase parameters. We address this problem and present such an assessment …
First Demonstration Of Electrostatic Damping Of Parametric Instability At Advanced Ligo,
2017
University of Texas Rio Grande Valley
First Demonstration Of Electrostatic Damping Of Parametric Instability At Advanced Ligo, Carl Blair, Slawek Gras, Richard Abbott, Stuart Aston, Joseph Betzwieser, David Blair, Ryan Derosa, Matthew Evans, Valera Frolov
Physics & Astronomy Faculty Publications
Interferometric gravitational wave detectors operate with high optical power in their arms in order to achieve high shot-noise limited strain sensitivity. A significant limitation to increasing the optical power is the phenomenon of three-mode parametric instabilities, in which the laser field in the arm cavities is scattered into higher-order optical modes by acoustic modes of the cavity mirrors. The optical modes can further drive the acoustic modes via radiation pressure, potentially producing an exponential buildup. One proposed technique to stabilize parametric instability is active damping of acoustic modes. We report here the first demonstration of damping a parametrically unstable mode …
First Search For Gravitational Waves From Known Pulsars With Advanced Ligo,
2017
The University of Texas Rio Grande Valley
First Search For Gravitational Waves From Known Pulsars With Advanced Ligo, B. P. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Marc E. Normandin, Volker Quetschke, Malik Rakhmanov, Robert Stone, Darkhan Tuyenbayev, Guillermo Valdes
Physics & Astronomy Faculty Publications
We present the result of searches for gravitational waves from 200 pulsars using data from the first observing run of the Advanced LIGO detectors. We find no significant evidence for a gravitational-wave signal from any of these pulsars, but we are able to set the most constraining upper limits yet on their gravitational-wave amplitudes and ellipticities. For eight of these pulsars, our upper limits give bounds that are improvements over the indirect spin-down limit values. For another 32, we are within a factor of 10 of the spin-down limit, and it is likely that some of these will be reachable …
Absolute Ages And Distances Of 22 Gcs Using Monte Carlo Main-Sequence Fitting,
2017
Dartmouth College
Absolute Ages And Distances Of 22 Gcs Using Monte Carlo Main-Sequence Fitting, Erin M. O'Malley, Christina Gilligan, Brian Chaboyer
Dartmouth Scholarship
The recent Gaia Data Release 1 of stellar parallaxes provides ample opportunity to find metal-poor main-sequence stars with precise parallaxes. We select 21 such stars with parallax uncertainties better than σ π /π ≤ 0.10 and accurate abundance determinations suitable for testing metal-poor stellar evolution models and determining the distance to Galactic globular clusters (GCs). A Monte Carlo analysis was used, taking into account uncertainties in the model construction parameters, to generate stellar models and isochrones to fit to the calibration stars. The isochrones that fit the calibration stars best were then used to determine the distances and ages …
Detection Methods For Stochastic Gravitational-Wave Backgrounds: A Unified Treatment,
2017
The University of Texas Rio Grande Valley
Detection Methods For Stochastic Gravitational-Wave Backgrounds: A Unified Treatment, Joseph D. Romano, Neil J. Cornish
Physics & Astronomy Faculty Publications
We review detection methods that are currently in use or have been proposed to search for a stochastic background of gravitational radiation. We consider both Bayesian and frequentist searches using ground-based and space-based laser interferometers, spacecraft Doppler tracking, and pulsar timing arrays; and we allow for anisotropy, non-Gaussianity, and non-standard polarization states. Our focus is on relevant data analysis issues, and not on the particular astrophysical or early Universe sources that might give rise to such backgrounds. We provide a unified treatment of these searches at the level of detector response functions, detection sensitivity curves, and, more generally, at the …
Kelt-12b: A P ~ 5 Day, Highly Inflated Hot Jupiter Transiting A Mildly Evolved Hot Star,
2017
Swarthmore College
Kelt-12b: A P ~ 5 Day, Highly Inflated Hot Jupiter Transiting A Mildly Evolved Hot Star, D. J. Stevens, K. A. Collins, B. S. Gaudi, T. G. Beatty, R. J. Siverd, A. Bieryla, B. J. Fulton, J. R. Crepp, E. J. Gonzales, C. T. Coker, K. Penev, K. G. Stassun, Eric L.N. Jensen, A. W. Howard, D. W. Latham, J. E. Rodriguez, R. Zambelli, V. Bozza, P. A. Reed, J. Gregorio, L. A. Buchhave, M. T. Penny, J. Pepper, P. Berlind, S. Calchi Novati, M. L. Calkins, G. D'Ago, J. D. Eastman, D. Bayliss, K. D. Colón, I. A. Curtis, D. L. Depoy, G. A. Esquerdo, A. Gould, M. D. Joner, J. F. Kielkopf, J. Labadie-Bartz, M. B. Lund, M. Manner, J. L. Marshall, K. K. Mcleod, T. E. Oberst, R. W. Pogge, G. Scarpetta, D. C. Stephens, C. Stockdale, T. G. Tan, M. Trueblood, P. Trueblood
Physics & Astronomy Faculty Works
We announce the discovery of KELT-12b, a highly inflated Jupiter-mass planet transiting the mildly evolved, V = 10.64 host star TYC 2619-1057-1. We followed up the initial transit signal in the KELT-North survey data with precise ground-based photometry, high-resolution spectroscopy, precise radial velocity measurements, and high-resolution adaptive optics imaging. Our preferred best-fit model indicates that the host star has = 6279 ± 51 K, = 3.89 ± 0.05,[Fe/H] = , = , and = 2.37 ± 0.17 . The planetary companion has = 0.95 ± 0.14 , = , = , and density = g cm −3 , making it …
Magnetic Massive Stars As Progenitors Of ‘Heavy’ Stellar-Mass Black Holes,
2017
Swarthmore College
Magnetic Massive Stars As Progenitors Of ‘Heavy’ Stellar-Mass Black Holes, V. Petit, Z. Keszthelyi, R. Macinnis, David H. Cohen, R. H. D. Townsend, G. A. Wade, S. L. Thomas, S. P. Owocki, J. Puls, A. Ud-Doula
Physics & Astronomy Faculty Works
The groundbreaking detection of gravitational waves produced by the inspiralling and coalescence of the black hole (BH) binary GW150914 confirms the existence of ‘heavy’ stellar-mass BHs with masses >25 M⊙. Initial characterization of the system by Abbott et al. supposes that the formation of BHs with such large masses from the evolution of single massive stars is only feasible if the wind mass-loss rates of the progenitors were greatly reduced relative to the mass-loss rates of massive stars in the Galaxy, concluding that heavy BHs must form in low-metallicity (Z ≲ 0.25-0.5 Z⊙) environments. However, strong surface magnetic fields also …
Optimized Multilayered Thermal Emitters For Photovoltaic, Lighting, And Countermeasure Technologies,
2017
Louisiana State University
Optimized Multilayered Thermal Emitters For Photovoltaic, Lighting, And Countermeasure Technologies, Simón G. Lorenzo
Honors Capstones
No abstract provided.
Early Science With The Large Millimeter Telescope: Detection Of Dust Emission In Multiple Images Of A Normal Galaxy At Z > 4 Lensed By A Frontier Fields Cluster,
2017
University of Massachusetts Amherst
Early Science With The Large Millimeter Telescope: Detection Of Dust Emission In Multiple Images Of A Normal Galaxy At Z > 4 Lensed By A Frontier Fields Cluster, Alexandra Pope, Alfredo Montaña, Andrew Battisti, Marceau Limousin, Danilo Marchesini, Grant W. Wilson, Stacy Alberts, Itziar Aretxaga, Vladimir Avila-Reese, José Ramón Bermejo-Climent, Gabriel Brammer, Hector Bravo-Alfaro, Daniela Calzetti, Ranga-Ram Chary, Ryan Cybulski, Mauro Giavalisco, David Hughes, Erin Kado-Fong, Erica Keller, Allison Kirkpatrick, Ivo Labbe, Daniel Lange-Vagle, James Lowenthal, Eric Murphy, Pascal Oesch, Daniel Rosa Gonzalez, David Sánchez-Argüelles, Heath Shipley, Mauro Stefanon, Olga Vega, Katherine Whitaker, Christina C. Williams, Min Yun, Jorge A. Zavala, Milagros Zeballos
Astronomy: Faculty Publications
We directly detect dust emission in an optically detected, multiply imaged galaxy lensed by the Frontier Fields cluster MACSJ0717.5+3745. We detect two images of the same galaxy at 1.1 mm with the AzTEC camera on the Large Millimeter Telescope leaving no ambiguity in the counterpart identification. This galaxy, MACS0717_Az9, is at z > 4 and the strong lensing model (μ=7.5) allows us to calculate an intrinsic IR luminosity of 9.7 × 1010 Le and an obscured star formation rate of 14.6 ± 4.5 Me yr−1. The unobscured star formation rate from the UV is only 4.1 ± 0.3 Me yr−1, which …
Table Of Contents,
2017
University of South Carolina
Table Of Contents
Journal of the South Carolina Academy of Science
No abstract provided.
