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Articles 3361 - 3390 of 8858

Full-Text Articles in Astrophysics and Astronomy

Have We Found Our Neighbors? The Search For Habitable Planets Outside Our Solar System, Madeline Galbraith Apr 2017

Have We Found Our Neighbors? The Search For Habitable Planets Outside Our Solar System, Madeline Galbraith

D.U.Quark

No abstract provided.

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Quantum Correlation Measurements In Interferometric Gravitational-Wave Detectors, D. V. Martynov, V. V. Frolov, S. Kandhasamy, K. Izumi, H. Miao, N. Mavalvala, E. D. Hall, R. Lanza, Volker Quetschke, Guillermo Valdes Apr 2017

Quantum Correlation Measurements In Interferometric Gravitational-Wave Detectors, D. V. Martynov, V. V. Frolov, S. Kandhasamy, K. Izumi, H. Miao, N. Mavalvala, E. D. Hall, R. Lanza, Volker Quetschke, Guillermo Valdes

Physics & Astronomy Faculty Publications

Quantum fluctuations in the phase and amplitude quadratures of light set limitations on the sensitivity of modern optical instruments. The sensitivity of the interferometric gravitational-wave detectors, such as the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO), is limited by quantum shot noise, quantum radiation pressure noise, and a set of classical noises. We show how the quantum properties of light can be used to distinguish these noises using correlation techniques. Particularly, in the first part of the paper we show estimations of the coating thermal noise and gas phase noise, hidden below the quantum shot noise in the Advanced LIGO sensitivity …

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Dust-Polarization Maps And Interstellar Turbulence, Robert R. Caldwell, Chris Hirata, Marc Kamionkowski Apr 2017

Dust-Polarization Maps And Interstellar Turbulence, Robert R. Caldwell, Chris Hirata, Marc Kamionkowski

Dartmouth Scholarship

Perhaps the most intriguing result of Planck's dust-polarization measurements is the observation that the power in the E-mode polarization is twice that in the B mode, as opposed to pre-Planck expectations of roughly equal dust powers in the E and B modes. Here we show how the E- and B-mode powers depend on the detailed properties of the fluctuations in the magnetized interstellar medium (ISM). These fluctuations can be decomposed into slow, fast, and Alfvén magnetohydrodynamic (MHD) waves, which comprise a complete basis that can be used to describe linear fluctuations of a magnetized fluid. They can …

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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 Apr 2017

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 …

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Fermi-Lat Daily Monitoring Observations Of The Microquasar Cygnus X-1, Austin P. Waldron, Stephen R. Hood, Arash Bodaghee Apr 2017

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.

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Prospecting For Iron In The Galactic Supernova Remnant W49b, Eddi Akers, Taylor Ray, Thomas G. Pannuti Apr 2017

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.

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Psr B1509-58: When The Galaxy Has A Question, Brandy Anderson, Austin Howard, Maggie Quesinberry, Thomas G. Pannuti, Jeannie Justice Apr 2017

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.

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Rice, Laban Lacy, 1870-1973 (Mss 605), Manuscripts & Folklife Archives Apr 2017

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.

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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 Apr 2017

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.

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Physoon: High Altitude Radiation Detection, Everett Cavanaugh, Christopher Helmerich, T. Jemison, J. Kim, Jennifer Miller, Elena Pradhan, Sean Widmier, Cory Wolfe Apr 2017

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.

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Radial And Longitudinal Extent Of Sep Radiation Environment: Modeling Gradual Sep Events With Ipath, Junxiang Hu, Gang Li, Xianzhi Ao, Olga Verkhoglyadova Apr 2017

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.

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Multiple Phase Transitions In An Agent-Based Evolutionary Model With Neutral Fitness, Sonya Bahar, Dawn King, Adam Scott Apr 2017

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 …

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Pulsar Timing Array Based Search For Supermassive Black Hole Binaries In The Square Kilometer Array Era, Yan Wang, Soumya D. Mohanty Apr 2017

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 …

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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 Apr 2017

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 …

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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 Apr 2017

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 …

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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 Apr 2017

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 …

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Absolute Ages And Distances Of 22 Gcs Using Monte Carlo Main-Sequence Fitting, Erin M. O'Malley, Christina Gilligan, Brian Chaboyer Apr 2017

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 …

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Detection Methods For Stochastic Gravitational-Wave Backgrounds: A Unified Treatment, Joseph D. Romano, Neil J. Cornish Apr 2017

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 …

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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 Apr 2017

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 …

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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 Apr 2017

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 …

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Optimized Multilayered Thermal Emitters For Photovoltaic, Lighting, And Countermeasure Technologies, Simón G. Lorenzo Apr 2017

Optimized Multilayered Thermal Emitters For Photovoltaic, Lighting, And Countermeasure Technologies, Simón G. Lorenzo

Honors Capstones

No abstract provided.

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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 Apr 2017

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 …

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Table Of Contents Apr 2017

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.

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A Feasibility Study For Using The Erau ÉChelle Spectrograph To Improve Orbital Parameters Of Spectroscopic Binary Systems, Stanimir Letchev Apr 2017

A Feasibility Study For Using The Erau ÉChelle Spectrograph To Improve Orbital Parameters Of Spectroscopic Binary Systems, Stanimir Letchev

Doctoral Dissertations and Master's Theses

Binary stars are critical for establishing knowledge of stellar masses and refining the mass-luminosity relationship when used in conjunction with precise parallax measurements. However, many spectroscopic binaries have poorly defined orbital parameters as they have not been revisited with newer CCD technology since their first observations on photographic plates. This thesis examines the feasibility of using the high-resolution échelle spectrograph at Embry-Riddle Aeronautical University (ERAU) to obtain radial velocities of spectroscopic binary stars, and establishes a software pipeline to obtain their orbital parameters. This was done by looking at the double-lined binaries HD 205539 and Pegasi, as well as the …

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On The Absence Of Non-Thermal X-Ray Emission Around Runaway O Stars, Jesus A. Toalá, Lidia M. Oskinova, Richard Ignace Apr 2017

On The Absence Of Non-Thermal X-Ray Emission Around Runaway O Stars, Jesus A. Toalá, Lidia M. Oskinova, Richard Ignace

ETSU Faculty Works

Theoretical models predict that the compressed interstellar medium around runaway O stars can produce high-energy non-thermal diffuse emission, in particular, non-thermal X-ray and γ-ray emission. So far, detection of non-thermal X-ray emission was claimed for only one runaway star, AE Aur. We present a search for non-thermal diffuse X-ray emission from bow shocks using archived XMM-Newton observations for a clean sample of six well-determined runaway O stars. We find that none of these objects present diffuse X-ray emission associated with their bow shocks, similarly to previous X-ray studies toward ζ Oph and BD+43°3654. We carefully investigated multi-wavelength observations of …

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Diverse Stellar Haloes In Nearby Milky Way Mass Disc Galaxies., Benjamin Harmsen, Antonela Monachesi, Eric F. Bell, Roelof S. De Jong, Jeremy Bailin, David J. Radburn-Smith, Benne W. Holwerda Apr 2017

Diverse Stellar Haloes In Nearby Milky Way Mass Disc Galaxies., Benjamin Harmsen, Antonela Monachesi, Eric F. Bell, Roelof S. De Jong, Jeremy Bailin, David J. Radburn-Smith, Benne W. Holwerda

Faculty and Staff Scholarship

We have examined the resolved stellar populations at large galactocentric distances along the minor axis (from 10 kpc up to between 40 and 75 kpc), with limited major axis coverage, of six nearby highly inclined MilkyWay (MW) mass disc galaxies using Hubble Space Telescope data from the Galaxy haloes, Outer discs, Substructure, Thick discs, and Star clusters (GHOSTS) survey. We select red giant branch stars to derive stellar halo density profiles. The projected minor axis density profiles can be approximated by power laws with projected slopes of −2 to −3.7 and a diversity of stellar halo masses of 1–6 × …

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Lorentz-Symmetry Test At Planck-Scale Suppression With Nucleons In A Spin-Polarized 133 Cs Cold Atom Clock, H. Pihan-Le Bars, C. Guerlin, R.-D. Lasseri, J.-P. Ebran, Q. G. Bailey, S. Bize, E. Khan, P. Wolf Apr 2017

Lorentz-Symmetry Test At Planck-Scale Suppression With Nucleons In A Spin-Polarized 133 Cs Cold Atom Clock, H. Pihan-Le Bars, C. Guerlin, R.-D. Lasseri, J.-P. Ebran, Q. G. Bailey, S. Bize, E. Khan, P. Wolf

Publications

The authors introduce an improved model that links the frequency of the 133 Cs hyperfine Zeeman transitions.

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Ultra-Diffuse And Ultra-Compact Galaxies In The Frontier Fields Cluster Abell 2744, Steven Janssens, Roberto Abraham, Jean Brodie, Duncan Forbes, Aaron Romanowsky, Pieter Van Dokkum Apr 2017

Ultra-Diffuse And Ultra-Compact Galaxies In The Frontier Fields Cluster Abell 2744, Steven Janssens, Roberto Abraham, Jean Brodie, Duncan Forbes, Aaron Romanowsky, Pieter Van Dokkum

Faculty Publications

We report the discovery of a large population of ultra-diffuse galaxies (UDGs) in the massive galaxy cluster Abell 2744 (z = 0.308) as observed by the Hubble Frontier Fields program. Since this cluster is ~5 times more massive than Coma, our observations allow us to extend 0.7 dex beyond the high-mass end of the relationship between UDG abundance and cluster mass reported by van der Burg et al. Using the same selection criteria as van der Burg et al., A2744 hosts an estimated 1961 ± 577 UDGs, 10 times the number in Coma. As noted by Lee & Jang, A2744 …

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Local Time Dependence Of Turbulent Magnetic Fields In Saturn's Magnetodisc, V. Kaminker, P. A. Delamere, C. S. Ng, T. Dennis, A. Otto, X. Ma Apr 2017

Local Time Dependence Of Turbulent Magnetic Fields In Saturn's Magnetodisc, V. Kaminker, P. A. Delamere, C. S. Ng, T. Dennis, A. Otto, X. Ma

Publications

Net plasma transport in magnetodiscs around giant planets is outward. Observations of plasma temperature have shown that the expanding plasma is heating nonadiabatically during this process. Turbulence has been suggested as a source of heating. However, the mechanism and distribution of magnetic fluctuations in giant magnetospheres are poorly understood. In this study we attempt to quantify the radial and local time dependence of fluctuating magnetic field signatures that are suggestive of turbulence, quantifying the fluctuations in terms of a plasma heating rate density. In addition, the inferred heating rate density is correlated with magnetic field configurations that include azimuthal bend …

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Book Review: From The Realm Of The Nebulae To Populations Of Galaxies: Dialogues On A Century Of Research, Astrophysics And Space Science Library, 435, T. D. Oswalt Apr 2017

Book Review: From The Realm Of The Nebulae To Populations Of Galaxies: Dialogues On A Century Of Research, Astrophysics And Space Science Library, 435, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of From the Realm of the Nebulae to Populations of Galaxies : Dialogues on a Century of Research, Astrophysics and Space Science Library, 435. by Mauro D'Onofrio, Roberto Rampazzo, and Simone Zaggia Springer, 2016 785p bibl index afp, 9783319310046 $279.00, 9783319310060 $219.00

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