Instrument For Precision Long-Term Ss-Decay Rate Measurements,
2015
Brigham Young University
Instrument For Precision Long-Term Ss-Decay Rate Measurements, M. J. Ware, Scott D. Bergeson, J. E. Ellsworth, M. Groesbeck, J. E. Hansen, D. Pace, J. Peatross
Faculty Publications
We describe an experimental setup for making precision measurements of relative ß-decay rates of 22Na, 36Cl, 54Mn, 60Co, 90Sr, 133Ba, 137Cs, 152Eu, and 154Eu. The radioactive samples are mounted in two automated sample changers that sequentially position the samples with high spatial precision in front of sets of detectors. The set of detectors for one sample changer consists of four Geiger-Müller (GM) tubes and the other set of detectors consists of two NaI scintillators. The statistical uncertainty in the count rate is few times 0.01% per day for the GM …
Koi-3158: The Oldest Known System Of Terrestrial-Size Planets,
2015
University of Birmingham
Koi-3158: The Oldest Known System Of Terrestrial-Size Planets, Tiago L. Campante, Darin A. Ragozzine
Aerospace, Physics, and Space Science Faculty Publications
The first discoveries of exoplanets around Sun-like stars have fueled efforts to find ever smaller worlds evocative of Earth and other terrestrial planets in the Solar System. While gas-giant planets appear to form preferentially around metal-rich stars, small planets (with radii less than four Earth radii) can form under a wide range of metallicities. This implies that small, including Earth-size, planets may have readily formed at earlier epochs in the Universe's history when metals were far less abundant. We report Kepler spacecraft observations of KOI-3158, a metal-poor Sun-like star from the old population of the Galactic thick disk, which hosts …
Koi-3158: The Oldest Known System Of Terrestrial-Size Planets,
2015
University of Birmingham
Koi-3158: The Oldest Known System Of Terrestrial-Size Planets, Tiago L. Campante, Darin A. Ragozzine
Aerospace, Physics, and Space Science Faculty Publications
The first discoveries of exoplanets around Sun-like stars have fueled efforts to find ever smaller worlds evocative of Earth and other terrestrial planets in the Solar System. While gas-giant planets appear to form preferentially around metal-rich stars, small planets (with radii less than four Earth radii) can form under a wide range of metallicities. This implies that small, including Earth-size, planets may have readily formed at earlier epochs in the Universe's history when metals were far less abundant. We report Kepler spacecraft observations of KOI-3158, a metal-poor Sun-like star from the old population of the Galactic thick disk, which hosts …
The Effect Of Direct Electron-Positron Pair Production On Relativistic Feedback Rates,
2015
Florida Institute of Technology
The Effect Of Direct Electron-Positron Pair Production On Relativistic Feedback Rates, Igor B. Vodopiyanov, Joseph R. Dwyer, Eric S. Cramer, R. J. Lucia, Hamid K. Rassoul
Aerospace, Physics, and Space Science Faculty Publications
Runaway electron avalanches developing in thunderclouds in high electric field become self-sustaining due to relativistic feedback via the production of backward propagating positrons and backscattered X-rays. To date, only positrons created from pair production by gamma rays interacting with the air have been considered. In contrast, direct electron-positron pair production, also known as "trident process," occurs from the interaction of energetic runaway electrons with atomic nuclei, and so it does not require the generation of a gamma ray mediator. The positrons produced in this process contribute to relativistic feedback and become especially important when the feedback factor value approaches unity. …
Search For Dark Photons From Neutral Meson Decays In P+P And D+ Au Collisions At √Snn =200 Gev,
2015
University of Colorado, Boulder
Search For Dark Photons From Neutral Meson Decays In P+P And D+ Au Collisions At √Snn =200 Gev, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Marcus Hohlmann, S. Rembeczki, Phenix Collaboration
Aerospace, Physics, and Space Science Faculty Publications
The standard model (SM) of particle physics is spectacularly successful, yet the measured value of the muon anomalous magnetic moment (g-2)μ deviates from SM calculations by 3.6σ. Several theoretical models attribute this to the existence of a "dark photon," an additional U(1) gauge boson, which is weakly coupled to ordinary photons. The PHENIX experiment at the Relativistic Heavy Ion Collider has searched for a dark photon, U, in π0,η→γe+e- decays and obtained upper limits of O(2×10‐⁶) U-γ mixing at 90% C.L. for the mass range 30< mᵤ < 90 MeV/c². Combined with other experimental limits, the remaining region in the U-γ mixing parameter space that can explain the (g-2)ᵤ deviation from its SM value is nearly completely excluded at the 90% confidence level, with only a small region of 29
Φ Meson Production In D + Au Collisions At √Snn =200 Gev,
2015
University of Colorado, Boulder
Φ Meson Production In D + Au Collisions At √Snn =200 Gev, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Marcus Hohlmann, S. Rembeczki, Phenix Collaboration
Aerospace, Physics, and Space Science Faculty Publications
The PHENIX Collaboration has measured φ meson production in d+Au collisions at √sNN=200 GeV using the dimuon and dielectron decay channels. The φ meson is measured in the forward (backward) d-going (Au-going) direction, 1.2 < y < 2.2 (-2.2 < y < -1.2) in the transverse-momentum (pT) range from 1-7 GeV/c and at midrapidity │y│< 0.35 in the pT range below 7 GeV/c. The φ meson invariant yields and nuclear-modification factors as a function of pT, rapidity, and centrality are reported. An enhancement of φ meson production is observed in the Au-going direction, while suppression is seen in the d-going direction, and no modification is observed at midrapidity relative to the yield in p+p collisions scaled by the number of binary collisions. Similar behavior was previously observed for inclusive charged hadrons and open heavy flavor, indicating similar cold-nuclear-matter effects.
Unmatter Plasma, Relativistic Oblique-Length Contraction Factor, Neutrosophic Diagram And Neutrosophic Degree Of Paradoxicity: Articles And Notes,
2015
University of New Mexico
Unmatter Plasma, Relativistic Oblique-Length Contraction Factor, Neutrosophic Diagram And Neutrosophic Degree Of Paradoxicity: Articles And Notes, Florentin Smarandache
Branch Mathematics and Statistics Faculty and Staff Publications
This book has four parts. In the first part, we collected five recent papers, published before in Progress in Physics, but reviewed. In the first paper, we approach a novel form of plasma, Unmatter Plasma. The electron-positron beam plasma was generated in the laboratory in the beginning of 2015. This experimental fact shows that unmatter, a new form of matter that is formed by matter and antimatter bind together (mathematically predicted a decade ago) really exists. That is the electron-positron plasma experiment of 2015 is the experimentum crucis verifying the mathematically predicted unmatter. In the second paper, we generalize the …
Prospects For Detection Of Extragalactic Stellar Black Hole Binaries In The Nearby Universe,
2015
The University of Texas Rio Grande Valley
Prospects For Detection Of Extragalactic Stellar Black Hole Binaries In The Nearby Universe, Matthew Benacquista, Jesus Hinojosa, Alberto Mata, Krzysztof Belczynski
Physics and Astronomy Faculty Publications and Presentations
Stellar mass black hole binaries have individual masses between 10-80 solar masses. These systems may emit gravitational waves at frequencies detectable at Megaparsec distances by space-based gravitational wave observatories. In a previous study, we determined the selection effects of observing these systems with detectors similar to the Laser Interferometer Space Antenna by using a generated population of binary black holes that covered a reasonable parameter space and calculating their signal-to-noise ratio. We further our study by populating the galaxies in our nearby (less than 30 Mpc) universe with binary black hole systems drawn from a distribution found in the Synthetic …
Analogs Of Ldl Receptor Ligand Motifs In Dengue Envelope And Capsid Proteins As Potential Codes For Cell Entry,
2015
The University of Texas Rio Grande Valley
Analogs Of Ldl Receptor Ligand Motifs In Dengue Envelope And Capsid Proteins As Potential Codes For Cell Entry, Juan Guevara Jr., Jamie Romo Jr., Troy Mcwhorter, Natalia Valentinova Guevara
Physics and Astronomy Faculty Publications and Presentations
It is established that cell entry of low density lipoprotein particles (LLPs) containing Apo B100 and Apo E is mediated by receptors and GAGs. Receptor ligand motifs, XBBBXXBX, XBBXBX, and ΨBΨXB, and mono- and bipartite NLS sequences are abundant in Apo E and Apo B100 as well as in envelope and capsid proteins of Dengue viruses 1-4 (DENV1-4). Synthetic, fluorescence-labeled peptides of sequences in DENV2 envelope protein, and DENV3 capsid that include these motifs were used to conduct a qualitative assessment of cell binding and entry capacity using …
Human Behavior During Spaceflight - Evidence From An Analog Environment,
2015
Embry-Riddle Aeronautical University
Human Behavior During Spaceflight - Evidence From An Analog Environment, Kenny M. Arnaldi, Guy Smith, Jennifer E. Thropp
Journal of Aviation/Aerospace Education & Research
Spaceflight offers a multitude of stressors to humans living and working in space, originating from the external space environment and the life-support system. Future space participants may be ordinary people with different medical and psychosocial backgrounds who may not receive the intense spaceflight preparation of astronauts. Consequently, during a mission, a space participant’s mood and behavior could differ from a trained astronaut. This study was an exploratory research project that used an artificial habitat to replicate an orbital environment and the activities performed by humans in space. The study evaluated whether the type of environment affects mood and temperament. Two …
Note: Improved Line Strengths Of Rovibrational And Rotational Transitions Within The X3Σ⁻ Ground State Of Nh,
2015
Old Dominion University
Note: Improved Line Strengths Of Rovibrational And Rotational Transitions Within The X3Σ⁻ Ground State Of Nh, James S.A. Brooke, Peter F. Bernath, Colin M. Western
Chemistry & Biochemistry Faculty Publications
Recently, a line list including positions and transition strengths was published for the NH X3Σ− rovibrational and rotational transitions. The calculation of the transition strengths requires a conversion of transition matrix elements from Hund’s case (b) to (a). The method of this conversion has recently been improved during other work on the OH X2Π rovibrational transitions, by removing an approximation that was present previously. The adjusted method has been applied to the NH line list, resulting in more accurate transition strengths. An updated line list is presented that contains all possible transitions with v′ and …
On X-Ray Pulsations In Beta Cephei-Type Variables,
2015
University of Potsdam
On X-Ray Pulsations In Beta Cephei-Type Variables, L. Oskinova, H. Todt, D. Huenemoerder, S. Hubrig, Richard Ignace, W.-R. Hamann, L. Balona
ETSU Faculty Works
Beta Cephei-type variables are early B-type stars that are characterized by oscillations observable in their optical light curves. At least one Beta Cep-variable also shows periodic variability in X-rays. Here we study the X-ray light curves in a sample of beta Cep-variables to investigate how common X-ray pulsations are for this type of stars. We searched the Chandra and XMM-Newton X-ray archives and selected stars that were observed by these telescopes for at least three optical pulsational periods. We retrieved and analyzed the X-ray data for kappa Sco, beta Cru, and alpha Vir. The X-ray light curves of these objects …
Advanced Ligo,
2015
Andrews University
Advanced Ligo, Tiffany Summerscales, Ligo Scientific Collaboration
Faculty Publications
No abstract provided.
Characterization Of The Ligo Detectors During Their Sixth Science Run,
2015
Andrews University
Characterization Of The Ligo Detectors During Their Sixth Science Run, Tiffany Summerscales, Ligo Collaboration
Faculty Publications
In 2009–2010, the Laser Interferometer Gravitational-Wave Observatory (LIGO) operated together with international partners Virgo and GEO600 as a network to search for gravitational waves (GWs) of astrophysical origin. The sensitivity of these detectors was limited by a combination of noise sources inherent to the instrumental design and its environment, often localized in time or frequency, that couple into the GW readout. Here we review the performance of the LIGO instruments during this epoch, the work done to characterize the detectors and their data, and the effect that transient and continuous noise artefacts have on the sensitivity of LIGO to a …
The Host Galaxies Of X-Ray Selected Active Galactic Nuclei To Z = 2.5: Structure, Star Formation, And Their Relationships From Candels And Herschel/Pacs,
2015
University of Kentucky
The Host Galaxies Of X-Ray Selected Active Galactic Nuclei To Z = 2.5: Structure, Star Formation, And Their Relationships From Candels And Herschel/Pacs, Dale D. Kocevski, D. J. Rosario, D. H. Mcintosh, A. Van Der Wel, J. Kartaltepe, P. Lang, P. Santini, S. Wuyts, D. Lutz, M. Rafelski, C. Villforth
Physics and Astronomy Faculty Publications
We study the relationship between the structure and star formation rate (SFR) of X-ray selected low and moderate luminosity active galactic nuclei (AGNs) in the two Chandra Deep Fields, using Hubble Space Telescope imaging from the Cosmic Assembly Near Infrared Extragalactic Legacy Survey (CANDELS) and deep far-infrared maps from the PEP+GOODS-Herschel survey. We derive detailed distributions of structural parameters and FIR luminosities from carefully constructed control samples of galaxies, which we then compare to those of the AGNs. At z ~ 1, AGNs show slightly diskier light profiles than massive inactive (non-AGN) galaxies, as well as modestly higher levels …
The Lyman Alpha Reference Sample: Iv. Morphology At Low And High Redshift,
2014
Macalester College
The Lyman Alpha Reference Sample: Iv. Morphology At Low And High Redshift, L. Guaita, J. Melinder, M. Hayes, G. Ostlin, J. Gonzalez, A. Adamo, J. Mas-Hesse, A. Sandberg, H. Oti-Floranes, D. Schaerer, A. Verhamme, E. Freeland, I. Orlitova, P. Laursen, John Cannon, F. Duval, T. Rivera-Thorsen, E. Herenz, D. Kunth, H. Atek, J. Puschnig, P. Gruyters, S. Pardy
John Cannon
No abstract provided.
Oxygen Abundance Measurements Of Shield Galaxies,
2014
Macalester College
Oxygen Abundance Measurements Of Shield Galaxies, N. Haurberg, J. Salzer, John Cannon, M. Marshall
John Cannon
No abstract provided.
Agc198606: A Gas-Bearing Dark Matter Minihalo?,
2014
Macalester College
Agc198606: A Gas-Bearing Dark Matter Minihalo?, E. Adams, Y. Faerman, W. Janesh, S. Janowiecki, T. Oosterloo, K. Rhode, R. Giovanelli, M. Haynes, J. Salzer, A. Sternberg, John Cannon, R. Munoz
John Cannon
No abstract provided.
The Alfalfa "Almost Darks" Campaign: Pilot Vla Hi Observations Of Five High Mass-To-Light Ratio Systems,
2014
Macalester College
The Alfalfa "Almost Darks" Campaign: Pilot Vla Hi Observations Of Five High Mass-To-Light Ratio Systems, John Cannon, C. Martinkus, L. Leisman, M. Haynes, E. Adams, R. Giovanelli, G. Hallenbeck, S. Janowiecki, M. Jones, G. Josza, R. Koopmann, N. Nichols, E. Papastergis, K. Rhode, J. Salzer, P. Trosicht
John Cannon
No abstract provided.
(Almost) Dark Hi Sources In The Alfalfa Survey: The Intriguing Case Of Hi1232+20,
2014
Macalester College
(Almost) Dark Hi Sources In The Alfalfa Survey: The Intriguing Case Of Hi1232+20, Steven Janowiecki, Lukas Leisman, Gyula Jozsa, John Salzer, Martha Haynes, Riccardo Giovanelli, Katherine Rhode, John Cannon, Elizabeth Adams, William Janesh
John Cannon
No abstract provided.
