Search For Gravitational Waves From Low Mass Compact Binary Coalescence In Ligo’S Sixth Science Run And Virgo’S Science Runs 2 And 3,
2012
The University of Texas Rio Grande Valley
Search For Gravitational Waves From Low Mass Compact Binary Coalescence In Ligo’S Sixth Science Run And Virgo’S Science Runs 2 And 3, J. Abadie, B. P. Abbott, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, Soumya Mohanty, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano, Robert Stone
Physics & Astronomy Faculty Publications
We report on a search for gravitational waves from coalescing compact binaries using LIGO and Virgo observations between July 7, 2009, and October 20, 2010. We searched for signals from binaries with total mass between 2 and 25M⊙; this includes binary neutron stars, binary black holes, and binaries consisting of a black hole and neutron star. The detectors were sensitive to systems up to 40 Mpc distant for binary neutron stars, and further for higher mass systems. No gravitational-wave signals were detected. We report upper limits on the rate of compact binary coalescence as a function of total mass, including …
The Influence Of Soft Spectral Components On The Structure And Stability Of Warm Absorbers In Active Galactic Nuclei,
2012
IUCAA, India
The Influence Of Soft Spectral Components On The Structure And Stability Of Warm Absorbers In Active Galactic Nuclei, Susmita Chakravorty, Ranjeev Misra, Martin Elvis, Ajit K. Kembhavi, Gary J. Ferland
Physics and Astronomy Faculty Publications
The radiation from the central regions of active galactic nuclei, including that from the accretion disc surrounding the black hole, is likely to peak in the extreme-ultraviolet ∼13–100 eV. However, due to Galactic absorption, we are limited to constrain the physical properties, i.e. the black hole mass and the accretion rate, from what observations we have below ∼10 eV or above ∼100 eV. In this paper, we predict the thermal and ionization states of warm absorbers as a function of the shape of the unobservable continuum. In particular we model an accretion disc at kTin∼ 10 eV and …
Herschel Observations Of Extended Atomic Gas In The Core Of The Perseus Cluster,
2012
Rochester Institute of Technology
Herschel Observations Of Extended Atomic Gas In The Core Of The Perseus Cluster, R. Mittal, J. B. R. Oonk, Gary J. Ferland, A. C. Edge, C. P. O'Dea, S. A. Baum, J. T. Whelan, R. M. Johnstone, F. Combes, P. Salomé, A. C. Fabian, G. R. Tremblay, M. Donahue, Russell H. H.
Physics and Astronomy Faculty Publications
We present Herschel observations of the core of the Perseus cluster of galaxies. Especially intriguing is the network of filaments that surround the brightest cluster galaxy, NGC 1275, previously imaged extensively in Hα and CO. In this work, we report detections of far-infrared (FIR) lines, in particular, [C II] 158, [O I] 63, [N II] 122, [O IB] 145 and [O III] 88 μm, withHerschel. All lines are spatially extended, except [O III], with the [C II] line emission extending up to 25 kpc from the core. [C II] emission is found to be co-spatial with Hα and …
Multiphase Signatures Of Active Galactic Nucleus Feedback In Abell 2597,
2012
European Southern Observatory, Germany
Multiphase Signatures Of Active Galactic Nucleus Feedback In Abell 2597, G. R. Tremblay, C. P. O'Dea, S. A. Baum, T. E. Clarke, C. L. Sarazin, J. N. Bregman, F. Combes, M. Donahue, A. C. Edge, A. C. Fabian, Gary J. Ferland, B. R. Mcnamara, R. Mittal, J. B. R. Oonk, A. C. Quillen, H. R. Russell, J. S. Sanders, P. Salomé, G. M. Voit, R. J. Wilman, M. W. Wise
Physics and Astronomy Faculty Publications
We present new Chandra X-ray observations of the brightest cluster galaxy (BCG) in the cool-core cluster Abell 2597 (z= 0.0821). The data reveal an extensive kpc-scale X-ray cavity network as well as a 15-kpc filament of soft-excess gas exhibiting strong spatial correlation with archival Very Large Array radio data. In addition to several possible scenarios, multiwavelength evidence may suggest that the filament is associated with multiphase (103–107 K) gas that has been entrained and dredged-up by the propagating radio source. Stemming from a full spectral analysis, we also present profiles and 2D spectral maps of …
Table Of Contents,
2012
University of South Carolina
Table Of Contents
Journal of the South Carolina Academy of Science
No abstract provided.
Scas Officers And Council Members 2011 - 2012,
2012
University of South Carolina
Scas Officers And Council Members 2011 - 2012
Journal of the South Carolina Academy of Science
No abstract provided.
Stellar Astrophysics With Undergraduate Students,
2012
University of South Carolina
Stellar Astrophysics With Undergraduate Students, Saul J. Adelman
Journal of the South Carolina Academy of Science
No abstract provided.
The Allen Telescope Array Search For Electrostatic Discharges On Mars,
2012
University of California, Berkley
The Allen Telescope Array Search For Electrostatic Discharges On Mars, Marin M. Anderson, Andrew P.V. Siemion, William C. Barott, Geoffery C. Bower, Gregory T. Delory, Imke De Pater, Dan Werthimer
Department of Electrical Engineering and Computer Science - Daytona Beach
The Allen Telescope Array was used to monitor Mars between 2010 March 9 and June 2, over a total of approximately 30 hr, for radio emission indicative of electrostatic discharge. The search was motivated by the report from Ruf et al. of the detection of non-thermal microwave radiation from Mars characterized by peaks in the power spectrum of the kurtosis, or kurtstrum, at 10 Hz, coinciding with a large dust storm event on 2006 June 8. For these observations, we developed a wideband signal processor at the Center for Astronomy Signal Processing and Electronics Research. This 1024 channel spectrometer calculates …
Variability In X-Ray Line Ratios In Helium-Like Ions Of Massive Stars: The Radiation-Driven Case.,
2012
East Tennessee State University
Variability In X-Ray Line Ratios In Helium-Like Ions Of Massive Stars: The Radiation-Driven Case., K. Hole, Richard Ignace
ETSU Faculty Works
Line ratios in "fir" triplets of helium-like ions have proven to be a powerful diagnostic of conditions in X-ray emitting gas surrounding massive stars. Recent observations indicate that these ratios can be variable with time. The possible causes of variation in line ratios are limited: changes in the radiation field or changes in density, and changes in mass-loss or geometry. In this paper, we investigate the ability of changes in the radiation field to induce variability in the ratio R=f/i. To isolate the radiative effect, we use a heuristic model of temperature and radius changes in variable stars in the …
Interacting Dark Energy Models And The Cosmic Coincidence Problem,
2012
Arkansas Tech University
Interacting Dark Energy Models And The Cosmic Coincidence Problem, H. Shojaei, C. Smith, D. Waters
Journal of the Arkansas Academy of Science
Interacting dark energy models have been employed to study the behavior of dark energy and matter in the presence of an interaction between the two. One of the successful aspects of these models is how they explain the cosmic coincidence problem. In this work we consider a specific interaction to study the behavior of dark energy and matter through the history of evolution.
A Reverberation Lag For The High-Ionization Component Of The Broad-Line Region In The Narrow-Line Seyfert 1 Mrk 335,
2012
The Ohio State University
A Reverberation Lag For The High-Ionization Component Of The Broad-Line Region In The Narrow-Line Seyfert 1 Mrk 335, C. J. Grier, B. M. Peterson, R. W. Pogge, K. D. Denney, M. C. Bentz, Paul Martini, S. G. Sergeev, S. Kaspi, Y. Zu, C. S. Kochanek, B. J. Shappee, C. Araya Salvo, T G. Beatty, J. C. Bird, D. J. Bord, G. A. Borman, X. Che, C. Chen
Dartmouth Scholarship
We present the first results from a detailed analysis of photometric and spectrophotometric data on the narrow-line Seyfert 1 (NLS1) galaxy Mrk 335, collected over a 120 day span in the fall of 2010. From these data we measure the lag in the He ii λ 4686 broad emission line relative to the optical continuum to be 2.7 °æ 0.6 days and the lag in the Hβλ 4861 broad emission line to be 13.9 °æ 0.9 days. Combined with the line width, the He ii lag yields a black hole mass MBH = (2. 6 °æ 0. 8) °ø 107M …
Evidence For The Onset Of Color Transparency In Ρ0 Electroproduction Off Nuclei,
2012
Old Dominion University
Evidence For The Onset Of Color Transparency In Ρ0 Electroproduction Off Nuclei, L. El Fassi, L. Zana, H. Hafidi, M. Holtrop, B. Mustapha, W. K. Brooks, H. Hakobyan, Z. Zheng, K. P. Adhikari, D. Adikaram, M. J. Amaryan, H. Baghdasaryan, S. Bültmann, G. E. Dodge, C. E. Hyde, A. Klein, S. E. Kuhn, M. Mayer, H. Seraydaryan, L. B. Weinstein
Physics Faculty Publications
We have measured the nuclear transparency of the incoherent diffractive A( e , e ′ ρ0 ) process in 12C and 56Fe targets relative to 2H using a 5 GeV electron beam. The nuclear transparency, the ratio of the produced ρ0 ʼs on a nucleus relative to deuterium, which is sensitive to ρA interaction, was studied as function of the coherence length (lc), a lifetime of the hadronic fluctuation of the virtual photon, and the four-momentum transfer squared (Q2). While the transparency for both 12C and 56Fe …
The Legendre Transform Of The Holst Action,
2012
University of Mississippi
The Legendre Transform Of The Holst Action, Caixia Gao
Electronic Theses and Dissertations
I start with a short introduction on 3+1 ADM form and the tetrad form of General Relativity, then I review the Legendre transform of the Einstein-Hilbert action and the Palatini action. The Holst action is a generalization of the Palatini action by including a topological term. I derive Ashtekar's connection form directly from this action by doing the Legendre transformation rather than by a canonical transformation in the usual phase space. This is done in both Remmanian signature with half-flat connection and Lorentz signature with general Barbero-Immirzi parameter.
Comparative Study Of High-Order Positivity-Preserving Weno Schemes,
2012
NASA Ames Research Cellter
Comparative Study Of High-Order Positivity-Preserving Weno Schemes, D. V. Kotov, Helen C. Yee, Bjorn Sjögreen
United States National Aeronautics and Space Administration: Publications
In gas dynamics and magnetohydrodynamics flows, physically, the density ρ and the pressure p should both be positive. In a standard conservative numerical scheme, however, the computed internal energy is obtained by subtracting the kinetic energy from the total energy, resulting in a computed p that may be negative. Examples are problems in which the dominant energy is kinetic. Negative ρ may often emerge in computing blast waves. In such situations the computed eigenvalues of the Jacobian will become imaginary. Consequently, the initial value problem for the linearized system will be ill posed. This explains why failure of preserving positivity …
Detecting And Characterizing Exoplanets: The Gj 436 And Hd 149026 Systems,
2012
University of Central Florida
Detecting And Characterizing Exoplanets: The Gj 436 And Hd 149026 Systems, Kevin Stevenson
Electronic Theses and Dissertations
This dissertation investigates two stellar systems known to contain extrasolar planets. It is comprised of five chapters that are readily divided into three independent but related analyses. Chapter 1 reports on the analysis of low signal-to-noise secondary-eclipse observations of the Neptune-sized exoplanet GJ 436b using the Spitzer Space Telescope in multiple infrared channels. The measured wavelength-dependent eclipse depths provide constraints on the planet’s dayside atmospheric composition and thermal profile. The analysis indicates that GJ 436b’s atmosphere is abundant in carbon monoxide and deficient in methane relative to thermochemical equilibrium models for the predicted hydrogen-dominated atmosphere. Chapter 2 discusses the techniques …
Phreatomagmatic Activity On The Moon: Possibility Of Pseudocraters At Mare Frigoris,
2012
University of Texas at El Paso
Phreatomagmatic Activity On The Moon: Possibility Of Pseudocraters At Mare Frigoris, Jose Humberto Garcia
Open Access Theses & Dissertations
The discovery of water on the Moon raises the possibility that lava-water, or phreatomagmatic, interactions have occurred on the lunar surface in the past. Such interactions may have formed pseudocraters, crater-like landforms that result from steam explosions that occur when lava flows come in contact with surface or near-surface water or ice. We present a study of Mare Frigoris, a volcanic plain just north of the Mare Imbrium impact basin on the Moon. Clusters of irregular, circular features on the basaltic lava flows in this area resemble pseudocrater fields in Iceland, and they are located in a region with inferred …
Characterization Of Thrust Faults On The Moon Using Fault Dynamics And 3d Visualizations,
2012
University of Texas at El Paso
Characterization Of Thrust Faults On The Moon Using Fault Dynamics And 3d Visualizations, Jaclyn Danielle Clark
Open Access Theses & Dissertations
Many small, lobate scarps, interpreted to be the surface traces of thrust faults, have been found all over Earth's moon by previous researchers. Fault dynamical calculations, assuming an initially completely molten Moon, have shown that these scarps can form due to compressional stresses that accumulate over time as the result of large-scale contraction of the Moon as it cooled. With high-resolution images from the Lunar Reconnaissance Orbiter Camera (LROC), previously undetected lobate scarps can be found globally and viewed at high resolution. By investigating these fault scarps, we can determine better constraints on the amount of crustal shortening and improve …
The Ongoing Assembly Of A Central Cluster Galaxy: Phase-Space Substructures In The Halo Of M87,
2012
San Jose State University
The Ongoing Assembly Of A Central Cluster Galaxy: Phase-Space Substructures In The Halo Of M87, Aaron J. Romanowsky, J. Strader, J. P. Brodie, C. Mihos, L. R. Spitler, D. A. Forbes, C. Foster, J. A. Arnold
Faculty Publications
The halos of galaxies preserve unique records of their formation histories. We carry out the first combined observational and theoretical study of phase-space halo substructure in an early-type galaxy: M87, the central galaxy in the Virgo cluster. We analyze an unprecedented wide-field, high-precision photometric and spectroscopic data set for 488 globular clusters (GCs), which includes new, large-radius Subaru/Suprime-Cam and Keck/DEIMOS observations. We find signatures of two substructures in position-velocity phase space. One is a small, cold stream associated with a known stellar filament in the outer halo; the other is a large shell-like pattern in the inner halo that implies …
Radially Extended Kinematics In The S0 Galaxy Ngc 2768 From Planetary Nebulae, Globular Clusters And Starlight,
2012
Swinburne University
Radially Extended Kinematics In The S0 Galaxy Ngc 2768 From Planetary Nebulae, Globular Clusters And Starlight, D. A. Forbes, A. Cortesi, V. Pota, C. Foster, Aaron J. Romanowsky, M. R. Merrifield, J. P. Strader, L. Coccato, N. Napolitano
Faculty Publications
There are only a few tracers available to probe the kinematics of individual early-type galaxies beyond one effective radius. Here we directly compare a sample of planetary nebulae (PNe), globular clusters (GCs) and galaxy starlight velocities out to approximately four effective radii, in the S0 galaxy NGC 2768. Using a bulge-to-disc decomposition of a K-band image we assign PNe and starlight to either the disc or the bulge. We show that the bulge PNe and bulge starlight follow the same radial density distribution as the red subpopulation of GCs, whereas the disc PNe and disc starlight are distinct components. We …
Deciphering The Arrangement Of Dust In The Clumpy Tori Of Active Galactic Nuclei,
2012
University of Kentucky
Deciphering The Arrangement Of Dust In The Clumpy Tori Of Active Galactic Nuclei, Grant David Thompson
Theses and Dissertations--Physics and Astronomy
In the framework of active galactic nuclei (AGNs), a galaxy’s supermassive black hole is surrounded by a dusty torus whose clumpy configuration allows for either direct or obscured views toward the central engine. Viewing AGNs from different angles gives rise to a variety of AGN classifications; for example, the generic Type 1 AGN class requires the detection of optically broad emission lines, which arise from quickly moving material within the torus, whereas Type 2 AGNs lack these observations. While these viewing angles are not directly observable, synthetic torus models generated with CLUMPY provide a means to determine them along with …
