Swift Follow-Up Observations Of Candidate Gravitational-Wave Transient Events,
2012
The University of Texas Rio Grande Valley
Swift Follow-Up Observations Of Candidate Gravitational-Wave Transient Events, P. A. Evans, J. K. Fridriksson, N. Gehrels, J. Homan, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Malik Rakhmanov, Joseph D. Romano
Physics & Astronomy Faculty Publications
We present the first multi-wavelength follow-up observations of two candidate gravitational-wave (GW) transient events recorded by LIGO and Virgo in their 2009-2010 science run. The events were selected with low latency by the network of GW detectors (within less than 10 minutes) and their candidate sky locations were observed by the Swift observatory (within 12 hr). Image transient detection was used to analyze the collected electromagnetic data, which were found to be consistent with background. Off-line analysis of the GW data alone has also established that the selected GW events show no evidence of an astrophysical origin; one of them …
Exploring The Surface Liquid And Lake Regions Of Titan With Laboratory Experimentation And Cassini Spacecraft Data,
2012
University of Arkansas, Fayetteville
Exploring The Surface Liquid And Lake Regions Of Titan With Laboratory Experimentation And Cassini Spacecraft Data, Felix Casimir Wasiak
Graduate Theses and Dissertations
The surface liquids and lake regions of Titan are studied utilizing three unique techniques, the results of which are reported in this dissertation. The development of a facility to simulate the surface conditions of Titan, and to conduct experiments on samples within that facility, brings an understanding of Titan's surface not possible through observation and modeling alone. The properties of this facility are presented, including conceptual methodology, design, implementation, performance, and experimental results. The facility, the main component of which is a simulation chamber, allows for Titan temperatures of 90 - 94 K and a 1.5 bar N2 atmosphere. The …
Penetration Forces For Subsurface Regolith Probes,
2012
University of Arkansas, Fayetteville
Penetration Forces For Subsurface Regolith Probes, Ahmed Elshafie
Graduate Theses and Dissertations
Investigating planetary bodies using penetrometers can provide detailed information about its history and evolution. An estimation of subsurface density and porosity can be made from the shape of the penetration curve. Using penetrometers mounted on planetary platforms could be challenging due to the uncertainty of the subsurface composition and since the maximum allowed force for penetration is the weight of the lander or rover on the surface. Estimation of penetration forces can provide a reliable constraint on the maximum reachable depth without endangering the whole mission. Therefore, knowledge of the required penetration force to specific depths can be helpful in …
The Discovery Of Hd 37605c And A Dispositive Null Detection Of Transits Of Hd 37605b,
2012
Pennsylvania State University
The Discovery Of Hd 37605c And A Dispositive Null Detection Of Transits Of Hd 37605b, Sharon Xuesong Wang, Jason T. Wright, William D. Cochran, Stephen R. Kane, Gregory W. Henry, Matthew J. Payne, Michael Endl, Phillip J. Macqueen, Jeff A. Valenti, Victoria Antoci, Diana Dragomir, Jaymie M. Matthews, Andrew W. Howard, Geoffrey W. Marcy, Howard Isaacson, Eric B. Ford, Suvrath Mahadevan, Kaspar Von Braun
Information Systems and Engineering Management Research Publications
We report the radial velocity discovery of a second planetary mass companion to the K0 V star HD 37605, which was already known to host an eccentric, P ∼ 55 days Jovian planet, HD 37605b. This second planet, HD 37605c, has a period of ∼7.5 years with a low eccentricity and an Msin i of ∼3.4 MJup. Our discovery was made with the nearly 8 years of radial velocity follow-up at the Hobby–Eberly Telescope and Keck Observatory, including observations made as part of the Transit Ephemeris Refinement and Monitoring Survey effort to provide precise ephemerides to long-period planets for transit …
Search For Gravitational Waves Associated With Gamma-Ray Bursts During Ligo Science Run 6 And Virgo Science Runs 2 And 3,
2012
California Institute of Technology
Search For Gravitational Waves Associated With Gamma-Ray Bursts During Ligo Science Run 6 And Virgo Science Runs 2 And 3, J. Abadie, B. P. Abbott, R. Abbott, T. D. Abbott, M. Abernathy, T. Accadia, F. Acernese, C. Adams, R. X. Adhikari, C. Affeldt, M. Agathos, K. Agatsuma, P. Ajith, B. Allen, E. Amador Ceron, D. Amariutei, S. B. Anderson, W. G. Anderson, K. Arai, M. A. Arain, M. C. Araya, S. M. Aston, P. Astone, D. Atkinson, P. Aufmuth, C. Aulbert, B. E. Aylott, S. Babak, P. Baker, G. Ballardin, S. Ballmer, Tiffany Z. Summerscales
Faculty Publications
We present the results of a search for gravitational waves associated with 154 gamma-ray bursts (GRBs) that were detected by satellite-based gamma-ray experiments in 2009-2010, during the sixth LIGO science run and the second and third Virgo science runs. We perform two distinct searches: a modeled search for coalescences of either two neutron stars or a neutron star and black hole, and a search for generic, unmodeled gravitational-wave bursts. We find no evidence for gravitational-wave counterparts, either with any individual GRB in this sample or with the population as a whole. For all GRBs we place lower bounds on the …
Abrupt Longitudinal Magnetic Field Changes And Ultraviolet Emissions Accompanying Solar Flares,
2012
West Chester University of Pennsylvania
Abrupt Longitudinal Magnetic Field Changes And Ultraviolet Emissions Accompanying Solar Flares, B. M. Johnstone, G. J.D. Petrie, Jeffrey J. Sudol
Physics & Engineering Faculty Publications
No abstract provided.
The Metallicity Of The Cm Draconis System,
2012
The Pennsylvania State University
The Metallicity Of The Cm Draconis System, Ryan C. Terrien, Scott W. Fleming, Suvrath Mahadevan, Rohit Deshpande, Gregory A. Feiden
Dartmouth Scholarship
The CM Draconis system comprises two eclipsing mid-M dwarfs of nearly equal mass in a 1.27-day orbit. This well-studied eclipsing binary has often been used for benchmark tests of stellar models, since its components are amongst the lowest mass stars with well-measured masses and radii (~ 1% relative precision). However, as with many other low-mass stars, non-magnetic models have been unable to match the observed radii and effective temperatures for CM Dra at the 5-10% level. To date, the uncertain metallicity of the system has complicated comparison of theoretical isochrones with observations. In this Letter, we use data from the …
Search For Gravitational Waves Associated With Gamma-Ray Bursts During Ligo Science Run 6 And Virgo Science Runs 2 And 3,
2012
The University of Texas Rio Grande Valley
Search For Gravitational Waves Associated With Gamma-Ray Bursts During Ligo Science Run 6 And Virgo Science Runs 2 And 3, J. Abadie, B. P. Abbott, R. Abbott, T. D. Abbott, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, Soumya D. Mohanty, Volker Quetschke, Joseph D. Romano
Physics & Astronomy Faculty Publications
We present the results of a search for gravitational waves associated with 154 gamma-ray bursts (GRBs) that were detected by satellite-based gamma-ray experiments in 2009-2010, during the sixth LIGO science run and the second and third Virgo science runs. We perform two distinct searches: a modeled search for coalescences of either two neutron stars or a neutron star and black hole, and a search for generic, unmodeled gravitational-wave bursts. We find no evidence for gravitational-wave counterparts, either with any individual GRB in this sample or with the population as a whole. For all GRBs we place lower bounds on the …
Raman Spectroscopy Of Isotactic Polypropylene-Halloysite Nanocomposites,
2012
The University of Texas Rio Grande Valley
Raman Spectroscopy Of Isotactic Polypropylene-Halloysite Nanocomposites, Elamin E. Ibrahim, Dorina M. Chipara, Ram Thapa, Karen Lozano, Mircea Chipara
Physics & Astronomy Faculty Publications
Raman spectroscopy investigations on nanocomposites obtained by dispersing halloysite within isotactic polypropylene are reported. A detailed analysis of the modifications of the regularity band associated to the polymeric matrix is presented. The Raman lines assigned to the polymeric matrix are broadened and weakened as the loading with halloysite is increased. The analysis of Raman lines indicates that the polymeric matrix becomes less crystalline upon the loading with halloysite and that the nanofiller is experiencing a weak dehydration upon dispersion within the polymeric matrix, probably due to the related thermal processing used to achieve the dispersion of halloysite. © 2012 Elamin …
Two-Component Structure Of The HΒ Broad-Line Region In Quasars. I. Evidence From Spectral Principal Component Analysis,
2012
Chinese Academy of Sciences, China
Two-Component Structure Of The HΒ Broad-Line Region In Quasars. I. Evidence From Spectral Principal Component Analysis, Chen Hu, Jian-Min Wang, Luis C. Ho, Gary J. Ferland, Jack A. Baldwin, Ye Wang
Physics and Astronomy Faculty Publications
We report on a spectral principal component analysis (SPCA) of a sample of 816 quasars, selected to have small Fe II velocity shifts with spectral coverage in the rest wavelength range 3500-5500 Å. The sample is explicitly designed to mitigate spurious effects on SPCA induced by Fe II velocity shifts. We improve the algorithm of SPCA in the literature and introduce a new quantity, the fractional-contribution spectrum, that effectively identifies the emission features encoded in each eigenspectrum. The first eigenspectrum clearly records the power-law continuum and very broad Balmer emission lines. Narrow emission lines dominate the second eigenspectrum. The …
Breaks In Thin And Thick Disks Of Edge-On Galaxies Imaged In The Spitzer Survey Of Stellar Structure In Galaxies (S4g),
2012
University of Oulu
Breaks In Thin And Thick Disks Of Edge-On Galaxies Imaged In The Spitzer Survey Of Stellar Structure In Galaxies (S4g), Sébastien Comerón, Trisha Mizusawa
Aerospace, Physics, and Space Science Faculty Publications
Breaks in the radial luminosity profiles of galaxies have until now been mostly studied averaged over disks. Here, we study separately breaks in thin and thick disks in 70 edge-on galaxies using imaging from the Spitzer Survey of Stellar Structure in Galaxies. We built luminosity profiles of the thin and thick disks parallel to midplanes and we found that thin disks often truncate (77%). Thick disks truncate less often (31%), but when they do, their break radius is comparable with that in the thin disk. This suggests either two different truncation mechanisms—one of dynamical origin affecting both disks simultaneously and …
Photocatalytic Activity Of Core/Shell Semiconductor Nanocrystals Featuring Spatial Separation Of Charges,
2012
Bowling Green State University
Photocatalytic Activity Of Core/Shell Semiconductor Nanocrystals Featuring Spatial Separation Of Charges, Dimuthu Perera, Ryan Lorek, Rony S. Khnayzer, Pavel Moroz, Timothy O’Connor, Dmitry Khon, Geoffrey Diederich, Erich Kinder, Scott Lambright, Felix N. Castellano, Mikhail Zamkov
Physics and Astronomy Faculty Publications
The present study investigates the photocatalytic activity of ZnSe/CdS core/shell semiconductor nanocrystals. These nanoparticles exhibit a spatial separation of photoinduced charges between the core and the shell domains, which makes them potentially viable for photocatalytic applications. Unfortunately, one of the excited charges remains inside the core semiconductor and thus cannot efficiently react with the external environment. Here, we explore this issue by investigating the mechanisms of hole extraction from the ZnSe core to the surface of the CdS shell. In particular, the effect of shell thickness in ZnSe/CdS core/shell nanocrystals on the ability of core-localized charges to perform oxidative reactions …
The Disk-Wind-Jet Connection In The Black Hole H 1743-322,
2012
University of Michigan
The Disk-Wind-Jet Connection In The Black Hole H 1743-322, J. M. Miller, J. Raymond, A. C. Fabian, C. S. Reynolds, A. L. King, T. R. Kallman, E. M. Cackett, M. Van Der Klis, D. T. H. Steeghs
Physics and Astronomy Faculty Research Publications
X-ray disk winds are detected in spectrally soft, disk-dominated phases of stellar-mass black hole outbursts. In contrast, compact, steady, relativistic jets are detected in spectrally hard states that are dominated by non-thermal X-ray emission. Although these distinctive outflows appear to be almost mutually exclusive, it is possible that a disk wind persists in hard states but cannot be detected via X-ray absorption lines owing to very high ionization. Here, we present an analysis of a deep, 60 ks Chandra/HETGS observation of the black hole candidate H 1743-322 in the low/hard state. The spectrum shows no evidence of a disk wind, …
Exploring The Effects Of Stellar Rotation And Wind Clearing: Debris Disks Around F Stars,
2012
Florida Institute of Technology
Exploring The Effects Of Stellar Rotation And Wind Clearing: Debris Disks Around F Stars, Trisha F. Mizusawa, Luisa M. Rebull, John R. Stauffer, Geoffrey Bryden, Michael Meyer, Inseok Song
Aerospace, Physics, and Space Science Faculty Publications
We have conducted a study of debris disks around F stars in order to explore correlations between rotation, stellar winds, and circumstellar disks. We obtained new 24 {mu}m photometry from the Multiband Imaging Photometer for Spitzer (MIPS) camera for a sample of 188 relatively nearby F dwarfs with various rotation rates and optical colors, and combined it with archival MIPS data for 66 more F stars, as well as Wide-field Infrared Survey Explorer data for the entire sample, plus 9 more F stars. Based on the objects' K{sub s} - [24] and [3.4] - [22] colors, we identify 22 stars …
Supernova Resonance-Scattering Line Profiles In The Absence Of A Photosphere,
2012
University of Oklahoma
Supernova Resonance-Scattering Line Profiles In The Absence Of A Photosphere, Brian Friesen, E. Baron, David Branch, Bin Chen, Jerod T. Parrent, R. C. Thomas
Dartmouth Scholarship
In supernova (SN) spectroscopy relatively little attention has been given to the properties of optically thick spectral lines in epochs following the photosphere's recession. Most treatments and analyses of post-photospheric optical spectra of SNe assume that forbidden-line emission comprises most if not all spectral features. However, evidence exists that suggests that some spectra exhibit line profiles formed via optically thick resonance-scattering even months or years after the SN explosion. To explore this possibility, we present a geometrical approach to SN spectrum formation based on the "Elementary Supernova" model, wherein we investigate the characteristics of resonance-scattering in optically thick lines while …
Breaks In Thin And Thick Disks Of Edge-On Galaxies Imaged In The Spitzer Survey Of Stellar Structure In Galaxies (S4g).,
2012
University of Oulu
Breaks In Thin And Thick Disks Of Edge-On Galaxies Imaged In The Spitzer Survey Of Stellar Structure In Galaxies (S4g)., Sebastien Comeron, Bruce G. Elmegreen, Heikki Salo, Eija Laurikainen, E. Athanassoula, Albert Bosma, Johan H. Knapen, Dimitri A. Gadotti, Kartik Sheth, Joannah L. Hinz, Michael W. Regan, Armando Gil De Paz, Juan Carlos Munoz-Mateos, Karin Menendez-Delmestre, Mark Seibert, Taehyun Kim, Trisha Mizusawa, Jarkko Laine, Luis C. Ho, Benne W. Holwerda
Faculty and Staff Scholarship
Breaks in the radial luminosity profiles of galaxies have until now been mostly studied averaged over disks. Here, we study separately breaks in thin and thick disks in 70 edge-on galaxies using imaging from the Spitzer Survey of Stellar Structure in Galaxies. We built luminosity profiles of the thin and thick disks parallel to midplanes and we found that thin disks often truncate (77%). Thick disks truncate less often (31%), but when they do, their break radius is comparable with that in the thin disk. This suggests either two different truncation mechanisms—one of dynamical origin affecting both disks simultaneously and …
Trajectories And Distribution Of Interstellar Dust Grains In The Heliosphere,
2012
Harvard-Smithsonian Center for Astrophysics
Trajectories And Distribution Of Interstellar Dust Grains In The Heliosphere, Jonathan D. Slavin, Priscilla C. Frisch, Hans-Reinhard Müller, Jacob Heerikhuisen
Dartmouth Scholarship
The solar wind carves a bubble in the surrounding interstellar medium (ISM) known as the heliosphere. Charged interstellar dust grains (ISDG) encountering the heliosphere may be diverted around the heliopause or penetrate it depending on their charge-to-mass ratio. We present new calculations of trajectories of ISDG in the heliosphere, and the dust density distributions that result. We include up-to-date grain charging calculations using a realistic UV radiation field and full three-dimensional magnetohydrodynamic fluid + kinetic models for the heliosphere. Models with two different (constant) polarities for the solar wind magnetic field (SWMF) are used, with the grain trajectory calculations done …
Rotational And Cyclical Variability In Γ Cassiopeiae. Ii. Fifteen Seasons,
2012
Tennessee State University
Rotational And Cyclical Variability In Γ Cassiopeiae. Ii. Fifteen Seasons, Gregory W. Henry, Myron A. Smith
Information Systems and Engineering Management Research Publications
The B0.5 IVe star γ Cas is of great interest because it is the prototype of a small group of classical Be stars having hard X-ray emission of unknown origin. We discuss results from ongoing B and V observations of the γ Cas star–disk system acquired with an Automated Photometric Telescope during the observing seasons 1997–2011. In an earlier study, Smith, Henry, & Vishniac showed that light variations in γ Cas are dominated by a series of comparatively prominent cycles with amplitudes of 0.02–0.03 mag and lengths of 2–3 months, superimposed on a 1.21 day periodic signal some five times …
Modeling Spiral Galaxy Luminosity Profiles,
2012
Utah State University
Modeling Spiral Galaxy Luminosity Profiles, Jordan Rozum, Matt Garlock, Shane L. Larson, Bradley W. Carroll
Browse All Undergraduate research
The distribution of spiral and bar galaxy inclination an- gles is expected to be uniform. However, analysis of sev- eral major galaxy catalogs shows this is not the case; galaxies oriented near edge-on are significantly more common in these catalogs. In an attempt to explain this discrepancy, we have developed a galaxy simulation code to compute the appearance of a spiral type galaxy as a function of its morphological parameters. We examine the dependence of observed brightness upon inclination angle by using smooth luminous mass density and in- terstellar medium (ISM) density distributions. The lu- minous mass component is integrated …
Characterizing Sky Variability For Multi-Messenger Astronomy,
2012
Utah State University
Characterizing Sky Variability For Multi-Messenger Astronomy, Rachel Nydegger, Katie Breivik, Shane L. Larson
Browse All Undergraduate research
Multi-messenger astronomy employs both electromagnetic and gravitational wave detectors to paint a richer picture of celestial objects, providing more depth and in formation. Localizing sources with gravitational wave interferometers on the sky is difficult, with resolution of many square degrees. To have simultaneous electromagnetic observations (localized typically to less than one square degree) requires innovative techniques for the telescopes to find the origin of radiation. One idea is to tile the view of the interferometer, using multiple telescopes to simultaneously point at different areas of the field to observe the source. One problematic aspect of this observing paradigm is distinguishing …
