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8,856 full-text articles. Page 173 of 309.

The Statistical Mechanics Of Solar Wind Hydroxylation At The Moon, Within Lunar Magnetic Anomalies, And At Phobos, W. M. Farrell, D. M. Hurley, Vincent J. Esposito, J. L. McLain, M. I. Zimmerman 2017 NASA/Goddard Space Flight Center,

The Statistical Mechanics Of Solar Wind Hydroxylation At The Moon, Within Lunar Magnetic Anomalies, And At Phobos, W. M. Farrell, D. M. Hurley, Vincent J. Esposito, J. L. Mclain, M. I. Zimmerman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We present a new formalism to describe the outgassing of hydrogen initially implanted by the solar wind protons into exposed soils on airless bodies. The formalism applies a statistical mechanics approach similar to that applied recently to molecular adsorption onto activated surfaces. The key element enabling this formalism is the recognition that the interatomic potential between the implanted H and regolith-residing oxides is not of singular value but possess a distribution of trapped energy values at a given temperature, F(U,T). All subsequent derivations of the outward diffusion and H retention rely on the specific properties of this distribution. We …


Community Astronomy Lab Offered, Becky St. Clair 2017 Andrews University

Community Astronomy Lab Offered, Becky St. Clair

Andrews Agenda: Campus News

No abstract provided.


Eclipse Display, St. Charles City-County Library District 2017 Minnesota State University, Mankato

Eclipse Display, St. Charles City-County Library District

Space Exploration

Bibliography and photograph of a display of government documents from St. Charles City-County Library District, MO.


Multi-Messenger Observations Of A Binary Neutron Star Merger, B. P. Abbott, Gregory Snow 2017 California Institute of Technology

Multi-Messenger Observations Of A Binary Neutron Star Merger, B. P. Abbott, Gregory Snow

Gregory Snow Publications

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40 8 8 - + Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in …


M Dwarf Planet Habitability, Ben Koenigs 2017 Macalester College

M Dwarf Planet Habitability, Ben Koenigs

Gateway Prize for Excellent Writing

The habitability of M dwarf planets has been debated greatly, as their parent stars possess both beneficial and detrimental qualities for the development of life. Initially, the astrobiological community questioned their habitability (Dole 1964), but as research and modeling techniques have improved, astrobiologists have become more accepting of the idea of life on M dwarf planets (Shields et al. 2016). The question of these planets’ habitability has great significance, because their long lifespans and commonality in the universe make them legitimate candidates for a plethora of extrasolar spacecraft missions, and potentially for the first discovery of life in other systems.


Time-Dependent Spectropolarimetric Modeling Of Interacting Core Collapse Supernovae, Leah N. Huk 2017 University of Denver

Time-Dependent Spectropolarimetric Modeling Of Interacting Core Collapse Supernovae, Leah N. Huk

Electronic Theses and Dissertations

Explosive deaths of massive stars in core collapse supernovae are rare events that are only observed with any frequency at large intergalactic distances. This makes identification of progenitors difficult and massive star evolution a challenge to pin down. This dissertation addresses the question of how the properties of the circumstellar environment around supernovae can be used to identify progenitors via their mass loss history. Massive stars all lose mass through a variety of mechanisms that are characteristic of their mass, age, and binarity. This gives rise to a wide range of circumstellar environments which with supernovae may interact, producing multi-component …


Constraining The Physical State Of The Hot Gas Halos In Ngc 4649 And Ngc 5846, Alessandro Paggi, Dong-Woo Kim, Craig Anderson, Doug Burke, Raffaele D'Abrusco, Giuseppina Fabbiano, Antonella Fruscione, Tara Gokas, Jen Lauer, Michael McCollough, Doug Morgan, Amy Mossman, Ewan O'Sullivan, Ginevra Trinchieri, Saeqa Vrtilek, Silvia Pellegrini, Aaron Romanowsky, Jean Brodie 2017 Harvard-Smithsonian Center for Astrophysics

Constraining The Physical State Of The Hot Gas Halos In Ngc 4649 And Ngc 5846, Alessandro Paggi, Dong-Woo Kim, Craig Anderson, Doug Burke, Raffaele D'Abrusco, Giuseppina Fabbiano, Antonella Fruscione, Tara Gokas, Jen Lauer, Michael Mccollough, Doug Morgan, Amy Mossman, Ewan O'Sullivan, Ginevra Trinchieri, Saeqa Vrtilek, Silvia Pellegrini, Aaron Romanowsky, Jean Brodie

Faculty Publications

We present results of a joint Chandra/XMM-Newton analysis of the early-type galaxies NGC 4649 and NGC 5846 aimed at investigating differences between mass profiles derived from X-ray data and those from optical data, to probe the state of the hot interstellar medium (ISM) in these galaxies. If the hot ISM is at a given radius in hydrostatic equilibrium (HE), the X-ray data can be used to measure the total enclosed mass of the galaxy. Differences from optically derived mass distributions therefore yield information about departures from HE in the hot halos. The X-ray mass profiles in different angular …


Quantum Foundations With Astronomical Photons, Calvin Leung 2017 Claremont Colleges

Quantum Foundations With Astronomical Photons, Calvin Leung

HMC Senior Theses

Bell's inequalities impose an upper limit on correlations between measurements of two-photon states under the assumption that the photons play by a set of local rules rather than by quantum mechanics. Quantum theory and decades of experiments both violate this limit.

Recent theoretical work in quantum foundations has demonstrated that a local realist model can explain the non-local correlations observed in experimental tests of Bell's inequality if the underlying probability distribution of the local hidden variable depends on the choice of measurement basis, or ``setting choice''. By using setting choices determined by astrophysical events in the distant past, it is …


Draco, Christian Ekhoff 2017 Parkland College

Draco, Christian Ekhoff

Natural Sciences Student Research Presentations

This poster for the Natural Sciences Poster Session at Parkland College features the constellation Draco, which is positioned between the big and little dipper in the Northern sky. It is also circumpolar and contains a galaxy and a nebula in its boundaries. The student identified ten different key stars in the constellation, observed when they rose and set. He then graphed their altitudes and azimuth and identified their life spans.


Perihelion Precession In The General Theory Of Relativity, Charles G. Torre 2017 Department of Physics, Utah State University

Perihelion Precession In The General Theory Of Relativity, Charles G. Torre

Tutorials on... in 1 hour or less

This is a relatively quick and informal sketch of a demonstration that general relativistic corrections to the bound Kepler orbits introduce a perihelion precession. Any decent textbook on the general theory of relativity will derive this result. My analysis aligns with that found in the good old text "Introduction to General Relativity", by Adler, Bazin and Schiffer.


Ua35/3 Memoranda, WKU Provost 2017 Western Kentucky University

Ua35/3 Memoranda, Wku Provost

WKU Administration Documents

2017 memoranda issued by the WKU Provost to faculty and staff via email.

  • Faculty Mentoring Award
  • Undergraduae Mentoring Award Recipients
  • Fall 2017 Modified Class Schedule & the Great American Eclipse
  • Strategic Planning


Deconstructing A Galaxy: Colour Distributions Of Point Sources In Messier 83, A. K. Kiar, P. Barmby, A. Hidalgo 2017 The University of Western Ontario

Deconstructing A Galaxy: Colour Distributions Of Point Sources In Messier 83, A. K. Kiar, P. Barmby, A. Hidalgo

Physics and Astronomy Publications

What do we see when we look at a nearby, well-resolved galaxy? Thousands of individual sources are detected in multiband imaging observations of even a fraction of a nearby galaxy, and characterizing those sources is a complex process. This work analyses a ten-band photometric catalogue of nearly 70 000 point sources in a 7.3 square arcmin region of the nearby spiral galaxy Messier 83, made as part of the Early Release Science programme with the Hubble Space Telescope'sWide Field Camera 3. Colour distributions were measured for both broad-band and broad-and-narrow-band colours; colours made from broad-bands with large wavelength differences generally …


Short-Period Mesospheric Gravity Waves And Their Sources At The South Pole, Dhvanit Mehta, Andrew J. Gerrard, Yusuke Ebihara, Allan T. Weatherwax, Louis J. Lanzerotti 2017 Merrimack College

Short-Period Mesospheric Gravity Waves And Their Sources At The South Pole, Dhvanit Mehta, Andrew J. Gerrard, Yusuke Ebihara, Allan T. Weatherwax, Louis J. Lanzerotti

Physics Faculty Publications

The sourcing locations and mechanisms for short-period, upward-propagating gravity waves at high polar latitudes remain largely unknown. Using all-sky imager data from the Amundsen–Scott South Pole Station, we determine the spatial and temporal characteristics of 94 observed small-scale waves in 3 austral winter months in 2003 and 2004. These data, together with background atmospheres from synoptic and/or climatological empirical models, are used to model gravity wave propagation from the polar mesosphere to each wave's source using a ray-tracing model. Our results provide a compelling case that a significant proportion of the observed waves are launched in several discrete layers in …


Disk Heating, Galactoseismology, And The Formation Of Stellar Halos, Kathryn V. Johnston, Adrian M. Price-Whelan, Maria Bergemann, Chervin F. P. Laporte, Ting S. Li, Allyson A. Sheffield, Steven R. Majewski, Rachael S. Beaton, Branimir Sesar, Sanjib Sharma 2017 Columbia University

Disk Heating, Galactoseismology, And The Formation Of Stellar Halos, Kathryn V. Johnston, Adrian M. Price-Whelan, Maria Bergemann, Chervin F. P. Laporte, Ting S. Li, Allyson A. Sheffield, Steven R. Majewski, Rachael S. Beaton, Branimir Sesar, Sanjib Sharma

Publications and Research

Deep photometric surveys of the MilkyWay have revealed diffuse structures encircling our Galaxy far beyond the “classical” limits of the stellar disk. This paper reviews results from our own and other observational programs, which together suggest that, despite their extreme positions, the stars in these structures were formed in our Galactic disk. Mounting evidence from recent observations and simulations implies kinematic connections between several of these distinct structures. This suggests the existence of collective disk oscillations that can plausibly be traced all the way to asymmetries seen in the stellar velocity distribution around the Sun. There are multiple interesting implications …


Research At The University Of Kentucky Accelerator Laboratory, S. F. Hicks, Michael A. Kovash 2017 University of Dallas

Research At The University Of Kentucky Accelerator Laboratory, S. F. Hicks, Michael A. Kovash

Physics and Astronomy Faculty Publications

The Department of Physics and Astronomy at the University of Kentucky operates a 7-MV CN Van de Graaff accelerator that produces primary beams of protons, deuterons, and helium ions. An in-terminal pulsing and bunching system operates at 1.875 MHz and is capable of providing 1 ns beam bunches at an average current of several microamperes. Nearly all ongoing research programs involve secondary pulsed neutrons produced with gas cells containing deuterium or tritium, as well as with a variety of solid targets. Most experiments are performed at a target station positioned over a deep pit, so as to reduce the background …


The Space Race Piktograph, Katelyn Flanagan 2017 West Virginia University

The Space Race Piktograph, Katelyn Flanagan

West Virginia Connection

For this portion of the materials, I included two “Piktographs” for students to use as a resource for their research for the final assignment. The first is one on the contributions specifically from West Virginia to the space race. It includes specific people from West Virginia and their contributions to this portion of our nation’s history. This way students are able to make home connections to West Virginia. The second Piktograph is one specifically on The Green Bank Observatory located in Green Bank, WV. It is home to the first radio telescope, as well as being the first national astronomy …


The Green Bank Observatory Piktograph, Katelyn Flanagan 2017 West Virginia University

The Green Bank Observatory Piktograph, Katelyn Flanagan

West Virginia Connection

For this portion of the materials, I included two “Piktographs” for students to use as a resource for their research for the final assignment. The first is one on the contributions specifically from West Virginia to the space race. It includes specific people from West Virginia and their contributions to this portion of our nation’s history. This way students are able to make home connections to West Virginia. The second Piktograph is one specifically on The Green Bank Observatory located in Green Bank, WV. It is home to the first radio telescope, as well as being the first national astronomy …


The Green Bank Observatory And The Space Race - Introduction, Katelyn Flanagan 2017 West Virginia University

The Green Bank Observatory And The Space Race - Introduction, Katelyn Flanagan

West Virginia Connection

For this portion of the materials, I included two “Piktographs” for students to use as a resource for their research for the final assignment. The first is one on the contributions specifically from West Virginia to the space race. It includes specific people from West Virginia and their contributions to this portion of our nation’s history. This way students are able to make home connections to West Virginia. The second Piktograph is one specifically on The Green Bank Observatory located in Green Bank, WV. It is home to the first radio telescope, as well as being the first national astronomy …


Glass Plate Slides On Astronomy, Zach S. Henderson Library Special Collections 2017 Georgia Southern University

Glass Plate Slides On Astronomy, Zach S. Henderson Library Special Collections

Finding Aids

This collection consists of twenty-six glass plates slides used to teach Astronomy at Georgia Southern Teachers College, probably in the 1930s. They were produced by the Eastern Science Supply Company of Boston.

Find this collection in the University Libraries' catalog.


The Role Of Black Hole And Neutron Star Interaction On The Dynamical Evolution Of Dense Stellar Systems, Michael Pajkos 2017 Butler University

The Role Of Black Hole And Neutron Star Interaction On The Dynamical Evolution Of Dense Stellar Systems, Michael Pajkos

Undergraduate Honors Thesis Collection

With the recent detection of gravitational waves from the Laser Interferometer Gravitational-Wave Observatory, or LIGO, a new realm of gravitational astrophysics has been opened. As the process of observing gravitational wave signals is still in its infancy, there is a need to provide gravitational astronomers with observable signatures in the electromagnetic spectrum. Hence, we explore the impact of solar mass black holes on the morphology of globular clusters. It has long been thought that due to high kick velocities from compact object gravitational interaction, Galactic age Globular Clusters are unable to retain black holes. Recent simulations, however, suggest that a …


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