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Articles 2251 - 2280 of 8856
Full-Text Articles in Astrophysics and Astronomy
Creating A Sample Of Off-Color Galaxies Using Big Data Tools, Christopher Becker
Creating A Sample Of Off-Color Galaxies Using Big Data Tools, Christopher Becker
Honors Program Theses
This thesis begins an investigation into the presence of off-colored galaxies in the Sloan Digital Sky Survey. Through establishing the emergence and history of Astroinformatics, the thesis introduces the concepts surrounding both off-color galaxies and the Big Data tools helpful in analyzing the data to find them. A discussion of initial implementation methods and revised implementation due to difficulties with previous plans follows. Results are presented, with well in excess of 500,000 candidates for off-color galaxies present in the sample. Conclusions are then drawn regarding such a large sample and the implications this may have on the conventional understanding of …
The Large Millimeter Telescope (Lmt) Alfonso Serrano: Current Status And Telescope Performance, David H. Hughes, F. Peter Schloerb, Itziar Aretxaga, Edgar Castillo-Domínguez, Miguel Chávez Dagostino, Edgar Colín, Neal Erickson, Daniel Ferrusca Rodriguez, David M. Gale, Arturo Gómez-Ruiz, José Luis Hernández Rebollar, Mark Heyer, James Lowenthal, Alfredo Montaña, Marcos Emir Moreno Nolasco, Gopal Narayanan, Alexandra Pope, Iván Rodríguez-Montoya, David Sánchez-Argüelles, David Smith, Kamal Souccar, Miguel Velázquez De La Rosa Becerra, Grant W. Wilson, Min S. Yun
The Large Millimeter Telescope (Lmt) Alfonso Serrano: Current Status And Telescope Performance, David H. Hughes, F. Peter Schloerb, Itziar Aretxaga, Edgar Castillo-Domínguez, Miguel Chávez Dagostino, Edgar Colín, Neal Erickson, Daniel Ferrusca Rodriguez, David M. Gale, Arturo Gómez-Ruiz, José Luis Hernández Rebollar, Mark Heyer, James Lowenthal, Alfredo Montaña, Marcos Emir Moreno Nolasco, Gopal Narayanan, Alexandra Pope, Iván Rodríguez-Montoya, David Sánchez-Argüelles, David Smith, Kamal Souccar, Miguel Velázquez De La Rosa Becerra, Grant W. Wilson, Min S. Yun
Astronomy: Faculty Publications
The Large Millimeter Telescope (LMT) Alfonso Serrano is a 50m-diameter single-dish radio telescope constructed at an altitude of 4600 meters on the summit of Volcan Sierra Negra, an extinct volcano in the Mexican state of Puebla. The LMT is a bi-national scientific collaboration between Mexico and the USA, led by the Instituto Nacional de Astrofisica, Optica y Electronica (INAOE) and the University of Massachusetts at Amherst. The telescope currently operates at wavelengths from 4mm to 1mm, and during the dry winter months the LMT site provides the highest levels of atmospheric transmission and potential future access to submillimeter observing windows. …
First Resolved Scattered-Light Images Of Four Debris Disks In Scorpius-Centaurus With The Gemini Planet Imager, Justin Hom, Jennifer Patience, Thomas M. Esposito, Gaspard Duchene, Kadin Worthen, Paul Kalas, Hannah Jang-Condell, Kezman Saboi, Pauline Arriaga, Johan Mazoyer, Schuyler Wolff, Maxwell A. Millar-Blanchaer, Michael P. Fitzgerald, Marshall D. Perrin, Christine H. Chen, Bruce Macintosh, Brenda C. Matthews, Jason J. Wang, James R. Graham, Franck Marchis, S. Mark Ammons, Vanessa P. Bailey, Travis Barman, Joanna Bulger, Jeffrey K. Chilcote, Tara Cotten, Robert J. De Rosa, René Doyon, Katherine B. Follette, Steven Goodsell, Alexandra Z. Greenbaum, Pascale Hibon, Kimberly Ward-Duong, Et Al
First Resolved Scattered-Light Images Of Four Debris Disks In Scorpius-Centaurus With The Gemini Planet Imager, Justin Hom, Jennifer Patience, Thomas M. Esposito, Gaspard Duchene, Kadin Worthen, Paul Kalas, Hannah Jang-Condell, Kezman Saboi, Pauline Arriaga, Johan Mazoyer, Schuyler Wolff, Maxwell A. Millar-Blanchaer, Michael P. Fitzgerald, Marshall D. Perrin, Christine H. Chen, Bruce Macintosh, Brenda C. Matthews, Jason J. Wang, James R. Graham, Franck Marchis, S. Mark Ammons, Vanessa P. Bailey, Travis Barman, Joanna Bulger, Jeffrey K. Chilcote, Tara Cotten, Robert J. De Rosa, René Doyon, Katherine B. Follette, Steven Goodsell, Alexandra Z. Greenbaum, Pascale Hibon, Kimberly Ward-Duong, Et Al
Astronomy: Faculty Publications
We present the first spatially resolved scattered-light images of four debris disks around members of the Scorpius-Centaurus (Sco-Cen) OB association with high-contrast imaging and polarimetry using the Gemini Planet Imager (GPI). All four disks are resolved for the first time in polarized light, and one disk is also detected in total intensity. The three disks imaged around HD 111161, HD 143675, and HD 145560 are symmetric in both morphology and brightness distribution. The three systems span a range of inclinations and radial extents. The disk imaged around HD 98363 shows indications of asymmetries in morphology and brightness distribution, with some …
An Updated Visual Orbit Of The Directly Imaged Exoplanet 51 Eridani B And Prospects For A Dynamical Mass Measurement With Gaia, Robert J. De Rosa, Eric L. Nielsen, Jason J. Wang, S. Mark Ammons, Gaspard Duchene, Bruce Macintosh, Julien Rameau, Vanessa P. Bailey, Travis Barman, Joanna Bulger, Jeffrey Chilcote, Tara Cotten, Rene Doyon, Thomas M. Esposito, Michael P. Fitzgerald, Katherine B. Follette, Benjamin L. Gerard, Stephen J. Goodsell, James R. Graham, Alexandra Z. Greenbaum, Pascale Hibon, Justin Hom, Li Wei Hung, Patrick Ingraham, Paul Kalas, Quinn Konopacky, James E. Larkin, Jérôme Maire, Franck Marchis, Mark S. Marley, Christian Marois, Stanimir Metchev, Kimberly Ward-Duong, Et Al
An Updated Visual Orbit Of The Directly Imaged Exoplanet 51 Eridani B And Prospects For A Dynamical Mass Measurement With Gaia, Robert J. De Rosa, Eric L. Nielsen, Jason J. Wang, S. Mark Ammons, Gaspard Duchene, Bruce Macintosh, Julien Rameau, Vanessa P. Bailey, Travis Barman, Joanna Bulger, Jeffrey Chilcote, Tara Cotten, Rene Doyon, Thomas M. Esposito, Michael P. Fitzgerald, Katherine B. Follette, Benjamin L. Gerard, Stephen J. Goodsell, James R. Graham, Alexandra Z. Greenbaum, Pascale Hibon, Justin Hom, Li Wei Hung, Patrick Ingraham, Paul Kalas, Quinn Konopacky, James E. Larkin, Jérôme Maire, Franck Marchis, Mark S. Marley, Christian Marois, Stanimir Metchev, Kimberly Ward-Duong, Et Al
Astronomy: Faculty Publications
We present a revision to the visual orbit of the young, directly imaged exoplanet 51 Eridani b using four years of observations with the Gemini Planet Imager. The relative astrometry is consistent with an eccentric (e= 0.53-0.13+0.09) orbit at an intermediate inclination (i= 13611+10°), although circular orbits cannot be excluded due to the complex shape of the multidimensional posterior distribution. We find a semimajor axis of 11.1-1.3+4.2 au and a period of 28.1-4.9+17.2 yr, assuming a mass of 1.75 M· for the host star. We find consistent values with a recent analysis of VLT/SPHERE data covering a similar baseline. We …
Characterizing The Quantum Phase Transition Using A Flat Band In Circuit Qed Lattices, Gui-Lei Zhu, Xin-You Lü, Hamidreza Ramezani
Characterizing The Quantum Phase Transition Using A Flat Band In Circuit Qed Lattices, Gui-Lei Zhu, Xin-You Lü, Hamidreza Ramezani
Physics & Astronomy Faculty Publications
We show the superradiant phase transition (SPT) can control the existence of flat band in an extended Dicke-Hubbard lattice [1]
The Exogravity Project: Using Single Mode Interferometry To Characterize Exoplanets, S. Lacour, J. J. Wang, M. Nowak, L. Pueyo, F. Eisenhauer, A. M. Lagrange, P. Mollière, R. Abuter, A. Amorin, R. Asensio-Torres, M. Bauböck, M. Benisty, J. P. Berger, H. Beust, S. Blunt, A. Boccaletti, A. Bohn, M. Bonnefoy, H. Bonnet, W. Brandner, F. Cantalloube, P. Caselli, B. Charnay, G. Chauvin, E. Choquet, V. Christiaens, Y. Clénet, A. Cridland, P. T. De Zeeuw, R. Dembet, J. Dexter, A. Drescher, Kimberly Ward-Duong, Et Al
The Exogravity Project: Using Single Mode Interferometry To Characterize Exoplanets, S. Lacour, J. J. Wang, M. Nowak, L. Pueyo, F. Eisenhauer, A. M. Lagrange, P. Mollière, R. Abuter, A. Amorin, R. Asensio-Torres, M. Bauböck, M. Benisty, J. P. Berger, H. Beust, S. Blunt, A. Boccaletti, A. Bohn, M. Bonnefoy, H. Bonnet, W. Brandner, F. Cantalloube, P. Caselli, B. Charnay, G. Chauvin, E. Choquet, V. Christiaens, Y. Clénet, A. Cridland, P. T. De Zeeuw, R. Dembet, J. Dexter, A. Drescher, Kimberly Ward-Duong, Et Al
Astronomy: Faculty Publications
Combining adaptive optics and interferometric observations results in a considerable contrast gain compared to single-telescope, extreme AO systems. Taking advantage of this, the ExoGRAVITY project is a survey of known young giant exoplanets located in the range of 0.1"to 2"from their stars. The observations provide astrometric data of unprecedented accuracy, being crucial for refining the orbital parameters of planets and illuminating their dynamical histories. Furthermore, GRAVITY will measure non-Keplerian perturbations due to planet-planet interactions in multi-planet systems and measure dynamical masses. Over time, repetitive observations of the exoplanets at medium resolution (R = 500) will provide a catalogue of K-band …
Revised Astrometric Calibration Of The Gemini Planet Imager, Robert J. De Rosa, Meiji M. Nguyen, Jeffrey Chilcote, Bruce Macintosh, Marshall D. Perrin, Quinn Konopacky, Jason J. Wang, Gaspard Duchêne, Eric L. Nielsen, Julien Rameau, S. Mark Ammons, Vanessa P. Bailey, Travis Barman, Joanna Bulger, Tara Cotten, Rene Doyon, Thomas M. Esposito, Michael P. Fitzgerald, Katherine B. Follette, Benjamin L. Gerard, Stephen J. Goodsell, James R. Graham, Alexandra Z. Greenbaum, Pascale Hibon, Li Wei Hung, Patrick Ingraham, Paul Kalas, James E. Larkin, Jérôme Maire, Franck Marchis, Mark S. Marley, Christian Marois, Kimberly Ward-Duong, Et Al
Revised Astrometric Calibration Of The Gemini Planet Imager, Robert J. De Rosa, Meiji M. Nguyen, Jeffrey Chilcote, Bruce Macintosh, Marshall D. Perrin, Quinn Konopacky, Jason J. Wang, Gaspard Duchêne, Eric L. Nielsen, Julien Rameau, S. Mark Ammons, Vanessa P. Bailey, Travis Barman, Joanna Bulger, Tara Cotten, Rene Doyon, Thomas M. Esposito, Michael P. Fitzgerald, Katherine B. Follette, Benjamin L. Gerard, Stephen J. Goodsell, James R. Graham, Alexandra Z. Greenbaum, Pascale Hibon, Li Wei Hung, Patrick Ingraham, Paul Kalas, James E. Larkin, Jérôme Maire, Franck Marchis, Mark S. Marley, Christian Marois, Kimberly Ward-Duong, Et Al
Astronomy: Faculty Publications
We present a revision to the astrometric calibration of the Gemini Planet Imager (GPI), an instrument designed to achieve the high contrast at small angular separations necessary to image substellar and planetary-mass companions around nearby, young stars. We identified several issues with the GPI data reduction pipeline (DRP) that significantly affected the determination of the angle of north in reduced GPI images. As well as introducing a small error in position angle measurements for targets observed at small zenith distances, this error led to a significant error in the previous astrometric calibration that has affected all subsequent astrometric measurements. We …
Hunting For Ultra Diffuse Galaxies In The Hubble Space Telescope Data Archive, Nicholas Schragal
Hunting For Ultra Diffuse Galaxies In The Hubble Space Telescope Data Archive, Nicholas Schragal
Summer Community of Scholars Posters (RCEU and HCR Combined Programs)
No abstract provided.
On Entropy Conservation And Kinetic Energy Preservation Methods, H. C. Yee, Björn Sjögreen
On Entropy Conservation And Kinetic Energy Preservation Methods, H. C. Yee, Björn Sjögreen
United States National Aeronautics and Space Administration: Publications
The Tadmor-type entropy conservative method using the mathematical logarithmic entropy function and two forms of the Sjögreen & Yee entropy conservative methods using the Harten entropy function are examined for their nonlinear stability and accuracy in very long time integration of the Euler equations of compressible gas dynamics. Following the same procedure as Ranocha [6] these entropy conservative methods can be made kinetic energy preserving with minimum added computational effort. The focus of this work is to examine the nonlinear stability and accuracy of these newly introduced high order entropy conserving and kinetic energy preserving methods for very long time …
There Is No Constant In Physics: A Neutrosophic Explanation, Victor Christianto, Robert Neil Boyd, Florentin Smarandache
There Is No Constant In Physics: A Neutrosophic Explanation, Victor Christianto, Robert Neil Boyd, Florentin Smarandache
Branch Mathematics and Statistics Faculty and Staff Publications
In Neutrosophic Logic, a basic assertion is that there are variations of about everything that we can measure; the variations surround three parameters called T,I,F (truth, indeterminacy, falsehood) which can take a range of values. Similarly, in this paper we consider NL applications in physics constants. Those constants actually all have a window of plus and minus values, relative to the average value of the constant. For example, speed of light, c, can vary in a window up to +/- 3000 m/s. Therefore it should be written: 300000 km/s +/- 3 km/s. We also discuss some implications of this new …
Searching For The Common Suprathermal Power Law Tail In Parker Solar Probe's Isois Data, Asher S. Merrill
Searching For The Common Suprathermal Power Law Tail In Parker Solar Probe's Isois Data, Asher S. Merrill
Honors Theses and Capstones
Results from the Advanced Composition Explorer (ACE) and the Ulysses spacecraft suggested the existence of a pervasive power-law spectrum of suprathermal ions in the solar wind with a spectral index of -3/2. This distribution is of particular interest to humanity because the suprathermal ions it describes can serve as the seed population for large, destructive events that can harm ground- and air-based equipment. It has been suggested that various statistical mechanisms can produce the observed spectrum, however the underlying physical phenomena are not yet known. The spectrum of suprathermal ions is relatively unstudied closer to the Sun than 1 au. …
Retrieval Of The D/Sdl7+T7.5p Binary Sdss J1416+1348ab, Eileen C. Gonzales, Ben Burningham, Jacqueline K. Faherty, Colleen Cleary, Channon Visscher, Mark S. Marley, Roxana Lupu, Richard Freedman
Retrieval Of The D/Sdl7+T7.5p Binary Sdss J1416+1348ab, Eileen C. Gonzales, Ben Burningham, Jacqueline K. Faherty, Colleen Cleary, Channon Visscher, Mark S. Marley, Roxana Lupu, Richard Freedman
Faculty Work Comprehensive List
We present the distance-calibrated spectral energy distribution (SED) of the d/sdL7 SDSS J14162408+1348263A (J1416A) and an updated SED for SDSS J14162408+1348263B (J1416B). We also present the first retrieval analysis of J1416A using the Brewster retrieval code base and the second retrieval of J1416B. We find that the primary is best fit by a nongray cloud opacity with a power-law wavelength dependence but is indistinguishable between the type of cloud parameterization. J1416B is best fit by a cloud-free model, consistent with the results from Line et al. Most fundamental parameters derived via SEDs and retrievals are consistent within 1σ for both …
Exoplanets: Correlated Noise And Cautionary Tales, Ryan Challener
Exoplanets: Correlated Noise And Cautionary Tales, Ryan Challener
Electronic Theses and Dissertations, 2020-2023
Transiting exoplanets provide the best opportunity for planetary characterization, and thus the search for life outside the Solar System. These planets orbit such that they pass in front ("transit'') and behind ("eclipse'') their host star, and a spectrum of the lost flux constrains the atmospheric properties of the planet. In transits, the flux modulation scales with the cross-sectional area of the planet, and the spectrum includes signatures of molecules in the upper atmosphere of the planet's terminator, which the host star's light passes through on the way to the observer. With eclipses, the lost flux is the direct emission of …
Experimental And Numerical Investigations Of Granular Dynamics In Microgravity, Stephanie Jarmak
Experimental And Numerical Investigations Of Granular Dynamics In Microgravity, Stephanie Jarmak
Electronic Theses and Dissertations, 2020-2023
During the first stages of planet formation small particles (~0.1 – 1 µm) in the protoplanetary disk collide at low relative velocities (less than 1 m/s) and tend to aggregate into cm-size "pebbles" through a combination of electrostatic interactions and gravitational streaming instabilities. Particles in this size regime also compose a layer of regolith on small, airless bodies that evolves under conditions very different than those on Earth. Characterizing the response of regolith to low-energy impacts in a microgravity environment is therefore critical to our understanding of the processes that lead to the formation of these objects and our ability …
A Review On Superluminal Physics And Superluminal Communication In Light Of The Neutrosophic Logic Perspective, Victor Christianto, Florentin Smarandache
A Review On Superluminal Physics And Superluminal Communication In Light Of The Neutrosophic Logic Perspective, Victor Christianto, Florentin Smarandache
Branch Mathematics and Statistics Faculty and Staff Publications
In a recent paper, we describe a model of quantum communication based on combining consciousness experiment and entanglement, which can serve as impetus to stop 5G-network-caused diseases. Therefore, in this paper we consider superluminal physics and superluminal communication as a bridge or intermediate way between subluminal physics and action-at-a-distance (AAAD) physics, especially from neutrosophic logic perspective. Although several ways have been proposed to bring such a superluminal communication into reality, such as Telluric wave or Telepathy analog of Horejev and Baburin, here we also review two possibilities: quaternion communication and also quantum communication based on quantum noise. Further research is …
Measured Optical Absorption Cross Sections Of Tio, Peter Bernath
Measured Optical Absorption Cross Sections Of Tio, Peter Bernath
Chemistry & Biochemistry Faculty Publications
A laboratory emission spectrum of TiO in the visible and near-infrared regions (476–1176 nm) has been calibrated and corrected. High-resolution experimental absorption cross sections for TiO with natural isotopic abundance are provided at a temperature of about 2300 K. These cross sections have been compared with those derived from the ExoMol line list. The experimental cross sections can be used directly as a template for cross correlation TiO detection in hot Jupiter exoplanets.
Three Possible Applications Of Neutrosophic Logic In Fundamental And Applied Sciences, Victor Christianto, Robert Neil Boyd, Florentin Smarandache
Three Possible Applications Of Neutrosophic Logic In Fundamental And Applied Sciences, Victor Christianto, Robert Neil Boyd, Florentin Smarandache
Branch Mathematics and Statistics Faculty and Staff Publications
In Neutrosophic Logic, a basic assertion is that there are variations of about everything that we can measure; the variations surround three parameters called T,I,F (truth, indeterminacy, falsehood) which can take a range of values. This paper shortly reviews the links among aether and matter creation from the perspective of Neutrosophic Logic. Once we accept the existence of aether as physical medium, then we can start to ask on what causes matter ejection, as observed in various findings related to quasars etc. One particular cosmology model known as VMH (variable mass hypothesis) has been suggested by notable astrophysicists like Halton …
Impact Of Satellite Constellations On Optical Astronomy And Recommendations Toward Mitigations, Constance Walker, Jeffrey Hall, Lori Allen, Richard Green, Patrick Seitzer, Tony Tyson, Amanda Bauer, Kelsie Krafton, James D. Lowenthal, Et Al
Impact Of Satellite Constellations On Optical Astronomy And Recommendations Toward Mitigations, Constance Walker, Jeffrey Hall, Lori Allen, Richard Green, Patrick Seitzer, Tony Tyson, Amanda Bauer, Kelsie Krafton, James D. Lowenthal, Et Al
Astronomy: Faculty Publications
Existing and planned large constellations of bright satellites in low-Earth orbit (LEOsats) will fundamentally change astronomical observing at optical and near-infrared (NIR) wavelengths. Nighttime images without the passage of a Sun-illuminated satellite will no longer be the norm. If the 100,000 or more LEOsats proposed by many companies and many governments are deployed, no combination of mitigations can fully avoid the impacts of the satellite trails on the science programs of current and planned ground-based optical-NIR astronomy facilities. Astronomers are just beginning to understand the full range of impacts on the discipline. Astrophotography, amateur astronomy, and the human experience of …
A Photometric Study Of The South Polar Terrain Of Enceladus, Bereket Daniel Mamo
A Photometric Study Of The South Polar Terrain Of Enceladus, Bereket Daniel Mamo
All Graduate Theses, Dissertations, and Other Capstone Projects
Saturn's moon, Enceladus, is a unique body in the Solar System. It is an icy world with ongoing geologic activity that spews out jets of ice particles, water vapor, and other gases from active tectonic fractures (called sulci) near its south pole. Emission from these jets is the dominant source of particles for Saturn's diffuse E ring, which envelops other icy satellites. The south polar fractures are also sources of tidally generated high heat flow. Accurate determination of this endogenic thermal output requires knowledge of the thermophysical properties of the surface, which are reliably estimated by modeling the photometric behavior …
Significance Of Gravitational Nonlinearities On The Dynamics Of Disk Galaxies, Alexandre Deur, Corey Sargent, Balša Terzić
Significance Of Gravitational Nonlinearities On The Dynamics Of Disk Galaxies, Alexandre Deur, Corey Sargent, Balša Terzić
Physics Faculty Publications
The discrepancy between the visible mass in galaxies or galaxy clusters and that inferred from their dynamics is well known. The prevailing solution to this problem is dark matter. Here we show that a different approach, one that conforms to both the current standard model of particle physics and general relativity (GR), explains the recently observed tight correlation between the galactic baryonic mass and the measured accelerations in the galaxy. Using direct calculations based on GR's Lagrangian and parameter-free galactic models, we show that the nonlinear effects of GR make baryonic matter alone sufficient to explain this observation. Our approach …
Magnetic Structure And Radiative Captures Of Few-Nucleon Systems: Status And Prospects, Laura Elisa Marcucci, Rocco Schiavilla, Alex Gnech, Michele Viviani
Magnetic Structure And Radiative Captures Of Few-Nucleon Systems: Status And Prospects, Laura Elisa Marcucci, Rocco Schiavilla, Alex Gnech, Michele Viviani
Physics Faculty Publications
We review the main ingredients for an ab-initio study of few-nucleon reactions of astrophysical interest within the chiral effective field theory approach, with particular attention to radiative captures relevant for Big Bang Nucleosynthesis and stellar evolution. We conclude with an outlook for ongoing and future work.
Just A Bit Of Physics Can Tell So Much: A Unique Story Of The Start Of The Earth-Moon System, Fred J. Cadieu
Just A Bit Of Physics Can Tell So Much: A Unique Story Of The Start Of The Earth-Moon System, Fred J. Cadieu
Publications and Research
The start of the Earth-Moon system has been studied to show that this was an exceptionally violent event. One result was that Earth became the terrestrial planet with the highest average density. Another result was that Earth acquired enough mass and radioactive elements that it is expected to maintain a molten core region and magnetic field for the expected life of the Earth. Earth alone of the terrestrial planets was then able to develop plate tectonics as a long term energy release mechanism. The dipole magnetic field of the Sun reverses periodically, currently at the rate of about every 11 …
Identification Of Fragmented Brightest Cluster Galaxies, Andrew Guillory
Identification Of Fragmented Brightest Cluster Galaxies, Andrew Guillory
Summer Community of Scholars Posters (RCEU and HCR Combined Programs)
No abstract provided.
On The Detection Of Gw190814, Matthew E. Gill
On The Detection Of Gw190814, Matthew E. Gill
Theses and Dissertations
The eld of gravitational wave astronomy is currently at an all time high. The
rst half of the most recent observing run (April 1, 2019 - September 30, 2019) yielded
a total of 39 gravitational wave detections, including 13 from sources which had not
been identied by other astronomical observation methods before. This is three times
as many detections than were measured in the rst two observing runs combined.
In this paper, the design sensitivity decisions leading to this unprecedented rate of
detection are explored. In particular, we detail the nature of the LIGO and VIRGO
gravitational wave interferometers. One …
Model Comparison From Ligo–Virgo Data On Gw170817’S Binary Components And Consequences For The Merger Remnant, B. P. Abbott, R. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Karla E. Ramirez, Satzhan Sitmukhambetov, Robert Stone, Wenhui Wang
Model Comparison From Ligo–Virgo Data On Gw170817’S Binary Components And Consequences For The Merger Remnant, B. P. Abbott, R. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Karla E. Ramirez, Satzhan Sitmukhambetov, Robert Stone, Wenhui Wang
Physics & Astronomy Faculty Publications
GW170817 is the very first observation of gravitational waves originating from the coalescence of two compact objects in the mass range of neutron stars, accompanied by electromagnetic counterparts, and offers an opportunity to directly probe the internal structure of neutron stars. We perform Bayesian model selection on a wide range of theoretical predictions for the neutron star equation of state. For the binary neutron star hypothesis, we find that we cannot rule out the majority of theoretical models considered. In addition, the gravitational-wave data alone does not rule out the possibility that one or both objects were low-mass black holes. …
The Future Of Space Governance, Melissa J. Durkee
The Future Of Space Governance, Melissa J. Durkee
Scholarly Works
Fifty years after the first moonwalk, the prospect for a new set of multilateral agreements governing outer space is remote, yet the legal questions raised by activity in space are mounting. With little prospect of new treaties, nations will need to make do with existing treaty law, generate customary rules to govern new applications, or develop forms of sub-legal understanding and cooperation. This special conference issue of the Georgia Journal of International and Comparative Law addresses these questions.
Searching For Needles In The Cosmic Haystack, Thomas Ryan Devine
Searching For Needles In The Cosmic Haystack, Thomas Ryan Devine
Graduate Theses, Dissertations, and Problem Reports (ETD)
Searching for pulsar signals in radio astronomy data sets is a difficult task. The data sets are extremely large, approaching the petabyte scale, and are growing larger as instruments become more advanced. Big Data brings with it big challenges. Processing the data to identify candidate pulsar signals is computationally expensive and must utilize parallelism to be scalable. Labeling benchmarks for supervised classification is costly. To compound the problem, pulsar signals are very rare, e.g., only 0.05% of the instances in one data set represent pulsars. Furthermore, there are many different approaches to candidate classification with no consensus on a best …
Searches For Fast Radio Bursts Using Machine Learning, Devansh Agarwal
Searches For Fast Radio Bursts Using Machine Learning, Devansh Agarwal
Graduate Theses, Dissertations, and Problem Reports (ETD)
Fast Radio bursts (FRBs) are enigmatic astrophysical events with millisecond durations and flux densities in the range 0.1-100 Jy, with the prototype source discovered by Lorimer et al. (2007). Like pulsars, FRBs show the characteristic inverse square sweep in observing frequency due to propagation through an ionized medium. This effect is quantified by the dispersion measure (DM). Unlike pulsars, FRBs have anomalously high DMs, which are consistent with an extragalactic origin. Over 100 FRBs have been published at the time of writing, and 13 have been conclusively identified with host galaxies with spectroscopically determined redshifts in the range 0.003 ≤ …
Modeling The Galactic Compact Binary Neutron Star Population And Studying The Double Pulsar System, Nihan Pol
Modeling The Galactic Compact Binary Neutron Star Population And Studying The Double Pulsar System, Nihan Pol
Graduate Theses, Dissertations, and Problem Reports (ETD)
Binary neutron star (BNS) systems consisting of at least one neutron star provide an avenue for testing a broad range of physical phenomena ranging from tests of General Relativity to probing magnetospheric physics to understanding the behavior of matter in the densest environments in the Universe. Ultra-compact BNS systems with orbital periods less than few tens of minutes emit gravitational waves with frequencies ~mHz and are detectable by the planned space-based Laser Interferometer Space Antenna (LISA), while merging BNS systems produce a chirping gravitational wave signal that can be detected by the ground-based Laser Interferometer Gravitational-Wave Observatory (LIGO). Thus, BNS …
Galaxy And Mass Assembly (Gama): Properties And Evolution Of Red Spiral Galaxies, Smriti Mahajan, Kriti Kamal Gupta, Rahul Rana, M. J.I. Brown, S. Phillipps, Joss Bland-Hawthorn, M. N. Bremer, S. Brough, Benne W. Holwerda, A. M. Hopkins, J. Loveday, Kevin Pimbblet, Lingyu Wang
Galaxy And Mass Assembly (Gama): Properties And Evolution Of Red Spiral Galaxies, Smriti Mahajan, Kriti Kamal Gupta, Rahul Rana, M. J.I. Brown, S. Phillipps, Joss Bland-Hawthorn, M. N. Bremer, S. Brough, Benne W. Holwerda, A. M. Hopkins, J. Loveday, Kevin Pimbblet, Lingyu Wang
Faculty and Staff Scholarship
We use multiwavelength data from the Galaxy And Mass Assembly (GAMA) survey to explore the cause of red optical colours in nearby (0.002 < z < 0.06) spiral galaxies. We show that the colours of red spiral galaxies are a direct consequence of some environment-related mechanism(s) that has removed dust and gas, leading to a lower star formation rate. We conclude that this process acts on long time-scales (several Gyr) due to a lack of morphological transformation associated with the transition in optical colour. The specific star formation rate (sSFR) and dust-to-stellar mass ratio of red spiral galaxies is found to be statistically lower than blue spiral galaxies. On the other hand, red spirals are on average 0.9 dex more massive, and reside in environments 2.6 times denser than their blue counterparts. We find no evidence of excessive nuclear activity, or higher inclination angles to support these as the major causes for the red optical colours seen in ≳47 per cent of all spirals in our sample. Furthermore, for a small subsample of our spiral galaxies that are detected in H I, we find that the SFR of gas-rich red spiral galaxies is lower by ∼1 dex than their blue counterparts.