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Articles 1711 - 1740 of 8856

Full-Text Articles in Astrophysics and Astronomy

Search For Anisotropic Gravitational-Wave Backgrounds Using Data From Advanced Ligo And Advanced Virgo's First Three Observing Runs, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, A. Adams, C. Adams, R. X. Adhikari, V. B. Adya, C. Affeldt, D. Agarwal, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, T. Akutsu, Tiffany Z. Summerscales Jul 2021

Search For Anisotropic Gravitational-Wave Backgrounds Using Data From Advanced Ligo And Advanced Virgo's First Three Observing Runs, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, A. Adams, C. Adams, R. X. Adhikari, V. B. Adya, C. Affeldt, D. Agarwal, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, T. Akutsu, Tiffany Z. Summerscales

Faculty Publications

We report results from searches for anisotropic stochastic gravitational-wave backgrounds using data from the first three observing runs of the Advanced LIGO and Advanced Virgo detectors. For the first time, we include Virgo data in our analysis and run our search with a new efficient pipeline called pystoch on data folded over one sidereal day. We use gravitational-wave radiometry (broadband and narrow band) to produce sky maps of stochastic gravitational-wave backgrounds and to search for gravitational waves from point sources. A spherical harmonic decomposition method is employed to look for gravitational-wave emission from spatially-extended sources. Neither technique found evidence of …


Upper Limits On The Isotropic Gravitational-Wave Background From Advanced Ligo And Advanced Virgo’S Third Observing Run, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales Jul 2021

Upper Limits On The Isotropic Gravitational-Wave Background From Advanced Ligo And Advanced Virgo’S Third Observing Run, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales

Faculty Publications

We report results of a search for an isotropic gravitational-wave background (GWB) using data from Advanced LIGO’s and Advanced Virgo’s third observing run (O3) combined with upper limits from the earlier O1 and O2 runs. Unlike in previous observing runs in the advanced detector era, we include Virgo in the search for the GWB. The results of the search are consistent with uncorrelated noise, and therefore we place upper limits on the strength of the GWB. We find that the dimensionless energy density ΩGW≤5.8×10−9 at the 95% credible level for a flat (frequency-independent) GWB, using a prior which is uniform …


Search For Anisotropic Gravitational-Wave Backgrounds Using Data From Advanced Ligo And Advanced Virgo’S First Three Observing Runs, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales Jul 2021

Search For Anisotropic Gravitational-Wave Backgrounds Using Data From Advanced Ligo And Advanced Virgo’S First Three Observing Runs, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales

Faculty Publications

We report results from searches for anisotropic stochastic gravitational-wave backgrounds using data from the first three observing runs of the Advanced LIGO and Advanced Virgo detectors. For the first time, we include Virgo data in our analysis and run our search with a new efficient pipeline called pystoch on data folded over one sidereal day. We use gravitational-wave radiometry (broadband and narrow band) to produce sky maps of stochastic gravitational-wave backgrounds and to search for gravitational waves from point sources. A spherical harmonic decomposition method is employed to look for gravitational-wave emission from spatially-extended sources. Neither technique found evidence of …


Search For Gravitational Waves Associated With Gamma-Ray Bursts Detected By Fermi And Swift During The Ligo–Virgo Run O3a, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, Amit Aich, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov Jul 2021

Search For Gravitational Waves Associated With Gamma-Ray Bursts Detected By Fermi And Swift During The Ligo–Virgo Run O3a, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, Amit Aich, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov

Physics & Astronomy Faculty Publications

We search for gravitational-wave transients associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the first part of the third observing run of Advanced LIGO and Advanced Virgo (2019 April 1 15:00 UTC–2019 October 1 15:00 UTC). A total of 105 GRBs were analyzed using a search for generic gravitational-wave transients; 32 GRBs were analyzed with a search that specifically targets neutron star binary mergers as short GRB progenitors. We find no significant evidence for gravitational-wave signals associated with the GRBs that we followed up, nor for a population of unidentified subthreshold signals. We consider several …


Search For Gravitational Waves Associated With Gamma-Ray Bursts Detected By Fermi And Swift During The Ligo-Virgo Run O3a, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, C. Adams, R. X. Adhikari, V. B. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, A. Aich, L. Aiello, A. Ain, P. Ajith, G. Allen, A. Allocca, Tiffany Z. Summerscales Jul 2021

Search For Gravitational Waves Associated With Gamma-Ray Bursts Detected By Fermi And Swift During The Ligo-Virgo Run O3a, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, C. Adams, R. X. Adhikari, V. B. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, A. Aich, L. Aiello, A. Ain, P. Ajith, G. Allen, A. Allocca, Tiffany Z. Summerscales

Faculty Publications

We search for gravitational-wave transients associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the first part of the third observing run of Advanced LIGO and Advanced Virgo (2019 April 1 15:00 UTC-2019 October 1 15:00 UTC). A total of 105 GRBs were analyzed using a search for generic gravitational-wave transients; 32 GRBs were analyzed with a search that specifically targets neutron star binary mergers as short GRB progenitors. We find no significant evidence for gravitational-wave signals associated with the GRBs that we followed up, nor for a population of unidentified subthreshold signals. We consider several …


California Legacy Survey. Ii. Occurrence Of Giant Planets Beyond The Ice Line, Benjamin J. Fulton, Lee J. Rosenthal, Lea A. Hirsch, Howard Isaacson, Andrew W. Howard, Cayla M. Dedrick, Ilya A. Sherstyuk, Sarah C. Blunt, Erik A. Petigura, Heather A. Knutson, Aida Behmard, Ashley Chontos, Justin R. Crepp, Ian J. M. Crossfield, Paul A. Dalba, Debra A. Fischer, Gregory W. Henry, Stephen R. Kane, Molly Kosiarek, Geoffrey W. Marcy, Ryan A. Rubenzahl, Lauren M. Weiss, Jason T. Wright Jul 2021

California Legacy Survey. Ii. Occurrence Of Giant Planets Beyond The Ice Line, Benjamin J. Fulton, Lee J. Rosenthal, Lea A. Hirsch, Howard Isaacson, Andrew W. Howard, Cayla M. Dedrick, Ilya A. Sherstyuk, Sarah C. Blunt, Erik A. Petigura, Heather A. Knutson, Aida Behmard, Ashley Chontos, Justin R. Crepp, Ian J. M. Crossfield, Paul A. Dalba, Debra A. Fischer, Gregory W. Henry, Stephen R. Kane, Molly Kosiarek, Geoffrey W. Marcy, Ryan A. Rubenzahl, Lauren M. Weiss, Jason T. Wright

Information Systems and Engineering Management Research Publications

We used high-precision radial velocity measurements of FGKM stars to determine the occurrence of giant planets as a function of orbital separation spanning 0.03–30 au. Giant planets are more prevalent at orbital distances of 1–10 au compared to orbits interior or exterior of this range. The increase in planet occurrence at ∼1 au by a factor of ∼4 is highly statistically significant. A fall-off in giant planet occurrence at larger orbital distances is favored over models with flat or increasing occurrence. We measure ${14.1}_{-1.8}^{+2.0}$ giant planets per 100 stars with semimajor axes of 2–8 au and ${8.9}_{-2.4}^{+3.0}$ giant planets per …


Search For Gravitational Waves Associated With Gamma-Ray Bursts Detected By Fermi And Swift During The Ligo–Virgo Run O3a, Ligo Scientific Collaboration, Virgo Collaboration, Tiffany Z. Summerscales Jul 2021

Search For Gravitational Waves Associated With Gamma-Ray Bursts Detected By Fermi And Swift During The Ligo–Virgo Run O3a, Ligo Scientific Collaboration, Virgo Collaboration, Tiffany Z. Summerscales

Faculty Publications

We search for gravitational-wave transients associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the first part of the third observing run of Advanced LIGO and Advanced Virgo (2019 April 1 15:00 UTC–2019 October 1 15:00 UTC). A total of 105 GRBs were analyzed using a search for generic gravitational-wave transients; 32 GRBs were analyzed with a search that specifically targets neutron star binary mergers as short GRB progenitors. We find no significant evidence for gravitational-wave signals associated with the GRBs that we followed up, nor for a population of unidentified subthreshold signals. We consider several …


Resolving Galactic Binaries In Lisa Data Using Particle Swarm Optimization And Cross-Validation, Xue-Hao Zhang, Soumya Mohanty, Xiao-Bo Zou, Yu-Xiao Liu Jul 2021

Resolving Galactic Binaries In Lisa Data Using Particle Swarm Optimization And Cross-Validation, Xue-Hao Zhang, Soumya Mohanty, Xiao-Bo Zou, Yu-Xiao Liu

Physics & Astronomy Faculty Publications

The space-based gravitational wave detector Laser Interferometric Space Antenna is expected to observe signals from a large population of compact object binaries, comprised predominantly of white dwarfs, in the Milky Way. Resolving individual sources from this population against its self-generated confusion noise poses a major data analysis problem. We present an iterative source estimation and subtraction method to address this problem based on the use of particle swarm optimization (PSO). In addition to PSO, a novel feature of the method is the cross-validation of sources estimated from the same data using different signal parameter search ranges. This is found to …


Galaxy And Mass Assembly (Gama): The Clustering Of Galaxy Groups, S D. Riggs, R W Y M Barbhuiyan, J Loveday, S Brough, Benne Holwerda, A M. Hopkins, S Phillipps Jul 2021

Galaxy And Mass Assembly (Gama): The Clustering Of Galaxy Groups, S D. Riggs, R W Y M Barbhuiyan, J Loveday, S Brough, Benne Holwerda, A M. Hopkins, S Phillipps

Faculty and Staff Scholarship

We explore the clustering of galaxy groups in the Galaxy and Mass Assembly (GAMA) survey to investigate the dependence of group bias and profile on separation scale and group mass. Due to the inherent uncertainty in estimating the group selection function, and hence the group autocorrelation function, we instead measure the projected galaxy–group cross-correlation function. We find that the group profile has a strong dependence on scale and group mass on scales r⊥≲1h−1" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; font-variant: inherit; font-stretch: inherit; line-height: normal; font-family: inherit; vertical-align: baseline; display: inline; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; …


Tunable Non-Hermitian Acoustic Filter, S. Puri, J. Ferdous, A. Shakeri, A. Basiri, M. Dubois, Hamidreza Ramezani Jul 2021

Tunable Non-Hermitian Acoustic Filter, S. Puri, J. Ferdous, A. Shakeri, A. Basiri, M. Dubois, Hamidreza Ramezani

Physics & Astronomy Faculty Publications

We propose, design, and experimentally test a non-Hermitian acoustic superlattice that acts as a tunable precise filter. The superlattice is composed of two concatenated sublattices. The first sublattice is Hermitian, while the other can be adjusted to be Hermitian or non-Hermitian. The existence of non-Hermiticity, in terms of an induced loss in the second sublattice, results in the generation of absorption resonances that appear in the reflected spectrum. This provides us with a powerful knob to absorb or reflect several frequencies at will with high accuracy. The number of filtered frequencies can be controlled by designing the resonances in the …


Search For Bs0 →Η′Xs S ¯ At Belle Using A Semi-Inclusive Method Search For Bs0 →Η′Xs S ¯ ... Dubey Et Al., S. Dubey, T. E. Browder, H. Aihara, S. Al Said, D. M. Asner, T. Aushev, R. Ayad, V. Babu, S. Bahinipati, P. Behera, J. Bennett, M. Bessner, B. Bhuyan, S. Bilokin, J. Biswal, A. Bobrov, G. Bonvicini, A. Bozek, M. Bračko Jul 2021

Search For Bs0 →Η′Xs S ¯ At Belle Using A Semi-Inclusive Method Search For Bs0 →Η′Xs S ¯ ... Dubey Et Al., S. Dubey, T. E. Browder, H. Aihara, S. Al Said, D. M. Asner, T. Aushev, R. Ayad, V. Babu, S. Bahinipati, P. Behera, J. Bennett, M. Bessner, B. Bhuyan, S. Bilokin, J. Biswal, A. Bobrov, G. Bonvicini, A. Bozek, M. Bračko

Faculty and Student Publications

We report the first search for the penguin-dominated process Bs0→η′Xss¯ using a semi-inclusive method. A 121.4 fb-1 integrated luminosity ϒ(5S) data set collected by the Belle experiment, at the KEKB asymmetric-energy e+e- collider, is used. We observe no statistically significant signal and, including all uncertainties, we set a 90% confidence level upper limit on the partial branching fraction at 1.4×10-3 for M(Xss¯)≤2.4 GeV/c2.


The California Legacy Survey. I. A Catalog Of 178 Planets From Precision Radial Velocity Monitoring Of 719 Nearby Stars Over Three Decades, Lee J. Rosenthal, Benjamin J. Fulton, Lea A. Hirsch, Howard Isaacson, Andrew W. Howard, Cayla M. Dedrick, Ilya A. Sherstyuk, Sarah C. Blunt, Erik A. Petigura, Heather Knutson, Aida Behmard, Ashley Chontos, Justin R. Crepp, Ian J. M. Crossfield, Paul A. Dalba, Debra A. Fischer, Gregory W. Henry, Stephen R. Kane, Molly Kosiarek, Geoffrey W. Marcy, Ryan A. Rubenzahl, Lauren M. Weiss, Jason T. Wright Jul 2021

The California Legacy Survey. I. A Catalog Of 178 Planets From Precision Radial Velocity Monitoring Of 719 Nearby Stars Over Three Decades, Lee J. Rosenthal, Benjamin J. Fulton, Lea A. Hirsch, Howard Isaacson, Andrew W. Howard, Cayla M. Dedrick, Ilya A. Sherstyuk, Sarah C. Blunt, Erik A. Petigura, Heather Knutson, Aida Behmard, Ashley Chontos, Justin R. Crepp, Ian J. M. Crossfield, Paul A. Dalba, Debra A. Fischer, Gregory W. Henry, Stephen R. Kane, Molly Kosiarek, Geoffrey W. Marcy, Ryan A. Rubenzahl, Lauren M. Weiss, Jason T. Wright

Information Systems and Engineering Management Research Publications

We present a high-precision radial velocity (RV) survey of 719 FGKM stars, which host 164 known exoplanets and 14 newly discovered or revised exoplanets and substellar companions. This catalog updated the orbital parameters of known exoplanets and long-period candidates, some of which have decades-longer observational baselines than they did upon initial detection. The newly discovered exoplanets range from warm sub-Neptunes and super-Earths to cold gas giants. We present the catalog sample selection criteria, as well as over 100,000 RV measurements, which come from the Keck-HIRES, APF-Levy, and Lick-Hamilton spectrographs. We introduce the new RV search pipeline RVSearch (https://california-planet-search.github.io/rvsearch/) that we …


Measurements Of Partial Branching Fractions Of Inclusive B →Xuℓ+Νℓ Decays With Hadronic Tagging, L. Cao, W. Sutcliffe, R. Van Tonder, F. U. Bernlochner, I. Adachi, H. Aihara, S. Al Said, D. M. Asner, H. Atmacan, T. Aushev, R. Ayad, V. Babu, M. Bauer, P. Behera, K. Belous, J. Bennett, M. Bessner, V. Bhardwaj, T. Bilka Jul 2021

Measurements Of Partial Branching Fractions Of Inclusive B →Xuℓ+Νℓ Decays With Hadronic Tagging, L. Cao, W. Sutcliffe, R. Van Tonder, F. U. Bernlochner, I. Adachi, H. Aihara, S. Al Said, D. M. Asner, H. Atmacan, T. Aushev, R. Ayad, V. Babu, M. Bauer, P. Behera, K. Belous, J. Bennett, M. Bessner, V. Bhardwaj, T. Bilka

Faculty and Student Publications

We present measurements of partial branching fractions of inclusive semileptonic B→Xuℓ+νℓ decays using the full Belle dataset of 711 fb-1 of integrated luminosity at the ϒ(4S) resonance and for ℓ=e, μ. Inclusive semileptonic B→Xuℓ+νℓ decays are Cabibbo-Kobayashi-Maskawa (CKM) suppressed and measurements are complicated by the large background from CKM favored B→Xcℓ+νℓ transitions, which have a similar signature. Using machine learning techniques, we reduce this and other backgrounds effectively, while retaining access to a large fraction of the B→Xuℓ+νℓ phase space and high signal efficiency. We measure partial branching fractions in three phase-space regions covering about 31% to 86% of the …


Warm Jupiters In Tess Full-Frame Images: A Catalog And Observed Eccentricity Distribution For Year 1, J. Dong, C. X. Huang, R. I. Dawson, D. Foreman-Mackey, K. A. Collins, S. N. Quinn, J. J. Lissauer, T. Beatty, B. Quarles, L. Sha, A. Shporer, Z. Guo, S. R. Kane, L. Abe, K. Barkaoui, Z. Benkhaldoun, R. Brahm, F. Bouchy, T. W. Carmichael, K. I. Collins, D. M. Conti, N. Crouzet, G. Dransfield, P. Evans, T. Gan, M. Ghachoui, M. Gillon, N. Grieves, T. Guillot, C. Hellier, E. Jehin, Eric L.N. Jensen, A. Jordán, J. Kamler, J. F. Kielkopf, D. Mékarnia, L. D. Nielsen, F. J. Pozuelos, D. J. Radford, F.-X. Schmider, R. P. Schwarz, C. Stockdale, T.-G. Tan, M. Timmermans, A. H. M. J. Triaud, G. Wang, G. Ricker, R. Vanderspek, D. W. Latham, S. Seager, J. N. Winn, J. M. Jenkins, I. Mireles, D. A. Yahalomi, E. H. Morgan, M. Vezie, E. V. Quintana, M. E. Rose, J. C. Smith, B. Shiao Jul 2021

Warm Jupiters In Tess Full-Frame Images: A Catalog And Observed Eccentricity Distribution For Year 1, J. Dong, C. X. Huang, R. I. Dawson, D. Foreman-Mackey, K. A. Collins, S. N. Quinn, J. J. Lissauer, T. Beatty, B. Quarles, L. Sha, A. Shporer, Z. Guo, S. R. Kane, L. Abe, K. Barkaoui, Z. Benkhaldoun, R. Brahm, F. Bouchy, T. W. Carmichael, K. I. Collins, D. M. Conti, N. Crouzet, G. Dransfield, P. Evans, T. Gan, M. Ghachoui, M. Gillon, N. Grieves, T. Guillot, C. Hellier, E. Jehin, Eric L.N. Jensen, A. Jordán, J. Kamler, J. F. Kielkopf, D. Mékarnia, L. D. Nielsen, F. J. Pozuelos, D. J. Radford, F.-X. Schmider, R. P. Schwarz, C. Stockdale, T.-G. Tan, M. Timmermans, A. H. M. J. Triaud, G. Wang, G. Ricker, R. Vanderspek, D. W. Latham, S. Seager, J. N. Winn, J. M. Jenkins, I. Mireles, D. A. Yahalomi, E. H. Morgan, M. Vezie, E. V. Quintana, M. E. Rose, J. C. Smith, B. Shiao

Physics & Astronomy Faculty Works

Warm Jupiters—defined here as planets larger than 6 Earth radii with orbital periods of 8–200 days—are a key missing piece in our understanding of how planetary systems form and evolve. It is currently debated whether Warm Jupiters form in situ, undergo disk or high-eccentricity tidal migration, or have a mixture of origin channels. These different classes of origin channels lead to different expectations for Warm Jupiters' properties, which are currently difficult to evaluate due to the small sample size. We take advantage of the Transiting Exoplanet Survey Satellite (TESS) survey and systematically search for Warm Jupiter candidates around main-sequence host …


"Super Gzk" Particles In A Classic Kramers' Diffusion-Over-A-Barrier Model. I. The Case Of Protons, S. T. Alnussirat, A. F. Barghouty, G. M. Webb, P. L. Biermann Jul 2021

"Super Gzk" Particles In A Classic Kramers' Diffusion-Over-A-Barrier Model. I. The Case Of Protons, S. T. Alnussirat, A. F. Barghouty, G. M. Webb, P. L. Biermann

Faculty Publications

In interactions of ultra-high-energy cosmic ray (UHECR) protons with cosmic microwave background photons, we focus in this work on photopion production reactions and the effects of the measured, broad, energy-loss distributions in these reactions on the evolution of the protons' density functions in energy space. We rely on a Fokker-Planck transport equation in energy space whose transport coefficients are calculated using laboratory measurements. We also derive a Fokker-Planck potential that accounts for both systematic (drift) and stochastic (dispersive) energy losses due to photopion production reactions. Our results show that dispersive energy losses have significant effects on estimating the protons' horizon …


Relating Dust Reference Models To Conventional Systems In Manifestly Gauge Invariant Perturbation Theory, Kristina Giesel, Bao-Fei Li, Parampreet Singh Jul 2021

Relating Dust Reference Models To Conventional Systems In Manifestly Gauge Invariant Perturbation Theory, Kristina Giesel, Bao-Fei Li, Parampreet Singh

Faculty Publications

Models with dust reference fields in relational formalism have proved useful in understanding the construction of gauge invariant perturbation theory to arbitrary orders in the canonical framework. These reference fields modify the dynamical equations for perturbation equations. However, important questions remain open on the relation with conventional perturbation theories of inflaton coupled to gravity and of multifluid systems, and on understanding modifications in terms of physical degrees of freedom. These gaps are filled in this manuscript for Brown-Kuchar and Gaussian dust models, both of which involve three scalar physical degrees of freedom. We establish a relationship of these models with …


Octo-Tiger: A New, 3d Hydrodynamic Code For Stellar Mergers That Uses Hpx Parallelization, Dominic C. Marcello, Sagiv Shiber, Orsola De Marco, Juhan Frank, Geoffrey C. Clayton, Patrick M. Motl, Patrick Diehl, Hartmut Kaiser Jul 2021

Octo-Tiger: A New, 3d Hydrodynamic Code For Stellar Mergers That Uses Hpx Parallelization, Dominic C. Marcello, Sagiv Shiber, Orsola De Marco, Juhan Frank, Geoffrey C. Clayton, Patrick M. Motl, Patrick Diehl, Hartmut Kaiser

Faculty Publications

OCTO-TIGER is an astrophysics code to simulate the evolution of self-gravitating and rotating systems of arbitrary geometry based on the fast multipole method, using adaptive mesh refinement. OCTO-TIGER is currently optimized to simulate the merger of well-resolved stars that can be approximated by barotropic structures, such as white dwarfs (WDs) or main-sequence stars. The gravity solver conserves angular momentum to machine precision, thanks to a 'correction' algorithm. This code uses firx parallelization, allowing the overlap of work and communication and leading to excellent scaling properties, allowing for the computation of large problems in reasonable wall-clock times. In this paper, we …


Particle Acceleration At The Discontinuous Flow Boundary Of Collimated Cylindrical Jets, Stephen O'Sullivan, Andrew M. Taylor, Brian Reville Jul 2021

Particle Acceleration At The Discontinuous Flow Boundary Of Collimated Cylindrical Jets, Stephen O'Sullivan, Andrew M. Taylor, Brian Reville

Conference Papers

We revisit the issue of particle acceleration at the interface between a collimated laminar jet and a static ambient medium. The contrast between standard diffusive scattering treatments and anomalous transport in synthetic field constructions is explored. A particular emphasis is placed on the necessity for physically consistent particle transport considerations. The temporal, spatial and spectral features of the process are discussed, in the context of potential UHECR production, as well as further observational consequences.


An Experimental Study Of Evaporites On Titan: Implications For Lake Composition And Future Missions, Ellen Czaplinski Jul 2021

An Experimental Study Of Evaporites On Titan: Implications For Lake Composition And Future Missions, Ellen Czaplinski

Graduate Theses and Dissertations

Titan is the only other planetary body in the solar system with liquid on the surface. With a surface temperature and pressure of 89 – 94 K and 1.5 bar (N2), respectively, Titan’s lakes are comprised of liquid hydrocarbons, predominantly methane and ethane. Over time, Titan’s lakes may evaporate, leaving behind residual deposits (evaporites). The evaporation processes and composition of the evaporites is poorly understood. I address these outstanding questions by experimentally investigating the physical and spectral properties of evaporites at Titan surface conditions using an experimental chamber.

Chapter 1 addresses the formation of ethylene evaporites. Ethylene evaporites form more …


Observation Of Gravitational Waves From Two Neutron Star–Black Hole Coalescences, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Karla E. Ramirez, W. H. Wang Jul 2021

Observation Of Gravitational Waves From Two Neutron Star–Black Hole Coalescences, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Karla E. Ramirez, W. H. Wang

Physics & Astronomy Faculty Publications

We report the observation of gravitational waves from two compact binary coalescences in LIGO's and Virgo's third observing run with properties consistent with neutron star–black hole (NSBH) binaries. The two events are named GW200105_162426 and GW200115_042309, abbreviated as GW200105 and GW200115; the first was observed by LIGO Livingston and Virgo and the second by all three LIGO–Virgo detectors. The source of GW200105 has component masses and , whereas the source of GW200115 has component masses and (all measurements quoted at the 90% credible level). The probability that the secondary's mass is below the maximal mass of a neutron star is …


A Numerical Study Of Jovian Moist Convection With A New Convective Adjustment Scheme, And Implications For Jupiter’S Water Abundance, Ramanakumar Sankar Jul 2021

A Numerical Study Of Jovian Moist Convection With A New Convective Adjustment Scheme, And Implications For Jupiter’S Water Abundance, Ramanakumar Sankar

Theses and Dissertations

Jupiter’s atmosphere features a variety of clouds that are formed from the interplay of chemistry and atmospheric dynamics, from the deep red of the Great Red Spot to the high altitude white ammonia clouds present in the zones. Beneath these upper level clouds, water condensation occurs, and sporadically leads to the formation of towering convective storms, driven by the release of large amounts of latent heat. These storms result in a widespread disruption of the cloud and dynamical structure of the atmosphere at the latitude where they form, making the study of these events paramount in understanding the dynamics at …


Tess As A Low-Surface-Brightness Observatory: Cutouts From Wide-Area Coadded Images, G. Bruce Berriman, John C. Good, Benne Holwerda Jul 2021

Tess As A Low-Surface-Brightness Observatory: Cutouts From Wide-Area Coadded Images, G. Bruce Berriman, John C. Good, Benne Holwerda

Faculty and Staff Scholarship

We present a mosaic of those co-added Full Frame Images acquired by the TESS satellite that had been released in 2020 April. The mosaic shows substantial stray light over the sky. Yet over spatial scales of a few degrees, the background appears uniform. This result indicates that TESS has considerable potential as a Low Surface Brightness Observatory. The co-added images are freely available as a High Level Science Product (HLSP) at MAST and accessible through a Jupyter Notebook.


Observation Of Gravitational Waves From Two Neutron Star-Black Hole Coalescences, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, A. Adams, C. Adams, R. X. Adhikari, V. B. Adya, C. Affeldt, D. Agarwal, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, T. Akutsu, Tiffany Z. Summerscales Jul 2021

Observation Of Gravitational Waves From Two Neutron Star-Black Hole Coalescences, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, A. Adams, C. Adams, R. X. Adhikari, V. B. Adya, C. Affeldt, D. Agarwal, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, T. Akutsu, Tiffany Z. Summerscales

Faculty Publications

We report the observation of gravitational waves from two compact binary coalescences in LIGO's and Virgo's third observing run with properties consistent with neutron star-black hole (NSBH) binaries. The two events are named GW200105_162426 and GW200115_042309, abbreviated as GW200105 and GW200115; the first was observed by LIGO Livingston and Virgo and the second by all three LIGO-Virgo detectors. The source of GW200105 has component masses, whereas the source of GW200115 has component masses and (all measurements quoted at the 90% credible level). The probability that the secondary's mass is below the maximal mass of a neutron star is 89%-96% and …


Automated Photometry Of Γ Cassiopeiae: The Last Roundup, M. A. Smith, Gregory W. Henry Jun 2021

Automated Photometry Of Γ Cassiopeiae: The Last Roundup, M. A. Smith, Gregory W. Henry

Information Systems and Engineering Management Research Publications

γ Cassiopeiae (B0.5IVe) is the noted prototype of a subgroup of classical Be stars exhibiting hard thermal X-ray emission. This paper reports results from a 23 yr optical campaign on this star with an automated photometric telescope (APT). A series of unstable long cycles of length 56–91 days has nearly ceased over the last decade. Also, we revise the frequency of the dominant coherent signal at 0.82238 days−1. This signal's amplitude has nearly disappeared in the last 15 yr but has somewhat recovered its former strength. We confirm the presence of secondary nonradial pulsation signals found by other authors at …


Observation Of Gravitational Waves From Two Neutron Star–Black Hole Coalescences, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales Jun 2021

Observation Of Gravitational Waves From Two Neutron Star–Black Hole Coalescences, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales

Faculty Publications

We report the observation of gravitational waves from two compact binary coalescences in LIGO's and Virgo's third observing run with properties consistent with neutron star–black hole (NSBH) binaries. The two events are named GW200105_162426 and GW200115_042309, abbreviated as GW200105 and GW200115; the first was observed by LIGO Livingston and Virgo and the second by all three LIGO–Virgo detectors. The source of GW200105 has component masses and , whereas the source of GW200115 has component masses and (all measurements quoted at the 90% credible level). The probability that the secondary's mass is below the maximal mass of a neutron star is …


Searching For The Global 21 Cm Cosmic Dawn Absorption Signal With The Long Wavelength Array, Christopher Dilullo Jun 2021

Searching For The Global 21 Cm Cosmic Dawn Absorption Signal With The Long Wavelength Array, Christopher Dilullo

Physics & Astronomy ETDs

The redshifted 21 cm signal from neutral hydrogen offers one of the best observational probes of Cosmic Dawn and the Epoch of Reionization. This dissertation presents an effort to detect the redshifted 21 cm signal using the Long Wavelength Array station located on the Sevilleta National Wildlife Refuge in New Mexico, USA (LWA-SV). The major goal is to validate the potential detection reported by the EDGES collaboration. This measurement requires a dynamic range on the order of 105 in order to disentangle the cosmological signal from the Galactic foregrounds. The beamforming capability of LWA-SV is novel to this search. …


Corrigendum: The Remote Observatories Of The Southeastern Association For Research In Astronomy (Sara), William C. Keel, Terry Oswalt, Peter Mack, Gary Henson, Todd Hillwig, Daniel Batcheldor, Robert Berrington, Chris De Pree, Dieter Hartmann, Martha Leake, Javier Licandro, Brian Murphy, James Webb, Matt A. Wood Jun 2021

Corrigendum: The Remote Observatories Of The Southeastern Association For Research In Astronomy (Sara), William C. Keel, Terry Oswalt, Peter Mack, Gary Henson, Todd Hillwig, Daniel Batcheldor, Robert Berrington, Chris De Pree, Dieter Hartmann, Martha Leake, Javier Licandro, Brian Murphy, James Webb, Matt A. Wood

Publications

Bill Gray of Project Pluto brought to our attention an error of 0.03° in the listed latitude of our Kitt Peak telescope. While correcting the table where this occurred, we also take the opportunity to update the instrument properties and weather statistics of our remote telescopes


Collisions In A Gas-Rich White Dwarf Planetary Debris Disc, Ted Von Hippel, University College London, Scott J. Kenyon, Jay Farihi, Erik Dennihy, Boris T. Gänsicke, J.J. Hermes, Carl Melis Jun 2021

Collisions In A Gas-Rich White Dwarf Planetary Debris Disc, Ted Von Hippel, University College London, Scott J. Kenyon, Jay Farihi, Erik Dennihy, Boris T. Gänsicke, J.J. Hermes, Carl Melis

Publications

WD 0145+234 is a white dwarf that is accreting metals from a circumstellar disc of planetary material. It has exhibited a substantial and sustained increase in 3–5 μm flux since 2018. Follow-up Spitzer photometry reveals that emission from the disc had begun to decrease by late 2019. Stochastic brightening events superimposed on the decline in brightness suggest the liberation of dust during collisional evolution of the circumstellar solids. A simple model is used to show that the observations are indeed consistent with ongoing collisions. Rare emission lines from circumstellar gas have been detected at this system, supporting the emerging picture …


Constraints On Cosmic Strings Using Data From The Third Advanced Ligo-Virgo Observing Run, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, A. Adams, C. Adams, R. X. Adhikari, V. B. Adya, C. Affeldt, D. Agarwal, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, T. Akutsu, Tiffany Z. Summerscales Jun 2021

Constraints On Cosmic Strings Using Data From The Third Advanced Ligo-Virgo Observing Run, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, A. Adams, C. Adams, R. X. Adhikari, V. B. Adya, C. Affeldt, D. Agarwal, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, T. Akutsu, Tiffany Z. Summerscales

Faculty Publications

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop …


Constraints On Cosmic Strings Using Data From The Third Advanced Ligo–Virgo Observing Run, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales Jun 2021

Constraints On Cosmic Strings Using Data From The Third Advanced Ligo–Virgo Observing Run, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales

Faculty Publications

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop …