# Astrophysics and Astronomy Commons™

## All Articles in Astrophysics and Astronomy

7,539 full-text articles. Page 5 of 237.

The Sizes Of Z ∼ 9-10 Galaxies Identified In The Brightest Of Reionizing Galaxies (Borg) Survey, 2020 University of Louisville

#### The Sizes Of Z ∼ 9-10 Galaxies Identified In The Brightest Of Reionizing Galaxies (Borg) Survey, Benne W. Holwerda, Joanna S. Bridge, Rebecca L. Steele, Samir Kusmic, Larry Bradley, Rachael Livermore, Stephanie Bernard, Alice Jacques

##### Faculty Scholarship

Redshift z = 9-10 object selection is the effective limit of Hubble Space Telescope (HST) imaging capability, even when confirmed with Spitzer. If only a few photometry data points are available, it becomes attractive to add criteria based on their morphology in these J- and H-band images. One could do so through visual inspection, a size criterion, or alternate morphometrics. We explore a vetted sample of Brightest of Reionizing Galaxies (BoRG) z ∼ 9 and z ∼ 10 candidate galaxies and the object rejected by Morishita+ to explore the utility of a size criterion in z = 9-10 candidate selection. A stringent, point-spread function ...

Very High Energy Studies Of The Crab Nebula, 2020 DePauw University

#### Very High Energy Studies Of The Crab Nebula, Madeline Claus, Ashna Coondiah, Omer Sajid

##### Science Research Fellows Posters

The Crab Nebula is the remnant of a powerful stellar explosion first observed in 1054 AD and is the most studied object outside of our solar system. Our three-pronged research is focused on understanding the emission mechanisms responsible for energy range 100 MeV – 10 TeV. Our project consisted of 1) making light curves of Crab Nebula from Fermi-LAT’s data, 2) extending and investigating the pre-existing VERITAS light curve, and 3) phaseograms of the Crab Pulsar using VERITAS’s data.

Supervisor: Prof. Avery Archer, PhD

This research is supported by grants from the U.S. Department of Energy Office of ...

Gravitational-Wave Constraints On The Equatorial Ellipticity Of Millisecond Pulsars, 2020 The University of Texas Rio Grande Valley

#### Gravitational-Wave Constraints On The Equatorial Ellipticity Of Millisecond Pulsars, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, Teviet Creighton, Mario C. Diaz, S. Mukherjee, V. Quetschke, Malik Rakhmanov, K. E. Ramirez, W. H. Wang

##### Physics and Astronomy Faculty Publications and Presentations

We present a search for continuous gravitational waves from five radio pulsars, comprising three recycled pulsars (PSR J0437−4715, PSR J0711−6830, and PSR J0737−3039A) and two young pulsars: the Crab pulsar (J0534+2200) and the Vela pulsar (J0835−4510). We use data from the third observing run of Advanced LIGO and Virgo combined with data from their first and second observing runs. For the first time we are able to match (for PSR J0437−4715) or surpass (for PSR J0711−6830) the indirect limits on gravitational-wave emission from recycled pulsars inferred from their observed spin-downs, and constrain their ...

Two Portions Of Sagittarius Stream In The Lamost Complete Spectroscopic Survey Of Pointing Area At Southern Galactic Cap, 2020 Chinese Academy of Sciences

#### Two Portions Of Sagittarius Stream In The Lamost Complete Spectroscopic Survey Of Pointing Area At Southern Galactic Cap, J. K. Zhao, Terry D. Oswalt, X. H. Ye, H. Wu, M. Yang, X. X. Xue, Y. Q. Chen, J. J. Zhan, G. Zhao

##### Publications

We constructed a sample of 13,798 stars with Teﬀ , log g, [Fe/H], radial velocity, proper motions and parallaxes from LAMOST DR5 and Gaia DR2 in the LAMOST Complete Spectroscopic Survey of Pointing Area (LaCoSSPAr) at the Southern Galactic Cap consisting of areas A and B. Using the distributions in both proper motions and radial velocity, we detected very signiﬁcant overdensi- ties in these two areas. These substructures most likely are portions of Sagittarius (Sgr) stream. With the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm, 220 candidates stream members were identiﬁed. Based upon distance to the Sun ...

Interplay Of Quantum Phase Transition And Flat Band In Hybrid Lattices, 2020 The University of Texas Rio Grande Valley

#### Interplay Of Quantum Phase Transition And Flat Band In Hybrid Lattices, Gui-Lei Zhu, Hamidrez Ramezani, Clive Emary, Jin-Hua Gao, Ying Wu, Xin-You Lü

##### Physics and Astronomy Faculty Publications and Presentations

We establish a connection between quantum phase transitions (QPTs) and energy band theory in an extended Dicke-Hubbard lattice, where the periodical critical curves modulated by wave number k leads to rich equilibrium dynamics. Interestingly, the chiral-symmetry-protected flat band and the localization that it engenders exclusively occurs in the normal phase and disappears in the superradiant phase. This originates from the QPT induced simultaneous breaking up of the on-site resonance condition and off-site chiral symmetry of the system, which prohibits the destructive interference for obtaining a flat band. Our work offers an approach to identify different phases of the lattice via ...

Optical Study Of Pks B1322-110, The Intra-Hour Variable Radio Source, 2020 The University of Texas Rio Grande Valley

#### Optical Study Of Pks B1322-110, The Intra-Hour Variable Radio Source, Juan P. Madrid, Artem V. Tuntsov, Mischa Schirmer, Mark A. Walker, Carlos J. Donzelli, Keith W. Bannister, Hayley E. Bignall, Jamie Stevens, Cormac Reynolds, Simon Johnston

##### Physics and Astronomy Faculty Publications and Presentations

Observations with the Australia Telescope Compact Array revealed intra-hour variations in the radio source PKS B1322-110 (Bignall et al. 2019). As part of an optical follow-up, we obtained Gemini Hα and Hα continuum (HαC) images of the PKS B1322-110 field. A robust 19 σ detection of PKS B1322- 110 in the Hα−HαC image prompted us to obtain the first optical spectrum of PKS B1322-110. With the Gemini spectrum we determine that PKS B1322-110 is a flat-spectrum radio quasar at a redshift of z = 3.007 ± 0.002. The apparent flux detected in the Hα filter is likely to originate ...

26 Results Of Hyperbolic Partial Differential Equations In B-Poly Basis, 2020 The University of Texas Rio Grande Valley

#### 26 Results Of Hyperbolic Partial Differential Equations In B-Poly Basis, Muhammad I. Bhatti, Emilio Hinojosa

##### Physics and Astronomy Faculty Publications and Presentations

A two-variable process to estimate results of Hyperbolic Partial Differentiation (HPD) equations in a B-Polynomial (B-Poly) bases is established. In the proposed process, a linear product of variable coefficients and B-Polys is manipulated to express the predicted solution of the HPD equation. The variable coefficients of the linear mixture in the results are concluded using Galerkin technique. The HPD equation is converted into a matrix which when inverted provided the unknown coefficients in the linear mixture of the solution. The anticipated solution is constructed from the variable coefficients and B-Poly basis set as a product with initial conditions implemented. Both ...

Sensitivity And Performance Of The Advanced Ligo Detectors In The Third Observing Run, 2020 The University of Texas Rio Grande Valley

#### Sensitivity And Performance Of The Advanced Ligo Detectors In The Third Observing Run, A. Buikema, C. Cahillane, G. L. Mansell, C. D. Blair, R. Abbott, C. Adams, R. Adhikari, K. E. Ramirez

##### Physics and Astronomy Faculty Publications and Presentations

On April 1st, 2019, the Advanced Laser Interferometer Gravitational-Wave Observatory (aLIGO), joined by the Advanced Virgo detector, began the third observing run, a year-long dedicated search for gravitational radiation. The LIGO detectors have achieved a higher duty cycle and greater sensitivity to gravitational waves than ever before, with LIGO Hanford achieving angle-averaged sensitivity to binary neutron star coalescences to a distance of 111 Mpc, and LIGO Livingston to 134 Mpc with duty factors of 74.6% and 77.0% respectively. The improvement in sensitivity and stability is a result of several upgrades to the detectors, including doubled intracavity power, the ...

Gw190521: A Binary Black Hole Merger With A Total Mass Of 150  M⊙, 2020 Missouri University of Science and Technology

#### Gw190521: A Binary Black Hole Merger With A Total Mass Of 150  M⊙, R. Abbott, T. D. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

##### Physics Faculty Research & Creative Works

On May 21, 2019 at 03:02:29 UTC Advanced LIGO and Advanced Virgo observed a short duration gravitational-wave signal, GW190521, with a three-detector network signal-to-noise ratio of 14.7, and an estimated false-alarm rate of 1 in 4900 yr using a search sensitive to generic transients. If GW190521 is from a quasicircular binary inspiral, then the detected signal is consistent with the merger of two black holes with masses of 85+21−14  M⊙ and 66+17−18  M⊙ (90% credible intervals). We infer that the primary black hole mass lies within the gap produced by (pulsational) pair-instability supernova ...

Directional Limits On Persistent Gravitational Waves Using Data From Advanced Ligo’S First Two Observing Runs, 2020 Andrews University

#### Directional Limits On Persistent Gravitational Waves Using Data From Advanced Ligo’S First Two Observing Runs, Tiffany Summerscales, Ligo Scientific Collaboration And The Virgo Collaboration

##### Faculty Publications

We perform an unmodeled search for persistent, directional gravitational wave (GW) sources using data from the first and second observing runs of Advanced LIGO. We do not find evidence for any GW signals. We place limits on the broadband GW flux emitted at 25 Hz from point sources with a power law spectrum at Fα,Θ<(0.05–25)×10−8  erg cm−2 s−1 Hz−1 and the (normalized) energy density spectrum in GWs at 25 Hz from extended sources at Ωα(Θ)<(0.19–2.89)×10−8  sr−1 where α is the spectral index of the energy density spectrum. These represent improvements ...

Gw190521: A Binary Black Hole Merger With A Total Mass Of 150 M, 2020 California Institute of Technology

#### Gw190521: A Binary Black Hole Merger With A Total Mass Of 150 M, 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, S. Akcay, G. Allen, A. Allocca, P. A. Altin, A. Amato, S. Anand, A. Ananyeva, S. B. Anderson, W. G. Anderson, S. V. Angelova, S. Ansoldi, S. Antier, S. Appert, K. Arai, Tiffany Z. Summerscales

##### Faculty Publications

© 2020 authors. Published by the American Physical Society. On May 21, 2019 at 03:02:29 UTC Advanced LIGO and Advanced Virgo observed a short duration gravitational-wave signal, GW190521, with a three-detector network signal-to-noise ratio of 14.7, and an estimated false-alarm rate of 1 in 4900 yr using a search sensitive to generic transients. If GW190521 is from a quasicircular binary inspiral, then the detected signal is consistent with the merger of two black holes with masses of 85-14+21 Mm and 66-18+17 Mm (90% credible intervals). We infer that the primary black hole mass lies within the ...

Gw190521: A Binary Black Hole Merger With A Total Mass Of 150 M⊙, 2020 The University of Texas Rio Grande Valley

#### Gw190521: A Binary Black Hole Merger With A Total Mass Of 150 M⊙, R. Abbott, T. D. Abbott, A. Aich, G. Bissenbayeva, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, K. E. Ramirez, P. K. Roy, W. H. Wang, A. K. Zadrozny

##### Physics and Astronomy Faculty Publications and Presentations

On May 21, 2019 at 03:02:29 UTC Advanced LIGO and Advanced Virgo observed a short duration gravitational-wave signal, GW190521, with a three-detector network signal-to-noise ratio of 14.7, and an estimated false-alarm rate of 1 in 4900 yr using a search sensitive to generic transients. If GW190521 is from a quasicircular binary inspiral, then the detected signal is consistent with the merger of two black holes with masses of 85+21−14  M⊙ and 66+17−18  M⊙ (90% credible intervals). We infer that the primary black hole mass lies within the gap produced by (pulsational) pair-instability supernova ...

Properties And Astrophysical Implications Of The 150 M ⊙ Binary Black Hole Merger Gw190521, 2020 The University of Texas Rio Grande Valley

#### Properties And Astrophysical Implications Of The 150 M ⊙ Binary Black Hole Merger Gw190521, R. Abbott, T. D. Abbott, A. Aich, G. Bissenbayeva, Teviet Creighton, Mario C. Diaz, S. Mukherjee, V. Quetschke, Malik Rakhmanov, K. E. Ramirez, P. K. Roy, W. H. Wang, A. K. Zadrozny

##### Physics and Astronomy Faculty Publications and Presentations

The gravitational-wave signal GW190521 is consistent with a binary black hole (BBH) merger source at redshift 0.8 with unusually high component masses, M ⊙ and M ⊙, compared to previously reported events, and shows mild evidence for spin-induced orbital precession. The primary falls in the mass gap predicted by (pulsational) pair-instability supernova theory, in the approximate range 65–120 M ⊙. The probability that at least one of the black holes in GW190521 is in that range is 99.0%. The final mass of the merger ( M ⊙) classifies it as an intermediate-mass black hole. Under the assumption of a quasi-circular BBH coalescence ...

Variability Of Active Galactic Nuclei From Differential Photometry, 2020 California Polytechnic State University, San Luis Obispo

#### Variability Of Active Galactic Nuclei From Differential Photometry, Nicholas Steven Yee

##### Physics

The Seoul AGN Monitoring Project, or SAMP for short, is an international project (PI Jonghak Woo from Korea) with the goal of measuring the masses of black holes residing in the center of massive active galactic nuclei (AGNs). AGNs are some of the brightest objects in the universe. Their light is attributed to the accretion of material onto the black hole. However, these objects are too distant to spatially resolve the gravitational sphere of influence of the black hole directly. Instead, we use a technique called reverberation mapping which observes the variability of the AGN power-law continuum emission and the ...

Global Patterns Of Recent Mass Movement On Asteroid (101955) Bennu, 2020 Rowan University

#### Global Patterns Of Recent Mass Movement On Asteroid (101955) Bennu, E. R. Jawin, K. J. Walsh, O. S. Barnouin, T. J. Mccoy, R.-L. Ballouz, D. N. Dellagiustina, Harold Connolly Jr.

##### School of Earth & Environment Faculty Scholarship

The exploration of near‐Earth asteroids has revealed dynamic surfaces characterized by mobile, unconsolidated material that responds to local geophysical gradients, resulting in distinct morphologies and boulder distributions. The OSIRIS‐REx (Origins, Spectral Interpretation, Resource Identification, and Security‐Regolith Explorer) mission confirmed that asteroid (101955) Bennu is a rubble pile with an unconsolidated surface dominated by boulders. In this work, we documented morphologies indicative of mass movement on Bennu and assessed the relationship to slope and other geologic features on the surface. We found globally distributed morphologic evidence of mass movement on Bennu up to ~70° latitude and on spatial ...

Understanding Atmospheres Across The Stellar-Substellar Boundary, 2020 The Graduate Center, City University of New York

#### Understanding Atmospheres Across The Stellar-Substellar Boundary, Eileen C. Gonzales

##### Dissertations, Theses, and Capstone Projects

Complexities in the atmospheres of sources that straddle the boundary between low-mass stars and planets drive the spectral features we observe and the fundamental parameters that we derive. In an effort to understand the underlying cause of these spectral features, this work examines low-mass stars and brown dwarfs using two approaches: distance-calibrated spectral energy distributions (SEDs) and atmospheric retrievals. SEDs allow for the determination of semi-empirical fundamental parameters, while atmospheric retrievals allow us to derive the atmospheric structure and composition, as well as extrapolated fundamental parameters for a source. Low-metallicity and high surface gravity sources, known as subdwarfs, are the ...

Kelt-25 B And Kelt-26 B: A Hot Jupiter And A Substellar Companion Transiting Young A Stars Observed By Tess, 2020 Swarthmore College

#### Kelt-25 B And Kelt-26 B: A Hot Jupiter And A Substellar Companion Transiting Young A Stars Observed By Tess, R. R. Martínez, R. R. Martínez, B. S. Gaudi, J. E. Rodriguez, G. Zhou, J. Labadie-Bartz, S. N. Quinn, K. Penev, T.-G. Tan, D. W. Latham, L. A. Paredes, J. F. Kielkopf, B. Addison, D. J. Wright, J. Teske, S. B. Howell, D. Ciardi, C. Ziegler, K. G. Stassun, M. C. Johnson, J. D. Eastman, R. J. Siverd, T. G. Beatty, L. Bouma, T. Bedding, J. Pepper, J. Winn, M. B. Lund, S. Villanueva Jr., D. J. Stevens, Eric L.N. Jensen, C. Kilby, J. D. Crane, A. Tokovinin, M. E. Everett, C. G. Tinney, M. Fausnaugh, David H. Cohen, D. Bayliss, A. Bieryla, P. A. Cargile, K. A. Collins, D. M. Conti, K. D. Colón, I. A. Curtis, D. L. Depoy, P. Evans, D. L. Feliz, J. Gregorio, J. Rothenberg, D. J. James, M. D. Joner, R. B. Kuhn, M. Manner, S. Khakpash, J. L. Marshall, K. K. Mcleod, M. T. Penny, P. A. Reed, H. M. Relles, D. C. Stephens, C. Stockdale, M. Trueblood, P. Trueblood, X. Yao, R. Zambelli, R. Vanderspek, S. Seager, J. M. Jenkins, T. J. Henry, H.-S. James, W.-C. Jao, S. X. Wang, P. Butler, I. Thompson, S. Schectman, R. Wittenmyer, B. P. Bowler, J. Horner, S. R. Kane, M. W. Mengel, T. D. Morton, J. Okumura, P. Plavchan, H. Zhang, N. J. Scott, R. A. Matson, A. W. Mann, D. Dragomir, M. Günther, E. B. Ting, A. Glidden, E. V. Quintana

##### Physics & Astronomy Faculty Works

We present the discoveries of KELT-25 b (TIC 65412605, TOI-626.01) and KELT-26 b (TIC 160708862, TOI-1337.01), two transiting companions orbiting relatively bright, early A stars. The transit signals were initially detected by the KELT survey and subsequently confirmed by Transiting Exoplanet Survey Satellite (TESS) photometry. KELT-25 b is on a 4.40 day orbit around the V = 9.66 star CD-24 5016 (${T}_{\mathrm{eff}}={8280}_{-180}^{+440}$ K, Msstarf = ${2.18}_{-0.11}^{+0.12}$ M⊙), while KELT-26 b is on a 3.34 day orbit around the V = 9.95 star HD 134004 ...

The First Habitable-Zone Earth-Sized Planet From Tess. I. Validation Of The Toi-700 System, 2020 Swarthmore College

#### The First Habitable-Zone Earth-Sized Planet From Tess. I. Validation Of The Toi-700 System, E. A. Gilbert, T. Barclay, J. E. Schlieder, E. V. Quintana, B. J. Hord, V. B. Kostov, E. D. Lopez, J. F. Rowe, K. Hoffman, L. M. Walkowicz, M. L. Silverstein, J. E. Rodriguez, A. Vanderburg, G. Suissa, V. S. Airapetian, M. S. Clement, S. N. Raymond, A. W. Mann, E. Kruse, J. J. Lissauer, K. D. Colón, R. K. Kopparapu, L. Kreidberg, S. Zieba, K. A. Collins, S. N. Quinn, S. B. Howell, C. Ziegler, E. H. Vrijmoet, F. C. Adams, G. N. Arney, P. T. Boyd, J. Brande, C. J. Burke, L. Cacciapuoti, Q. Chance, J. L. Christiansen, G. Covone, T. Daylan, D. Dineen, C. D. Dressing, Z. Essack, T. J. Fauchez, B. Galgano, A. R. Howe, L. Kaltenegger, S. R. Kane, C. Lam, E. J. Lee, N. K. Lewis, S. E. Logsdon, A. M. Mandell, T. Monsue, F. Mullally, S. E. Mullally, R. R. Paudel, D. Pidhorodetska, P. Plavchan, N. T. Reyes, S. A. Rinehart, B. Rojas-Ayala, J. C. Smith, K. G. Stassun, P. Tenenbaum, L. D. Vega, G. L. Villanueva, E. T. Wolf, A. Youngblood, G. R. Ricker, R. K. Vanderspek, D. W. Latham, S. Seager, J. N. Winn, J. M. Jenkins, G. Å. Bakos, C. Briceño, D. R. Ciardi, R. Cloutier, D. M. Conti, A. Couperus, M. Di Sora, N. L. Eisner, M. E. Everett, T. Gan, J. D. Hartman, T. Henry, G. Isopi, W.-C. Jao, Eric L.N. Jensen, N. Law, F. Mallia, R. A. Matson, B. J. Shappee, M. Le Wood, J. G. Winters

##### Physics & Astronomy Faculty Works

We present the discovery and validation of a three-planet system orbiting the nearby (31.1 pc) M2 dwarf star TOI-700 (TIC 150428135). TOI-700 lies in the TESS continuous viewing zone in the Southern Ecliptic Hemisphere; observations spanning 11 sectors reveal three planets with radii ranging from 1 R⊕ to 2.6 R⊕ and orbital periods ranging from 9.98 to 37.43 days. Ground-based follow-up combined with diagnostic vetting and validation tests enables us to rule out common astrophysical false-positive scenarios and validate the system of planets. The outermost planet, TOI-700 d, has a radius of 1.19 ± 0.11 ...

2020 Air Force Institute of Technology

#### Chronos Spacecraft With Chiron Probe: Exploration Of The Hydrosphere, Principle Satellites, Atmosphere, And Rings Of Uranus, Payton E. Pearson

##### Theses and Dissertations

A design reference mission using more modern technological innovations has been developed for exploration of the outer reaches of our Solar System, specifically Uranus and its system of satellites. This mission will utilize theoretical technologies mostly without regard to their current technological readiness level (TRL), though most systems have a TRL of at least 5. The primary innovations explored in this thesis are the new launch systems that provide far greater payload capacity potentially sent to anywhere in the Solar System, new Stirling-engine radioisotope thermoelectric generators (SRTGs), vastly improved data storage technologies, optimized satellite antenna relay of data using much ...

Prospects For Observing And Localizing Gravitational-Wave Transients With Advanced Ligo, Advanced Virgo And Kagra, 2020 The University of Texas Rio Grande Valley

#### Prospects For Observing And Localizing Gravitational-Wave Transients With Advanced Ligo, Advanced Virgo And Kagra, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, K. Ackley, C. Adams, T. Adams, P. Addesso, R. X. Adhikari, V. B. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, T. Akutsu, B. Allen, A. Allocca, P. A. Altin, A. Ananyeva, S. B. Anderson, W. G. Anderson, M. Ando, S. Appert, K. Arai, A. Araya, Teviet Creighton, Mario C. Diaz, S. Mukherjee, V. Quetschke, Malik Rakhmanov, K. E. Ramirez, Satzhan Sitmukhambetov, Robert Stone, D. Tuyenbayev, W. H. Wang, A. K. Zadrozny

##### Physics and Astronomy Faculty Publications and Presentations

We present our current best estimate of the plausible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next several years, with the intention of providing information to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals for the third (O3), fourth (O4) and fifth observing (O5) runs, including the planned upgrades of the Advanced LIGO and Advanced Virgo detectors. We study the capability of the network to determine the sky location of the source for gravitational-wave signals from the inspiral of binary systems of ...