Astrophysics and Astronomy Commons^™

Galaxy And Mass Assembly (Gama): Demonstrating The Power Of Wise In The Study Of Galaxy Groups To Z < 0.1, M. E. Cluver, T. H. Jarrett, E. N. Taylor, A. M. Hopkins, S. Brough, S. Casura, B. W. Holwerda, J. Liske, K. A. Pimbblet, A. H. Wright

Faculty and Staff Scholarship

Combining high-fidelity group characterization from the Galaxy and Mass Assembly survey and source-tailored z < 0.1 photometry from the Wide-Field Infrared Survey Explorer (WISE) survey, we present a comprehensive study of the properties of ungrouped galaxies, compared to 497 galaxy groups (4 ≤ N FoF ≤ 20) as a function of stellar and halo mass. Ungrouped galaxies are largely unimodal in WISE color, the result of being dominated by star-forming, late-type galaxies. Grouped galaxies, however, show a clear bimodality in WISE color, which correlates strongly with stellar mass and morphology. We find evidence for an increasing early-type fraction, in stellar mass bins between 1010 M o˙ ≲ M stellar ≲ 1011 M o˙, with increasing halo mass. Using ungrouped, late-type galaxies with star-forming colors (W2-W3 > 3), we define a star-forming main sequence (SFMS), which we use to delineate systems that have moved below the sequence ("quenched"for the purposes of this work). We find that with increasing halo mass, the relative number of late-type systems on the SFMS decreases, with a corresponding increase in early-type, quenched systems at high stellar mass (M stellar > 1010.5 M o˙), consistent with mass quenching. Group galaxies with masses M stellar < 1010.5 M o˙ show evidence of quenching consistent with environmentally driven processes. The stellar mass distribution of late-type, quenched galaxies suggests that it may be an intermediate population as systems transition from being star-forming and late-type to the "red sequence."Finally, we use the projected area of groups on the sky to extract groups that are (relatively) compact for their halo mass. Although these show a marginal increase in their proportion of high-mass and early-type galaxies compared to nominal groups, a clear increase in quenched fraction is not evident.

Using The Baryonic Tully–Fisher Relation To Measure Ho, Stacy S. Mcgaugh

Faculty Scholarship

We explore the use of the baryonic Tully-Fisher relation (bTFR) as a new distance indicator. Advances in near-IR imaging and stellar population models, plus precise rotation curves, have reduced the scatter in the bTFR such that distance is the dominant source of uncertainty. Using 50 galaxies with accurate distances from Cepheids or the tip magnitude of the red giant branch, we calibrate the bTFR on a scale independent of H o . We then apply this calibrated bTFR to 95 independent galaxies from the SPARC sample, using CosmicFlows-3 velocities, to deduce the local value of H o . We find …

Expres. I. Hd 3651 As An Ideal Rv Benchmark, John M. Brewer, Debra A. Fischer, Ryan T. Blackman, Samuel H. C. Cabot, Allen B. Davis, Gregory Laughlin, Christopher Leet, J. M. Joel Ong, Ryan R. Petersburg, Andrew E. Szymkowiak, Lily L. Zhao, Gregory W. Henry, Joe Llama

Information Systems and Engineering Management Research Publications

The next generation of exoplanet-hunting spectrographs should deliver up to an order of magnitude improvement in radial velocity (RV) precision over the standard 1 ${\rm{m}}\ {{\rm{s}}}^{-1}$ state-of-the-art spectrographs. This advance is critical for enabling the detection of Earth-mass planets around Sun-like stars. New calibration techniques such as laser frequency combs and stabilized etalons ensure that the instrumental stability is well characterized. However, additional sources of error include stellar noise, undetected short-period planets, and telluric contamination. To understand and ultimately mitigate error sources, the contributing terms in the error budget must be isolated to the greatest extent possible. Here, we introduce …

Globe Observer Data: 2016–2019, Helen M. Amos, Matthew J. Starke, Tina M. Rogerson, Marilé Colón Robles, Travis Anderson, Rebecca Boger, Brian A. Campbell, Russanne D. Low, Peder Nelson, David Overoye, Jessica E. Taylor, Kristen L. Weaver, Trena M. Ferrell, Holli Kohl, Theresa G. Schwerin

Publications and Research

This technical report summarizes the GLOBE Observer data set from 1 April 2016 to 1 December 2019. GLOBE Observer is an ongoing NASA‐sponsored international citizen science project that is part of the larger Global Learning and Observations to Benefit the Environment (GLOBE) Program, which has been in operation since 1995. GLOBE Observer has the greatest number of participants and geographic coverage of the citizen science projects in the Earth Science Division at NASA. Participants use the GLOBE Observer mobile app (launched in 2016) to collect atmospheric, hydrologic, and terrestrial observations. The app connects participants to satellite observations from Aqua, Terra, …

Staerkel Planetarium's Doors Closed, But Skies Are Always Open, Erik Johnson

Natural Science Faculty

Ask any astronomer and they will tell you that the best night skies are found when you get away from light pollution. The COVID-19 pandemic has not taken away our ability to enjoy watching the stars, but it has prevented the staff of the William M. Staerkel Planetarium at Parkland College from sharing the immersive environment of the dome with the public for the rest of 2020. Since the cycles of the sky are still in motion, the staff have strived to keep everyone informed about what they can see under dark skies or in their backyard.

All-Sky Search For Short Gravitational-Wave Bursts In The Second Advanced Ligo And Advanced Virgo Run, Tiffany Summerscales, Ligo Scientific Collaboration And The Virgo Collaboration

Faculty Publications

We present the results of a search for short-duration gravitational-wave transients in the data from the second observing run of Advanced LIGO and Advanced Virgo. We search for gravitational-wave transients with a duration of milliseconds to approximately one second in the 32–4096 Hz frequency band with minimal assumptions about the signal properties, thus targeting a wide variety of sources. We also perform a matched-filter search for gravitational-wave transients from cosmic string cusps for which the waveform is well modeled. The unmodeled search detected gravitational waves from several binary black hole mergers which have been identified by previous analyses. No other …

Visual Orbits Of Spectroscopic Binaries With The Chara Array. Iii. Hd 8374 And Hd 24546, Kathryn V. Lester, Francis C. Fekel, Matthew W. Muterspaugh, Douglas R. Gies, Gail Schaefer, Chris D. Farrington, Zhao Guo, Rachel A. Matson, John D. Monnier, Theo A. Ten Brummelaar, Judit Sturmann, Samuel A. Weiss

Information Systems and Engineering Management Research Publications

We present the visual orbits of two long-period spectroscopic binary stars, HD 8374 and HD 24546, using interferometric observations acquired with the CHARA Array and the Palomar Testbed Interferometer. We also obtained new radial velocities from echelle spectra using the APO 3.5 m and Fairborn 2.0 m telescopes. By combining the visual and spectroscopic observations, we solve for the full, three-dimensional orbits and determine the stellar masses and distances to within 3% uncertainty. We then estimate the effective temperature and radius of each component star through Doppler tomography and spectral energy distribution analyses, in order to compare the observed stellar …

Absence Of Landau-Peierls Instability In The Magnetic Dual Chiral Density Wave Phase Of Dense Qcd, Efrain J. Ferrer, Vivian De La Incera

Physics & Astronomy Faculty Publications

We investigate the stability of the magnetic dual chiral density wave (MDCDW) phase of cold and dense QCD against collective low-energy fluctuations of the order parameter. The appearance of additional structures in the system free energy due to the explicit breaking of the rotational and isospin symmetries by the external magnetic field play a crucial role in the analysis. The new structures stiffen the spectrum of the thermal fluctuations in the transverse direction, thereby avoiding the Landau-Peierls instability that affects single-modulated phases at arbitrarily low temperatures. The lack of Landau-Peierls instabilities in the MDCDW phase makes this inhomogeneous phase of …

Earth-Like Planet In A Binary Star System, Melissa Kamrowski

Scholarly Horizons: University of Minnesota, Morris Undergraduate Journal

This paper was written as a final lab report for a computer modeling class. It uses dynamical simulations to investigate the behavior of a planet with the mass and velocity magnitude of the Earth placed in a low mass binary star system, which was loosely based on the Sirius binary. The simulations are completed using gravitational force properties along with the Verlet algorithm, then the results were observed through a modeling program, in which each set was set as an animation to determine behavior. Results came from 40 strategic starting points, which were chosen to cover a large spread of …

The Hubble Space Telescope Pancet Program: An Optical To Infrared Transmission Spectrum Of Hat-P-32ab, Munazza K. Alam, Mercedes López-Morales, Nikolay Nikolov, David K. Sing, Gregory W. Henry, Claire Baxter, Jean-Michel Désert, Joanna K. Barstow, Thomas Mikal-Evans, Vincent Bourrier, Panayotis Lavvas, Hannah R. Wakeford, Michael H. Williamson, Jorge Sanz-Forcada, Lars A. Buchhave, Ofer Cohen, Antonio García Muñoz

Information Systems and Engineering Management Research Publications

We present a 0.3−5 μm transmission spectrum of the hot Jupiter HAT-P-32Ab observed with the Space Telescope Imaging Spectrograph and Wide Field Camera 3 instruments mounted on the Hubble Space Telescope, combined with Spitzer Infrared Array Camera photometry. The spectrum is composed of 51 spectrophotometric bins with widths ranging between 150 and 400 Å, measured to a median precision of 215 ppm. Comparisons of the observed transmission spectrum to a grid of 1D radiative-convective equilibrium models indicate the presence of clouds/hazes, consistent with previous transit observations and secondary eclipse measurements. To provide more robust constraints on the planet's atmospheric properties, …

Simulating The Outer Layers Of Rapidly Rotating Stars, Frank J. Robinson, Joel Tanner, Sarbani Basu

Chemistry & Physics Faculty Publications

This paper presents the results of a set of radiative hydrodynamic (RHD) simulations of convection in the near-surface regions of a rapidly rotating star. The simulations use microphysics consistent with stellar models, and include the effects of realistic convection and radiative transfer. We find that the overall effect of rotation is to reduce the strength of turbulence. The combination of rotation and radiative cooling creates a zonal velocity profile in which the motion of fluid parcels near the surface is independent of rotation. Their motion is controlled by the strong up and down flows generated by radiative cooling. The fluid …

A Remnant Planetary Core In The Hot-Neptune Desert, D. J. Armstrong, T. A. Lopez, V. Adibekyan, R. A. Booth, E. M. Bryant, K. A. Collins, A. Esmenhuber, C. X. Huang, G. W. King, J. Lillo-Box, J. J. Lissauer, E. C. Matthews, O. Mousis, L. D. Nielsen, H. Osborn, J. Otegi, N. C. Santos, S. G. Sousa, K. G. Stassun, D. Veras, C. Ziegler, J. S. Acton, J. M. Almenara, D. R. Anderson, D. Barrado, S. C. C. Barros, D. Bayliss, C. Belardi, F. Bouchy, C. Briceño, M. Brogi, D. J. A. Brown, M. R. Burleigh, S. L. Casewell, A. Chaushev, D. R. Ciardi, K. I. Collins, K. D. Colón, B. F. Cooke, I. J. M. Crossfield, R. F. Díaz, Magali Deleuil, E. Delgado Mena, O. D. S. Demangeon, C. Dorn, X. Dumusque, P. Eigmüller, M. Fausnaugh, P. Figueira, T. Gan, S. Gandhi, S. Gill, M. R. Goad, M. N. Günther, R. Helled, S. Hojjatpanah, S. B. Howell, J. Jackman, J. S. Jenkins, J. M. Jenkins, Eric L.N. Jensen, G. M. Kennedy, D. W. Latham, N. Law, M. Lendl, M. Lozovsky, A. W. Mann, M. Moyano, J. Mccormac, F. Meru, C. Mordasini, A. Osborn, D. Pollacco, D. Queloz, L. Raynard, G. R. Ricker, P. Rowqden, A. Santerne, J. E. Schlieder, S. Seager, L. Sha, T.-G. Tan, R. H. Tilbrook, E. Ting, S. Udry, R. Vanderspek, C. A. Watson, R. G. West, P. A. Wilson, J. N. Winn, P. Wheatley, J. N. Villasenor, J. I. Vines, Z Zhan

Physics & Astronomy Faculty Works

The interiors of giant planets remain poorly understood. Even for the planets in the Solar System, difficulties in observation lead to large uncertainties in the properties of planetary cores. Exoplanets that have undergone rare evolutionary processes provide a route to understanding planetary interiors. Planets found in and near the typically barren hot-Neptune ‘desert’1,2 (a region in mass–radius space that contains few planets) have proved to be particularly valuable in this regard. These planets include HD149026b3, which is thought to have an unusually massive core, and recent discoveries such as LTT9779b4 and NGTS-4b5, on which photoevaporation has removed a substantial part …

Toi-1235 B: A Keystone Super-Earth For Testing Radius Valley Emergence Models Around Early M Dwarfs, R. Cloutier, J. E. Rodriguez, J. Irwin, D. Charbonneau, K. G. Stassun, A. Mortier, D. W. Latham, H. Isaacson, A. W. Howard, S. Udry, T. G. Wilson, C. A. Watson, M. Pinamonti, F. Lienhard, P. Giacobbe, P. Guerra, K. A. Collins, A. Bieryla, G. A. Esquerdo, E. Matthews, R. A. Matson, S. B. Howell, E. Furlan, I. J. M. Crossfield, J. G. Winters, C. Nava, K. Ment, E. D. Lopez, G. Ricker, R. Vanderspek, S. Seager, J. M. Jenkins, E. B. Ting, P. Tenenbaum, A. Sozzetti, L. Sha, D. Ségransan, J. E. Schlieder, D. Sasselov, A. Roy, P. Robertson, K. Rice, E. Poretti, G. Piotto, D. Phillips, J. Pepper, F. Pepe, E. Molinari, T. Mocnik, G. Micela, M. Mayor, A. F. Martinez Fiorenzano, F. Mallia, J. Lubin, C. Lovis, M. López-Morales, M. R. Kosiarek, J. F. Kielkopf, S. R. Kane, Eric L.N. Jensen, G. Isopi, D. Huber, M. L. Hill, A. Harutyunyan, E. Gonzales, S. Giacalone, A. Ghedina, A. Ercolino, X. Dumusque, C. D. Dressing, M. Damasso, P. A. Dalba, R. Cosentino, D. M. Conti, K. D. Colón, K. I. Collins, A. Collier Cameron, D. Ciardi, J. Christiansen, A. Chontos, M. Cecconi, D. A. Caldwell, C. Burke, L. Buchhave, C. Beichman, A. Behmard, C. Beard, J. M. Akana Murphy

Physics & Astronomy Faculty Works

Small planets on close-in orbits tend to exhibit envelope mass fractions of either effectively zero or up to a few percent depending on their size and orbital period. Models of thermally driven atmospheric mass loss and of terrestrial planet formation in a gas-poor environment make distinct predictions regarding the location of this rocky/nonrocky transition in period–radius space. Here we present the confirmation of TOI-1235 b (P = 3.44 days, ${r}_{{\rm{p}}}={1.738}_{-0.076}^{+0.087}$ ${R}_{\oplus }$), a planet whose size and period are intermediate between the competing model predictions, thus making the system an important test case for emergence models of the rocky/nonrocky transition …

Precise Mass And Radius Of A Transiting Super-Earth Planet Orbiting The M Dwarf Toi-1235: A Planet In The Radius Gap?, P. Bluhm, R. Luque, N. Espinoza, E. Pallé, J. A. Caballero, S. Dreizler, J. H. Livingston, S. Mathur, A. Quirrenbach, S. Stock, V. Van Eylen, G. Nowak, E. D. López, S. Csizmadia, M. R. Zapatero Osorio, P. Schöfer, J. Lillo-Box, M. Oshagh, E. González-Álvarez, P. J. Amado, D. Barrado, V. J. S. Béjar, B. Cale, P. Chaturvedi, M. El Mufti, A. Ercolino, M. Fridlund, E. Gaidos, R. A. García, I. Georgieva, L. González-Cuesta, P. Guerra, A. P. Hatzes, T. Henning, E. Herrero, D. Hidalgo, G. Isopi, S. V. Jeffers, J. M. Jenkins, Eric L.N. Jensen, P. Kábath, A. Kaminski, J. Kemmer, J. Korth, D. Kossakowski, M. Kürster, M. Lafarga, F. Mallia, D. Montes, J. C. Morales, M. Morales-Calderón, F Murgas, N. Narita, V. M. Passegger, S. Pedraz, C. M. Persson, P. Plavchan, H. Rauer, S. Redfield, S. Reffert, A. Reiners, I. Ribas, G. R. Ricker, C. Rodríguez-López, A. R. G. Santos, S. Seager, M. Schlecker, A. Schweitzer, Y. Shan, M. G. Soto, J. Subjak, L. Tal-Or, T. Trifonov, S. Vanaverbeke, R. Vanderspek, J. Wittrock, M. Zechmeister, F. Zohrabi

Physics & Astronomy Faculty Works

We report the confirmation of a transiting planet around the bright weakly active M0.5 V star TOI-1235 (TYC 4384–1735–1, V ≈ 11.5 mag), whose transit signal was detected in the photometric time series of sectors 14, 20, and 21 of the TESS space mission. We confirm the planetary nature of the transit signal, which has a period of 3.44 d, by using precise RV measurements with the CARMENES, HARPS-N, and iSHELL spectrographs, supplemented by high-resolution imaging and ground-based photometry. A comparison of the properties derived for TOI-1235 b with theoretical models reveals that the planet has a rocky composition, with …

A Pair Of Tess Planets Spanning The Radius Valley Around The Nearby Mid-M Dwarf Ltt 3780, R. Cloutier, J. D. Eastman, J. E. Rodriguez, N. Astudillo-Defru, X. Bonfils, A. Mortier, C. A. Watson, M. Stalport, M. Pinamonti, F. Lienhard, A. Harutyunyan, M. Damasso, D. W. Latham, K. A. Collins, R. Massey, J. Irwin, J. G. Winters, D. Charbonneau, C. Ziegler, E. Matthews, I. J. M. Crossfield, L. Kreidberg, S. N. Quinn, G. Ricker, R. Vanderspek, S. Seager, J. Winn, J. M. Jenkins, M. Vezie, S. Udry, J. D. Twicken, P. Tenenbaum, A. Sozzetti, D. Ségransan, J. E. Schlieder, D. Sasselov, N. C. Santos, K. Rice, B. V. Rackham, E. Poretti, G. Piotto, D. Phillips, F. Pepe, E. Molinari, L. Mignon, G. Micela, C. Melo, J. R. De Medeiros, M. Mayor, R. A. Matson, A. F. Martinez Fiorenzano, A. W. Mann, A. Magazzú, C. Lovis, M. López-Morales, E. Lopez, J. J. Lissauer, S. Lépine, N. Law, J. F. Kielkopf, J. A. Johnson, Eric L.N. Jensen, S. B. Howell, E. Gonzales, A. Ghedina, T. Forveille, P. Figueira, X. Dumusque, C. D. Dressing, R. Doyon, R. F. Díaz, L. Di Fabrizio, X. Delfosse, R. Cosentino, D. M. Conti, K. I. Collins, A. C. Cameron, D. Ciardi, D. A. Caldwell, C. Burke, L. Buchhave, C. Briceño, P. Boyd, F. Bouchy, C. Beichman, É. Artigau, J. M. Almenara

Physics & Astronomy Faculty Works

We present the confirmation of two new planets transiting the nearby mid-M dwarf LTT 3780 (TIC 36724087, TOI-732, V = 13.07, K s = 8.204, R s = 0.374 R ⊙, M s = 0.401 M ⊙, d = 22 pc). The two planet candidates are identified in a single Transiting Exoplanet Survey Satellite sector and validated with reconnaissance spectroscopy, ground-based photometric follow-up, and high-resolution imaging. With measured orbital periods of P b = 0.77, P c = 12.25 days and sizes r p,b = 1.33 ± 0.07, r p,c = 2.30 ± 0.16 R ⊕, the two planets span …

Debris Disk Results From The Gemini Planet Imager Exoplanet Survey's Polarimetric Imaging Campaign, Thomas M. Esposito, Paul Kalas, Michael P. Fitzgerald, Maxwell A. Millar-Blanchaer, Gaspard Duch Ne, Jennifer Patience, Justin Hom, Marshall D. Perrin, Robert J. De Rosa, Eugene Chiang, Ian Czekala, Bruce Macintosh, James R. Graham, Megan Ansdell, Pauline Arriaga, Sebastian Bruzzone, Joanna Bulger, Christine H. Chen, Tara Cotten, Ruobing Dong, Zachary H. Draper, Katherine B. Follette, Li Wei Hung, Ronald Lopez, Brenda C. Matthews, Johan Mazoyer, Stan Metchev, Julien Rameau, Bin Ren, Malena Rice, Inseok Song, Kevin Stahl, Et Al, Kimberly Ward-Duong

Astronomy: Faculty Publications

We report the results of a ∼4 yr direct imaging survey of 104 stars to resolve and characterize circumstellar debris disks in scattered light as part of the Gemini Planet Imager (GPI) Exoplanet Survey. We targeted nearby (≲150 pc), young (≲500 Myr) stars with high infrared (IR) excesses (L IR/L ∗ > 10-5), including 38 with previously resolved disks. Observations were made using the GPI high-contrast integral field spectrograph in H-band (1.6 μm) coronagraphic polarimetry mode to measure both polarized and total intensities. We resolved 26 debris disks and 3 protoplanetary/transitional disks. Seven debris disks were resolved in scattered light for …

Astroalign: A Python Module For Astronomical Image Registration, Martin Beroiz, Juan B. Cabral, Bruno Sanchez

Physics & Astronomy Faculty Publications

We present an algorithm implemented in the Astroalign Python module for image registration in astronomy. Our module does not rely on WCS information and instead matches three-point asterisms (triangles) on the images to find the most accurate linear transformation between them. It is especially useful in the context of aligning images prior to stacking or performing difference image analysis. Astroalign can match images of different point-spread functions, seeing, and atmospheric conditions.

Python Implementation Of Batch Least-Squares Filter For Satellite Orbit Determination, Austin Ogle

Doctoral Dissertations and Master's Theses

Accurate orbit determination techniques are fundamental to the maintenance and execution of any ongoing space-based mission. This project serves as a guide and demonstration of a batch sequential least-squares filter for Earth-orbiting satellites using exclusively open-source technologies. The target audience for this project was an academic institution aiming to keep track of an irregularly documented satellite. The observation function mimics a telescope, accepting right ascension and declination as measured values.

State propagation was handled using the Poliastro library. This package boasts FORTRANlevel speed by utilizing the DOPRI8 integrator, explicitly calling FORTRAN code. Matrix inversion was solved using the SciPy banded …

Using Artificial Neural Networks To Detect Astronomical Transients, Katarzyna Wardęga

Theses and Dissertations

A kilonova is an r-process-powered thermal transient created in the aftermath of a binary neutron star or black hole-neutron star merger. During these merger events, gravitational waves act as alert signals for telescopes to respond and search for potential optical counterparts. The localization probability regions for gravitational waves on the sky can be large. Additionally, kilonovae are rapidly-fading transients, making it crucial to develop an efficient method to detect them in image data. The standard method to detect transients is to subtract an image containing the plausible transient from a reference image of the same region taken at a different …

Topics In Gravitational Wave Physics, Aaron David Johnson

Graduate Theses and Dissertations

We begin with a brief introduction to gravitational waves. Next we look into the origin of the Chandrasekhar transformations between the different equations found by perturbing a Schwarzschild black hole. Some of the relationships turn out to be Darboux transformations. Then we turn to GW150914, the first detected black hole binary system, to see if the nonlinear memory might be detectable by current and future detectors. Finally, we develop an updated code for computing equatorial extreme mass ratio inspirals which will be open sourced as soon as it has been generalized for arbitrary inclinations.

Wallaby – An Ska Pathfinder H I Survey, Bärbel S. Koribalski, L. Staveley-Smith, T. Westmeier, P. Serra, K. Spekkens, O. I. Wong, K. Lee-Waddell, C. D.P. Lagos, D. Obreschkow, E. V. Ryan-Weber, M. Zwaan, V. Kilborn, G. Bekiaris, K. Bekki, F. Bigiel, A. Boselli, A. Bosma, B. Catinella, G. Chauhan, M. E. Cluver, M. Colless, H. M. Courtois, R. A. Crain, W. J.G. De Blok, H. Dénes, A. R. Duffy, A. Elagali, C. J. Fluke, B. Q. For, G. Heald, P. A. Henning, K. M. Hess, Benne W. Holwerda

Faculty and Staff Scholarship

The Widefield ASKAP L-band Legacy All-sky Blind surveY (wallaby) is a next-generation survey of neutral hydrogen (H i) in the Local Universe. It uses the widefield, high-resolution capability of the Australian Square Kilometer Array Pathfinder (ASKAP), a radio interferometer consisting of 36 × 12 -m dishes equipped with Phased-Array Feeds (PAFs), located in an extremely radio-quiet zone in Western Australia. wallaby aims to survey three-quarters of the sky (− 90 ∘< δ< + 30 ∘) to a redshift of z≲ 0.26 , and generate spectral line image cubes at ∼30 arcsec resolution and ∼1.6 mJy beam−1 per 4 km s−1 channel sensitivity. ASKAP’s instantaneous field of view at 1.4 GHz, delivered by the PAF’s 36 beams, is about 30 sq deg. At an integrated signal-to-noise ratio of five, wallaby is expected to detect around half a million galaxies with a mean redshift of z∼ 0.05 (∼200 Mpc). The scientific goals of wallaby include: (a) a census of gas-rich galaxies in the vicinity of the Local Group; (b) a study of the H i properties of galaxies, groups and clusters, in particular the influence of the environment on galaxy evolution; and (c) the refinement of cosmological parameters using the spatial and redshift distribution of low-bias gas-rich galaxies. For context we provide an overview of recent and planned large-scale H i surveys. Combined with existing and new multi-wavelength sky surveys, wallaby will enable an exciting new generation of panchromatic studies of the Local Universe. — First results from the wallaby pilot survey are revealed, with initial data products publicly available in the CSIRO ASKAP Science Data Archive (CASDA).

Absence Of Landau-Peierls Instability In The Magnetic Dual Chiral Density Wave Phase Of Dense Qcd, Efrain J. Ferrer, Vivian De La Incera

Physics & Astronomy Faculty Publications

We investigate the stability of the magnetic dual chiral density wave (MDCDW) phase of cold and dense QCD against collective low-energy fluctuations of the order parameter. The appearance of additional structures in the system free energy due to the explicit breaking of the rotational and isospin symmetries by the external magnetic field play a crucial role in the analysis. The new structures stiffen the spectrum of the thermal fluctuations in the transverse direction, thereby avoiding the Landau-Peierls instability that affects single-modulated phases at arbitrarily low temperatures. The lack of Landau-Peierls instabilities in the MDCDW phase makes this inhomogeneous phase of …

An Experimental Investigation Of Liquid Hydrocarbons In A Simulated Titan Environment, Kendra Farnsworth

Graduate Theses and Dissertations

Saturn’s moon, Titan, has surface conditions (89–94 K, 1.5-bar atmosphere) that permit lakes of methane, ethane, and dissolved atmospheric nitrogen. The effects of atmospheric nitrogen on methane-ethane liquid properties is poorly understood, leading to uncertainty in Titan modeling. I address this question by experimentally investigating the physical properties of methane-ethane liquids under a 1.5-bar nitrogen atmosphere in a simulated Titan environmental chamber.

Chapter 1 addresses nitrogen dissolution kinetics in Titan’s liquid hydrocarbons. I found an exponential increase in nitrogen quantity and diffusion coefficients with increasing methane mol%. I find that Titan’s liquids are likely not saturated in nitrogen, with dissolution …

Mapping Jupiter's Mischief, Channon Visscher

Faculty Work Comprehensive List

New results (Grassi et al., 2020, https://doi.org/10.1029/2019JE006206) from analysis of Juno Jovian Infrared Auroral Mapper (JIRAM) 4‐ to 5‐μm observations provide updated latitudinal abundance profiles and measurements of the spatial distribution of H2O, NH3, PH3, GeH4, and AsH3 in Jupiter's troposphere near the 3‐ to 5‐bar level. The observed compositional variations provide new constraints on processes shaping chemical abundances in the cloud‐forming region of the troposphere, including vertical and horizontal atmospheric mixing, meteorology and cloud formation, transport‐induced quenching, and photochemistry. Along with recent results from the Juno Microwave Radiometer (MWR) for NH3 and H2O abundances far below the clouds, the …

Gw190814: Gravitational Waves From The Coalescence Of A 23 Solar Mass Black Hole With A 2.6 Solar Mass Compact Object, 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. The American Astronomical Society.. We report the observation of a compact binary coalescence involving a 22.2-24.3 M o˙ black hole and a compact object with a mass of 2.50-2.67 M o˙ (all measurements quoted at the 90% credible level). The gravitational-wave signal, GW190814, was observed during LIGO's and Virgo's third observing run on 2019 August 14 at 21:10:39 UTC and has a signal-to-noise ratio of 25 in the three-detector network. The source was localized to 18.5 deg2 at a distance of 241 +41-41 Mpc; no electromagnetic counterpart has been confirmed to date. The source has the most unequal …

Kr Persei, A Mid-F Eclipsing Binary With A One-Day Period, James R. Sowell, Emily Hollingworth, Francis C. Fekel, Matthew W. Muterspaugh, Horace Dale, Alexander D. Savello, Jeffrey L. Coughlin, Richard M. Williamon

Information Systems and Engineering Management Research Publications

KR Per is a partially eclipsing binary with an orbital period of 0.9960798 days, very close to one sidereal day, making it difficult to obtain extensive phase coverage in a reasonable amount of time. We used the Wilson–Devinney program to determine its orbital elements and stellar absolute dimensions from recently acquired radial velocities and differential BVRI observations that were supplemented with previous differential UBV measurements and published times of minima. The two components are each F5 V stars with masses of and . The radii are and . The orbital period of the eclipsing system is variable and more times …

Reliable Extraction Of Energy Landscape Properties From Critical Force Distributions, Sudeep Adhikari, K. S. D. Beach

Faculty and Student Publications

The structural dynamics of a biopolymer is governed by a process of diffusion through its conformational energy landscape. In pulling experiments using optical tweezers, features of the energy landscape can be extracted from the probability distribution of the critical force at which the polymer unfolds. The analysis is often based on rate equations having Bell-Evans form, although it is understood that this modeling is inadequate and leads to unreliable landscape parameters in many common situations. Dudko et al. [Phys. Rev. Lett. 96, 108101 (2006)PRLTAO0031-900710.1103/PhysRevLett.96.108101] have emphasized this critique and proposed an alternative form that includes an additional shape parameter (and …

The Gemini Planet Imager View Of The Hd 32297 Debris Disk, Gaspard Duchene, Malena Rice, Justin Hom, Joseph Zalesky, Thomas M. Esposito, Maxwell A. Millar-Blanchaer, Bin Ren, Paul Kalas, Michael P. Fitzgerald, Pauline Arriaga, Sebastian Bruzzone, Joanna Bulger, Christine H. Chen, Eugene Chiang, Tara Cotten, Ian Czekala, Robert J. De Rosa, Ruobing Dong, Zachary H. Draper, Katherine B. Follette, James R. Graham, Li Wei Hung, Ronald Lopez, Bruce Macintosh, Brenda C. Matthews, Et Al, Kimberly Ward-Duong

Astronomy: Faculty Publications

We present new H-band scattered light images of the HD 32297 edge-on debris disk obtained with the Gemini Planet Imager. The disk is detected in total and polarized intensity down to a projected angular separation of 0.?15, or 20 au. On the other hand, the large-scale swept-back halo remains undetected, likely a consequence of its markedly blue color relative to the parent body belt. We analyze the curvature of the disk spine and estimate a radius of ?100 au for the parent body belt, smaller than past scattered light studies but consistent with thermal emission maps of the system. We …

Stability Of Regular Thin Shell Wormholes Supported By Vdw Quintessence, A. Eid

Applications and Applied Mathematics: An International Journal (AAM)

The dynamical equations of motion for a thin shell wormhole from regular black holes that are supported by Van der Waals (VDW) quintessence equation of state (EoS) are constructed, through cut and -paste technique. The linearized stability of regular wormhole is derived. The presences of unstable and stable static solutions with different value of some parameters are analyzed.

Spherically Symmetric Charged Anisotropic Solution In Higher Dimensional Bimetric General Relativity, D. N. Pandya, A. H. Hasmani

Applications and Applied Mathematics: An International Journal (AAM)

In this paper we have obtained a solution of field equations of Rosen’s bimetric general relativity (BGR) for the static spherically symmetric space-time with charged anisotropic fluid distribution in (n+2)-dimensions. An exact solution is obtained and a special case is considered. This work is an extension of our previous work where four-dimensional case was discussed.