Astrophysics and Astronomy Commons^™

Tess-Keck Survey. V. Twin Sub-Neptunes Transiting The Nearby G Star Hd 63935, N. Scarsdale, J. M. Akana Murphy, N. M. Batalha, I. J. M. Crossfield, C. D. Dressing, B. Fulton, A. W. Howard, D. Huber, H. Isaacson, S. R. Kane, E. A. Petigura, P. Robertson, A. Roy, L. M. Weiss, C. Beard, A. Behmard, A. Chontos, J. L. Christiansen, D. R. Ciardi, Z. R. Claytor, K. A. Collins, K. I. Collins, F. Dai, P. A. Dalba, D. Dragomir, T. Fetherolf, A. Fukui, S. Giacalone, E. J. Gonzales, M. L. Hill, L. A. Hirsch, Eric L.N. Jensen, M. R. Kosiarek, J. P. De Leon, J. Lubin, M. B. Lund, R. Luque, A. W. Mayo, T. Močnik, M. Mori, N. Narita, G. Nowak, E. Pallé, M. Rabus, L. J. Rosenthal, R. A. Rubenzahl, J. E. Schlieder, A. Shporer, K. G. Stassun, J. Twicken, G. Wang, D. A. Yahalomi, J. Jenkins, D. W. Latham, G. R. Ricker, S. Seager, R. Vanderspek, J. N. Winn

Physics & Astronomy Faculty Works

We present the discovery of two nearly identically sized sub-Neptune transiting planets orbiting HD 63935, a bright (V = 8.6 mag), Sun-like (T_eff = 5560 K) star at 49 pc. TESS identified the first planet, HD 63935 b (TOI-509.01), in Sectors 7 and 34. We identified the second signal (HD 63935 c) in Keck High Resolution Echelle Spectrometer and Lick Automated Planet Finder radial velocity data as part of our follow-up campaign. It was subsequently confirmed with TESS photometry in Sector 34 as TOI-509.02. Our analysis of the photometric and radial velocity data yielded a robust detection …

Searches For Continuous Gravitational Waves From Young Supernova Remnants In The Early Third Observing Run Of Advanced Ligo And Virgo, R. Abbott, T. D. Abbott, S. Abraham, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Karla E. Ramirez, Wenhui Wang

Physics & Astronomy Faculty Publications

We present results of three wide-band directed searches for continuous gravitational waves from 15 young supernova remnants in the first half of the third Advanced LIGO and Virgo observing run. We use three search pipelines with distinct signal models and methods of identifying noise artifacts. Without ephemerides of these sources, the searches are conducted over a fRequency band spanning from 10 to 2 kHz. We find no evidence of continuous gravitational radiation from these sources. We set upper limits on the intrinsic signal strain at 95% confidence level in sample subbands, estimate the sensitivity in the full band, and derive …

Search Full Text Options Here 1 Of 1 Constraints From Ligo O3 Data On Gravitational-Wave Emission Due To R-Modes In The Glitching Pulsar Psr J0537-6910, R. Abbott, T. D. Abbott

Faculty Publications

We present a search for continuous gravitational-wave emission due to r-modes in the pulsar PSR J0537-6910 using data from the LIGO-Virgo Collaboration observing run O3. PSR J0537-6910 is a young energetic X-ray pulsar and is the most frequent glitcher known. The inter-glitch braking index of the pulsar suggests that gravitational-wave emission due to r-mode oscillations may play an important role in the spin evolution of this pulsar. Theoretical models confirm this possibility and predict emission at a level that can be probed by ground-based detectors. In order to explore this scenario, we search for r-mode emission in the epochs between …

Constraints From Ligo O3 Data On Gravitational-Wave Emission Due To R-Modes In The Glitching Pulsar Psr J0537–6910, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Karla E. Ramirez, Wenhui Wang

Physics & Astronomy Faculty Publications

We present a search for continuous gravitational-wave emission due to r-modes in the pulsar PSR J0537-6910 using data from the LIGO-Virgo Collaboration observing run O3. PSR J0537-6910 is a young energetic X-ray pulsar and is the most frequent glitcher known. The inter-glitch braking index of the pulsar suggests that gravitational-wave emission due to r-mode oscillations may play an important role in the spin evolution of this pulsar. Theoretical models confirm this possibility and predict emission at a level that can be probed by ground-based detectors. In order to explore this scenario, we search for r-mode emission in the epochs between …

Global 3d Radiation Hydrodynamic Simulations Of Proto-Jupiter’S Convective Envelope, Zhaohuan Zhu, Yan-Fei Jiang, Hans Baehr, Andrew N. Youdin, Philip J. Armitage, Rebecca G. Martin

Physics & Astronomy Faculty Research

The core accretion model of giant planet formation has been challenged by the discovery of recycling flows between the planetary envelope and the disc that can slow or stall envelope accretion. We carry out 3D radiation hydrodynamic simulations with an updated opacity compilation to model the proto-Jupiter’s envelope. To isolate the 3D effects of convection and recycling, we simulate both isolated spherical envelopes and envelopes embedded in discs. The envelopes are heated at given rates to achieve steady states, enabling comparisons with 1D models. We vary envelope properties to obtain both radiative and convective solutions. Using a passive scalar, we …

Galaxy And Mass Assembly (Gama): The Merging Potential Of Brightest Group Galaxies, K. Banks, S. Brough, Benne Holwerda, A. M. Hopkins, Á. R. López-Sánchez, S. Phillipps, K. A. Pimbblet, A. S. G. Robotham

Faculty and Staff Scholarship

Using a volume-limited sample of 550 groups from the Galaxy And Mass Assembly Galaxy Group Catalogue spanning the halo mass range , we investigate the merging potential of central Brightest Group Galaxies (BGGs). We use spectroscopically confirmed close-companion galaxies as an indication of the potential stellar mass buildup of low-redshift BGGs, z ≤ 0.2. We identify 17 close-companion galaxies with projected separations rp < 30 kpc, relative velocities Δv ≤ 300 km s−1, and stellar mass ratios MBGG/MCC ≤ 4 relative to the BGG. These close-companion galaxies yield a total pair fraction of 0.03 ± 0.01. Overall, we find that BGGs …

The Solar Memory From Hours To Decades, Markus J. Aschwanden, Jay R. Johnson

Faculty Publications

Waiting-time distributions allow us to distinguish at least three different types of dynamical systems, including (i) linear random processes (with no memory); (ii) nonlinear, avalanche-type, nonstationary Poisson processes (with memory during the exponential growth of the avalanche rise time); and (iii) chaotic systems in the state of a nonlinear limit cycle (with memory during the oscillatory phase). We describe the temporal evolution of the flare rate λ(t) ∝ t p with a polynomial function, which allows us to distinguish linear (p ≈ 1) from nonlinear (p  2) events. The power-law slopes α of the observed waiting times (with full …

All-Sky Search For Short Gravitational-Wave Bursts In The Third Advanced Ligo And Advanced Virgo Run, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Volker Quetschke, Wen Hui Wang

Physics & Astronomy Faculty Publications

This paper presents the results of a search for generic short-duration gravitational-wave transients in data from the third observing run of Advanced LIGO and Advanced Virgo. Transients with durations of milliseconds to a few seconds in the 24–4096 Hz frequency band are targeted by the search, with no assumptions made regarding the incoming signal direction, polarization, or morphology. Gravitational waves from compact binary coalescences that have been identified by other targeted analyses are detected, but no statistically significant evidence for other gravitational wave bursts is found. Sensitivities to a variety of signals are presented. These include updated upper limits on …

Technique To Solve Linear Fractional Differential Equations Using B-Polynomials Bases, Muhammad I. Bhatti, Md. Habibur Rahman

Physics & Astronomy Faculty Publications

A multidimensional, modified, fractional-order B-polys technique was implemented for finding solutions of linear fractional-order partial differential equations. To calculate the results of the linear Fractional Partial Differential Equations (FPDE), the sum of the product of fractional B-polys and the coefficients was employed. Moreover, minimization of error in the coefficients was found by employing the Galerkin method. Before the Galerkin method was applied, the linear FPDE was transformed into an operational matrix equation that was inverted to provide the values of the unknown coefficients in the approximate solution. A valid multidimensional solution was determined when an appropriate number of basis sets …

Planetarium Celebrates 50 Years Since Apollo Missions, Erik Johnson

Natural Science Faculty

It is mind-boggling how humanity went from the invention of powered aircraft to rockets carrying people safely to the Moon in fewer than 70 years. The William M. Staerkel Planetarium at Parkland College is celebrating the 50th anniversary of the Apollo missions with several exhibits on these achievements.

Visitors can see "Many Inspired Steps," a pictorial timeline offering highlights of the mid-20th century space program up to Apollo 11. It includes earlier advancements of air travel and ancient mythological inspirations of human flight.

Establishing Α Oph As A Prototype Rotator: Precision Orbit With New Keck, Chara, And Rv Observations, Tyler Gardner, John D. Monnier, Francis C. Fekel, Michael H. Williamson, Fabien Baron, Sasha Hinkley, Michael Ireland, Adam L. Kraus, Stefan Kraus, Rachael M. Roettenbacher, Gail Schaefer, Judit Sturmann, Laszlo Sturmann, Theo A. Ten Brummelaar

Information Systems and Engineering Management Research Publications

Alpha Ophiuchi (Rasalhague) is a nearby rapidly rotating A5IV star that has been imaged by infrared interferometry. α Oph is also part of a known binary system, with a companion semimajor axis of ∼430 mas and a high eccentricity of 0.92. The binary companion provides the unique opportunity to measure the dynamical mass to compare with the results of rapid rotator evolution models. The lack of data near periastron passage limited the precision of mass measurements in previous work. We add new interferometric data from the MIRC combiner at the CHARA Array as well as new Keck adaptive optics imaging …

Classifying Soft X-Ray Objects In The Galactic Bulge, Joshua D. Wetuski

LSU Doctoral Dissertations

The Galactic Bulge Survey (GBS) is a broad and shallow X-ray survey designed to detect quiescent X-ray binary systems in the direction of the Milky Way bulge, which include objects such as low-mass X-ray binaries, cataclysmic variables, and symbiotic binaries. LMXBs can provide constraints to the neutron star equation of state and symbiotic systems and are likely progenitors of double white dwarf systems which are themselves candidate progenitors to type Ia supernova. We seek to improve identification and classification of optical counterparts to GBS in several ways. By improving upon the original GBS, an updated catalog was created to help …

Searching For Solar Kdar With Dune, The Dune Collaboration, A. Abed Abud, B. Abi, R. Acciarri, M. A. Acero, M. R. Adames, G. Adamov, D. Adams, M. Adinolfi, A. Aduszkiewicz, J. Aguilar, Z. Ahmad, J. Ahmed, B. Ali-Mohammadzadeh, T. Alion, K. Allison, S. Alonso Monsalve, M. Alrashed, C. Alt, A. Alton, Roberto Petti, Sanjib R. Mishra Ph.D., Et. Al.

Faculty Publications

The observation of 236 MeV muon neutrinos from kaon-decay-at-rest (KDAR) originating in the core of the Sun would provide a unique signature of dark matter annihilation. Since excellent angle and energy reconstruction are necessary to detect this monoenergetic, directional neutrino flux, DUNE with its vast volume and reconstruction capabilities, is a promising candidate for a KDAR neutrino search. In this work, we evaluate the proposed KDAR neutrino search strategies by realistically modeling both neutrino-nucleus interactions and the response of DUNE. We find that, although reconstruction of the neutrino energy and direction is difficult with current techniques in the relevant energy …

The Baryonic Tully-Fisher Relation In The Local Group And The Equivalent Circular Velocity Of Pressure-Supported Dwarfs, Stacy S. Mcgaugh, Pengfei Li, Tiffany Visgaitis

Faculty Scholarship

We explore the baryonic Tully-Fisher relation in the Local Group. Rotationally-supported Local Group galaxies adhere precisely to the relation defined by more distant galaxies. For pressure-supported dwarf galaxies, we determine the scaling factor β c that relates their observed velocity dispersion to the equivalent circular velocity of rotationally-supported galaxies of the same mass such that V o = β c σ ∗. For a typical mass-to-light ratio ϒ∗ = 2 M /L in the V band, we find that β c = 2. More generally, β {c}=0.25∗ +0.226. This provides a common kinematic scale relating pressure and rotationally-supported dwarf galaxies.

Raman Investigations Of The Radiation-Induced Modifications In Ipp-Vgcnf Nanocomposites: The Nanofillers’ Tale, Dorina M. Chipara, Mihail Secu, Karen Lozano, Corina Secu, Mircea Chipara

Physics & Astronomy Faculty Publications

Nanocomposites of isotactic polypropylene loaded by various amounts of vapor-grown carbon nanotubes ranging from 0 to 20% wt. were obtained by extrusion. Raman investigations on these nanocomposites are reported. The nanocomposites were irradiated using a 60Co, with an integral dose of 1 kGy/h up to integral doses of 9 kGy, 18 kGy, and 27 kGy, in air, at room temperature. Raman measurements were performed by using a Bruker Senterra confocal Raman spectrometer operating at 785 nm. The research is focused on the information contained within the D and G Raman lines of these nanocomposites as a function of nanotube loading …

Modeling Initial Breakdown Pulses Of Intracloud Lightning Flashes, Nilmini Karunarathne, Thomas C. Marshall, Sumedhe Karunarathne, Maribeth Stolzenburg

Faculty and Student Publications

In this study 29 initial breakdown pulses (IBPs) from four intracloud (IC) lightning flashes are modeled using data from five or more electric field change (E-change) sites. For each flash the first 5–9 located IBPs are investigated. For each IBP the modeling first extracts the IBP current waveform from the E-change data by matrix inversion and then determines the best channel length and current velocity to match the IBP data. Derived IBP quantities of total charge, charge moment, peak current, peak radiated power, and total energy are calculated. Resulting IBP vertical lengths varied from 27 m to 1300 m; most …

Multi-Messenger Astrophysics With Theseus In The 2030s, Bing Zhang, Numerous Authors, See Full List Below

Physics & Astronomy Faculty Research

Multi-messenger astrophysics is becoming a major avenue to explore the Universe, with the potential to span a vast range of redshifts. The growing synergies between different probes is opening new frontiers, which promise profound insights into several aspects of fundamental physics and cosmology. In this context, THESEUS will play a central role during the 2030s in detecting and localizing the electromagnetic counterparts of gravitational wave and neutrino sources that the unprecedented sensitivity of next generation detectors will discover at much higher rates than the present. Here, we review the most important target signals from multi-messenger sources that THESEUS will be …

All-Sky Search For Continuous Gravitational Waves From Isolated Neutron Stars In The Early O3 Ligo Data, 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 on an all-sky search for continuous gravitational waves in the frequency band 20-2000 Hz and with a frequency time derivative in the range of [-1.0,+0.1]×10-8 Hz/s. Such a signal could be produced by a nearby, spinning and slightly nonaxisymmetric isolated neutron star in our Galaxy. This search uses the LIGO data from the first six months of Advanced LIGO's and Advanced Virgo's third observational run, O3. No periodic gravitational wave signals are observed, and 95% confidence-level (C.L.) frequentist upper limits are placed on their strengths. The lowest upper limits on worst-case (linearly polarized) strain amplitude h0 are ∼1.7×10-25 …

Measuring Cosmic Density Of Neutral Hydrogen Via Stacking The Dingo-Vla Data, Qingxiang Chen, Martin Meyer, Attila Popping, Lister Staveley-Smith, Julia Bryant, Jacinta Delhaize, Benne Holwerda, M E. Cluver, J Loveday, Angel R. Lopez-Sanchez, Martin Zwaan, E N. Taylor, A M. Hopkins, Angus Wright, Simon Driver, S Brough

Faculty and Staff Scholarship

We use the 21-cm emission-line data from the Deep Investigation of Neutral Gas Origin-Very Large Array (DINGO-VLA) project to study the atomic hydrogen gas H I of the Universe at redshifts z < 0.1. Results are obtained using a stacking analysis, combining the H I signals from 3622 galaxies extracted from 267 VLA pointings in the G09 field of the Galaxy and Mass Assembly Survey (GAMA). Rather than using a traditional one-dimensional spectral stacking method, a three-dimensional cubelet stacking method is used to enable deconvolution and the accurate recovery of average galaxy fluxes from this high-resolution interferometric data set. By probing down to galactic scales, this experiment also overcomes confusion corrections that have been necessary to include in previous single-dish studies. After stacking and deconvolution, we obtain a 30σ H I mass measurement from the stacked spectrum, indicating an average H I mass of MHI=(1.67±0.18)×109 M⊙" 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; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; position: relative;">MHI=(1.67±0.18)×109 M⊙MHI=(1.67±0.18)×109 M⊙⁠. The corresponding cosmic density of neutral atomic hydrogen is ΩHI=(0.38±0.04)×10−3" 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; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; position: relative;">ΩHI=(0.38±0.04)×10−3ΩHI=(0.38±0.04)×10−3 at redshift of z = 0.051. These values are in good agreement with …

Mosaic: A Satellite Constellation To Enable Groundbreaking Mars Climate System Science And Prepare For Human Exploration, Robert J. Lillis, David Mitchell, Luca Montabone, Nicholas Heavens, Tanya Harrison, Cassie Stuurman, Et. Al.

Publications

The Martian climate system has been revealed to rival the complexity of Earth's. Over the last 20 yr, a fragmented and incomplete picture has emerged of its structure and variability; we remain largely ignorant of many of the physical processes driving matter and energy flow between and within Mars' diverse climate domains. Mars Orbiters for Surface, Atmosphere, and Ionosphere Connections (MOSAIC) is a constellation of ten platforms focused on understanding these climate connections, with orbits and instruments tailored to observe the Martian climate system from three complementary perspectives. First, low-circular near-polar Sun-synchronous orbits (a large mothership and three smallsats spaced …