Magnetic Activity Of Radio Stars Based On Tess And Lamost Surveys,
2024
Guizhou University
Magnetic Activity Of Radio Stars Based On Tess And Lamost Surveys, Yinpeng Wang, Liyun Zhang, Tianhao Su, Xianming Han, Prabhakar Misra
Astronomy and Physics
Stellar flares serve as crucial indicators stellar magnetic activity. Radio emissions were detectable across all stages of stellar evolution. We define radio stars in our paper as stars with radio continuum emission in the frequency region of about 1.4–375 GHz from the catalog published by Wendker (1995, A&AS, 109, 177; 2015, VizieR Online Data Catalog, VIII/99). We also include de- tected radio stars from the LOFAR Two-metre Sky Survey (LoTSS) and the Australian Square Kilometre Array Pathfinder (ASKAP), and VLA Sky Survey (VLASS) surveys, and present comparative discussions. We used the light curves from the Transiting Exoplanet Survey Satellite (TESS) …
Adsorption Of Crystal Violet Dye From Synthetic Wastewater By Ball-Milled Royal Palm Leaf Sheath,
2024
The University of Texas Rio Grande Valley
Adsorption Of Crystal Violet Dye From Synthetic Wastewater By Ball-Milled Royal Palm Leaf Sheath, Neloy Sen, Nawrin Rahman Shefa, Kismot Reza, Sk Md Ali Zaker Shawon, Md. Wasikur Rahman
Physics & Astronomy Faculty Publications
The current study shows that using a batch approach to remove crystal violet dye from synthetic wastewater is feasible when using royal palm leaf sheath powder as an adsorbent. In order to investigate the effects of many parameters, including starting concentration, pH effect, dye concentration, adsorbent dose, contact time, and temperature, experiments were carried out under various operating conditions. Maximum removal was obtained at pH 6 and at a concentration of 100 ppm, which are considered as ideal values. The influence of pH and dye concentration was shown to be substantial. Langmuir, Freundlich, and Temkin isotherm models were fitted to …
A Shining Star In The Field Of Astronomy,
2024
Parkland College
A Shining Star In The Field Of Astronomy, Erik Johnson
Natural Science Faculty
Humans have observed stars since prehistory. Although Earth's rotation and orbit adjust where they are in the sky each night, they appear to be fixed in place relative to each other. This allowed people to recognize consistent patterns over time which we now identify as constellations.
On Skew-Symmetric Splitting And Entropy
Conservation Schemes For The Euler Equations,
2024
Lawrence Livermore National Laboratory
On Skew-Symmetric Splitting And Entropy Conservation Schemes For The Euler Equations, Björn Sjögreen, H.C. Yee
United States National Aeronautics and Space Administration: Publications
The Tadmor type of entropy conservation formulation for the Euler equations and various skew-symmetric splittings of the inviscid flux derivatives are discussed. Numerical stability of high order central and Padé type (centered compact) spatial discretization is enhanced through the application of these formulations. Numerical test on a 2-D vortex convection problem indicates that the stability and accuracy of these formulations using the same high order central spatial discretization are similar for vortex travel up to a few periods. For two to three times longer time integrations, their corresponding stability and accuracy behaviors are very different. The goal of this work …
Toi-2266 B: A Keystone Super-Earth At The Edge Of The M Dwarf Radius Valley,
2024
Swarthmore College
Toi-2266 B: A Keystone Super-Earth At The Edge Of The M Dwarf Radius Valley, H. Parviainen, F. Murgas, E. Esparza-Borges, A. Peláez-Torres, E. Palle, R. Luque, M. R. Zapatero-Osorio, J. Korth, A. Fukui, N. Narita, K. A. Collins, V. J. S. Béjar, G. Morello, M. Monelli, N. Abreu Garcia, G. Chen, N. Crouzet, J. P. De Leon, K. Isogai, T. Kagetani, K. Kawauchi, P. Klagyivik, T. Kodama, N. Kusakabe, J. H. Livingston, P. Meni, M. Mori, G. Nowak, M. Tamura, Y. Terada, N. Watanabe, D. R. Ciardi, M. B. Lund, J. L. Christiansen, C. D. Dressing, S. Giacalone, A. B. Savel, L. Hirsch, S. G. Parsons, P. Brown, K. I. Collins, K. Barkaoui, M. Timmermans, M. Ghachoui, A. Soubkiou, Z. Benkhaldoun, S. Mcdermott, T. Pritchard, P. Rowden, S. Striegel, T. Gan, K. Horne, Eric L.N. Jensen, R. P. Schwarz, A. Shporer, G. Srdoc, S. Seager, J. N. Winn, J. M. Jenkins, G. Ricker, R. Vanderspek, D. Dragomir
Physics & Astronomy Faculty Works
We validate the Transiting Exoplanet Survey Satellite (TESS) object of interest TOI-2266.01 (TIC 8348911) as a small transiting planet (most likely a super-Earth) orbiting a faint M5 dwarf (V = 16.54) on a 2.33 d orbit. The validation is based on an approach where multicolour transit light curves are used to robustly estimate the upper limit of the transiting object's radius. Our analysis uses SPOC-pipeline TESS light curves from Sectors 24, 25, 51, and 52, simultaneous multicolour transit photometry observed with MuSCAT2, MuSCAT3' and HiPERCAM, and additional transit photometry observed with the LCOGT telescopes. TOI-2266 b is found to …
Toi-1994b: A Low-Mass Eccentric Brown Dwarf Transiting A Subgiant Star,
2024
Swarthmore College
Toi-1994b: A Low-Mass Eccentric Brown Dwarf Transiting A Subgiant Star, E. Page, J. Pepper, D. Wright, J. E. Rodriguez, R. A. Wittenmyer, S. R. Kane, B. Addison, T. Bedding, B. P. Bowler, T. Barclay, K. A. Collins, P. Evans, J. Horner, Eric L.N. Jensen, M. C. Johnson, J. Kielkopf, I. Mireles, P. Plavchan, S. N. Quinn, S. Seager, A. Shporer, K. G. Stassun, S. Striegal, J. N. Winn, G. Zhou, C. Ziegler
Physics & Astronomy Faculty Works
We present the discovery of TOI-1994b, a low-mass brown dwarf transiting a hot subgiant star on a moderately eccentric orbit. TOI-1994 has an effective temperature of 7700 +720/-410 K, V magnitude of 10.51 mag and log(g) of 3.982 +0.067/-0.065. The brown dwarf has a mass of 22.1 +2.6/-2.5 MJ, a period of 4.034 days, an eccentricity of 0.341 +0.054/-0.059, and a radius of 1.220 +0.082/-0.071 RJ. TOI-1994b is more eccentric than other transiting brown dwarfs with similar masses and periods. The population of low-mass brown dwarfs may have properties similar to planetary systems …
The Jwst Early Release Science Program For Direct Observations Of Exoplanetary Systems. Iv. Niriss Aperture Masking Interferometry Performance And Lessons Learned,
2024
University of California, Irvine
The Jwst Early Release Science Program For Direct Observations Of Exoplanetary Systems. Iv. Niriss Aperture Masking Interferometry Performance And Lessons Learned, Steph Sallum, Shrishmoy Ray, Jens Kammerer, Anand Sivaramakrishnan, Rachel Cooper, Alexandra Z. Greebaum, Deepashri Thatte, Matthew De Furio, Samuel M. Factor, Michael R. Meyer, Jordan M. Stone, Aarynn Carter, Beth Biller, Sasha Hinkley, Andrew Skemer, Genaro Suárez, Jarron M. Leisenring, Marshall D. Perrin, Adam L. Kraus, Olivier Absil, William O. Balmer, Sarah K. Betti, Anthony Boccaletti, Mariangela Bonavita, Mickael Bonnefoy, Mark Booth, Brendan P. Bowler, Zackery W. Briesemeister, Marta L. Bryan, Per Calissendorff, Et Al, Kimberly Ward-Duong
Astronomy: Faculty Publications
We present a performance analysis for the aperture masking interferometry (AMI) mode on board the James Webb Space Telescope Near Infrared Imager and Slitless Spectrograph (JWST/NIRISS). Thanks to self-calibrating observables, AMI accesses inner working angles down to and even within the classical diffraction limit. The scientific potential of this mode has recently been demonstrated by the Early Release Science (ERS) 1386 program with a deep search for close-in companions in the HIP 65426 exoplanetary system. As part of ERS 1386, we use the same data set to explore the random, static, and calibration errors of NIRISS AMI observables. We compare …
Dynamical Architectures Of S-Type Transiting Planets In Binaries. I. Target Selection Using Hipparcos And Gaia Proper Motion Anomalies,
2024
Swarthmore College
Dynamical Architectures Of S-Type Transiting Planets In Binaries. I. Target Selection Using Hipparcos And Gaia Proper Motion Anomalies, J. Zhang, L. M. Weiss, D. Huber, Eric L.N. Jensen, T. D. Brandt, K. Collins, D. M. Conti, H. Isaacson, P. Lewin, G. Marino, B. Massey, F. Murgas, E. Palle, D. J. Radford, H. M. Relles, G. Srdoc, C. Stockdale, T.-G. Tan, G. Wang
Physics & Astronomy Faculty Works
The effect of stellar multiplicity on planetary architecture and orbital dynamics provides an important context for exoplanet demographics. We present a volume-limited catalog of up to 300 pc of 66 stars hosting planets and planet candidates from Kepler, K2, and TESS with significant Hipparcos-Gaia proper motion anomalies, which indicates the presence of companions. We assess the reliability of each transiting planet candidate using ground-based follow-up observations, and find that the TESS Objects of Interest (TOIs) with significant proper anomalies show nearly four times more false positives due to eclipsing binaries compared to TOIs with marginal proper anomalies. In addition, we …
Strongly Magnetized Accretion In Two Ultracompact Binary Systems,
2024
The University of Texas Rio Grande Valley
Strongly Magnetized Accretion In Two Ultracompact Binary Systems, Thomas J. Maccarone, Thomas Kupfer, Edgar Najera Casarrubias, Liliana E. Rivera Sandoval, Aarran W. Shaw, Christoper T. Britt, Jan Van Roestel, David R. Zurek
Physics & Astronomy Faculty Publications
We present the discoveries of two of AM CVn systems, Gaia14aae and SDSS J080449.49+161624.8, which show X-ray pulsations at their orbital periods, indicative of magnetically collimated accretion. Both also show indications of higher rates of mass transfer relative to the expectations from binary evolution driven purely by gravitational radiation, based on existing optical data for Gaia14aae, which show a hotter white dwarf temperature than expected from standard evolutionary models, and X-ray data for SDSS J080449.49+161624.8 which show a luminosity 10−100 times higher than those for other AM CVn at similar orbital periods. The higher mass transfer rates could be driven …
Powerful Radio Sources In The Southern Sky. Iii. First Results Of The Optical Spectroscopic Campaign,
2024
The University of Texas Rio Grande Valley
Powerful Radio Sources In The Southern Sky. Iii. First Results Of The Optical Spectroscopic Campaign, A. García-Pérez, H. A. Peña-Herazo, A. Jimenez-Gallardo, V. Chavushyan, F. Massaro, S. V. White, A. Capetti, B. Balmaverde, W. R. Forman, Juan P. Madrid
Physics & Astronomy Faculty Publications
We recently built the G4Jy-3CRE catalog of extragalactic radio sources. This catalog lists 264 powerful radio sources selected with similar criteria to those of the revised Third Cambridge Catalog, but visible from the Southern Hemisphere. A literature search revealed that 119 sources in the G4Jy-3CRE catalog (i.e., 45%) lack a firm spectroscopic redshift measurement. Here, we present a campaign aimed at acquiring optical spectra of G4Jy-3CRE sources and measuring their redshifts. We used single-slit observations obtained with the Víctor Blanco Telescope, the New Technology Telescope, the Southern Astrophysical Research Telescope, and the 2.1 m telescope of the Observatorio Astronómico Nacional …
Comment On “Spectral Shifts In General Relativity,” [Am. J. Phys. 62(10), 903–907 (1994)],
2024
The University of Texas Rio Grande Valley
Comment On “Spectral Shifts In General Relativity,” [Am. J. Phys. 62(10), 903–907 (1994)], Joseph D. Romano, Teviet Creighton
Physics & Astronomy Faculty Publications
No abstract provided.
Single Domain Soft Ferromagnetic Ferrofluid Suitable For Intratumoural Magnetic Hyperthermia,
2024
The University of Texas Rio Grande Valley
Single Domain Soft Ferromagnetic Ferrofluid Suitable For Intratumoural Magnetic Hyperthermia, Karthickraja Duraisamy, Muthu Devaraj, Ajithkumar Gangadharan, Karen S. Martirosyan, Niroj Kumar Sahu, Prasath Manogaran, Girija Easwaradas Kreedapathy
Physics & Astronomy Faculty Publications
Magnetic hyperthermia is an effective modality for treating cancerous cells selectively at the intracellular level via proper administration, surface tagging and appropriate choice of magnetic nanoparticle. Also, achieving the therapeutic temperature with as much low concentration of nanoparticles, as possible, is desirable. Recently, ferromagnetic nanoparticles or ferrofluid are gaining attention as effective magnetic hyperthermia agents due to their enhanced heating potential under in vivo conditions. In the present work, we have fabricated citrate capped cobalt ferrite ferrofluid via a simple two-step process and investigated the physicochemical, magnetic and induction heating performance. The average size of the synthesized nanoparticle …
Roaring To Softly Whispering: X-Ray Emission After ∼3.7 Yr At The Location Of The Transient At2018cow And Implications For Accretion-Powered Scenarios,
2024
The University of Texas Rio Grande Valley
Roaring To Softly Whispering: X-Ray Emission After ∼3.7 Yr At The Location Of The Transient At2018cow And Implications For Accretion-Powered Scenarios, Giulia Migliori, R. Margutti, B. D. Metzger, R. Chornock, C. Vignali, D. Brethauer, Liliana E. Rivera Sandoval, J. S. Bright, T. Laskar, D. Milisavljevic
Physics & Astronomy Faculty Publications
We present the first deep X-ray observations of luminous fast blue optical transient (LFBOT) AT 2018cow at ∼3.7 yr since discovery, together with the reanalysis of the observation at δt ∼ 220 days. X-ray emission is significantly detected at a location consistent with AT 2018cow. The very soft X-ray spectrum and sustained luminosity are distinct from the spectral and temporal behavior of the LFBOT in the first ∼100 days and would possibly signal the emergence of a new emission component, although a robust association with AT 2018cow can only be claimed at δt ∼ 220 days, while at …
Research Experiences Via Integrating Simulations And Experiments (Revise): A Model Collaborative Research Project For Undergraduate Students In Co2 Sorbent Design,
2024
The University of Texas Rio Grande Valley
Research Experiences Via Integrating Simulations And Experiments (Revise): A Model Collaborative Research Project For Undergraduate Students In Co2 Sorbent Design, Anthony Griffin, Neziah Smith, Mark Robertson, Bianca Nunez, Jacob Mccraw, Haoyuan Chen, Zhe Qiang
Physics & Astronomy Faculty Publications
Undergraduate research experiences are an instrumental component of student development, increasing conceptual understanding, promoting inquiry-based learning, and guiding potential career aspirations. Moving one step further, as research continues to become more interdisciplinary, there exists potential to accelerate student growth by granting additional perspectives through collaborative research. This study demonstrates the utilization of a model collaborative research project, specifically investigating the development of sorbent technologies for efficient CO2 capture, which is an important research area for improving environmental sustainability. A model CO2 sorbent system of heteroatom-doped porous carbon is utilized to enable students to gain knowledge of adsorption processes, through combined …
Thermal Phonon Fluctuations And Stability Of The Magnetic Dual Chiral Density Wave Phase In Dense Qcd,
2024
The University of Texas Rio Grande Valley
Thermal Phonon Fluctuations And Stability Of The Magnetic Dual Chiral Density Wave Phase In Dense Qcd, Efrain J. Ferrer, William Gyory, Vivian De La Incera
Physics & Astronomy Faculty Publications
We study the stability against thermal phonon fluctuations of the magnetic dual chiral density wave (MDCDW) phase, an inhomogeneous phase arising in cold, dense QCD in a magnetic field. Following a recent study that demonstrated the absence of the Landau-Peierls (LP) instability from this phase, we calculate the (threshold) temperature at which the phonon fluctuations wash out the long-range order over a range of magnetic fields and densities relevant to astrophysical applications. Using a high-order Ginzburg-Landau expansion, we find that the threshold temperature is very near the critical temperature for fields of order 10 18 G and still a sizable …
Research Experiences Via Integrating Simulations And Experiments (Revise): A Model Collaborative Research Project For Undergraduate Students In Co2 Sorbent Design,
2024
The University of Texas Rio Grande Valley
Research Experiences Via Integrating Simulations And Experiments (Revise): A Model Collaborative Research Project For Undergraduate Students In Co2 Sorbent Design, Anthony Griffin, Neziah Smith, Mark Robertson, Bianca Nunez, Jacob Mccraw, Haoyuan Chen, Zhe Qiang
Physics & Astronomy Faculty Publications
Undergraduate research experiences are an instrumental component of student development, increasing conceptual understanding, promoting inquiry-based learning, and guiding potential career aspirations. Moving one step further, as research continues to become more interdisciplinary, there exists potential to accelerate student growth by granting additional perspectives through collaborative research. This study demonstrates the utilization of a model collaborative research project, specifically investigating the development of sorbent technologies for efficient CO2 capture, which is an important research area for improving environmental sustainability. A model CO2 sorbent system of heteroatom-doped porous carbon is utilized to enable students to gain knowledge of adsorption processes, through combined …
Observed Epochal Variations In X-Ray Lines From The O Supergiant Ζ Puppis Do Not Require Substantial Changes In The Wind Mass Flux,
2024
Embry-Riddle Aeronautical University
Observed Epochal Variations In X-Ray Lines From The O Supergiant Ζ Puppis Do Not Require Substantial Changes In The Wind Mass Flux, Sean J. Gunderson, Kenneth G. Gayley, David P. Huenemoerder, Pragati Pradhan, Nathan A. Miller
Publications
We fit the high-resolution Chandra X-ray spectra of the O supergiant ζ Puppis using the variable boundary condition (VBC) line model to test the stability of its mass-loss rate between two epochs of observation: 2000 March and 2018 July – 2019 August. At issue is whether the observed variations are induced by global changes in the cool (unshocked) wind itself or are isolated to the local pockets of hot gas (i.e. changes in the frequency and location of the shocks). Evidence in the literature favoured the possibility of a 40 per cent increase in the mass flux of the entire …
Inferring Binary Parameters With Dual-Line Gravitational Wave Detection From Tight Inspiraling Double Neutron Stars,
2024
The University of Texas Rio Grande Valley
Inferring Binary Parameters With Dual-Line Gravitational Wave Detection From Tight Inspiraling Double Neutron Stars, Wen-Fan Feng, Jie-Wen Chen, Tan Liu, Yan Wang, Soumya D. Mohanty
Physics & Astronomy Faculty Publications
Neutron star (NS) binaries can be potentially intriguing gravitational wave sources, with both high- and low-frequency radiation from the possibly aspherical individual stars and the binary orbit, respectively. The successful detection of such a dual-line source could provide fresh insights into binary geometry and NS physics. In the absence of electromagnetic observations, we develop a strategy for inferring the spin-orbit misalignment angle using the tight dual-line double NS system under the spin-orbit coupling. Based on the four-year joint detection of a typical dual-line system with the Laser Interferometer Space Antenna and Cosmic Explorer, we find that the misalignment angle and …
Anomaly Detection On Small Wind Turbine Blades Using Deep Learning Algorithms,
2024
Utah State University
Anomaly Detection On Small Wind Turbine Blades Using Deep Learning Algorithms, Bridger Altice, Edwin Nazario, Mason Davis, Mohammad Shekaramiz, Todd K. Moon, Mohammad A. S. Masoum
Electrical and Computer Engineering Faculty Publications
Wind turbine blade maintenance is expensive, dangerous, time-consuming, and prone to misdiagnosis. A potential solution to aid preventative maintenance is using deep learning and drones for inspection and early fault detection. In this research, five base deep learning architectures are investigated for anomaly detection on wind turbine blades, including Xception, Resnet-50, AlexNet, and VGG-19, along with a custom convolutional neural network. For further analysis, transfer learning approaches were also proposed and developed, utilizing these architectures as the feature extraction layers. In order to investigate model performance, a new dataset containing 6000 RGB images was created, making use of indoor and …
Swarm Intelligence Methods For Extreme Mass Ratio Inspiral Search: First Application Of Particle Swarm Optimization,
2024
The University of Texas Rio Grande Valley
Swarm Intelligence Methods For Extreme Mass Ratio Inspiral Search: First Application Of Particle Swarm Optimization, Xiao-Bo Zou, Soumya D. Mohanty, Hong-Gang Luo, Yu-Xiao Liu
Physics & Astronomy Faculty Publications
Swarm intelligence (SI) methods are nature-inspired metaheuristics for global optimization that exploit a coordinated stochastic search strategy by a group of agents. Particle swarm optimization (PSO) is an established SI method that has been applied successfully to the optimization of rugged high-dimensional likelihood functions, a problem that represents the main bottleneck across a variety of gravitational wave (GW) data analysis challenges. We present results from the first application of PSO to one of the most difficult of these challenges, namely the search for the Extreme Mass Ratio Inspiral (EMRI) in data from future spaceborne GW detectors such as LISA, Taiji, …
