News and Events

Jason W. Barnes
Friday, January 24, 12:00 PM (C215 ESC, and online)
Roving through the Air on Titan with Dragonfly

The Dragonfly mission will land a robotic octocopter on Saturn's moon Titan in 2034 to study its prebiotic chemistry, constrain its habitability, and search for potential chemical biosignatures.  Taking advantage of Titan's low gravity and thick air, Dragonfly will aerially traverse to over twenty distinct landing sites on dune, interdune, and icy crater terrains.  On the ground at those sites we will employ our four scientific instruments:  a mass spectrometer, a gamma-ray/neutron spectrometer, seven cameras, and a geophysical and meteorological suite.  We seek to determine how far organic chemistry has progressed, to ground-truth the global methane meteorological cycle, to measure the modes and rates of surface geologic processes, to constrain when and where water and organics might have mixed, and to look for evidence that either water- or hydrocarbon-based life may have existed on Titan.  The engineering design is presently being finalized to begin hardware fabrication ahead of our launch period that opens on 2028 July 5.

Thumbnail of NGC 7814: Little Sombrero
Point your telescope toward the high flying constellation Pegasus and you can find this cosmic expanse of Milky Way stars and distant galaxies. NGC 7814 is centered in the sharp field of view that would almost be covered by a full moon. NGC 7814 is sometimes called the Little Sombrero for its resemblance to the brighter more famous M104, the Sombrero Galaxy. Both Sombrero and Little Sombrero are spiral galaxies seen edge-on, and both have extensive halos and central bulges cut by a thin disk with thinner dust lanes in silhouette. In fact, NGC 7814 is some 40 million light-years away and an estimated 60,000 light-years across. That actually makes the Little Sombrero about the same physical size as its better known namesake, appearing smaller and fainter only because it is farther away.
Mount Timpanogos with sky above
Temperature:30.1 F
Rel. Humidity: 38%
Pressure:30.59 Inches Hg
Image for Adam Fennimore's Insights for Students
Alumni Adam Fennimore shares career insights for current students
Image for New Faculty Member, Dr. Greg Francis
Dr. Greg Francis joins faculty, specializing in Physics Education
Image for Dr. Ragozzine's Nice, France Obersvatoire Sabbatical
Darin Ragozzine collaborates with leading planetary scientists in France

Selected Publications

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By Mylan R. Cook, Kent L. Gee, and Mark. K. Transtrum (et al.)
Abstract:

The National Transportation Noise Map predicts time-averaged road traffic noise across the continental United States (CONUS) based on annual average daily traffic counts. However, traffic noise can vary greatly with time. This paper outlines a method for predicting nationwide hourly varying source traffic sound emissions called the Vehicular Reduced-Order Observation-based Model (VROOM). The method incorporates three models that predict temporal variability of traffic volume, predict temporal variability of different traffic classes, and use Traffic Noise Model (TNM) 3.0 equations to give traffic noise emission levels based on vehicle numbers and class mix. Location-specific features are used to predict average class mix across CONUS. VROOM then incorporates dynamic traffic class mix data to obtain dynamic traffic class mix. TNM 3.0 equations then give estimated equivalent sound level emission spectra near roads with up to hourly resolution. Important temporal traffic noise characteristics are modeled, including diurnal traffic patterns, rush hours in urban locations, and weekly and yearly variation. Examples of the temporal variability are depicted and possible types of uncertainties are identified. Altogether, VROOM can be used to map national transportation noise with temporal and spectral variability.

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By Jared R. Davidson, Benjamin D. Boizelle, and Emma Rasmussen (et al.)
Abstract:

Dusty circumnuclear disks (CNDs) in luminous early-type galaxies (ETGs) show regular, dynamically cold molecular gas kinematics. For a growing number of ETGs, Atacama Large Millimeter/sub-millimeter Array (ALMA) CO imaging and detailed gas-dynamical modeling facilitate moderate-to-high precision black hole (BH) mass (M BH) determinations. From the ALMA archive, we identified a subset of 26 ETGs with estimated M BH/M circle dot greater than or similar to 108 to a few x 109 and clean CO kinematics but that previously did not have sufficiently high-angular-resolution near-IR observations to mitigate dust obscuration when constructing stellar luminosity models. We present new optical and near-IR Hubble Space Telescope (HST) images of this sample to supplement the archival HST data, detailing the sample properties and data-analysis techniques. After masking the most apparent dust features, we measure stellar surface-brightness profiles and model the luminosities using the multi-Gaussian expansion (MGE) formalism. Some of these MGEs have already been used in CO dynamical modeling efforts to secure quality M BH determinations, and the remaining ETG targets here are expected to significantly improve the high-mass end of the current BH census, facilitating new scrutiny of local BH mass-host galaxy scaling relationships. We also explore stellar isophotal behavior and general dust properties, finding these CNDs generally become optically thick in the near-IR (A H greater than or similar to 1 mag). These CNDs are typically well aligned with the larger-scale stellar photometric axes, with a few notable exceptions. Uncertain dust impact on the MGE often dominates the BH mass error budget, so extensions of this work will focus on constraining CND dust attenuation.

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By Trevor Reay, John Carmen, Taylor Barton, Richard L. Sandberg, and Shiuh-Hua Wood Chiang (et al.)
Abstract:

This paper describes a compact, highly scalable, low-power, and multi-channel charge digitizer (MCCD) designed for synchrotron beam profile monitoring. The MCCD utilizes charge amplifiers, voltage amplifiers, programmable-gain ampli-fiers (PGAs), and ADCs to amplify and digitize input signals. The MCCD also demonstrates a novel stackable PCB design to easily reconfigure the channel count. Laboratory measurement results show a sample rate of 200 Hz per channel, gain of 6.64×1011 V/C, noise of 1.36×105e−rms , and power of 97 mW/channel.

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By Spencer Hopson, Carson Mildon, Kyle Hassard, Paul M. Urie, and Dennis Della Corte
Abstract:

Advances in artificial intelligence (AI) in the medical sector necessitate the development of AI literacy among future physicians. This article explores the pioneering efforts of the AI in Medicine Association (AIM) at Brigham Young University, which offers a framework for undergraduate pre-medical students to gain hands-on experience, receive principled education, explore ethical considerations, and learn appraisal of AI models. By supplementing formal, university-organized pre-medical education with a student-led, faculty-supported introduction to AI through an extracurricular academic association, AIM alleviates apprehensions regarding AI in medicine early and empowers students preparing for medical school to navigate the evolving landscape of AI in healthcare responsibly.

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Abstract:

The mathematical structure, description and classification of magnetic space groups is briefly reviewed, with special emphasis on the recently proposed notation, the so-called UNI symbols [Campbell et al. (2022). Acta Cryst. A78, 99–106]. As illustrative examples, very simple magnetic space groups from each of the four possible types are described in detail.

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By Emma Zappala and Benjamin A. Frandsen (et al.)
Abstract:

CrMnFeCoNi, also called the Cantor alloy, is a well-known high-entropy alloy whose magnetic properties have recently become a focus of attention. We present a detailed muon spin relaxation study of the influence of chemical composition and sample processing protocols on the magnetic phase transitions and spin dynamics of several different Cantor alloy samples. Specific samples studied include a pristine equiatomic sample, samples with deficient and excess Mn content, and equiatomic samples magnetized in a field of 9 T or plastically deformed in pressures up to 0.5 GPa. The results confirm the sensitive dependence of the transition temperature on composition and demonstrate that post-synthesis pressure treatments cause the transition to become significantly less homogeneous throughout the sample volume. In addition, we observe critical spin dynamics in the vicinity of the transition in all samples, reminiscent of canonical spin glasses and magnetic materials with ideal continuous phase transitions. Application of an external magnetic field suppresses the critical dynamics in the Mn-deficient sample, while the equiatomic and Mn-rich samples show more robust critical dynamics. The spin-flip thermal activation energy in the paramagnetic phase increases with Mn content, ranging from 3.1(3) ×10−21J for 0% Mn to 1.2(2)×10−20J for 30% Mn content. These results shed light on critical magnetic behavior in environments of extreme chemical disorder and demonstrate the tunability of spin dynamics in the Cantor alloy via chemical composition and sample processing.