Search Publications
Spectral Properties and the Influence of Coronal Mass Ejections in 3He-rich Solar Energetic Particle Events
Ho, G. C.; Mason, G. M.; Desai, M. I. +5 more
We analyze the spectral properties of 3He and 4He as well as the heavy ions (oxygen, neon, magnesium, silicon, and iron) in 80 3He-rich solar energetic particle (SEP) events observed by the Ultra-Low-Energy Ion Spectrometer on board the Advanced Composition Explorer spacecraft since its launch in 1997 until 2024. W…
Probing the Dust Grain Alignment Mechanisms in Spiral Galaxies with M51 as the Case Study
Tram, Le Ngoc; Lopez-Rodriguez, Enrique
Magnetic fields (B fields) in galaxies have recently been traced using far-infrared and submillimeter polarimetric observations with the Stratospheric Observatory for Infrared Astronomy, James Clerk Maxwell Telescope, and Atacama Large Millimeter/submillimeter Array. The main assumption is that dust grains are magnetically aligned with the local B…
Maser Investigation toward Off-Plane Stars (MIOPS): Detection of SiO Masers in the Galactic Thick Disk and Halo
Li, Juan; Gong, Yan; Menten, Karl M. +7 more
Studying stars that are located off the Galactic plane is important for understanding the formation history of the Milky Way. We searched for SiO masers toward off-plane O-rich asymptotic giant branch (AGB) stars from the catalog presented by Mauron et al. in order to shed light on the origins of these objects. A total of 102 stars were observed i…
Neglected Silicon Dioxide Polymorphs as Clouds in Substellar Atmospheres
Moran, Sarah E.; Marley, Mark S.; Crossley, Samuel D.
Direct mid-infrared signatures of silicate clouds in substellar atmospheres were first detected in Spitzer observations of brown dwarfs, although their existence was previously inferred from near-infrared spectra. With JWST's Mid-Infrared Instrument, we can now more deeply probe silicate features from 8 to 10 µm, exploring specific particle …
Spectroscopic Constraints on the Mid-infrared Attenuation Curve. I. Attenuation Model Using Polycyclic Aromatic Hydrocarbon Emission
Nakagawa, Takao; Baba, Shunsuke; Imanishi, Masatoshi +4 more
We introduce a novel model to spectroscopically constrain the mid-infrared (MIR) extinction/attenuation curve from 3–17 µm, using polycyclic aromatic hydrocarbon (PAH) emission drawn from an AKARI–Spitzer extragalactic cross-archival data set. Currently proposed MIR extinction curves vary significantly in their slopes toward the near-infrare…
Absorption Troughs of Lyα Emitters in HETDEX
Schneider, Donald P.; Chisholm, John; Kollatschny, Wolfram +21 more
The Hobby–Eberly Telescope Dark Energy Experiment (HETDEX) is designed to detect and measure the redshifts of more than 1 million Lyα emitting galaxies (LAEs) 1.88 < z < 3.52. In addition to its cosmological measurements, these data enable studies of Lyα spectral profiles and the underlying radiative transfer. Using the roughly half a millio…
Very Large and Long-lasting Anisotropies Caused by Sunward Streaming Energetic Ions: Solar Orbiter and STEREO A Observations
Luhmann, J. G.; Palmerio, E.; Jebaraj, I. C. +14 more
The anisotropy of energetic particles provides essential information to help resolve the underlying fundamental physics of their spatial distributions, injection, acceleration, and transport processes. In this work, we report an energetic ion enhancement that is characterized by very large and long-lasting anisotropies observed by STEREO A and Sol…
Signatures of Active Galactic Nucleus Feedback Modes: A Green Bean Galaxy with 150 kpc Jet-induced Radio Emission
Prescott, Moire K. M.; Kapińska, Anna D.; Sanderson, Kelly N. +4 more
Jetted active galactic nuclei (AGN) hosting extended photoionized nebulae provide us with a unique view of the timescales associated with AGN activity. Here, we present a new green bean galaxy at z = 0.304458 ± 0.000007 with large-scale jet-induced radio emission. The spectral energy distributions of the radio components show steep spectral indice…
Probing Turbulent Scattering Effects on Suprathermal Electrons in the Solar Wind: Modeling, Observations, and Implications
Maksimovic, Milan; Kasper, Justin C.; Kontar, Eduard P. +7 more
This study explores the impact of a turbulent scattering mechanism, akin to those influencing solar and galactic cosmic rays propagating in the interplanetary medium, on the population of suprathermal electrons in the solar wind. We employ a Fokker–Planck equation to model the radial evolution of electron pitch angle distributions under the action…
A Model for Flux Rope Formation and Disconnection in Pseudostreamer Coronal Mass Ejections
Lynch, B. J.; Antiochos, S. K.; Kumar, P. +3 more
Coronal mass ejections (CMEs) from pseudostreamers represent a significant fraction of large-scale eruptions from the Sun. In some cases, these CMEs take a narrow jet-like form reminiscent of coronal jets; in others, they have a much broader fan-shaped morphology like CMEs from helmet streamers. We present results from a magnetohydrodynamic simula…