Search Publications
A Three-dimensional Model for the Evolution of Magnetohydrodynamic Turbulence in the Outer Heliosphere
Oughton, Sean; Fichtner, Horst; Kleimann, Jens +1 more
We present a time-dependent, three-dimensional single-fluid model for the transport of magnetohydrodynamic (MHD) turbulence that is self-consistently evolving with a dynamic large-scale solar wind in the outer heliosphere. The emphasis is on the region beyond the termination shock, where the solar wind expands subsonically, as well as sub-Alfvénic…
Shedding New Light on Weak Emission-line Quasars in the C IV-Hβ Parameter Space
Brandt, W. N.; Myers, Adam D.; Strauss, Michael A. +20 more
Weak emission-line quasars (WLQs) are a subset of type 1 quasars that exhibit extremely weak Lyα + N V λ1240 and/or C IV λ1549 emission lines. We investigate the relationship between emission-line properties and accretion rate for a sample of 230 "ordinary" type 1 quasars and 18 WLQs at z < 0.5 and 1.5 < z < 3.5 that have rest-frame ultra…
The Complex X-Ray Obscuration Environment in the Radio-loud Type 2 Quasar 3C 223
Heckman, Timothy; Gandhi, Poshak; Yaqoob, Tahir +4 more
3C 223 is a radio-loud, Type 2 quasar at z = 0.1365 with an intriguing X-ray Multi-mirror Mission (XMM)-Newton spectrum that implicated it as a rare, Compton-thick (N H ≳ 1.25 × 1024 cm-2) active galactic nucleus (AGN). We obtained contemporaneous XMM-Newton and Nuclear Spectroscopic Telescope Array (NuSTAR) spectr…
High-energy (>40 MeV) Proton Intensity Enhancements Associated with the Passage of Interplanetary Shocks at 1 au
Lario, D.; Richardson, I. G.; Aran, A. +1 more
We analyze periods with elevated >40 MeV proton intensities observed near Earth over a time span of 43 yr (1973-2016) that coincide with the passage of interplanetary (IP) shocks. Typically, elevated proton intensities result from large solar energetic particle (SEP) events. The IP shocks observed during these elevated-intensity periods may or …
MeV Gamma-Ray Source Contribution to the Inner Galactic Diffuse Emission
Mukherjee, Reshmi; Yoneda, Hiroki; Inoue, Yoshiyuki +2 more
The origin of the inner Galactic emission, measured by COMPTEL with a flux of ~10-2 MeV cm-2 s-1 sr-1 in the 1-30 MeV energy range from the inner Galactic region, has remained unsettled since its discovery. In this paper, we elaborate on a model of individual MeV gamma-ray sources unresolved by COMPTEL. …
An Independent Determination of the Distance to Supernova SN 1987A by Means of the Light Echo AT 2019xis
Baade, Dietrich; Wang, Lifan; Höflich, Peter +5 more
Accurate distance determination to astrophysical objects is essential for the understanding of their intrinsic brightness and size. The distance to SN 1987A has been previously measured by the expanding photosphere method and by using the angular size of the circumstellar rings with absolute sizes derived from light curves of narrow UV emission li…
Multi-spacecraft Observations of the 2022 March 25 CME and EUV Wave: An Analysis of Their Propagation and Interrelation
Telloni, Daniele; Liberatore, Alessandro; Vourlidas, Angelos +5 more
This paper reports on a well-defined EUV wave associated with a coronal mass ejection (CME) observed on 2022 March 25. The CME was observed by Solar Orbiter (SolO) during its first close perihelion (0.32 au) and by several other spacecraft from different viewpoints. The EUV wave was visible by the Extreme Ultraviolet Imager on board the Solar Terr…
Simulation of a Solar Jet Formed from an Untwisting Flux Rope Interacting with a Null Point
Schmieder, Brigitte; Ding, Mingde; Zhu, Jiahao +1 more
Coronal jets are eruptions identified by a collimated, sometimes twisted spire. They are small-scale energetic events compared with flares. Using multiwavelength observations from the Solar Dynamics Observatory/Atmospheric Imaging Assembly and a magnetogram from Hinode/Spectro-Polarimeter (Hinode/SP), we study the formation and evolution of a jet …
PAH Emission from Star-forming Galaxies in JWST Mid-infrared Imaging of the Lensing Cluster SMACS J0723.3-7327
Langeroodi, Danial; Hjorth, Jens
The mid-infrared spectra of star-forming galaxies (SFGs) are characterized by characteristic broad polycyclic aromatic hydrocarbon (PAH) emission features at 3-20 µm. As these features are redshifted, they are predicted to dominate the flux at specific mid-infrared wavelengths, leading to substantial redshift-dependent color variations in br…
Unraveling the Thermodynamic Enigma between Fast and Slow Coronal Mass Ejections
Wang, Yuming; Zhang, Jie; Mishra, Wageesh +3 more
Coronal mass ejections (CMEs) are the most energetic expulsions of magnetized plasma from the Sun that play a crucial role in space weather dynamics. This study investigates the diverse kinematics and thermodynamic evolution of two CMEs (CME1: 2011 September 24 and CME2: 2018 August 20) at coronal heights where thermodynamic measurements are limit…