Search Publications
Coronal Microjets in Quiet-Sun Regions Observed with the Extreme Ultraviolet Imager on Board the Solar Orbiter
Teriaca, Luca; Chen, Yajie; He, Jiansen +8 more
We report the smallest coronal jets ever observed in the quiet Sun with recent high-resolution observations from the High Resolution Telescopes (HRIEUV and HRILyα) of the Extreme Ultraviolet Imager on board the Solar Orbiter (SO). In the HRIEUV (174 Å) images, these microjets usually appear as nearly collimated str…
Coronal Conditions for the Occurrence of Type II Radio Bursts
Monstein, Christian; Kouloumvakos, Athanasios; Warmuth, Alexander +5 more
Type II radio bursts are generally observed in association with flare-generated or coronal-mass-ejection-driven shock waves. The exact shock and coronal conditions necessary for the production of type II radio emission are still under debate. Shock waves are important for the acceleration of electrons necessary for the generation of the radio emis…
Temperature and Distance Dependence of Tidal Circularization in Close Binaries: A Catalog of Eclipsing Binaries in the Southern Hemisphere Observed by the TESS Satellite
Albrecht, Simon; Justesen, Anders B.
Tidal forces are important for understanding how close binary stars and compact exoplanetary systems form and evolve. However, tides are difficult to model, and significant uncertainties exist about the strength of tides. Here, we investigate tidal circularization in close binaries using a large sample of well-characterized eclipsing systems. We s…
Extragalactic Magnetism with SOFIA (Legacy Program). I. The Magnetic Field in the Multiphase Interstellar Medium of M51
Beckman, John E.; Tram, Le Ngoc; Hughes, Annie +18 more
The recent availability of high-resolution far-infrared (FIR) polarization observations of galaxies using HAWC+/SOFIA has facilitated studies of extragalactic magnetic fields in the cold and dense molecular disks. We investigate whether any significant structural differences are detectable in the kiloparsec-scale magnetic field of the grand design…
Magnetic Flux and Magnetic Nonpotentiality of Active Regions in Eruptive and Confined Solar Flares
Veronig, Astrid M.; Hou, Yijun; Li, Ting +3 more
With the aim of understanding how the magnetic properties of active regions (ARs) control the eruptive character of solar flares, we analyze 719 flares of Geostationary Operational Environmental Satellite (GOES) class ≥C5.0 during 2010-2019. We carry out the first statistical study that investigates the flare-coronal mass ejection (CME) associatio…
An ALMA Survey of Protoplanetary Disks in Lynds 1641
Fischer, William J.; Calvet, Nuria; Megeath, S. Thomas +8 more
We present ALMA observations of 101 protoplanetary disks within the star-forming region Lynds 1641 in the Orion Molecular Cloud A. Our observations include 1.33 mm continuum emission and spectral windows covering the J = 2-1 transition of 12CO, 13CO, and C18O. We detect 89 protoplanetary disks in the dust continuum…
Which Molecular Cloud Structures Are Bound?
Miville-Deschênes, Marc-Antoine; Heyer, Mark; Evans, Neal J., II +2 more
We analyze surveys of molecular cloud structures defined by tracers ranging from CO J = 1 → 0 through 13CO J = 1 → 0 to dust emission together with NH3 data. The mean value of the virial parameter and the fraction of mass in bound structures depends on the method used to identify structures. Generally, the virial parameter de…
Evidence for Ultra-diffuse Galaxy Formation through Tidal Heating of Normal Dwarfs
Sand, David J.; Jones, Michael G.; Zaritsky, Dennis +5 more
We have followed up two ultra-diffuse galaxies (UDGs), detected adjacent to stellar streams, with Hubble Space Telescope (HST) imaging and H I mapping with the Jansky Very Large Array in order to investigate the possibility that they might have a tidal origin. With the HST F814W and F555W images we measure the globular cluster (GC) counts for NGC …
The Second Discovery from the COCONUTS Program: A Cold Wide-orbit Exoplanet around a Young Field M Dwarf at 10.9 pc
Siverd, Robert J.; Claytor, Zachary R.; Dupuy, Trent J. +3 more
We present the identification of the second discovery from the COol Companions ON Ultrawide orbiTS (COCONUTS) program, the COCONUTS-2 system, composed of the M3 dwarf L 34-26 and the T9 dwarf WISEPA J075108.79-763449.6. Given their common proper motions and parallaxes, these two field objects constitute a physically bound pair with a projected sep…
Photometric Variability as a Proxy for Magnetic Activity and Its Dependence on Metallicity
Amard, Louis; See, Victor; Roquette, Julia +1 more
Understanding how the magnetic activity of low-mass stars depends on their fundamental parameters is an important goal of stellar astrophysics. Previous studies have shown that activity levels are largely determined by the stellar Rossby number, defined as the rotation period divided by the convective turnover time. However, we currently have litt…