Search Publications
Magnetic Braids in Eruptions of a Spiral Structure in the Solar Atmosphere
Tian, Hui; Chen, Yao; Li, Bo +6 more
We report on high-resolution imaging and spectral observations of eruptions of a spiral structure in the transition region, which were taken with the Interface Region Imaging Spectrograph, and the Atmospheric Imaging Assembly (AIA) and the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO). The eruption coincided w…
Shocked Interstellar Clouds and Dust Grain Destruction in the LMC Supernova Remnant N132D
Ruiter, Ashley J.; Dopita, Michael A.; Sutherland, Ralph S. +3 more
From integral field data we extract the optical spectra of 20 shocked clouds in the supernova remnant N132D in the Large Magellanic Cloud (LMC). Using self-consistent shock modeling, we derive the shock velocity, pre-shock cloud density, and shock ram pressure in these clouds. We show that the [Fe X] and [Fe XIV] emission arises in faster, partial…
Detection of Magnetic Nulls around Reconnection Fronts
Divin, A.; Xu, Y.; Fu, H. S. +2 more
Magnetic nulls, where magnetic-field strength becomes zero, play a crucial role in energy conversion and particle acceleration during magnetic reconnection. Recent simulations have suggested that reconnection fronts (RFs) inside the reconnection jet can host magnetic nulls. However, observational evidence for the RF-associated magnetic nulls remai…
PEPSI deep spectra. II. Gaia benchmark stars and other M-K standards
Strassmeier, K. G.; Weber, M.; Ilyin, I.
Context. High-resolution échelle spectra confine many essential stellar parameters once the data reach a quality appropriate to constrain the various physical processes that form these spectra. Aim. We provide a homogeneous library of high-resolution, high-S/N spectra for 48 bright AFGKM stars, some of them approaching the quality of solar-flux sp…
Models of Saturn's Equatorial Ionosphere Based on In Situ Data From Cassini's Grand Finale
Wahlund, J. -E.; Waite, J. H.; Cravens, T. E. +8 more
We present new models of Saturn's equatorial ionosphere based on the first in situ measurements of its upper atmosphere. The neutral spectrum measured by Cassini's Ion and Neutral Mass Spectrometer, which includes substantial methane, ammonia, and organics in addition to the anticipated molecular hydrogen, helium, and water, serves as input for un…
ΛCDM predictions for the satellite population of M33
Carlin, Jeffrey L.; Patel, Ekta; Tollerud, Erik J. +2 more
Triangulum (M33) is the most massive satellite galaxy of Andromeda (M31), with a stellar mass of about 3 × 109 M⊙. Based on abundance matching techniques, M33's total mass at infall is estimated to be of order 1011 M⊙. ΛCDM simulations predict that M33-mass halos host several of their own low-mass satell…
Physical, spectral, and dynamical properties of asteroid (107) Camilla and its satellites
Kervella, P.; Berthier, J.; Carry, B. +24 more
The population of large 100+ km asteroids is thought to be primordial. As such, they are the most direct witnesses of the early history of our Solar System available. Those among them with satellites allow study of the mass, and hence density and internal structure. We study here the dynamical, physical, and spectral properties of the triple aster…
A 100 kpc nebula associated with the `Teacup' fading quasar
Humphrey, A.; Villar-Martín, M.; Ramos Almeida, C. +4 more
We report the discovery of an ∼100 kpc ionized nebula associated with the radio-quiet type 2 quasar (QSO2) nicknamed the `Teacup' (z = 0.085). The giant nebula is among the largest known around active galaxies at any z. We propose that it is part of the circumgalactic medium (CGM) of the QSO2 host, which has been populated with tidal debris by gal…
Gamma-ray astrophysics
De Angelis, A.; Mallamaci, M.
High-energy photons are a powerful probe for astrophysics and for fundamental physics in extreme conditions. In recent years, our knowledge of the most violent phenomena in the Universe has impressively progressed thanks to the advent of new detectors for gamma rays, for both ground-based and space-borne observations. This article reviews the pres…
A reanalysis of ozone on Mars from assimilation of SPICAM observations
Lefèvre, Franck; Holmes, James A.; Lewis, Stephen R. +1 more
We have assimilated for the first time SPICAM retrievals of total ozone into a Martian global circulation model to provide a global reanalysis of the ozone cycle. Disagreement in total ozone between model prediction and assimilation is observed between 45°S-10°S from LS = 135-180° and at northern polar (60°N-90°N) latitudes during north…