Search Publications
Active Longitude and Solar Flare Occurrences
Ludmány, A.; Baranyi, T.; Gyenge, N.
The aim of the present work is to specify the spatio-temporal characteristics of flare activity observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and the Geostationary Operational Environmental Satellite (GOES) in connection with the behavior of the longitudinal domain of enhanced sunspot activity known as active longit…
The Effects of Kinetic Instabilities on Small-scale Turbulence in Earth’s Magnetosheath
Vaivads, A.; Alexandrova, O.; Breuillard, H. +1 more
The Earth's magnetosheath is the region delimited by the bow shock and the magnetopause. It is characterized by highly turbulent fluctuations covering all scales from MHD down to kinetic scales. Turbulence is thought to play a fundamental role in key processes such as energy transport and dissipation in plasma. In addition to turbulence, different…
Down-the-barrel and Transverse Observations of the Large Magellanic Cloud: Evidence for a Symmetric Galactic Wind on the Near and Far Sides of the Galaxy
Lehner, N.; Howk, J. C.; Barger, K. A.
We compare the properties of gas flows on both the near and far side of the Large Magellanic Cloud (LMC) disk using Hubble Space Telescope UV absorption-line observations toward an active galactic nucleus behind (transverse) and a star within (down-the-barrel) the LMC disk at an impact parameter of 3.2 {kpc}. We find that even in this relatively q…
Deep Morphological and Spectral Study of the SNR RCW 86 with Fermi-LAT
Troja, E.; Orlando, E.; Hill, A. B. +107 more
RCW 86 is a young supernova remnant (SNR) showing a shell-type structure at several wavelengths and is thought to be an efficient cosmic-ray (CR) accelerator. Earlier Fermi Large Area Telescope results reported the detection of γ-ray emission coincident with the position of RCW 86 but its origin (leptonic or hadronic) remained unclear due to the p…
Distance-dependent Offsets between Parallaxes for Nearby Stars and Gaia DR1 Parallaxes
Gies, Douglas R.; Henry, Todd J.; Winters, Jennifer G. +3 more
We use 612 single stars with previously published trigonometric parallaxes placing them within 25 pc to evaluate parallaxes released in Gaia’s first data release (DR1). We find that the Gaia parallaxes are, on average, 0.24 ± 0.02 mas smaller than the weighted mean trigonometric parallax values for these stars in the solar neighborhood. We also fi…
Isotropic at the Break? 3D Kinematics of Milky Way Halo Stars in the Foreground of M31
Gilbert, Karoline M.; van der Marel, Roeland P.; Sohn, Sangmo Tony +6 more
We present the line-of-sight (LOS) velocities for 13 distant main sequence Milky Way halo stars with published proper motions (PMs). The PMs were measured using long baseline (5-7 years) multi-epoch Hubble Space Telescope/Advanced Camera for Surveys photometry, and the LOS velocities were extracted from deep (5-6 hr integrations) Keck II/DEIMOS sp…
X-Ray Observations of Bow Shocks around Runaway O Stars. The Case of ζ Oph and BD+43°3654
Pohl, M.; Guerrero, M. A.; Toalá, J. A. +3 more
Non-thermal radiation has been predicted within bow shocks around runaway stars by recent theoretical works. We present X-ray observations toward the runaway stars ζ Oph by Chandra and Suzaku and of BD+43°3654 by XMM-Newton to search for the presence of non-thermal X-ray emission. We found no evidence of non-thermal emission spatially coincident w…
Slipping Magnetic Reconnection of Flux-rope Structures as a Precursor to an Eruptive X-class Solar Flare
Hou, Yijun; Li, Ting; Zhang, Jun +1 more
We present the quasi-periodic slipping motion of flux-rope structures prior to the onset of an eruptive X-class flare on 2015 March 11, obtained by the Interface Region Imaging Spectrograph and the Solar Dynamics Observatory. The slipping motion occurred at the north part of the flux rope and seemed to successively peel off the flux rope. The spee…
Characterizing the Youngest Herschel-detected Protostars. II. Molecular Outflows from the Millimeter and the Far-infrared
Manoj, P.; Wyrowski, Friedrich; Fischer, William J. +7 more
We present Combined Array for Research in Millimeter-wave Astronomy (CARMA) CO (J=1\to 0) observations and Herschel PACS spectroscopy, characterizing the outflow properties toward extremely young and deeply embedded protostars in the Orion molecular clouds. The sample comprises a subset of the Orion protostars known as the PACS Bright Red Sources …
Radio Diagnostics of Electron Acceleration Sites During the Eruption of a Flux Rope in the Solar Corona
Gallagher, Peter T.; Carley, Eoin P.; Vilmer, Nicole
Electron acceleration in the solar corona is often associated with flares and the eruption of twisted magnetic structures known as flux ropes. However, the locations and mechanisms of such particle acceleration during the flare and eruption are still subject to much investigation. Observing the exact sites of particle acceleration can help confirm…