Search Publications
CCD Parallaxes for 309 Late-type Dwarfs and Subdwarfs
Harris, Hugh C.; Vrba, Frederick J.; Munn, Jeffrey A. +16 more
New, updated, and/or revised CCD parallaxes determined with the Strand Astrometric Reflector at the Naval Observatory Flagstaff Station are presented. Included are results for 309 late-type dwarf and subdwarf stars observed over the 30+ years that the program operated. For 124 of the stars, parallax determinations from other investigators have alr…
CLASH-VLT: constraints on f(R) gravity models with galaxy clusters using lensing and kinematic analyses
Grillo, C.; Balestra, I.; Rosati, P. +10 more
We perform a maximum likelihood kinematic analysis of the two dynamically relaxed galaxy clusters MACS J1206.2-0847 at z=0.44 and RXC J2248.7-4431 at z=0.35 to determine the total mass profile in modified gravity models, using a modified version of the MAMPOSSt code of Mamon, Biviano and Bou&apose. Our work is based on the kinematic and lensin…
Disproving the validated planets K2-78b, K2-82b, and K2-92b. The importance of independently confirming planetary candidates
Zucker, S.; Alonso, R.; Deleuil, M. +13 more
Context. Transiting super-Earths orbiting bright stars in short orbital periods are interesting targets for the study of planetary atmospheres.
Aims: While selecting super-Earths suitable for further characterisation from the ground from a list of confirmed and validated exoplanets detected by K2, we found some suspicious cases that led to us…
Non-Gaussian Velocity Distributions in Solar Flares from Extreme Ultraviolet Lines: A Possible Diagnostic of Ion Acceleration
Fletcher, Lyndsay; Jeffrey, Natasha L. S.; Labrosse, Nicolas
In a solar flare, a large fraction of the magnetic energy released is converted rapidly to the kinetic energy of non-thermal particles and bulk plasma motion. This will likely result in non-equilibrium particle distributions and turbulent plasma conditions. We investigate this by analyzing the profiles of high temperature extreme ultraviolet emiss…
On the Collision Nature of Two Coronal Mass Ejections: A Review
Wang, Yuming; Shen, Fang; Shen, Chenglong +1 more
Observational and numerical studies have shown that the kinematic characteristics of two or more coronal mass ejections (CMEs) may change significantly after a CME collision. The collision of CMEs can have a different nature, i.e. inelastic, elastic, and superelastic processes, depending on their initial kinematic characteristics. In this article,…
Stellar Dynamics and Star Formation Histories of z ∼ 1 Radio-loud Galaxies
Bell, Eric F.; Maseda, Michael V.; van Dokkum, Pieter G. +18 more
We investigate the stellar kinematics and stellar populations of 58 radio-loud galaxies of intermediate luminosities (L 3 GHz > 1023 W Hz-1) at 0.6 < z < 1. This sample is constructed by cross-matching galaxies from the deep VLT/VIMOS LEGA-C spectroscopic survey with the VLA 3 GHz data set. The LEGA-C cont…
Spatial distribution of star formation related to ionized regions throughout the inner Galactic plane
Umana, G.; Moore, T. J. T.; Palmeirim, P. +35 more
We present a comprehensive statistical analysis of star-forming objects located in the vicinities of 1360 bubble structures throughout the Galactic plane and their local environments. The compilation of ~70 000 star-forming sources, found in the proximity of the ionized (HII) regions and detected in both Hi-GAL and GLIMPSE surveys, provided a broa…
Occurrence rate of whistler waves in the magnetotail reconnection region
Sahraoui, F.; Deng, X. H.; Huang, S. Y. +9 more
It has long been suggested that whistler waves play an active role during magnetic reconnection. However, all previous observations were based on case studies and could not give a detailed picture as to where the whistler waves occur in the reconnection region. In this paper, a statistical study by using the Cluster data is performed to investigat…
The Discovery of λ Bootis Stars: The Southern Survey I
Neff, J. E.; Cheng, K. -P.; Gray, R. O. +5 more
The λ Boo stars are a class of chemically peculiar Population I A-type stars characterized by under-abundances of the refractory elements, but near-solar abundances of carbon, nitrogen, oxygen, and sulfur. There is some evidence that λ Boo stars have higher frequencies of “bright” debris disks than normal A-type stars. The discovery of four exopla…
A concordant scenario to explain FU Orionis from deep centimeter and millimeter interferometric observations
Henning, Thomas; Dong, Ruobing; Tamura, Motohide +13 more
Aims: The aim of this work is to constrain properties of the disk around the archetype FU Orionis object, FU Ori, with as good as 25 au resolution.
Methods: We resolved FU Ori at 29-37 GHz using the Karl G. Jansky Very Large Array (JVLA) in the A-array configuration, which provided the highest possible angular resolution to date at this …