Search Publications

Observations of Continuous Quasiperiodic Auroral Pulsations on Saturn in High Time-Resolution UV Auroral Imagery
DOI: 10.1029/2018JA026320 Bibcode: 2019JGRA..124.2451B

Badman, S. V.; Yao, Z. H.; Bader, A. +2 more

Saturn's aurora represents the ionospheric response to plasma processes occurring in the planet's entire magnetosphere. Short-lived ∼1-hr quasiperiodic high-energy electron injections, frequently observed in in situ particle and radio measurements, should therefore entail an associated flashing auroral signature. This study uses high time-resoluti…

2019 Journal of Geophysical Research (Space Physics)
eHST 12
Fundamental properties of Kepler and CoRoT targets - IV. Masses and radii from frequencies of minimum Δν and their implications
DOI: 10.1093/mnras/stz2223 Bibcode: 2019MNRAS.489.1753Y

Yıldız, M.; Kayhan, C.; çelik Orhan, Z.

Recently, by analysing the oscillation frequencies of 90 stars, Yıldız, Çelik Orhan & Kayhan have shown that the reference frequencies (νmin0, νmin1, and νmin2) derived from glitches due to He II ionization zone have very strong diagnostic potential for the determination of thei…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 12
Observation of narrow polar jets in the nascent wind of oxygen-rich AGB star EP Aqr
DOI: 10.1093/mnras/stz1281 Bibcode: 2019MNRAS.487..622T

Winters, J. M.; Tuan-Anh, P.; Hoai, D. T. +6 more

Using ALMA observations of 12CO(2-1), 28SiO(5-4), and 32SO2(166,10-175,13) emissions of the circumstellar envelope of AGB star EP Aqr, we describe the morpho-kinematics governing the nascent wind. Main results are as follows: (1) Two narrow polar structures, referred to as jets, lau…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 12
Chromospheric observations and magnetic configuration of a supergranular structure
DOI: 10.1051/0004-6361/201833246 Bibcode: 2019A&A...621A...1R

Leenaarts, Jorrit; Robustini, Carolina; de la Cruz Rodríguez, Jaime +1 more

Context. Unipolar magnetic regions are often associated with supergranular cells. The chromosphere above these regions is regulated by the magnetic field, but the field structure is poorly known. In unipolar regions, the fibrillar arrangement does not always coincide with magnetic field lines, and polarimetric observations are needed to establish …

2019 Astronomy and Astrophysics
Hinode 12
Discovery of s-process enhanced stars in the LAMOST survey
DOI: 10.1093/mnras/stz2630 Bibcode: 2019MNRAS.490.2219N

Casey, Andrew R.; Ho, Anna Y. Q.; Ji, Alexander P. +7 more

Here we present the discovery of 895 s-process-rich candidates from 454 180 giant stars observed by the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST) using a data-driven approach. This sample constitutes the largest number of s-process enhanced stars ever discovered. Our sample includes 187 s-process-rich candidates that are e…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 11
Turbulent Heating in Solar Wind Thermodynamics
DOI: 10.3847/1538-4357/ab528b Bibcode: 2019ApJ...887..117L

Livadiotis, G.

This paper considers the concept of wave-particle thermodynamic equilibrium in order to improve our understanding of the role of turbulent heating in the solar wind proton plasma. The thermodynamic equilibrium in plasmas requires the energy of a plasmon—the quantum of plasma fundamental oscillation—to be balanced by the proton-magnetized plasma en…

2019 The Astrophysical Journal
Cluster 11
Low-frequency GMRT observations of ultra-cool dwarfs
DOI: 10.1093/mnras/sty3163 Bibcode: 2019MNRAS.483..614Z

Chandra, Poonam; Kaplan, David L.; Murphy, Tara +2 more

Observations of radio emission in about 10 per cent of ultra-cool dwarfs (UCDs) indicate the presence of strong, persistent magnetic fields in these stars. These results are in contrast to early theoretical expectations on fully convective dynamos, and to other tracers of magnetic activity, such as H α and X-ray luminosity. Radio-frequency observa…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 11
Cosmology with extragalactic proper motions: harmonic formalism, estimators, and forecasts
DOI: 10.1093/mnras/stz648 Bibcode: 2019MNRAS.486..145H

Hall, Alex

We conduct a thorough study into the feasibility of measuring large-scale correlated proper motions of galaxies with astrometric surveys. We introduce a harmonic formalism for analysing proper motions and their correlation functions on the sphere based on spin-weighted spherical harmonics, and study the statistics of the transverse velocity field …

2019 Monthly Notices of the Royal Astronomical Society
Gaia 11
Tracking the Footprints of the Radio Pulsar B1727-47: Proper Motion, Host Supernova Remnant, and the Glitches
DOI: 10.3847/1538-4357/ab1905 Bibcode: 2019ApJ...877...78S

Shternin, P.; Kirichenko, A.; Zyuzin, D. +4 more

The bright radio pulsar B1727-47, with a characteristic age of 80 kyr, was among the first pulsars discovered 50 yr ago. Using regular timing observations and its interferometric positions at three epochs, we measured, for the first time, the pulsar proper motion of 151 ± 19 mas yr-1. At the dispersion measure distance of ≳2.7 kpc, this…

2019 The Astrophysical Journal
Gaia 11
First Detection of Submillimeter-wave [13C I] 3 P 1-3 P 0 Emission in a Gaseous Debris Disk of 49 Ceti with ALMA
DOI: 10.3847/2041-8213/ab518d Bibcode: 2019ApJ...885L..39H

Yamamoto, Satoshi; Higuchi, Aya E.; Oya, Yoko

We have detected the submillimeter-wave fine-structure transition (3 P 1-3 P 0) of 13C, [13C I], in the gaseous debris disk of 49 Ceti with the Atacama Large Millimeter/submillimeter Array (ALMA). Recently, the [C I] 3 P 1-3 P 0 emission h…

2019 The Astrophysical Journal
Gaia 11