Search Publications
Constraints on the sum of neutrino masses using cosmological data including the latest extended Baryon Oscillation Spectroscopic Survey DR14 quasar sample
Wang, Sai; Wang, Yi-Fan; Xia, Dong-Mei
We investigate the constraints on the sum of neutrino masses ({{Σ }}{m}ν ) using the most recent cosmological data, which combines the distance measurement from baryonic acoustic oscillation in the extended Baryon Oscillation Spectroscopic Survey DR14 quasar sample with the power spectra of temperature and polarization anisotropies in t…
Observing Kelvin-Helmholtz instability in solar blowout jet
Hou, Yijun; Yang, Shuhong; Zhang, Jun +2 more
Kelvin-Helmholtz instability (KHI) is a basic physical process in fluids and magnetized plasmas, with applications successfully modelling e.g. exponentially growing instabilities observed at magnetospheric and heliospheric boundaries, in the solar or Earth's atmosphere and within astrophysical jets. Here, we report the discovery of the KHI in sola…
LAMOST views δ Scuti pulsating stars
Zhang, J.; Qian, S. -B.; He, J. -J. +3 more
About 766 δ Scuti stars were observed by LAMOST by 2017 June 16. Stellar atmospheric parameters of 525 variables were determined, while spectral types were obtained for all samples. In the paper, those spectroscopic data are catalogued. We detect a group of 131 unusual and cool variable stars (UCVs) that are distinguished from the normal δ Scuti s…
The r-process Pattern of a Bright, Highly r-process-enhanced Metal-poor Halo Star at [Fe/H] ∼ -2
Beers, Timothy C.; Placco, Vinicius M.; Venn, Kim A. +9 more
A high-resolution spectroscopic analysis is presented for a new highly r-process-enhanced ([Eu/Fe] = 1.27, [Ba/Eu] = -0.65), very metal-poor ([Fe/H] = -2.09), retrograde halo star, RAVE J153830.9-180424, discovered as part of the R-Process Alliance survey. At V = 10.86, this is the brightest and most metal-rich r-II star known in the Milky Way hal…
The fastest travel together: chemical tagging of the fastest stars in Gaia DR2 to the stellar halo
Wyse, Rosemary F. G.; Hawkins, Keith
The fastest moving stars provide insight into several fundamental properties of the Galaxy, including the escape velocity as a function of Galactocentric radius, the total mass, and the nature and frequency of stellar encounters with the central supermassive black hole. The recent second data release of Gaia has allowed the identification of new s…
Super-Earth of 8 M⊕ in a 2.2-day orbit around the K5V star K2-216
Kuzuhara, M.; Erikson, A.; Fridlund, M. +37 more
Context. Although thousands of exoplanets have been discovered to date, far fewer have been fully characterised, in particular super-Earths. The KESPRINT consortium identified K2-216 as a planetary candidate host star in the K2 space mission Campaign 8 field with a transiting super-Earth. The planet has recently been validated as well.
Aims: …
The Ground-Level Enhancement Event of September 2017 and Other Large Solar Energetic Particle Events of Cycle 24
Cohen, C. M. S.; Mewaldt, R. A.
The 10 September 2017 solar energetic particle (SEP) event was the largest since June 2015 and one of only two ground-level enhancement (GLE) events of solar cycle 24. GLE events are subset of large SEP events ( 15% of events identified by Space Weather Prediction Center) with particularly hard spectra, making them a substantial space weather haza…
Candidate high-z protoclusters among the Planck compact sources, as revealed by Herschel-SPIRE
Valtchanov, I.; Clements, D. L.; Harrison, D. L. +19 more
By determining the nature of all the Planck compact sources within 808.4 deg2 of large Herschel surveys, we have identified 27 candidate protoclusters of dusty star-forming galaxies (DSFGs) that are at least 3σ overdense in either 250, 350, or 500 µm sources. We find roughly half of all the Planck compact sources are resolved by H…
The development of lower-atmosphere turbulence early in a solar flare
Fletcher, L.; Labrosse, N.; Jeffrey, N. L. S. +1 more
We present the first observational study of the onset and evolution of solar flare turbulence in the lower solar atmosphere on an unprecedented time scale of 1.7 s using the Interface Region Imaging Spectrograph observing plasma at a temperature of 80,000 K. At this time resolution, nonthermal spectral line broadening, indicating turbulent velocit…
Infrared Variability of Two Dusty White Dwarfs
Dufour, Patrick; Xu, Siyi; Gänsicke, Boris T. +11 more
The most heavily polluted white dwarfs often show excess infrared radiation from circumstellar dust disks, which are modeled as a result of tidal disruption of extrasolar minor planets. Interaction of dust, gas, and disintegrating objects can all contribute to the dynamical evolution of these dust disks. Here, we report two infrared variable dusty…