Search Publications
Spatial Distribution and Low-frequency Disturbance Modulation of Magnetosheath Ion Polytropic Index
Cao, Jinbin; Pang, Xuexia; Geng, Xiyao +6 more
We, using the Cluster data from 2001 to 2010, studied spatial distribution of the ion polytropic index in the magnetosheath, and the modulation of polytropic process by the low-frequency disturbances (4-18 mHz). The total of 30,3283 samples is divided into two sorts: quasi-perpendicular and quasi-parallel propagating ones. The median polytropic in…
On the Nature of the Photospheric Horizontal Magnetic Field Increase in Major Solar Flares
Wang, Yuming; Sun, Xudong; Liu, Lijuan +2 more
The rapid increase of the horizontal magnetic field (B h ) around the flaring polarity inversion line is the most prominent photospheric field change during flares. It is considered to be caused by the contraction of flare loops, the details behind which is still not fully understood. Here we investigate the B h increase i…
A New Approach to Kinetic Energy Flux at the Different Frequencies above the IRIS Bright Points
Tavabi, Ehsan; Sadeghi, Rayhane
Various bright structures abound in the chromosphere playing an essential role in the dynamics and evolution therein. Tentatively identifying the wave characteristics in the outer solar atmosphere helps to understand this layer better. One of the most significant aspects of these characteristics is the wave phase speed (PS), which is a dominant co…
The Wind Temperature and Mass-loss Rate of Arcturus (K1.5 III)
Ayres, Thomas R.; Harper, Graham M.; O'Gorman, Eamon
In this paper we aim to constrain the wind temperature, outflow and turbulent velocities, ionization state, and mass-loss rate of the single red giant Arcturus (α Boo K1.5 III) using high spectral resolution Hubble Space Telescope Space Telescope Imaging Spectrograph profiles of Si III 1206.5 Å , O I 1304 Å and 1306 Å, C II 1334 Å and 1335 Å, and …
The Lyα Emission in a C1.4 Solar Flare Observed by the Extreme Ultraviolet Imager aboard Solar Orbiter
Krucker, Säm; Gan, Weiqun; Ding, M. D. +7 more
The hydrogen Lyα (H I Lyα) emission during solar flares has rarely been studied in spatially resolved images, and its physical origin has not been fully understood. In this paper, we present novel Lyα images for a C1.4 solar flare (SOL2021-08-20T22:00) from the Extreme Ultraviolet Imager aboard Solar Orbiter, together with multi-wave-band and mult…
Informed Systematic Method to Identify Variable Mid- and Late-T Dwarfs
Karalidi, Theodora; Manjavacas, Elena; Faherty, Jacqueline K. +5 more
The majority of brown dwarfs show some level of photometric or spectrophotometric variability in different wavelength ranges. This variability allow us to trace the 3D atmospheric structures of variable brown dwarfs and directly-imaged exoplanets with radiative-transfer models and mapping codes. Nevertheless, to date, we do not have an informed me…
Detection of Gravitational Redshift in Open Cluster Nondegenerate Stars
Gutiérrez, Carlos M.; Ramos-Chernenko, Nataliya
A key observational prediction of Einstein's Equivalence Principle is that light undergoes redshift when it escapes from a gravitational field. Although astrophysics provides a wide variety of physical conditions in which this redshift should be significant, until very recently the observational evidence for this gravitational effect was limited t…
The Temporal and Spatial Behaviors of CME Occurrence Rate at Different Latitudes
Mei, Ying; Wang, Feng; Deng, Hui +3 more
The statistical study of the coronal mass ejections (CMEs) is a hot topic in solar physics. To further reveal the temporal and spatial behaviors of the CMEs at different latitudes and heights, we analyzed the correlation and phase relationships between the occurrence rate of CMEs, the coronal brightness index (CBI), and the 10.7 cm solar radio flu…
A Statistical Detection of Wide Binary Systems in the Ultrafaint Dwarf Galaxy Reticulum II
Loeb, Abraham; Simon, Joshua D.; Safarzadeh, Mohammadtaher
Binary stars can inflate the observed velocity dispersion of stars in dark matter-dominated systems such as ultrafaint dwarf galaxies (UFDs). However, the population of binaries in UFDs is poorly constrained by observations, with preferred binary fractions for individual galaxies ranging from a few percent to near unity. Searching for wide binarie…
The Massive and Distant Clusters of WISE Survey. XI. Stellar Mass Fractions and Luminosity Functions of MaDCoWS Clusters at z 1
Mroczkowski, Tony; Connor, Thomas; Eisenhardt, Peter R. M. +14 more
We present stellar mass fractions and composite luminosity functions (LFs) for a sample of 12 clusters from the Massive and Distant Clusters of WISE Survey (MaDCoWS) in the redshift range 0.951 ≤ z ≤ 1.43. Using spectral energy distribution fitting of optical and deep mid-infrared photometry, we establish the membership of objects along the lines …