Search Publications
Are There Two Distinct Solar Energetic Particle Releases in the 2012 May 17 Ground Level Enhancement Event?
Li, Gang; Ding, Liu-Guan; Jiang, Yong
We examine ion release times in the solar vicinity for the 2012 May 17 Ground Level Enhancement event using the velocity dispersion analysis method. In situ energetic proton data from Solar and Heliospheric Observatory (SOHO)/Energetic and Relativistic Nuclei and Electron and Geostationary Operational Environmental Satellite are used. We find two …
First Simultaneous Views of the Axial and Lateral Perspectives of a Coronal Mass Ejection
Balmaceda, L.; Cremades, H.; Cabello, I. +1 more
The different appearances exhibited by coronal mass ejections (CMEs) are believed to be in part the result of different orientations of their main axis of symmetry, consistent with a flux-rope configuration. There are observational reports of CMEs seen along their main axis (axial perspective) and perpendicular to it (lateral perspective), but no …
Solar-cycle variation of the rotational shear near the solar surface
Schou, J.; Gizon, L.; Barekat, A.
Context. Helioseismology has revealed that the angular velocity of the Sun increases with depth in the outermost 35 Mm of the Sun. Recently, we have shown that the logarithmic radial gradient (dlnΩ/dlnr) in the upper 10 Mm is close to -1 from the equator to 60° latitude.
Aims: We aim to measure the temporal variation of the rotational shear o…
An Apparent Precessing Helical Outflow from a Massive Evolved Star: Evidence for Binary Interaction
Morris, M. R.; Mills, E. A. C.; Ressler, M. E. +3 more
Massive, evolved stars play a crucial role in the metal enrichment, dust budget, and energetics of the interstellar medium; however, the details of their evolution are uncertain because of their rarity and short lifetimes before exploding as supernovae. Discrepancies between theoretical predictions from single-star evolutionary models and observat…
Template matching method for the analysis of interstellar cloud structure
Juvela, M.
Context. The structure of interstellar medium can be characterised at large scales in terms of its global statistics (e.g. power spectra) and at small scales by the properties of individual cores. Interest has been increasing in structures at intermediate scales, resulting in a number of methods being developed for the analysis of filamentary stru…
The Metallicity Evolution of Blue Compact Dwarf Galaxies from the Intermediate Redshift to the Local Universe
Fang, Guanwen; Kong, Xu; Lian, Jianhui +2 more
We present oxygen abundance measurements for 74 blue compact dwarf (BCD) galaxies in the redshift range of [0.2, 0.5] using the strong-line method. The spectra of these objects are taken using Hectospec on the Multiple Mirror Telescope. More than half of these BCDs had dust attenuation corrected using the Balmer decrement method. For comparison, w…
Longitudinal and local time asymmetries of magnetospheric turbulence in Saturn's plasma sheet
Saur, Joachim; von Papen, Michael
Based on earlier studies that have shown Saturn's middle magnetosphere to contain turbulent magnetic field fluctuations, we analyze the spatial and temporal variations of the magnetic fluctuations and turbulent heating rate as a function of local time and magnetic phase. The region of study is Saturn's plasma sheet at a distance of 6-20 Rs
X-Ray Sources in the Dwarf Spheroidal Galaxy Draco
Sonbas, E.; Dhuga, K. S.; Kargaltsev, O. +3 more
We present the spectral analysis of an 87 ks XMM-Newton observation of Draco, a nearby dwarf spheroidal galaxy. Of the approximately 35 robust X-ray source detections, we focus our attention on the brightest of these sources, for which we report X-ray and multiwavelength parameters. While most of the sources exhibit properties consistent with acti…
A comparison of properties of different population radio galaxies based on the Planck mission microwave data
Verkhodanov, O. V.; Solovyov, D. I.; Khabibullina, M. L. +1 more
Applying the stacking method, we examine the areas of the cosmic microwave background radiation (CMB) maps, constructed according to the Planck SpaceObservatory data in the neighbourhood of different populations of radio sources and giant elliptical galaxies. The samples of objects include giant radio galaxies (GRG), radio sources, selected by the…
A Global Astrometric Solution for Pan-STARRS Referenced to ICRF2
Frouard, J.; Dorland, B. N.; Makarov, V. V. +13 more
We describe the development and application of a Global Astrometric Solution (GAS) to the problem of Pan-STARRS1 (PS1) astrometry. Current PS1 astrometry is based on differential astrometric measurements using 2MASS reference stars, and thus PS1 astrometry inherits the errors of the 2MASS catalog. The GAS, based on a single, least-squares adjustme…