Search Publications
Venus lightning: Comparison with terrestrial lightning
Russell, C. T.; Wei, H. Y.; Zhang, T. L. +2 more
Terrestrial lightning is generated by the separation of electric charge residing on water-ice particles in clouds, a few kilometers above the electrically conducting surface of the Earth. It is detected optically, electromagnetically, and aurally. The majority of discharges occur within or between clouds with about one third discharging to the sur…
The M81 Group Dwarf Irregular Galaxy DDO 165. II. Connecting Recent Star Formation with Interstellar Medium Structures and Kinematics
Cannon, John M.; Dolphin, Andrew E.; Skillman, Evan D. +8 more
We compare the stellar populations and complex neutral gas dynamics of the M81 group dIrr galaxy DDO 165 using data from the Hubble Space Telescope and the Very Large Array. Cannon et al. in Paper I of this series identified two kinematically distinct H I components, multiple localized high velocity gas features, and eight H I holes and shells (th…
AGN feedback and iron enrichment in the powerful radio galaxy, 4C+55.16
Fabian, A. C.; Hlavacek-Larrondo, J.; Sanders, J. S. +1 more
We present a detailed X-ray analysis of 4C+55.16, an unusual and interesting radio galaxy, located at the centre of a cool core cluster of galaxies. 4C+55.16 is X-ray bright (LX(cluster)∼ 1045 erg s-1), radio powerful, and shows clear signs of interaction with the surrounding intracluster medium (ICM). By combining…
“Crater” flux transfer events: Highroad to the X line?
Farrugia, C. J.; Lucek, E.; André, M. +12 more
We examine Cluster observations of a so-called magnetosphere “crater FTE,” employing data from five instruments (FGM, CIS, EDI, EFW, and WHISPER), some at the highest resolution. The aim of doing this is to deepen our understanding of the reconnection nature of these events by applying recent advances in the theory of collisionless reconnection an…
Hypsometry of Titan
Lorenz, Ralph D.; Turtle, Elizabeth P.; Le Gall, Alice +6 more
Cassini RADAR topography data are used to evaluate Titan's hypsometric profile, and to make comparisons with other planetary bodies. Titan's hypsogram is unimodal and strikingly narrow compared with the terrestrial planets. To investigate topographic extremes, a novel variant on the classic hypsogram is introduced, with a logarithmic abscissa to h…
Observation of intensity oscillations above X-ray bright points from the Hinode/XRT: signature of magnetohydrodynamic oscillations in the solar corona
Srivastava, A. K.; Dwivedi, B. N.; Kumar, Mukul
We analyse the temporal image data of the quiet Sun observed by the X-ray Telescope (XRT) onboard the Hinode spacecraft and Al-poly filter on 2007 March 31. We choose these temporal image data of ∼30 s cadence from 11:34:48 UT to 14:19:35 UT to study intensity oscillations above selected X-ray bright points (XBPs) with an exposure time 8.193 s of …
Solar winds along curved magnetic field lines
Chen, Y.; Li, B.; Xia, L. D.
Context. Both remote-sensing measurements using the interplanetary scintillation (IPS) technique and in-situ measurements by the Ulysses spacecraft show a bimodal structure for the solar wind at solar minimum conditions. At present it still remains to address why the fast wind is fast and the slow wind is slow. While a robust empirical correlation…
Synthetic differential emission measure curves of prominence fine structures. II. The SoHO/SUMER prominence of 8 June 2004
Heinzel, P.; Vial, J. -C.; Anzer, U. +2 more
Aims: This study is the first attempt to combine the prominence observations in Lyman, UV, and EUV lines with the determination of the prominence differential emission measure derived using two different techniques, one based on the inversion of the observed UV and EUV lines and the other employing 2D non-LTE prominence fine-structure modelin…
Extended dust shell of the carbon star U Hydrae observed with AKARI
Izumiura, H.; Matsunaga, N.; Tanabé, T. +8 more
Context. Low- to intermediate-mass stars lose a significant fraction of their mass while they are on the asymptotic giant branch (AGB). This mass loss is considered to determine the final stages of their evolution. The material ejected from the stellar photosphere forms a circumstellar envelope in its surroundings. Layers of circumstellar envelope…
Nonlinear force-free field extrapolation of the coronal magnetic field using the data obtained by the Hinode satellite
Yan, Yihua; Wang, Huaning; He, Han
The Hinode satellite can obtain high-quality photospheric vector magnetograms of solar active regions and the simultaneous coronal loop images in soft X-ray and extreme ultraviolet (EUV) bands. In this paper, we continue the work of He and Wang (2008) and apply the newly developed upward boundary integration computational scheme for the nonlinear …