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CONFERENCES AND SYMPOSIA: A 'wild surmise': first results from the Huygens probe into Titan's atmosphere
Owen, Tobias; Niemann, Hasso; Atreya, Sushil
Model of the all-sky He II 30.4 nm solar flux
Auchère, F.; von Steiger, R.; Witte, M. +3 more
Because of the orbit characteristics of the vast majority of spacecraft, the solar flux has been generally measured at Earth or in the plane of the ecliptic. So far, most published studies did not consider the fact that the extreme ultraviolet (EUV) solar flux is largely anisotropic. Indeed, in the EUV, the distribution of very contrasted bright a…
Separating C Stars from Dust in the Central Region of the Seyfert 2 Galaxy NGC 1241
Díaz, Rubén J.; Dottori, Horacio; Carranza, Gustavo +2 more
The Seyfert 2 galaxy NGC 1241 presents a 1.5 kpc large circumnuclear ring (CNR) of star formation embracing a small bar plus leading arms. Those structures are Paα emitters but barely seen in Hα. It also presents stellar trailing arms inside the CNR. Gemini and HST imagery allow the construction of high-resolution (V-H) and (J-Ks) color…
Cluster scaling and its redshift evolution from XMM-Newton
Zhang, Y. -Y.; Finoguenov, A.; Böhringer, H. +4 more
We put together the results of XMM-Newton observations of a number of representative group and cluster samples at low and high redshifts. These results confirm the entropy ramp as an explanation of the observed scaling relations. We observe a mild evolution in the entropy of clusters. The observed degree of evolution is consistent with expectation…
Resonant Heating of Ions by Parallel Propagating Alfvén Waves in Solar Coronal Holes
Xiao, Chi-Jie; Wang, Jing-Xiu; Zhang, Tian-Xi
Resonant heating of H, O+5, and Mg+9 by parallel propagating ion-cyclotron Alfvén waves in solar coronal holes at a heliocentric distance is studied using the heating rate derived from the quasilinear theory. It is shown that the particle-Alfvén-wave interaction is a significant microscopic process. The temperatures of the io…
UX Ret and CN Hyi: hipparcos photometry analysis
Wadhwa, Surjit S.; Zealey, William J.
We present an analysis of the Hipparcos photometry of the contact binary systems UX Ret and CN Hyi. The Wilson-Devinney code is employed to model the V band light curve for several fixed values of the mass ratio. From the quality-of-fit of the different solutions a final solution is derived for each system. Absolute values of the system are derive…
Properties of the Solar Acoustic Source Inferred from Nonadiabatic Oscillation Spectra
Kosovichev, A. G.; Wachter, R.
Severino et al. suggested in 2001 that observed power and cross spectra of medium-degree p-modes in velocity and intensity can be described by splitting the solar background noise into correlated, coherent, and uncoherent components. We account for the nonadiabatic nature of solar oscillations by including the perturbations of the radiative energy…
Precession from Hipparcos and FK5 proper motions compared with current values: Reasons for discrepancies
Walter, H. G.; Hering, R.
The comparison of Hipparcos and FK5 proper motions points to an inconsistency with the correction, Δ p, of the luni-solar precession derived from VLBI and LLR observations with unprecedented accuracy. An attempt is made to explain this inconsistency of approximately -1.3 mas/yr by rotational offsets of the Hipparcos and FK5 proper motion systems. …
Determination of the Mass Loss Rate and the Terminal Velocity of Stellar Winds. I. Genetic Algorithm for Automatic Line Profile Fitting
Georgiev, L.; Hernández, X.
A new method for automatic fitting of Pline profiles in UV spectra of stellar winds is presented. The line source function is calculated using Sobolev's approximation and the emergent flux is obtained by exact integration of the equation of the radiation transport (similar to the SEI method described by Lamers et al. (1987)). The quality of the fi…
Global observations of energetic electrons around the time of a substorm on 27 August 2001
Davies, J. A.; Baker, D. N.; Li, X. +2 more
The magnetospheric substorm that occurred shortly after 04:00 UT on 27 August 2001 has been a topic of detailed study (Baker et al., 2002; Li et al., 2003). These studies included analysis of data from energetic electron detectors aboard the Cluster and Polar spacecraft that were located in the magnetotail during the substorm. Serendipitously, Cha…