Search Publications
Detection of molecular hydrogen at z = 1.15 toward HE 0515-4414
Reimers, D.; Baade, R.; Levshakov, S. A. +1 more
A new molecular hydrogen cloud is found in the sub-damped Lyalpha absorber [log N(H I) = 19.88+/-0.05] at the redshift zabs = 1.15 toward the bright quasar HE 0515-4414 (zem = 1.71). More than 30 absorption features in the Lyman band system of H2 are identified in the UV spectrum of this quasar obtained with the Sp…
On the existence of Alfvén waves in the terrestrial foreshock
Balogh, A.; Dandouras, I.; Eastwood, J. P. +2 more
The terrestrial foreshock is characterised by the existence of large amplitude ultra low frequency waves. The majority of such waves are observed to be left-handed in the spacecraft frame, but are in fact intrinsically right-handed and have been identified as fast-magnetosonic waves. More rarely observed are waves that are right-handed in the spac…
Molecular Outflows in the Young Open Cluster IC 348
Stanke, Thomas; Eislöffel, Jochen; McCaughrean, Mark J. +1 more
We present a wide-field survey of the young open cluster IC 348 for molecular H2 outflows. Outflow activity is only found at its southwestern limit, where a new subcluster of embedded sources is in an early phase of its formation. If the IC 348 cluster had been built up by such subclusters forming at different times, this could explain …
Buoyant disruption of magnetic arcades with self-induced shearing
Manchester, Ward
We present the results of magnetohydrodynamic (MHD) simulations of the nonlinear development of instabilities of magnetically sheared arcades and show how they relate to plasmoid ejections and coronal mass ejections (CMEs). To model the arcade disruptions, we capitalize on a family of analytical solutions for initial states; these describe magneti…
Is there really a Lutz-Kelker bias? Reconsidering calibration with trigonometric parallaxes
Smith, Haywood
In the recent literature there are indications of some confusion regarding the Lutz-Kelker bias: whether or not it exists, and if so, what it is and when it should be corrected. Here we carefully reexamine Lutz & Kelker's original work to understand what they actually did, and then look at their later papers and some other works on the subject…
Simultaneous observations of the quasar 3C 273 with INTEGRAL and RXTE
Grindlay, J. E.; Walter, R.; Lund, N. +15 more
INTEGRAL has observed the bright quasar 3C 273 on 3 epochs in January 2003 as one of the first observations of the open programme. The observation on January 5 was simultaneous with RXTE and XMM-Newton observations. We present here a first analysis of the continuum emission as observed by these 3 satellites in the band from =~ 3 keV to =~ 500 keV.…
Penetration of the heliosphere by the interstellar dust stream during solar maximum
Krüger, H.; Grün, E.; Altobelli, N. +1 more
We analyze the Ulysses in situ measurements of interstellar dust in the solar system with respect to the temporal variation of the flux density. The data set that is used covers the time from after Ulysses' fly-by of Jupiter up to the most recent data taken end of November 2002. The decrease in interstellar dust flux observed in 1996 can be explai…
The Coronal Mass Ejection Waiting-Time Distribution
Wheatland, M. S.
The distribution of times Δt between coronal mass ejections (CMEs) in the Large Angle and Spectrometric Coronagraph (LASCO) CME catalog for the years 1996-2001 is examined. The distribution exhibits a power-law tail ∼(Δt)γ with an index γ≈−2.36±0.11 for large waiting times (Δt>10 hours). The power-law index of the waiting-time distri…
XMM-Newton observations of High Mass X-ray Binaries in the SMC
Pietsch, W.; Haberl, F.; Sasaki, M.
Based on XMM-Newton EPIC data of four pointings towards the Small Magellanic Cloud (SMC), results on timing and spectral analyses of 16 known high mass X-ray binaries (HMXBs) and HMXB candidates in the SMC are presented. We confirm the pulse periods of four sources which were known to show pulsations. In addition, two new X-ray pulsars are discove…
On the source and acceleration of energetic He+: A long-term observation with ACE/SEPICA
Farrugia, C. J.; Galvin, A. B.; Klecker, B. +6 more
We report on a systematic study of the He+/He2+ abundance ratio in the energetic population during the years 1998-2000. For the investigation we have used data in the energy range 0.25-0.8 MeV/n from SEPICA on board ACE and from CELIAS STOF on SOHO in the energy range 0.085-0.28 MeV/q. The ratio is quite variable, with values…