Search Publications
Missions
Journals
Publication Years
Analysis of a multi-wavelength time-resolved observation of a coronal loop
Ciaravella, A.; Reale, F.
Aims.We analyze a well-defined loop system detected in a time-resolved observation in several spectral bands to characterize the structure and evolution of coronal loops. Methods.The dataset includes simultaneous sequences of images in the 171 Å, 195 Å and 284 Å filter bands of TRACE, and in one filter of Yohkoh/SXT, with a time coverage of about …
Ultraviolet Observations of Prominence Activation and Cool Loop Dynamics
Landi, E.; Kucera, T. A.
In this paper we investigate the thermal and dynamic properties of dynamic structures in and around a prominence channel observed on the limb on 2003 April 17. Observations were taken with the Solar and Heliospheric Observatory's Solar Ultraviolet Measurements of Emitted Radiation (SOHO SUMER) in lines formed at temperatures from 80,000 K to 1.6 M…
4U 1344-60: a bright intermediate Seyfert galaxy at z = 0.012 with a relativistic Fe Kα emission line
Motch, C.; Bianchi, S.; Guainazzi, M. +6 more
We present analysis of the optical and X-ray spectra of the low Galactic latitude bright (F_2-10 = 3.6 × 10-11 erg cm-2 s-1) source 4U 1344-60. On the basis of the optical data we propose to classify 4U 1344-60 as an intermediate type Seyfert galaxy and we measure a value of z = 0.012±0.001 for its redshift. From t…
Star-forming QSO host galaxies
Barthel, P. D.
Context: .The recent finding of substantial masses of cold molecular gas as well as young stellar populations in the host galaxies of intermediate luminosity quasars is at odds with results of Hubble Space Telescope imaging studies since the latter appear to yield mature, quiescent early type hosts.
Aims: .The characterization as "quiescent" f…
The coronal Ne/O abundance of α Centauri
Liefke, C.; Schmitt, J. H. M. M.
Recent improvements in the modeling of solar convection and line formation led to downward revisions of the solar photospheric abundances of the lighter elements, which in turn led to changes in the radiative opacity of the solar interior and hence to conflicts with the solar convection zone depth as inferred from helioseismic oscillation frequenc…
A global 2.5-dimensional three fluid solar wind model with alpha particles
Li, Xing; Li, Bo; Labrosse, Nicolas
A global 2.5-dimensional three fluid solar wind model is presented. Two ion species, namely protons and alpha particles, are heated by an empirical energy flux while electrons are heated by the classical heat flux and Coulomb coupling with ions. It is found that for a reasonable relative speed between alpha particles and protons at 1 AU to be achi…
Measuring 26Al and 60Fe in the Galaxy
Diehl, Roland
With the SPI high-resolution spectrometer on INTEGRAL, new results have been obtained for long-lived radioactive 26Al and 60Fe in our Galaxy: 26Al sources apparently share the pattern of Galactic rotation in the inner Galaxy, and thus allow to estimate a total mass of 26Al in the Galaxy of 2.8M⊙
4C +39.29 - extended emission around a powerful type 2 quasar
Fabian, A. C.; Gandhi, P.; Crawford, C. S.
We present new X-ray and optical spectroscopy of a type 2 quasar candidate selected from a follow-up programme of hard, optically dim, serendipitous Chandra sources. The source is confirmed to be a type 2 quasar at z = 0.536 with an intrinsic 2-10 keV luminosity L2-10 = 5 × 1044h-20.7 erg s-1,…
A statistical survey of the magnetotail current sheet
Balogh, A.; Zhang, T. L.; Nakamura, R. +8 more
Using Cluster magnetometer data during summer 2001 and 2002, when the spacecraft traversed the magnetotail, we have performed a survey of current sheet and its current. We applied a superposed epoch analysis to simple, monotonous current sheet crossings and obtained a statistical profile of the current sheet. We find that the averaged structure of…
Line Shape Changes and Doppler Measurements in Solar Active Regions. I. A Method for Correcting Dopplergrams from SOHO MDI
Schou, J.; Wachter, R.; Sankarasubramanian, K.
We present a method to correct MDI high-resolution Dopplergrams in active regions for systematic observational errors due to the spectral line shape changes. We use a measurement campaign with the Advanced Stokes Polarimeter to investigate the influence of line shape changes in active regions on MDI Dopplergram calibration. An estimate of the widt…