Search Publications
SUMER-Hinode observations of microflares: excitation of molecular hydrogen
Innes, D. E.
Context: Concentrations of H2 have been detected by SUMER in active region plage. The H2 is excited by O VI line emission at 1031.94 Å which, although not observed, must be brightening along with the observed transition region line, Si III 1113.24 Å.
Aims: We investigate the excitation of H2 and demonstrate the association between the observed…
The FERRUM project: experimental and theoretical transition rates of forbidden [Sc II] lines and radiative lifetimes of metastable Sc II levels
Lundberg, H.; Hartman, H.; Hibbert, A. +6 more
Context: In many plasmas, long-lived metastable atomic levels are depopulated by collisions (quenched) before they decay radiatively. In low-density regions, however, the low collision rate may allow depopulation by electric dipole (E1) forbidden radiative transitions, so-called forbidden lines (mainly M1 and E2 transitions). If the atomic transit…
Spitzer mid-infrared study of compact H II regions in the Magellanic Clouds
Heydari-Malayeri, M.; Charmandaris, V.; Chatzopoulos, E.
Aims: We present a study of the mid-infrared properties and dust content of a sample of 27 H ii “blobs”, a rare class of compact H ii regions in the Magellanic Clouds. A unique feature of this sample is that even though these H ii regions are of high and low excitation they have nearly the same physical sizes ~1.5-3 pc.
Methods: We base our an…
The INTEGRAL long monitoring of persistent ultra compact X-ray bursters
Bird, A. J.; Fiocchi, M.; Ubertini, P. +3 more
Context: The combination of compact objects, short period variability and peculiar chemical composition of the ultra compact X-ray binaries make up a very interesting laboratory to study accretion processes and thermonuclear burning on the neutron star surface. Improved large optical telescopes and more sensitive X-ray satellites have increased th…
Comparison of SOHO UVCS and MLSO MK4 coronameter densities
Cho, K. -S.; Moon, Y. -J.; Choe, G. S. +3 more
We have compared the density distributions of solar corona obtained by SOHO Ultraviolet Coronagraph Spectrometer (UVCS) and Mauna Loa Solar Observatory (MLSO) MK4 coronameter. This is the first attempt to compare the coronal densities estimated by the two instruments. In the spectral data of UVCS, we have selected two emission lines (O VI 1032 Åan…
ADONIS high contrast infrared imaging of Sirius-B
Pantin, E.; Bonnet-Bidaud, J. M.
Context: Sirius is the brightest star in the sky and a strong source of diffuse light for modern telescopes so that the immediate surroundings of the star are still poorly known.
Aims: We study the close surroundings of the star (2 to 25´´) by means of adaptive optics and coronographic device in the near-infrared, using the ESO/ADONIS system. …
Spectral analysis of LMC X-2 with XMM/Newton: unveiling the emission process in the extragalactic Z-source
Robba, N. R.; Iaria, R.; di Salvo, T. +2 more
Aims:We present the results of the analysis of an archival observation of LMC X-2 performed with XMM/Newton. The spectra taken by high-precision instruments have never been analyzed before.
Methods: We find an X-ray position for the source that is inconsistent with the one obtained by ROSAT, but in agreement with the Einstein position and that…
UV optical measurements of the Nozomi spacecraft interpreted with a two-component LIC-flow model
Bzowski, M.; Yoshikawa, I.; Takahashi, Y. +7 more
Aims: Following recent reports on spectroscopic observations by SWAN/SOHO suggesting that the flows of neutral interstellar helium and hydrogen in the inner heliosphere are slightly divergent, we tried to verify them on the basis of simultaneous photometric observations of heliospheric hydrogen and helium glows performed by a spacecraft located on…
SAX J1712.6-3739: a persistent hard X-ray source as monitored with INTEGRAL
Fiocchi, M.; Ubertini, P.; Bazzano, A. +1 more
Context: The X-ray source SAX J1712.6-3739 is a very weak low mass X-ray binary discovered in 1999 with BeppoSAX and located in the Galactic Center. This region has been intensively investigated by the INTEGRAL satellite with an unprecedented exposure time, providing an unique opportunity to study the hard X-ray behavior also for weak objects.
NLTE modelling of the flaring atmosphere above sunspot
Heinzel, P.; Schmieder, B.; Li, H. +1 more
Aims: We performed an analysis of the solar flaring atmosphere above sunspots. During the flare on October 20, 2003 many flaring structures were observed projected onto the sunspots. We analysed the Hα and Ca II line profiles emitted by the ribbons partially overlapping the sunspots. In the penumbra, the line intensity in the far wings is lower th…