Search Publications
Integral field near-infrared spectroscopy of II Zw 40
Cresci, G.; Vanzi, L.; Melnick, J. +1 more
We present integral field spectroscopy in the near-infrared of the nearby starburst galaxy II Zw 40. Our new observations provide an unprecedented detailed view of the interstellar medium and star formation of this galaxy. The radiation emitted by the galaxy is dominated by a giant HII region, which extends over an area of more than 400 pc in size…
Spectral irradiance variations: comparison between observations and the SATIRE model on solar rotation time scales
Solanki, S. K.; Krivova, N. A.; Kopp, G. +2 more
Aims: We test the reliability of the observed and calculated spectral irradiance variations between 200 and 1600 nm over a time span of three solar rotations in 2004.
Methods: We compare our model calculations to spectral irradiance observations taken with SORCE/SIM, SoHO/VIRGO, and UARS/SUSIM. The calculations assume LTE and are based on the …
Evidence of magnetic field wrapping around penumbral filaments
Solanki, S. K.; Lites, B. W.; Borrero, J. M.
We employ high-spatial resolution spectropolarimetric observations from the Solar Optical Telescope on-board the Hinode spacecraft to investigate the fine structure of the penumbral magnetic fields. The Stokes vector of two neutral iron lines at 630 nm is inverted at every spatial pixel to retrieve the depth-dependence of the magnetic field vector…
The X-ray cycle in the solar-type star HD 81809. XMM-Newton observations and implications for the coronal structure
Schmitt, J. H. M. M.; Orlando, S.; Hall, J. +3 more
Context: The 11-yr cycle is the best known manifestation of the Sun's activity. While chromospheric cycles have been studied in a number of solar-like stars, very little is known about how these are reflected in the cyclical behavior of the coronal X-ray emission in stars other than the Sun.
Aims: Our long-term XMM-Newton program of long-term …
Magnetic field measurements and wind-line variability of OB-type stars
Rygl, K. L. J.; Neiner, C.; Wiersema, K. +8 more
Context: The first magnetic fields in O- and B-type stars that do not belong to the Bp-star class, have been discovered. The cyclic UV wind-line variability, which has been observed in a significant fraction of early-type stars, is likely to be related to such magnetic fields.
Aims: We attempt to improve our understanding of massive-star magne…
The secrets of T Pyxidis. II. A recurrent nova that will not become a SN Ia
Selvelli, P.; González-Riestra, R.; Gilmozzi, R. +1 more
Aims: We compare the observed and theoretical parameters for the quiescent and outburst phases of the recurring nova T Pyx.
Methods: IUE data were used to derive the disk luminosity and the mass accretion rate, and to exclude the presence of quasi-steady burning at the WD surface. XMM-NEWTON data were used to verify this conclusion.
Result…
New XMM-Newton observations of supernova remnants in the Small Magellanic Cloud
Pietsch, W.; Haberl, F.; Filipović, M. D. +6 more
Context: A complete overview of the supernova remnant (SNR) population is required to investigate their evolution and interaction with the surrounding interstellar medium in the Small Magellanic Cloud (SMC).
Aims: Recent XMM-Newton observations of the SMC cover three known SNRs (DEM S5, SNR B0050-72.8, and SNR B0058-71.8), which are poorly stu…
Observations of Hα surges and ultraviolet jets above satellite sunspots
Jiang, Y. C.; Chen, H. D.; Ma, S. L.
Aims:To know more about the physical origin of surges and jets, we investigated seven successive surge events, which occurred above the satellite sunspots of active region NOAA 10720 on 2005 January 15.
Methods: Using data from the Transition Region and Coronal Explorer (TRACE), Big Bear Solar Observatory (BBSO) and Solar and Heliospheric Obse…
INTEGRAL discovery of non-thermal hard X-ray emission from the Ophiuchus cluster
Paltani, S.; Eckert, D.; Produit, N. +2 more
We present the results of deep observations of the Ophiuchus cluster of galaxies with INTEGRAL in the 3-80 keV band. We analyse 3 Ms of INTEGRAL data on the Ophiuchus cluster with the IBIS/ISGRI hard X-ray imager and the JEM-X X-ray monitor. In the X-ray band using JEM-X, we show that the source is extended, and that the morphology is compatible w…
INTEGRAL observations of the blazar Mrk 421 in outburst. Results of a multi-wavelength campaign
Lähteenmäki, A.; Ajello, M.; Horan, D. +15 more
Context: If one wants to understand the physics of blazars, better simultaneous observations are important at all wavelengths, so it was fortunate that a ToO observation of the TeV-emitting blazar Mrk 421 with INTEGRAL could be triggered in June 2006 by an increase in the RXTE count rate to more than 30 mCrab. The source was then observed with all…