Search Publications
Active longitudes in sunspot activity: Century scale persistence
Usoskin, I. G.; Berdyugina, S. V.
A novel analysis of sunspot group data for the past 120 years reveals that sunspots in both northern and southern hemispheres are formed preferably in two persistent active longitudes separated by 180°. In the Carrington reference frame, the active longitudes continuously migrate in phase with respect to the Carrington meridian with a variable rat…
XMM-Newton observation of the brightest X-ray flare detected so far from Sgr A*
Goldoni, P.; Grosso, N.; Decourchelle, A. +5 more
We report the high S/N observation on October 3, 2002 with XMM-Newton of the brightest X-ray flare detected so far from
ISM properties in low-metallicity environments. II. The dust spectral energy distribution of NGC 1569
Bernard, J. -P.; Madden, S. C.; Galliano, F. +3 more
We present new 450 and 850 mu m SCUBA data of the dwarf galaxy NGC 1569. We construct the mid-infrared to millimeter SED of NGC 1569, using ISOCAM, ISOPHOT, IRAS, KAO, SCUBA and MAMBO data, and model the SED in order to explore the nature of the dust in low metallicity environments. The detailed modeling is performed in a self-consistent way, synt…
Early SPI/INTEGRAL constraints on the morphology of the 511 keV line emission in the 4th galactic quadrant
Knödlseder, J.; Cordier, B.; Schönfelder, V. +11 more
We provide first constraints on the morphology of the 511 keV line emission from the galactic centre region on basis of data taken with the spectrometer SPI on the INTEGRAL gamma-ray observatory. The data suggest an azimuthally symmetric galactic bulge component with FWHM of ~ 9o with a 2sigma uncertainty range covering 6o-18…
The XMM-Newton EPIC background: Production of background maps and event files
Read, A. M.; Ponman, T. J.
XMM-Newton background maps for the 3 EPIC instruments in their different instrument/mode/filter combinations and in several energy bands have been constructed using a superposition of 72 pointed observations. Event datasets, with point sources excised, for the different instrument/mode/filter combinations have also been assembled, with longer expo…
Solar active regions: SOHO/CDS and TRACE observations of quiescent coronal loops
Mason, H. E.; Del Zanna, G.
This study focuses on the diagnostic capabilities of the TRACE and SOHO-CDS instruments to describe the physical characteristics of quiescent solar active regions. In particular we concentrate on the 1 MK loops, best seen in the TRACE EUV 173 Å passband. These are high-lying structures which can remain stable over timescales of hours to days. We p…
The age, life expectancy, and space density of Post Common Envelope Binaries
Gänsicke, B. T.; Schreiber, M. R.
We present a sample of 30 well observed Post Common Envelope Binaries (PCEBs). Deriving the cooling age of the white dwarfs, we show that the PCEB population is dominated by young systems. Having calculated the orbital evolution of the systems under the assumption of two different prescriptions for the angular momentum loss, we find that most of t…
Formation of polar ring galaxies
Bournaud, F.; Combes, F.
Polar ring galaxies are peculiar systems in which a gas-rich, nearly polar ring surrounds an early-type or elliptical host galaxy. Two formation scenarios for these objects have been proposed: they are thought to form either in major galaxy mergers or by tidal accretion of the polar material from a gas rich donor galaxy. Both scenarios are studied…
Formation and development of shock waves in the solar corona and the near-Sun interplanetary space
Mann, G.; Classen, H. -T.; Aurass, H. +1 more
At the Sun, shock waves are produced either by flares and/or by coronal mass ejections (CMEs) and are regarded as the source of solar energetic particle events. They can be able to generate solar type II radio bursts. The non-radial propagation of a disturbance is considered away from an active region through the corona into the interplanetary spa…
OMC: An Optical Monitoring Camera for INTEGRAL. Instrument description and performance
Hanlon, L.; McBreen, B.; Mas-Hesse, J. M. +48 more
The Optical Monitoring Camera (OMC) will observe the optical emission from the prime targets of the gamma-ray instruments onboard the ESA mission INTEGRAL, with the support of the JEM-X monitor in the X-ray domain. This capability will provide invaluable diagnostic information on the nature and the physics of the sources over a broad wavelength ra…