ESA Science & Technology - Publication Archive
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This report, the so-called Red Book, describes the outcome of the mission definition study (Phase A) for the Euclid mission.
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Significant advances have been made in the understanding of the diffuse Galactic hard X-ray continuum emission using data from the INTEGRAL observatory. The diffuse hard power-law component seen with the SPectrometer on INTEGRAL (SPI) has been identified with inverse-Compton emission from relativistic (GeV) electrons on the cosmic microwave background and Galactic interstellar radiation field. In the present analysis, SPI data from 2003 to 2009, with a total exposure time of ~108 s, are used to derive the Galactic ridge hard X-ray spatial distribution and spectrum between 20 keV and 2.4 MeV. Both are consistent with predictions from the GALPROP code. The good agreement between measured and predicted emission from keV to GeV energies suggests that the correct production mechanisms have been identified. We discuss the potential of the SPI data to provide an indirect probe of the interstellar cosmic-ray electron distribution, in particular for energies below a few GeV.
Methods. A bright source, XMMSL1 J070542.7-381442, was detected on 9 Oct. 2007 at a position where no previous X-ray source had been seen. The XMM slew data and optical data acquired with the Magellan Clay 6.5 m telescope were used to classify the new object.
Results. No XMM slew X-ray counts are detected above 1 keV and the source is seen to be ~750 times brighter than the ROSAT All-Sky Survey upper limit at that position. The normally mV ~ 16 star, USNO-A2.0 0450-03360039, which lies 3.5' from the X-ray position, was seen in our Magellan data to be very much enhanced in brightness. Our optical spectrum showed emission lines that identified the source as a nova in the auroral phase; hence, this optical source is undoubtedly the progenitor of the X-ray source - a new nova (now also known as V598 Pup). The X-ray spectrum indicates that the nova was in a super-soft state (with kTeff 35 eV). We estimate the distance to the nova to be ~3 kpc. Analysis of archival robotic optical survey data shows a rapid-decline light curve consistent with what is expected for a very fast nova.
Conclusions. The XMM-Newton slew data present a powerful opportunity to find new X-ray transient objects while they are still bright. Here we present the first such source discovered by the analysis of near real-time slew data.
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Comparative planetology has long been a field of general interest but with a fairly small number of scientists actively involved. During the last decade, until recently, there has been no significant growth, possibly much due to lack of new data from Venus; perhaps the most obvious planet to compare with the Earth. Availability of ample data of high quality is of paramount importance for proper comparisons. With the arrival of Venus Express at Venus in March 2006 a new impulse to the field has been injected. Venus Express addresses a large number of topics relevant to comparative planetology; in particular in the field of atmospheric dynamics and chemistry, clouds and atmospheresolar wind interaction.
Mars has been the subject of significant interest and many space missions in the recent years. Being smaller and cooler and in several aspects more evolved, Mars is still a planet of great interest for comparison with the Earth on the other end of the parameter space.
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The propagation of reconnection signatures and their associated energy are examined using kinetic particle-in-cell simulations and Cluster satellite observations. It is found that the quadrupolar out-of-plane magnetic field near the separatrices is associated with a kinetic Alfvén wave. For magnetotail parameters, the parallel propagation of this wave is super-Alfvénic (V||<~1500-5500 km/s) and generates substantial Poynting flux (S~10-5-10-4 W/m2) consistent with Cluster observations of magnetic reconnection. This Poynting flux substantially exceeds that due to frozen-in ion bulk outflows and is sufficient to generate white light aurora in Earth's ionosphere.
This report, the so-called Red Book, presents an overview of the Solar Orbiter mission in its present state of advanced definition. Solar Orbiter is a medium-size (M-class) mission of the ESA Cosmic Vision 2015-2025 programme, and competes for one of the two launch slots foreseen in 2017 and 2018.