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| LISA Pathfinder (Invited paper - 7th Edoardo Amaldi Conference) |
| LISA Pathfinder (formerly known as SMART-2) is an ESA mission designed to pave the way for the joint ESA/NASA Laser Interferometer Space Antenna (LISA) mission by testing in-flight the critical technologies required for spaceborne
gravitational wave detection; it will put two test masses in a nearperfect gravitational free fall, and control and measure their motion with an unprecedented accuracy. This is achieved through technology comprising inertial sensors, high-precision laser metrology, drag-free control and an ultraprecise micro-Newton propulsion system. The LISA Pathfinder mission is now in Phase C/Dthe Implementation Phase, and is due to be launched in 2010, with results on the performance of the system being available within 6 months thereafter. |
| Publication date: 07 Jun 2008 |
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| Marco Polo Workshop Presentations - June 2008 |
The first open Workshop on the Marco Polo mission, jointly organized by the Côte d'Azur Observatory and ESA, was held on 5 and 6 June 2008.
More than 80 participants attended the two-day workshop in Cannes, France, which included the following sessions:
| I. | Missions: general studies and programmatics |
| II. | Physical properties of NEOs from laboratory experiments, simulations and observations |
| III. | Instrumentation for global and local characterization |
| IV. | Sampling mechanisms and analysis |
| V. | Japanese-European Collaboration |
The 25+ presentations given at the workshop are available in PDF format via the following link:
Presentations
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| Publication date: 06 Jun 2008 |
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| The Next Decade with XMM-Newton - Its Scientific Impact and Challenges for the Next 10 Years |
| XMM-Newton is one of ESA's most
successful science missions. Launched in
December 1999, the spacecraft is
technically able to continue this scientific
success story and now, encouraged by its
impressive scientific output, ESA has already
extended XMM-Newton's operations well
beyond its original 10-year design lifetime.
This article looks at the impact of XMM-Newton since its launch in December 1999. |
| Publication date: 06 Jun 2008 |
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Multi-wavelength observations of Galactic hard X-ray sources discovered by INTEGRAL
I. The nature of the companion star |
Context. The INTEGRAL hard X-ray observatory has revealed an emerging population of highly obscured X-ray binary systems through multi-wavelength observations. Previous studies have shown that many of these sources are high-mass X-ray binaries hosting neutron stars orbiting around luminous and evolved companion stars.
Aims. To better understand this newly-discovered population, we have selected a sample of sources for which an accurate localisation is available to identify the stellar counterpart and reveal the nature of the companion star and of the binary system.
Methods. We performed an intensive study of a sample of thirteen INTEGRAL sources, through multi-wavelength optical to NIR photometric and spectroscopic observations, using EMMI and SofI instruments at the ESO NTT telescope. We performed accurate astrometry and identified candidate counterparts for which we give the optical and NIR magnitudes. We detected many spectral lines allowing us to determine the spectral type of the companion star. We fitted with stellar black bodies the mid-infrared to optical spectral energy distributions of these sources. From the spectral analysis and SED fitting we identified the nature of the companion stars and of the binary systems.
Results. Through spectroscopic analysis of the most likely candidates we found the spectral types of IGR J16320-4751, IGR J16358-4726, IGR J16479-4514, IGR J17252-3616, IGR J18027-2016: They all host OB type supergiant companion stars, with IGR J16358-4726 likely hosting an sgB[e]. Our spectra also confirm the supergiant O and B nature of IGR J17391-3021 and IGR J19140+0951. From SED fitting we found that IGR J16418-4532 is a (likely OB supergiant) HMXB, IGR J16393-4643 a (likely BIV-V star) HMXB, and IGR J18483-0311 a likely HMXB system.
-- Remainder of abstract is truncated -- |
| Publication date: 05 Jun 2008 |
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Multi-wavelength observations of Galactic hard X-ray sources discovered by INTEGRAL
II. The environment of the companion star |
Context. The INTEGRAL mission has led to the discovery of a new type of supergiant X-ray binaries (SGXBs), whose physical properties differ from those of previously known SGXBs. Those sources are in the course of being unveiled by means of multi-wavelength X-rays, optical, near- and mid-infrared observations, and two classes are appearing. The first class consists of obscured persistent SGXBs and the second is populated by the so-called supergiant fast X-ray transients (SFXTs).
Aims. We report here mid-infrared (MIR) observations of the companion stars of twelve SGXBs from these two classes in order to assess the contribution of the star and the material enshrouding the system to the total emission.
Methods. We used data from observations we carried out at ESO/VLT with VISIR, as well as archival and published data, to perform broad-band spectral energy distributions of the companion stars and fitted them with a combination of two black bodies representing the star and a MIR excess due to the absorbing material enshrouding the star, if there was any.
Results. We detect a MIR excess in the emission of IGR J16318-4848, IGR J16358-4726, and perhaps IGR J16195-4945. The other sources do not exhibit any MIR excess even when the intrinsic absorption is very high. Indeed, the stellar winds of supergiant stars are not suitable for dust production, and we show that this behaviour is not changed by the presence of the compact object. Concerning IGR J16318-4848 and probably IGR J16358-4726, the MIR excess can be explained by their sgB[e] nature and the presence of an equatorial disk around the supergiant companion in which dust can be produced.
-- Remainder of abstract is truncated --
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| Publication date: 05 Jun 2008 |
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| Study of near-Earth reconnection events with Cluster and Double Star |
| Observations made by a unique constellation of Cluster (at 14-16 RE), TC2, Goes10, and LANL spacecraft (near 6.6 RE) have allowed us to study the details of three reconnection events in the middle of a thick plasma sheet with the reconnection X-line located unusually close to Earth (10-12 RE). We use mapping along field lines with magnetospheric models adapted to magnetic field observations to confirm that the reconnection region mapped onto localized auroral brightenings. Using simultaneous observations in the inflow and outflow regions, we describe an encounter with a localized tailward Alfvénic jet produced by a short isolated reconnection pulse. A good correlation between intense E and ion [BV] indicates that the concurrent strong turbulence could not destroy the frozen-in ion behavior in the reconnection outflow. We find that a steady quadrupole-like distribution of the magnetic By component in the turbulent reconnection outflow extended far beyond the ion diffusion region and existed for several minutes. We demonstrate an apparent Vx flow reversal, formed owing to the reappearance (switch-on) of reconnection at another location, rather than to a continuous motion of the active X-line. Using the Liouville mapping technique, we show that the acceleration of outflow electrons, after the particles passed a potential drop of 180 V, is consistent with Fermi/betatron acceleration. We also suggest another interpretation of the energetic particle bursts at the onsets, to emphasize the role of seed population and explain the sudden burst as a consequence of changing magnetic topology. |
| Publication date: 05 Jun 2008 |
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| Downward current electron beam observed by Cluster and FAST |
| We report observations from a conjunction of FAST and Cluster during an interval of downward current at an MLT of 3-4 h on field lines mapping to the PSBL. Both spacecraft see upgoing electrons with an energy of a few hundred eV, suggesting substantial acceleration has occurred below FAST's altitude of 3200 km. At Cluster, isolated bursts of electrons are seen, and modeling indicates that the current mapped from the ionosphere exists as a collection of current filaments at Cluster (4-5 RE). The current filaments are aligned with the background magnetic field and have a perpendicular scale at Cluster of about 100 km (which maps to 10-20 km in the ionosphere), and is similar to the mapped width observed by FAST. The electron beams are quasi-steady during a Cluster spacecraft transit time of 1 min. The field aligned current densities at FAST and Cluster are of the order of a few microAms-2 and 0.05 microAm-2, respectively, and j/B is conserved along a current filament. |
| Publication date: 03 Jun 2008 |
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| Preliminary Planning for an International Mars Sample Return Mission |
The international Mars Architecture for the Return of Samples (iMARS) Working Group was chartered by the International Mars Exploration Working Group (IMEWG) in mid-2006 to develop a potential plan for an internationally sponsored and executed Mars sample return (MSR) mission. Its purpose is to outline the scientifi c and engineering requirements of such an international mission in the 2018-2023 time frame.
This report is a summary of Phase I of iMARS' efforts, which were carried out between September 2007, and May 2008.
Contents
- Executive Summary
- Introduction
- Science Objectives
- High-level Requirements
- Implementation of Mars Sample Return
- Development Timeline
- Management Planning
- Public Outreach and Education
- Conclusions and Next Steps
- Acknowledgements, References, and Appendices
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| Publication date: 01 Jun 2008 |
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| Report of the ESA-ESO working group on Galactic Populations, Chemistry and Dynamics |
| The main task of this Working Group has been to review the state-of-the art knowledge of the Milky Way galaxy, to identify the future challenges, and to propose which tools (in terms of facilities, infrastructures, instruments, science policies) would be needed to successfully tackle and solve the remaining open questions. Considering the leadership position that Europe has reached in the field of Galactic astronomy (thanks to the Hipparcos mission and the Very Large Telescope) and looking at the (near-)future major initiatives it has undertaken (VISTA and VST survey telescopes, Gaia mission), this work clearly has been very timely.
It is of uttermost importance for European astronomy to keep and further consolidate its leading position. This Working Group has made recommendations that would allow dissecting our backyard laboratory, the Galaxy, even further. ESO survey telescopes about to become operational and the upcoming ESA Gaia mission are a guarantee for opening new horizons and making new discoveries. We, the astronomers, with the support of our funding agencies, are ready to fully commit to the best exploitation of the treasure that is ahead of us. The main recommendations this Working Group has made to ESA and ESO are to guarantee the expected tremendous capabilities of these new facilities, to vigourously organise their synergies and to jointly give ways to European astronomers to be leaders in the exploitation of their output data. |
| Publication date: 01 Jun 2008 |
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| SWAP onboard PROBA 2, a new EUV imager for solar monitoring |
| SWAP (Sun Watcher using Active Pixel system detector and image processing) is a solar imager in the extreme ultraviolet (EUV) that has been selected to fly in 2007 on the PROBA 2 technological platform, an ESA program. SWAP will use an off-axis Ritchey Chrétien telescope equipped with an EUV enhanced active pixel sensor detector (coated APS). This type of detector has advantages that promise to be very profitable for solar EUV imaging. SWAP will provide solar coronal images at a 1-min cadence in a bandpass centered on 17.5 nm. Observations with this specific wavelength allow detecting phenomena, such as solar flares or EIT-waves, associated with the early phase of coronal mass ejections. Image processing software will be developed that automatically detects these phenomena and sends out space weather warnings. Together with its sister instrument LYRA, also onboard PROBA 2, SWAP will serve as a high performance solar monitoring tool to be used in operational space weather forecasting. The SWAP data will complement the solar observations provided by instruments like SOHO-EIT, and STEREO-SECCHI. |
| Publication date: 01 Jun 2008 |
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| Secondary anisotropies of the CMB |
| The Cosmic Microwave Background fluctuations provide a powerful probe of the dark ages of the universe through the imprint of the secondary anisotropies associated with the reionization of the universe and the growth of structure. We review the relation between the secondary anisotropies and the primary anisotropies that are directly generated by quantum fluctuations in the very early universe. The physics of secondary fluctuations is described, with emphasis on the ionization history and the evolution of structure. We discuss the different signatures arising from the secondary effects in terms of their induced temperature fluctuations, polarization and statistics. The secondary anisotropies are being actively pursued at present, and we review the future and current observational status. |
| Publication date: 01 Jun 2008 |
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| A comparison of Neutral Atom Detector Unit neutral atom image inversion with a comprehensive ring current model |
| We present energetic neutral atom (ENA) images in the energy range 45 to 50 keV for H and 92 to 138 keV for O measured by the Neutral Atom Detector Unit (NUADU) onboard Double Star TC-2 during a geomagnetic storm on 8 May 2005. We compare the ion fluxes deduced from inversion of the NUADU image with those calculated using the Comprehensive Ring Current Model (CRCM). This comparison shows that the two approaches are consistent when used to derive the configuration of the corresponding global ion distribution and the peak ion fluxes. The deduced peak ion flux is located in the premidnight sector at 1540 UT, while the deduced ion peak flux is located in the midnight sector at 1610 UT. There are strong ion fluxes in the region between L = 2 and L = 4 which form a closed loop configuration. The ion peak flux is about 2.2×106/cm²/sr/keV/s. The deduced ion distribution agrees well with the NUADU measurement. The agreement between the inverted ion distributions and the CRCM results give us confidence in applying our ENA imaging and modeling techniques to the study of the evolution of the inner magnetosphere plasma distribution and the global dynamics of the ring current during magnetic storms. |
| Publication date: 30 May 2008 |
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| High kinetic energy jets in the Earth's magnetosheath: Implications for plasma dynamics and anomalous transport |
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| Publication date: 30 May 2008 |
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| Carrier Module (Thales Alenia Space-Italy) |
| Carrier Module presentation given by Thales Alenia Space-Italy at the ExoMars Industry Day, hosted by Altec in Turin, Italy on 29 May 2008. |
| Publication date: 28 May 2008 |
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| Enhanced ExoMars Mission (ESA) |
| Enhanced ExoMars Mission presentation given by ESA at the ExoMars Industry Day, ExoMars Industry Day, hosted by Altec in Turin, Italy on 29 May 2008. |
| Publication date: 28 May 2008 |
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| Enhanced ExoMars Mission (Thales Alenia Space-Italy) |
| Enhanced ExoMars Mission presentation given by Thales Alenia Space-Italy at the ExoMars Industry Day, hosted by Altec in Turin, Italy on 29 May 2008. |
| Publication date: 28 May 2008 |
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| ExoMars Rover Vehicle (EADS Astrium-UK) |
| ExoMars Rover Vehicle presentation given by EADS Astrium-UK at the ExoMars Industry Day hosted by Altec in Turin, Italy on 29 May 2008. |
| Publication date: 28 May 2008 |
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| Rover Operations Control Centre (Altec) |
| Rover Operations Control Centre presentation given by Altec at the ExoMars Industry Day, hosted by Altec in Turin, Italy on 29 May 2008. |
| Publication date: 28 May 2008 |
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| Magnetosheath Plasma Turbulence and Its Spatiotemporal Evolution as Observed by the Cluster Spacecraft |
| We study the plasma turbulence, at scales larger than the ion inertial length scale, downstream of a quasiparallel bow shock using Cluster multispacecraft measurements. We show that turbulence is intermittent and well described by the extended structure function model, which takes into account the spatial inhomogeneity of the cascade rate. For the first time we use multispacecraft observations to characterize the evolution of magnetosheath turbulence, particularly its intermittency, as a function of the distance from the bow shock. The intermittency significantly changes over the distance of the order of 100 ion inertial lengths, being increasingly stronger and anisotropic away from the bow shock. |
| Publication date: 21 May 2008 |
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| PSR J0737-3039: Interacting Pulsars in X-Rays |
| We present the results of a ~230 ks long X-ray observation of the relativistic double-pulsar system PSR J0737-3039 obtained with the XMM-Newton satellite in 2006 October. We confirm the detection in X-rays of pulsed emission from PSR J0737-3039A (PSR A), mostly ascribed to a soft nonthermal power-law component with a 0.2-3 keV luminosity of ~1.9x1030 erg s-1 (assuming a distance of 500 pc). For the first time, pulsed X-ray emission from PSR J0737-3039B (PSR B) is also detected in part of the orbit. This emission, consistent with thermal radiation with temperature kBT ~ 30 eV and a bolometric luminosity of ~1032erg s-1, is likely powered by heating of PSR B's surface caused by PSR A's wind. A hotter (~130 eV) and fainter (~5x1029erg s-1) thermal component, probably originating from backfalling particles heating polar caps of either PSR A or PSR B, is also required by the data. No signs of X-ray emission from a bow shock between PSR A's wind and the interstellar medium or PSR B's magnetosphere are present. The upper limit on the luminosity of such a shock component (~1029 erg s-1) constrains the wind magnetization parameter of PSR A to values greater than 1. |
| Publication date: 20 May 2008 |
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