Publication archive

Publication archive

The International Gamma-Ray Astrophysics Laboratory (INTEGRAL), to be launched in 2001, is dedicated to the fine spectroscopy (DE: 2 keV FWHM @ 1.3 MeV) and fine imaging (angular resolution: 12' FWHM) of celestial gamma-ray sources in the energy range 15 keV to 10 MeV with concurrent source monitoring in the X-ray (3-35 keV) and optical (V, 550 nm) range. The mission is conceived as an observatory led by ESA with contributions from Russia and NASA. The INTEGRAL observatory will provide to the science community at large an unprecedented combination of imaging and spectroscopy over a wide range of gamma-ray energies. This paper summarises the key scientific goals of the mission, the current development status of the payload and spacecraft and it will give an overview of the science ground segment including the science data center, science operations and key elements of the observing program.
Published: 17 September 1999
Published: 02 May 1998
SUMER - the Solar Ultraviolet Measurements of the Emitted Radiation instrument on the Solar and Heliospheric Observatory (SOHO) - observed its first light on January 24, 1996, and subsequently obtained a detailed spectrum with detector B in the wavelength range from 660 to 1490 Å (in first order) inside and above the limb in the north polar coronal hole. Using detector A of the instrument, this range was later extended to 1610 Å. The second-order spectra of detectors A and B cover 330 to 805 Å and are superimposed on the first-order spectra. Many more features and areas of the Sun and their spectra have been observed since, including coronal holes, polar plumes and active regions. The atoms and ions emitting this radiation exist at temperatures below 2 ×106 K and are thus ideally suited to investigate the solar transition region where the temperature increases from chromospheric to coronal values. SUMER can also be operated in a manner such that it makes images or spectroheliograms of different sizes in selected spectral lines. A detailed line profile with spectral resolution elements between 22 and 45 mÅ is produced for each line at each spatial location along the slit. From the line width, intensity and wavelength position we are able to deduce temperature, density, and velocity of the emitting atoms and ions for each emission line and spatial element in the spectroheliogram. Because of the high spectral resolution and low noise of SUMER, we have been able to detect faint lines not previously observed and, in addition, to determine their spectral profiles. SUMER has already recorded over 2000 extreme ultraviolet emission lines and many identifications have been made on the disk and in the corona.
Published: 01 January 1997
SOHO, launched by an Atlas II-AS from Cape Canaveral on 2 December 1995, was inserted into its halo orbit around the L1 Lagrangian point on 14 February, six weeks ahead of schedule. The launch and the orbital manoeuvres were so accurate and efficient that sufficient fuel remains on board to maintain the halo orbit for more than a decade, i.e. for at least twice as long as originally foreseen. Already during their commissioning phase, the SOHO experiments have returned a wealth of data, impressive in terms of both its quality and diversity. Some of the images can be viewed via the SOHO pages (http://sohowww.nascom.nasa.gov) on the World Wide Web, and on the individual experiment pages, all with links from the SOHO home page. Typical examples of the unique results being obtained with SOHO's instruments are presented here. Although they have been obtained with single instruments, it is worth noting that the main scientific advances from SOHO are expected to come from the joint analysis of coordinated observations.
Published: 02 July 1996
Proceedings of the 3rd INTEGRAL Workshop, Taormina 1998
Published: 01 January 1999
The INTErnational Gamma Ray Astrophysics Laboratory (INTEGRAL) is being developed by ESA as the second medium-size satellite of the long-term scientific plan Horizon 2000. It is an observatory providing an excellent opportunity to the scientific community for detailed imaging and high-resolution spectroscopy of Gamma-ray sources.
After completion of the design and development phase the Structural Thermal Model of the Integral Spacecraft and its four scientific instruments is presently being tested. First tests took place in spring 1998 at the ESTEC test facilities. Late summer 1998 the Engineering Model test campaign will follow.
This paper summarises the key programmatic milestones of the project, highlights the final design characteristics of the satellite, reports on the first test results, and describes the orbital scenario of the mission and the herewith-related requirements to the satellite.
Published: 14 October 2000
Published: 02 May 1995
A couple years ago researchers announced that they had discovered traces of water on the sun. A team at Stanford University has just gone them one better, discovering entire rivers on the sun. These are not rivers in the familiar sense, of course; rather they are huge, snaking flows within the white-hot plasma (electrically charged gas) that makes up the sun.
Published: 16 September 1997
COBRAS/SAMBA: Report on the Phase A Study, ESA D/SCI (96)3, 1996,

(Note that at the time the Study was written, the Planck project was still referred to as COBRAS/SAMBA, so you will find the latter name extensively used.)

Published: 03 June 1996
The in-orbit imaging performance of the three X-ray telescopes on board of the X-ray astronomy observatory XMM-Newton is presented and compared with the performance measured on ground at the MPE PANTER test facility. The comparison shows an excellent agreement between the on ground and in-orbit performance.
Published: 19 July 2000
The International Gamma-Ray Astrophysics Laboratory (INTEGRAL) is dedicated to the fine spectroscopy (Delta-E: 2 keV FWHM @ 1.3 MeV) and fine imaging (angular resolution: 12 arcmin FWHM) of celestial gamma-ray sources in the energy range 15 keV to 10 MeV with concurrent source monitoring in the X-ray (3 - 35 keV) and optical (V, 550 nm) range. The mission is conceived as an observatory led by ESA with contributions from Russia and NASA. The INTEGRAL observatory will provide to the science community at large an unprecedented combination of imaging and spectroscopy over a wide range of energies. Most of the observing time will be open to the scientific community. This paper summarises the key scientific goals of the mission, the current development status of the payload and spacecraft and it will give an overview of the science ground segment including data centre, science operations and the key elements of the observing programme
Published: 02 August 1998
Gamma Ray Burst (GRB) afterglows close to their peak intensity are among the brightest X-ray sources in the sky. Despite their fast power-law like decay, when fluxes are integrated from minutes up to hours after the GRB event, the corresponding number counts (logN-logF relation) far exceeds that of any other high redshift (z>0.5) source, the flux of which is integrated over the same time interval. We discuss how to use X-ray afterglows of GRBs as distant beacons to probe the warm (105 K7 K) intergalactic matter in filaments and outskirts of clusters of galaxies by means of absorption features, the "X-ray forest''. According to current cosmological scenarios this matter may comprise 30-40% of the baryons in the Universe at z<1. Present-generation X-ray spectrometers such as those on Chandra and XMM-Newton can detect it along most GRBs' lines of sight, provided afterglows are observed fast enough (within hours) after the burst.
Published: 01 November 2000
The Core Programme of the INTEGRAL mission is defined as the portion of the scientific programme covering the guaranteed time observations for the INTEGRAL Science Working Team. This paper describes the current status of the Core Programme preparations and summarizes the key elements of the observing programme. Letters & Communications, 1999
Published: 02 August 1998
Planck is the third Medium-Sized Mission (M3) of ESA's Horizon 2000 Scientific Programme. It is designed to image the anisotropies of the Cosmic Microwave Background (CMB) over the whole sky, with unprecedented sensitivity (DeltaT/T ~ 2 x 10-6) and angular resolution (better than 10 arcminutes). Planck will provide a major source of information relevant to several cosmological and astrophysical issues, such as testing theories of the early universe and the origin of cosmic structure. The ability to measure to high accuracy the angular power spectrum of the CMB fluctuations will allow the determination of fundamental cosmological parameters such as the density parameter (Omega0) and the Hubble constant H0, with an uncertainty of order a few percent. In addition to the main cosmological goals of the mission, the Planck sky survey will be used to study in detail the very sources of emission which "contaminate" the signal due to the CMB, and will result in a wealth of information on the properties of extragalactic sources, and on the dust and gas in our own galaxy. One specific notable result will be the measurement of the Sunyaev-Zeldovich effect in many thousands of galaxy clusters. We will present an overview of the Planck mission, its scientific objectives, the key elements of its technical design, and its current status.
Published: 01 January 2001
The operations concept for the Cluster-II mission has had to evolve with respect to the original Cluster baseline, due mainly to changes in the spacecraft design and the reduction in the number of ground stations from two to only one for routine mission-operations support. The solutions adopted have allowed the overall impact on the ground segment and mission operations to be minimised, whilst still maintaining the scientific data return at the original level.
Published: 02 April 2000
The Cluster-II mission is designed to study the near-Earth space environment in three dimensions. This will be the first scientific mission with four identical spacecraft flying together in the Earth's environment. The relative distance between the four spacecraft will vary between 200 and 18 000 km, according to the scientific region of interest. Cluster-II and the Solar and Heliospheric Observatory (SOHO) together make up the Solar Terrestrial Science Programme, the first 'Cornerstone' of ESA's Horizons 2000 long-term science plan.
Published: 02 April 2000
5-Jun-2020 13:54 UT

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