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See detailThe Hot and Energetic Universe: The X-ray Integral Field Unit (X-IFU) for Athena+
Barret, D.; den Herder, J. W.; Piro, L. et al

Report (2013)

The Athena+ mission concept is designed to implement the Hot and Energetic Universe science theme submitted to the European Space Agency in response to the call for White Papers for the definition of the ... [more ▼]

The Athena+ mission concept is designed to implement the Hot and Energetic Universe science theme submitted to the European Space Agency in response to the call for White Papers for the definition of the L2 and L3 missions of its science program. The Athena+ science payload consists of a large aperture high angular resolution X-ray optics and twelve meters away, two interchangeable focal plane instruments: the X-ray Integral Field Unit (X-IFU) and the Wide Field Imager (WFI). The X-IFU is a cryogenic X-ray spectrometer, based on a large array of Transition Edge Sensors (TES), offering 2.5 eV spectral resolution, with ~5" pixels, over a field of view of 5 arc minutes in diameter. In this paper, we briefly describe the Athena+ mission concept and the X-IFU performance requirements. We then present the X-IFU detector and readout electronics principles, the current design of the focal plane assembly, the cooling chain and review the global architecture design. Finally, we describe the current performance estimates, in terms of effective area, particle background rejection, count rate capability and velocity measurements. Finally, we emphasize on the latest technology developments concerning TES array fabrication, spectral resolution and readout performance achieved to show that significant progresses are being accomplished towards the demanding X-IFU requirements. [less ▲]

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See detailORIGIN: metal creation and evolution from the cosmic dawn
den Herder, Jan-Willem; Piro, Luigi; Ohashi, Takaya et al

in Experimental Astronomy (2012), 34

ORIGIN is a proposal for the M3 mission call of ESA aimed at the study of metal creation from the epoch of cosmic dawn. Using high-spectral resolution in the soft X-ray band, ORIGIN will be able to ... [more ▼]

ORIGIN is a proposal for the M3 mission call of ESA aimed at the study of metal creation from the epoch of cosmic dawn. Using high-spectral resolution in the soft X-ray band, ORIGIN will be able to identify the physical conditions of all abundant elements between C and Ni to red-shifts of z = 10, and beyond. The mission will answer questions such as: When were the first metals created? How does the cosmic metal content evolve? Where do most of the metals reside in the Universe? What is the role of metals in structure formation and evolution? To reach out to the early Universe ORIGIN will use Gamma-Ray Bursts (GRBs) to study their local environments in their host galaxies. This requires the capability to slew the satellite in less than a minute to the GRB location. By studying the chemical composition and properties of clusters of galaxies we can extend the range of exploration to lower redshifts ( z ˜0.2). For this task we need a high-resolution spectral imaging instrument with a large field of view. Using the same instrument, we can also study the so far only partially detected baryons in the Warm-Hot Intergalactic Medium (WHIM). The less dense part of the WHIM will be studied using absorption lines at low redshift in the spectra for GRBs. The ORIGIN mission includes a Transient Event Detector (coded mask with a sensitivity of 0.4 photon/cm[SUP]2[/SUP]/s in 10 s in the 5-150 keV band) to identify and localize 2000 GRBs over a five year mission, of which ˜65 GRBs have a redshift >7. The Cryogenic Imaging Spectrometer, with a spectral resolution of 2.5 eV, a field of view of 30 arcmin and large effective area below 1 keV has the sensitivity to study clusters up to a significant fraction of the virial radius and to map the denser parts of the WHIM (factor 30 higher than achievable with current instruments). The payload is complemented by a Burst InfraRed Telescope to enable onboard red-shift determination of GRBs (hence securing proper follow up of high-z bursts) and also probes the mildly ionized state of the gas. Fast repointing is achieved by a dedicated Controlled Momentum Gyro and a low background is achieved by the selected low Earth orbit. [less ▲]

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See detailThe x-ray microcalorimeter spectrometer onboard Athena
den Herder, J. W.; Bagnali, D.; Bandler, S. et al

in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series (2012, September 01)

One of the instruments on the Advanced Telescope for High-Energy Astrophysics (Athena) which was one of the three missions under study as one of the L-class missions of ESA, is the X-ray Microcalorimeter ... [more ▼]

One of the instruments on the Advanced Telescope for High-Energy Astrophysics (Athena) which was one of the three missions under study as one of the L-class missions of ESA, is the X-ray Microcalorimeter Spectrometer (XMS). This instrument, which will provide high-spectral resolution images, is based on X-ray micro-calorimeters with Transition Edge Sensor (TES) and absorbers that consist of metal and semi-metal layers and a multiplexed SQUID readout. The array (32 x 32 pixels) provides an energy resolution of < 3 eV. Due to the large collection area of the Athena optics, the XMS instrument must be capable of processing high counting rates, while maintaining the spectral resolution and a low deadtime. In addition, an anti-coincidence detector is required to suppress the particle-induced background. Compared to the requirements for the same instrument on IXO, the performance requirements have been relaxed to fit into the much more restricted boundary conditions of Athena. In this paper we illustrate some of the science achievable with the instrument. We describe the results of design studies for the focal plane assembly and the cooling systems. Also, the system and its required spacecraft resources will be given. [less ▲]

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See detailExoplanet discoveries with the CoRoT space observatory
Lammer, H.; Dvorak, R.; Deleuil, M. et al

in Solar System Research (2010), 44

The CoRoT space observatory is a project which is led by the French space agency CNES and leading space research institutes in Austria, Brazil, Belgium, Germany and Spain and also the European Space ... [more ▼]

The CoRoT space observatory is a project which is led by the French space agency CNES and leading space research institutes in Austria, Brazil, Belgium, Germany and Spain and also the European Space Agency ESA. CoRoT observed since its launch in December 27, 2006 about 100 000 stars for the exoplanet channel, during 150 days uninterrupted high-precision photometry. Since the The CoRoT-team has several exoplanet candidates which are currently analyzed under its study, we report here the discoveries of nine exoplanets which were observed by CoRoT. Discovered exoplanets such as CoRoT-3b populate the brown dwarf desert and close the gap of measured physical properties between usual gas giants and very low mass stars. CoRoT discoveries extended the known range of planet masses down to about 4.8 Earth-masses (CoRoT-7b) and up to 21 Jupiter masses (CoRoT-3b), the radii to about 1.68 × 0.09 R [SUB]Earth[/SUB] (CoRoT-7b) and up to the most inflated hot Jupiter with 1.49 × 0.09 R [SUB]Earth[/SUB] found so far (CoRoT-1b), and the transiting exoplanet with the longest period of 95.274 days (CoRoT-9b). Giant exoplanets have been detected at low metallicity, rapidly rotating and active, spotted stars. Two CoRoT planets have host stars with the lowest content of heavy elements known to show a transit hinting towards a different planethost-star-metallicity relation then the one found by radial-velocity search programs. Finally the properties of the CoRoT-7b prove that rocky planets with a density close to Earth exist outside the Solar System. Finally the detection of the secondary transit of CoRoT-1b at a sensitivity level of 10[SUP]-5[/SUP] and the very clear detection of the "super-Earth" CoRoT-7b at 3.5 × 10[SUP]-4[/SUP] relative flux are promising evidence that the space observatory is being able to detect even smaller exoplanets with the size of the Earth. [less ▲]

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See detailInfluence of Exozodiacal Dust Clouds on Mid-IR Earth-like Planet Detection
Defrère, D.; Absil, Olivier ULg; den Hartog, R. et al

in Coudé du Foresto, Vincent; Gelino, Dawn; Ribas, Ignasi (Eds.) Pathways Towards Habitable Planets (2010, October 01)

The characterization of Earth-like extrasolar planets in the mid-infrared is a significant observational challenge that could be tackled by future space-based interferometers. A large effort has been ... [more ▼]

The characterization of Earth-like extrasolar planets in the mid-infrared is a significant observational challenge that could be tackled by future space-based interferometers. A large effort has been carried out the past two decades to define a design that provides the necessary scientific performance while minimizing cost and technical risks. These efforts have resulted in a consensus on a single mission architecture consisting of a non-coplanar X-array (the so-called Emma configuration), using four collector spacecraft and a single beam combiner spacecraft. The ability to study distant planets with an X-array interferometer will however depend on exozodiacal dust clouds, the counterparts of the solar zodiacal disk. In this paper, we briefly discuss the impact of exozodiacal clouds on the performance of an Emma X-array interferometer dedicated to Earth-like planet characterization. [less ▲]

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See detailTransiting exoplanets from the CoRoT space mission IX. CoRoT-6b: a transiting `hot Jupiter' planet in an 8.9d orbit around a low-metallicity star
Fridlund, M.; Hebrard, G.; Alonso, R. et al

in Astronomy and Astrophysics (2010), 512

The CoRoT satellite exoplanetary team announces its sixth transiting planet in this paper. We describe and discuss the satellite observations as well as the complementary ground-based observations ... [more ▼]

The CoRoT satellite exoplanetary team announces its sixth transiting planet in this paper. We describe and discuss the satellite observations as well as the complementary ground-based observations - photometric and spectroscopic - carried out to assess the planetary nature of the object and determine its specific physical parameters. The discovery reported here is a `hot Jupiter' planet in an 8.9d orbit, 18 stellar radii, or 0.08 AU, away from its primary star, which is a solar-type star (F9V) with an estimated age of 3.0 Gyr. The planet mass is close to 3 times that of Jupiter. The star has a metallicity of 0.2 dex lower than the Sun, and a relatively high $^7$Li abundance. While thelightcurveindicatesamuchhigherlevelof activity than, e.g., the Sun, there is no sign of activity spectroscopically in e.g., the [Ca ] H&K lines. [less ▲]

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See detailExozodiacal discs with ALADDIN: how faint can we detect them?
Absil, Olivier ULg; Coudé Du Foresto; Barillot, M. et al

in Spinoglio, L.; Epchtein, N. (Eds.) 3rd ARENA Conference: An Astronomical Observatory at CONCORDIA (Dome C, Antarctica) (2010)

In this paper, we describe the expected performance of ALADDIN, a nulling interferometer project optimised for operation at Dome C. After reviewing the main atmospheric parameters pertaining to infrared ... [more ▼]

In this paper, we describe the expected performance of ALADDIN, a nulling interferometer project optimised for operation at Dome C. After reviewing the main atmospheric parameters pertaining to infrared interferometry on the high Antarctic plateau, we shortly describe the ALADDIN instrument and compute its estimated performance in terms of the smallest exozodiacal dust disc density that can be detected. Our estimations are based on a thorough end-to-end software simulator previously developed for the GENIE nulling interferometer project at VLTI. We then propose a possible mission scenario, where the southern target stars of future exo-Earth characterisation missions can be surveyed for the presence of bright exozodiacal discs (>50 zodi) within one winter-over at Concordia. [less ▲]

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See detailCoRot observations of active giants: preliminary results
Gondoin, P.; Fridlund, M.; Goupil, M. J. et al

in American Institute of Physics Conference Series (2009, February 01)

We have analysed rotation modulated light-curves of active giants observed with CoRot using spots model. Preliminary results suggest an increase of the surface spot coverage with decreasing rotation ... [more ▼]

We have analysed rotation modulated light-curves of active giants observed with CoRot using spots model. Preliminary results suggest an increase of the surface spot coverage with decreasing rotation period. A maximum of the surface spot coverage seems to occur on giants with effective temperature around 5100 K. Confirmation and interpretation of these preliminary results require groundbased follow-up observations to measure activity indicators, to identify binary systems, and to determine the stellar parameters and evolutionary status of the sample giants. [less ▲]

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See detailNulling interferometry: performance comparison between space and ground-based sites for exozodiacal disc detection
Defrere, Denis ULg; Absil, Olivier ULg; Coudé Du Foresto, V. et al

in Astronomy and Astrophysics (2008), 490

Context: Characterising the circumstellar dust around nearby main sequence stars is a necessary step in understanding the planetary formation process and is crucial for future life-finding space missions ... [more ▼]

Context: Characterising the circumstellar dust around nearby main sequence stars is a necessary step in understanding the planetary formation process and is crucial for future life-finding space missions such as ESA's Darwin or NASA's terrestrial planet finder (TPF). Besides paving the technological way to Darwin/TPF, the space-based infrared interferometers Pegase and FKSI (Fourier-Kelvin Stellar Interferometer) will be valuable scientific precursors. Aims: We investigate the performance of Pegase and FKSI for exozodiacal disc detection and compare the results with ground-based nulling interferometers. Methods: We used the GENIEsim software (Absil et al. 2006, A&A, 448, 787) which was designed and validated to study the performance of ground-based nulling interferometers. The software has been adapted to simulate the performance of space-based nulling interferometers by disabling all atmospheric effects and by thoroughly implementing the perturbations induced by payload vibrations in the ambient space environment. Results: Despite using relatively small telescopes (<=0.5 m), Pegase and FKSI are very efficient for exozodiacal disc detection. They are capable of detecting exozodiacal discs 5 and 1 time respectively, as dense as the solar zodiacal cloud, and they outperform any ground-based instrument. Unlike Pegase, FKSI can achieve this sensitivity for most targets of the Darwin/TPF catalogue thanks to an appropriate combination of baseline length and observing wavelength. The sensitivity of Pegase could, however, be significantly boosted by considering a shorter interferometric baseline length. Conclusions: Besides their main scientific goal (characterising hot giant extrasolar planets), the space-based nulling interferometers Pegase and FKSI will be very efficient in assessing within a few minutes the level of circumstellar dust in the habitable zone around nearby main sequence stars down to the density of the solar zodiacal cloud. These space-based interferometers would be complementary to Antarctica-based instruments in terms of sky coverage and would be ideal instruments for preparing future life-finding space missions. [less ▲]

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See detailEarth-like planets: science performance predictions for future nulling interferometry missions
Defrere, Denis ULg; Lay, O.; den Hartog, R. et al

in Schöller, Markus; Danchi, William; Delplancke, Françoise (Eds.) Optical and Infrared Interferometry (2008, July 01)

With the launch of planet-transit missions such as CoRoT and Kepler, it is expected that Earth-sized planets orbiting distant stars will be detected soon. This milestone will open the path towards the ... [more ▼]

With the launch of planet-transit missions such as CoRoT and Kepler, it is expected that Earth-sized planets orbiting distant stars will be detected soon. This milestone will open the path towards the definition of missions able to study the atmosphere of Earth-sized extrasolar planets, with the identification of bio-signatures as one of the main objectives. In that respect, both the European Space Agency (ESA) and the National Aeronautics and Space Administration (NASA) have identified nulling interferometry as one of the most promising techniques. Trying to minimize the cost and the technological risks while maximizing the scientific return, ESA and NASA recently converged towards a single mission architecture, the Emma X-array. In this paper, we present the expected science performance of this concept computed with two independent mission simulators. The impact of different observational parameters such as planet radius and exozodiacal cloud density is specifically addressed. [less ▲]

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See detailGENIE: a Ground-Based European Nulling Instrument at ESO Very Large Telescope Interferometer
Gondoin, P.; den Hartog, R.; Fridlund, M. et al

in Richichi, A.; Delplancke, F.; Paresce, F. (Eds.) et al The Power of Optical/IR Interferometry: Recent Scientific Results and 2nd Generation Instrumentation (2008)

Darwin is one of the most challenging space projects ever considered by the European Space Agency (ESA). Its principal objectives are to detect Earth-like planets around nearby stars, to analyze the ... [more ▼]

Darwin is one of the most challenging space projects ever considered by the European Space Agency (ESA). Its principal objectives are to detect Earth-like planets around nearby stars, to analyze the composition of their atmospheres and to assess their ability to sustain life as we know it. Darwin is conceived as a space ``nulling interferometer'' which makes use of on-axis destructive interferences to extinguish the stellar light while keeping the off-axis signal of the orbiting planet. Within the frame of the Darwin program, definition studies of a Ground based European Nulling Interferometry Experiment, called GENIE, were completed in 2005. This instrument built around the Very Large Telescope Interferometer (VLTI) in Paranal will test some of the key technologies required for the Darwin Infrared Space Interferometer. GENIE will operate in the L' band around 3.8 microns as a single Bracewell nulling interferometer using either two Auxiliary Telescopes (ATs) or two 8m Unit Telescopes (UTs). Its science objectives include the detection and characterization of dust disks and low-mass companions around nearby stars. [less ▲]

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See detailPerformance study of ground-based infrared Bracewell interferometers. Application to the detection of exozodiacal dust disks with GENIE
Absil, Olivier ULg; den Hartog, R.; Gondoin, P. et al

in Astronomy and Astrophysics (2006), 448

Nulling interferometry, a powerful technique for high-resolution imaging of the close neighbourhood of bright astrophysical objets, is currently considered for future space missions such as Darwin or the ... [more ▼]

Nulling interferometry, a powerful technique for high-resolution imaging of the close neighbourhood of bright astrophysical objets, is currently considered for future space missions such as Darwin or the Terrestrial Planet Finder Interferometer (TPF-I), both aiming at Earth-like planet detection and characterization. Ground-based nulling interferometers are being studied for both technology demonstration and scientific preparation of the Darwin/TPF-I missions through a systematic survey of circumstellar dust disks around nearby stars. In this paper, we investigate the influence of atmospheric turbulence on the performance of ground-based nulling instruments, and deduce the major design guidelines for such instruments. End-to-end numerical simulations allow us to estimate the performance of the main subsystems and thereby the actual sensitivity of the nuller to faint exozodiacal disks. Particular attention is also given to the important question of stellar leakage calibration. This study is illustrated in the context of GENIE, the Ground-based European Nulling Interferometer Experiment, to be installed at the VLTI and working in the L' band. We estimate that this instrument will detect exozodiacal clouds as faint as about 50 times the Solar zodiacal cloud, thereby placing strong constraints on the acceptable targets for Darwin/TPF-I. [less ▲]

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See detailThe prospects of detecting exo-planets with the Ground-based European Nulling Interferometer Experiment (GENIE)
den Hartog, R.; Absil, Olivier ULg; Gondoin, P. et al

in Aime, C.; Vakili, F. (Eds.) Direct Imaging of Exoplanets: Science & Techniques (2006)

The European Space Agency's Darwin and NASA's Terrestrial Planet Finder (TPF) are among the most challenging space science missions ever considered. Their principal objective is to detect Earth-like ... [more ▼]

The European Space Agency's Darwin and NASA's Terrestrial Planet Finder (TPF) are among the most challenging space science missions ever considered. Their principal objective is to detect Earth-like planets around nearby stars and to characterize their atmospheres. Darwin and TPF-I are currently conceived as nulling interferometers with free-flying telescopes. Within the frame of the Darwin program, the ESA and the European Southern Observatory (ESO), supported by European industries and scientific institutes, have performed two parallel Phase A studies of a ground-based nulling interferometry experiment (GENIE) at the site of ESO's Very Large Telescope Interferometer (VLTI) in Paranal, Chile. GENIE will demonstrate several key technologies required for the Darwin mission. Its science objectives include the detection and characterization of dust disks and low-mass companions around nearby stars. These studies have established detailed instrumental designs, in which GENIE will operate in the L' band around 3.8 microns as a single Bracewell nulling or constructive interferometer, using either two Auxiliary or two Unit Telescopes. The studies were supported by detailed numerical simulations which indicated the possibility of detection and low-resolution spectroscopy in nulling mode of extra-solar giant planets (EGPs) with atmospheric temperatures down to 700 K, provided that a proper calibration of instrumental effects is applied. Detection of circumstellar exo-zodiacal (EZ) dust clouds is possible down to 0.5 mJy, with interesting prospects for the characterization of planet-forming disks. [less ▲]

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See detailThe Ground-based European Nulling Interferometry Experiment (DARWIN-GENIE)
Gondoin, P.; Absil, Olivier ULg; den Hartog, R. et al

in Fridlund, Malcolm; Henning, Thomas (Eds.) Towards Other Earths: DARWIN/TPF and the Search for Extrasolar Terrestrial Planets (2003, October 01)

Darwin is one of the most challenging space projects ever considered by the European Space Agency (ESA). Its principal objectives are to detect Earth-like planets around nearby stars and to characterise ... [more ▼]

Darwin is one of the most challenging space projects ever considered by the European Space Agency (ESA). Its principal objectives are to detect Earth-like planets around nearby stars and to characterise their atmospheres. Darwin is conceived as a space "nulling interferometer" which makes use of on-axis destructive interferences to extinguish the stellar light while keeping the off-axis signal of the orbiting planet. Within the frame of the Darwin program, the European Space Agency (ESA) and the European Southern Observatory (ESO) intend to build a ground-based technology demonstrator called GENIE (Ground based European Nulling Interferometry Experiment). Such a ground-based demonstrator built around the Very Large Telescope Interferometer (VLTI) in Paranal will test some of the key technologies required for the Darwin Infrared Space Interferometer. It will demonstrate that nulling interferometry can be achieved in a broad mid-IR band as a precursor to the next phase of the Darwin program. [less ▲]

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See detailGENIEsim: the GENIE simulation software
Absil, Olivier ULg; den Hartog, R.; Erd, C. et al

in Fridlund, Malcolm; Henning, Thomas (Eds.) Towards Other Earths: DARWIN/TPF and the Search for Extrasolar Terrestrial Planets (2003, October 01)

GENIEsim, the GENIE simulation software, is an IDL-based code to simulate future observations with the Ground-based European Nulling Interferometer Experiment, which should be commissioned on the Very ... [more ▼]

GENIEsim, the GENIE simulation software, is an IDL-based code to simulate future observations with the Ground-based European Nulling Interferometer Experiment, which should be commissioned on the Very Large Telescope Interferometer (VLTI) in 2007. The code simulates operation in the mid-infrared (L' and N bands) and includes all major noise sources. The atmospheric turbulence is described by a Kolmogorov power spectrum, from which random time series are computed for perturbations to the optical paths. The effect of turbulence is reduced by means of control loops, which are either included in the VLTI facility (MACAO, PRIMA) or specific to the GENIE instrument. The output of GENIEsim is a time series of fluxes computed by integration of a source field multiplied by the GENIE transmission map, projected onto the plane of the sky. Simulations have already allowed to identify critical points in the design of the instrument, such as OPD and dispersion control, calibration of stellar leakage and background subtraction. [less ▲]

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See detailCan GENIE characterize debris disks around nearby stars?
Absil, Olivier ULg; Kaltenegger, L.; Eiroa, C. et al

in Fridlund, Malcolm; Henning, Thomas (Eds.) Towards Other Earths: DARWIN/TPF and the Search for Extrasolar Terrestrial Planets (2003, October 01)

The Ground-based European Nulling Interferometer Experiment will combine the light collected by two or more VLT telescopes and make them interfere in a destructive way, thereby revealing the close ... [more ▼]

The Ground-based European Nulling Interferometer Experiment will combine the light collected by two or more VLT telescopes and make them interfere in a destructive way, thereby revealing the close neighborhood of nearby stars. Operating at mid-infrared wavelengths, GENIE will be particularly sensible to warm circumstellar dust. This paper presents simulated observations of the debris disk around the nearby A2V star zeta Leporis obtained with the GENIE simulation software. Parameters such as inclination, density power-law exponent and inner radius can be retrieved with a relative precision of 1% or better using only six observations of 15 minutes. In the context of the DARWIN/TPF mission, warm circumstellar dust could be a serious limitation to the detection of Earth-like exoplanets. This paper shows that GENIE will detect disks as faint as 23 times our local zodiacal cloud around Sun-like stars at 10 pc, and will thus allow to discard unsuitable targets for DARWIN/TPF. [less ▲]

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See detailThe Darwin Ground-based European Nulling Interferometry Experiment
Gondoin, P.; Absil, Olivier ULg; Fridlund, M. et al

in Lacoste, H. (Ed.) GENIE - DARWIN Workshop - Hunting for Planets (2003, March 01)

Darwin is one of the most challenging space pro jects ever considered by the European Space Agency (ESA). Its principal ob jectives are to detect Earth-like planets around nearby stars and to characterise ... [more ▼]

Darwin is one of the most challenging space pro jects ever considered by the European Space Agency (ESA). Its principal ob jectives are to detect Earth-like planets around nearby stars and to characterise their atmospheres. Darwin is conceived as a space nulling interferometer" which makes use of on-axis destructive interferences to extinguish the stellar light while keeping the o -axis signal of the orbiting planet. Within the frame of the Darwin program, the European Space Agency (ESA) and the European Southern Observatory (ESO) intend to build a ground-based technology demonstrator called GENIE (Ground based European Nulling Interferometry Experiment). Such a ground-based demonstrator built around the Very Large Telescope Interferometer (VLTI) in Paranal will test some of the key technologies required for the Darwin Infrared Space Interferometer. It will demonstrate that nulling interferometry can be achieved in a broad mid-IR band as a precursor to the next phase of the Darwin program. The present paper will describe the ob jectives and the status of the project. [less ▲]

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See detailThe Darwin-GENIE Experiment: An ESA-ESO Partnership
Gondoin, Ph; Absil, Olivier ULg; Erd, C. et al

in Sembach, K. R.; Blades, J. C.; Illingworth, G. D. (Eds.) et al Hubble's Science Legacy: Future Optical/Ultraviolet Astronomy from Space (2003)

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See detailCandidate VLTI Configurations for the GENIE Nulling Experiment
Absil, Olivier ULg; Gondoin, P.; Erd, C. et al

in Deming, Drake; Seager, Sara (Eds.) Scientific Frontiers in Research on Extrasolar Planets (2003)

The European Space Agency (ESA) and the European Southern Observatory (ESO) initiate a definition study for a Ground-based European Nulling Interferometer Experiment (Darwin-GENIE). The experiment will ... [more ▼]

The European Space Agency (ESA) and the European Southern Observatory (ESO) initiate a definition study for a Ground-based European Nulling Interferometer Experiment (Darwin-GENIE). The experiment will use the Very Large Telescope Interferometer (VLTI) operating on Mount Paranal (Chile). The objective of GENIE is to gain experience in the manufacture and operation of a nulling interferometer using a design concept and technology representative of the ESA IRSI-Darwin space mission. GENIE will prepare the IRSI-Darwin science program through a systematic search for exozodiacal dust clouds around IRSI-Darwin candidate targets. GENIE also aims to perform IRSI-Darwin related science achievable from ground including the detection of low-mass companions (if possible, hot jupiters) around nearby stars. Among the variety of telescope sizes and positions on the VLTI site, candidate interferometric configurations have been identified for GENIE, taking into account the limitation imposed by the Earth's atmosphere. They include a Bracewell interferometer for exozodiacal clouds detection in the N band and a double Bracewell configuration with internal modulation for extrasolar jupiter detection in the L' band. The present paper presents the prospective performance of these configurations in light of current specifications of major VLTI subsystems. [less ▲]

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See detailThe GENIE nulling experiment
Absil, Olivier ULg; Gondoin, Ph; den Hartog, R. et al

in Combes, F. (Ed.) SF2A-2002: Semaine de l'Astrophysique Francaise (2002, June)

Within the frame of the Darwin program, the European Space Agency and the European Southern Observatory (ESO) intend to build a ground-based technology demonstrator called Darwin-GENIE, using the Very ... [more ▼]

Within the frame of the Darwin program, the European Space Agency and the European Southern Observatory (ESO) intend to build a ground-based technology demonstrator called Darwin-GENIE, using the Very Large Telescope Interferometer (VLTI). The main objective of GENIE is to gain experience in the manufacture and operation of a nulling interferometer representative of the ESA IRSI-Darwin space mission. GENIE will prepare the Darwin science programme through a systematic search for exo-zodiacal dust clouds around Darwin candidate targets. GENIE also aims to perform Darwin related science including the detection of low-mass companions (if possible, hot Jupiters) around nearby stars. The prospective performances of some candidate configurations are presented in this paper. [less ▲]

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