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1. SNO KARST: A French Network of Observatories for the Multidisciplinary Study of Critical Zone Processes in Karst Watersheds and Aquifers

Author

H. Jourde, N. Massei, N. Mazzilli, S. Binet, C. Batiot-Guilhe, D. Labat, M. Steinmann, V. Bailly-Comte, J.L. Seidel, B. Arfib, J.B. Charlier, V. Guinot, A. Jardani, M. Fournier, M. Aliouache, M. Babic, C. Bertrand, P. Brunet, J.F. Boyer, J.P. Bricquet, T. Camboulive, S.D. Carrière, H. Celle-Jeanton, K. Chalikakis, N. Chen, C. Cholet, V. Clauzon, L. Dal Soglio, C. Danquigny, C. Défargue, S. Denimal, C. Emblanch, F. Hernandez, M. Gillon, A. Gutierrez, L. Hidalgo Sanchez, M. Hery, N. Houillon, A. Johannet, J. Jouves, N. Jozja, B. Ladouche, V. Leonardi, G. Lorette, C. Loup, P. Marchand, V. de Montety, R. Muller, C. Ollivier, V. Sivelle, R. Lastennet, N. Lecoq, J. C. Maréchal, L. Perotin, J. Perrin, M.A. Petre, N. Peyraube, S. Pistre, V. Plagnes, A. Probst, J.L. Probst, R. Simler, V. Stefani, D. Valdes-Lao, S. Viseur, and X. Wang

Subjects
Environmental sciences, GE1-350, Geology, QE1-996.5
Abstract

Karst aquifers and watersheds represent a major source of drinking water around the world. They are also known as complex and often highly vulnerable hydrosystems due to strong surface–groundwater interactions. Improving the understanding of karst functioning is thus a major issue for the efficient management of karst groundwater resources. A comprehensive understanding of the various processes can be achieved only by studying karst systems across a wide range of spatiotemporal scales under different geological, geomorphological, climatic, and soil cover settings. The objective of the French Karst National Observatory Service (SNO KARST) is to supply the international scientific community with appropriate data and tools, with the ambition of (i) facilitating the collection of long-term observations of hydrogeochemical variables in karst, and (ii) promoting knowledge sharing and developing cross-disciplinary research on karst. This paper provides an overview of the monitoring sites and collective achievements, such as the KarstMod modular modeling platform and the PaPRIKa toolbox, of SNO KARST. It also presents the research questions addressed within the framework of this network, along with major research results regarding (i) the hydrological response of karst to climate and anthropogenic changes, (ii) the influence of karst on geochemical balance of watersheds in the critical zone, and (iii) the relationships between the structure and hydrological functioning of karst aquifers and watersheds.

Published
2018
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4. SYNERGY OF ADVANCED PROCESSING TECHNIQUES USING COPERNICUS SAR AND OPTICAL SATELLITE IMAGERY TO DETECT GROUND DISPLACEMENTS: THE CASE STUDIES OF PYRGOS AND PAREKKLISIA VILLAGES IN CYPRUS

Author

M. Tzouvaras, S. Alatza, M. Prodromou, C. Theocharidis, K. Fotiou, A. Argyriou, C. Loupasakis, A. Apostolakis, Z. Pittaki, M. Kaskara, C. Kontoes, and D. Hadjimitsis

Subjects
Technology, Engineering (General). Civil engineering (General), TA1-2040, Applied optics. Photonics, TA1501-1820
Abstract

Cyprus has a long history of destructive tectonic activity and related geohazards. This is mainly due to its location on the Mediterranean fault zone and the interaction of the Eurasian and African plates. To study the occurrence of land displacements on a national scale, various space-based monitoring techniques exploiting the Copernicus program’s datasets were studied using Sentinel-1 and Sentinel-2 satellite images for the period of 2016–2021. More specifically, differential spectral indices were calculated by subtracting the reference 2016 Sentinel-2 image from an image for every year until 2021, and a parallelised version of Persistent Scatterer Interferometry (PSI) was conducted using a time series of Sentinel-1 data over the same period, to identify ground displacements over time. The PSI analysis in the area around Pyrgos and Parekklisia villages, detected Line-of-Sight (LoS) uplift phenomena of a maximum rate of 8 mm/y, in ascending and descending Sentinel-1 satellite passes. Similarly, deformation was identified from optical image processing. The integration of both techniques provided qualitative and quantitative information about ground deformation events in both areas, showcasing a complementarity of results obtained, with PSI detecting displacements in urban/built-up areas, and multispectral change detection in rural environment. In terms of correlation, the two techniques showed a fit of 31.34% in ascending and 26% in descending pass, providing additional information on the size of affected areas. This synergistic approach facilitates the systematic monitoring of areas of interest, providing significant and timely information to decision-makers, to take actions and adopt protective measures when and where it is required.

Published
2023
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5. Carbon Nanotube Based Sensor to Monitor Crack Growth in Cracked Aluminum Structures Underneath Composite Patching

Author

D. C. Hart, Young W. Kwon, D. C. Loup, T. M. Olson, and E. A. Rasmussen

Subjects
Materials science, business.industry, Tension (physics), Composite number, Fatigue testing, chemistry.chemical_element, Fracture mechanics, Carbon nanotube, Structural engineering, law.invention, Electrical resistance and conductance, chemistry, law, Aluminium, Ultimate tensile strength, Ceramics and Composites, Composite material, business
Abstract

The paper investigates a carbon nanotube-based sensor to detect crack propagation in aluminum structures underneath composite patching. Initial tests are conducted to determine the correct procedure and materials to properly fabricate a carbon nanotube (CNT) based sensor, which is then placed in between a composite patch and the aluminum structure. The CNTs have been utilized as sensors in previous studies but only for sensing crack propagation within the composite itself. This study focuses on crack propagation in the base material and is not concerned with the composite. In this application, the composite is only a patch and can be replaced if damaged. The study conducts both tension and fatigue testing to determine the usefulness of the CNT sensor. The CNT sensor is shown to be effective in giving an indication of the crack propagation in the aluminum. Correlation is done between the crack propagation length and the increase in electrical resistance in the CNT sensor under tensile and cyclic loading, respectively.

Published
2014
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6. Analytical Model for Prediction of Reduced Strain Energy Release Rate of Single-Side-Patched Plates

Author

W. Y. Lee, D. C. Hart, E. A. Rasmussen, Young W. Kwon, D. C. Loup, and Aaron S. McGee

Subjects
Strain energy release rate, Materials science, business.industry, Base (geometry), Modulus, Bending, Structural engineering, Finite element method, Ceramics and Composites, Composite material, Reduction (mathematics), business, Elastic modulus, Joint (geology)
Abstract

A study was undertaken to develop an analytical model that can predict how much reduction in Strain Energy Release Rate (SERR) can be achieved by repairing a cracked plate using a single-side bonded patch. The plate may be subjected to inplane or out-of-plane bending loading. Furthermore, the plate may be flat or curved in a cylindrical shape. The model helps to select patch material (i.e., elastic modulus of the material) and the appropriate patch size in order to reduce the SERR at the crack tip of the patched base plate. In other words, the analytical model can be utilized to select the patch material and patch dimensions required to achieve the desired SERR for a cracked base plate with known modulus, thickness, and crack size. The model is based on axial and bending stresses of the single-side strap joint configuration, which are related to the SERR at the crack tip of a plate with a single-side patch repair. In order to verify the analytical model, finite element analyses were conducted to determine stresses as well as SERR in many different patched plates. The numerical study confirmed the validity of the analytical model in predicting the reduction ratio of SERR resulting from the single-side patch repair.

Published
2013
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7. From your Paper to VizieR and SIMBAD

Author

T. Boch, F. Ochsenbein, Françoise Genova, Marc Wenger, L. Cambresy, and C. Loup

Subjects
Physics, business.industry, media_common.quotation_subject, SIMBAD, General Engineering, Astronomy and Astrophysics, Engineering physics, Data science, Work (electrical), Space and Planetary Science, Quality (business), Data center, business, media_common
Abstract

Scientific results strongly rely on previous studies, experiments, and observations. A huge quantity of data is produced by astronomers and needs to be available to the whole community. To support astronomers in their daily research work, the Centre de Donnees astronomiques de Strasbourg (Strasbourg astronomical data center – CDS) collects, verifies, homogenizes, and organizes information – in particular, those published in academic journals – in the most appropriate and comprehensible way. This CDS goal can reach the highest level of quality only through a close collaboration with journals, authors, and referees. This paper presents the succession of processes leading published data to the CDS databases, focusing on the strategy that maintains a high level of quality. Authors and referees are strongly encouraged to actively contribute to this endeavor. A few examples of how CDS databases are used through CDS services are also presented.

Published
2011
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8. Spitzer observations of acetylene bands in carbon-rich asymptotic giant branch stars in the Large Magellanic Cloud

Author

M. Matsuura, P. R. Wood, G. C. Sloan, A. A. Zijlstra, J. Th. Van Loon, M. A. T. Groenewegen, J. A. D. L. Blommaert, M.-R. L. Cioni, M. W. Feast, H. J. Habing, S. Hony, E. Lagadec, C. Loup, J. W. Menzies, L. B. F. M. Waters, and P. A. Whitelock

Subjects
Physics, Stars, Spitzer Space Telescope, Space and Planetary Science, Metallicity, Spectral energy distribution, Circumstellar dust, Astronomy and Astrophysics, Circumstellar envelope, Astrophysics, Large Magellanic Cloud, Spectral line
Abstract

We investigate the molecular bands in carbon-rich AGB stars in the Large Magellanic Cloud (LMC), using the InfraRed Spectrograph (IRS) on board the Spitzer Space Telescope (SST) over the 5–38 µm range. All 26 low-resolution spectra show acetylene (C2H2) bands at 7 and 14 µm. The hydrogen cyanide (HCN) bands at these wavelengths are very weak or absent. This is consistent with low nitrogen abundances in the LMC. The observed 14 µm C2H2 band is reasonably reproduced by an excitation temperature of 500 K. There is no clear dilution of the 14 µm C2H2 band by circumstellar dust emission. This 14 µm band originates from molecular gas in the circumstellar envelope in these high mass-loss rate stars, in agreement with previous findings for Galactic stars. The C2H2 column density, derived from the 13.7 µm band, shows a gas mass-loss rate in the range 3 ×10 −6 to 5 ×10 −5 M ⊙ yr −1 . This is comparable with the total mass-loss rate of these stars estimated from the spectral energy distribution. Additionally, we compare the line strengths of the 13.7 µm C2H2 band of our LMC sample with those of a Galactic sample. Despite the low metallicity of the LMC, there is no clear difference in the C2H2 abundance among LMC and Galactic stars. This reflects the effect of the 3rd dredge-up bringing self-produced carbon to the surface, leading to high C/O ratios at low metallicity.

Published
2006
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9. A Spitzer mid-infrared spectral survey of mass-losing carbon stars in the Large Magellanic Cloud

Author

Michael Feast, Albert A. Zijlstra, J. A. D. L. Blommaert, Gregory C. Sloan, Eric Lagadec, Martin Groenewegen, C. Loup, Sacha Hony, Jacco Th. van Loon, L. B. F. M. Waters, John W. Menzies, Patricia A. Whitelock, Peter R. Wood, Harm J. Habing, Mikako Matsuura, and M.-Rl. Cioni

Subjects
Physics, Metallicity, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Spectral line, Carbon star, Galaxy, Interstellar medium, Stars, Spitzer Space Telescope, Space and Planetary Science, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Large Magellanic Cloud, Astrophysics::Galaxy Astrophysics
Abstract

We present a Spitzer Space Telescope spectroscopic survey of mass-losing carbon stars (and one oxygen-rich star) in the Large Magellanic Cloud. The spectra cover the wavelength range 5--38 micron. They show varying combinations of dust continuum, dust emission features (SiC, MgS) and molecular absorption bands (C2H2, HCN). A set of four narrow bands, dubbed the Manchester system, is used to define the infrared continuum for dusty carbon stars. The relations between the continuum colours and the strength of the dust and molecular features are studied, and are compared to Galactic stars of similar colours. The circumstellar 7-micron C2H2 band is found to be stronger at lower metallicity, from a comparison of stars in the Galaxy, the LMC and the SMC. This is explained by dredge-up of carbon, causing higher C/O ratios at low metallicity (less O). A possible 10-micron absorption feature seen in our spectra may be due to C3. This band has also been identified with interstellar silicate or silicon-nitrite dust. The line-to-continuum ratio of theSiC and MgS bands shows some indication of being lower at low metallicity. The MgS band is only seen at dust temperatures below 600 K. We discuss the selection of carbon versus oxygen-rich AGB stars using the J-K vs. K-A colours, and show that these colours are relatively insensitive to chemical type. Metal-poor carbon stars form amorphous carbon dust from self-produced carbon. The formation efficiency of oxygen-rich dust depends more strongly on metallicity. We suggest that in lower-metallicity environments, the dust input into the Interstellar Medium by AGB stars is efficient but may be strongly biassed towards carbonaceous dust, as compare to the Galaxy.

Published
2006
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10. Long period variables detected by ISO in the Small Magellanic Cloud

Author

J. Hron, A. Omont, A. A. Zijlstra, J. Th. van Loon, C. Loup, Martin Groenewegen, J. A. D. L. Blommaert, H. J. Habing, Patricia A. Whitelock, Franz Kerschbaum, and M. R. L. Cioni

Subjects
Physics, 010308 nuclear & particles physics, Metallicity, Diagram, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Stars, Amplitude, Space and Planetary Science, Long period, 0103 physical sciences, Magnitude (astronomy), Astrophysics::Solar and Stellar Astrophysics, Spectral energy distribution, Astrophysics::Earth and Planetary Astrophysics, Supergiant, 10. No inequality, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

This article presents the study of the light-curves extracted from the MACHO database of a sample of stars observed by the ISO in the SMC. These stars belong to the ISO-Mini-Survey catalogue of the Magellanic Clouds (ISO-MCMS, Loup et al. in preparation). Most of them are in the AGB and supergiant phases. The dominant period and amplitude of pulsation have been derived and the stars have been classified as Mira or Semi-Regular pulsators. Furthermore, the cross-identification with near-infrared DENIS and 2MASS magnitudes available within the ISO-MCMS allowed us: (i) to investigate the properties of these stars in the combined near- and mid-infrared colour-magnitude diagrams, (ii) to derive the bolometric magnitude by integrating the spectral energy distribution and (iii) to estimate the mass-loss rate. The stars have been divided into carbon- (C-) and oxygen-rich (O-rich) using the (J-Ks, Ks) colour-magnitude diagram and their period and amplitude distributions have been compared. C-rich AGB stars have a sharp peak in their period distribution at about 250 days and have on average a larger amplitude than O-rich AGB stars. This effect, not previously detected from the study of similar stars in the LMC and in the Baade's window, might be closely related to the metallicity of the environment in which the stars have formed.

Published
2003
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11. Bulge microlensing optical depth from EROS 2 observations $^{\bullet}$

Author

C. Afonso, J. N. Albert, C. Alard, J. Andersen, R. Ansari, É. Aubourg, P. Bareyre, F. Bauer, J. P. Beaulieu, G. Blanc, A. Bouquet, S. Char, X. Charlot, F. Couchot, C. Coutures, F. Derue, R. Ferlet, P. Fouqué, J. F. Glicenstein, B. Goldman, A. Gould, D. Graff, M. Gros, J. Haissinski, C. Hamadache, J. C. Hamilton, D. Hardin, J. de Kat, A. Kim, T. Lasserre, L. LeGuillou, É. Lesquoy, C. Loup, C. Magneville, B. Mansoux, J. B. Marquette, É. Maurice, A. Maury, A. Milsztajn, M. Moniez, N. Palanque-Delabrouille, O. Perdereau, L. Prévot, N. Regnault, J. Rich, M. Spiro, P. Tisserand, A. Vidal-Madjar, L. Vigroux, and S. Zylberajch

Subjects
Physics, 010308 nuclear & particles physics, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Gravitational microlensing, 01 natural sciences, Stars, Space and Planetary Science, Bulge, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Optical depth
Abstract

We present a measurement of the microlensing optical depth toward the Galactic bulge based on the analysis of 15 contiguous1 square degrees fields centered on (l=2.5 deg, b=-4.0 deg) and containing 1.42 million clump-giant stars (belonging to the extended clump area) monitored during almost three bulge seasons by EROS (Experience de Recherche d'Objets Sombres). We find a microlensing optical depth towards the bulge tau_bulge=0.94 +/- 0.29 10^-6 averaged over all fields, based on 16 microlensing events with clump giants as sources. This value is substantially below several other determinations by the MACHO and OGLE groups and is more in agreement with what is expected from axisymmetric and non-axisymmetric bulge models.

Published
2003
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12. Variability and spectral classification of LMC giants: Results from DENIS and EROS

Author

Harm J. Habing, E. Lesquoy, Thierry Lasserre, M. R. L. Cioni, M. Azzopardi, J. B. Marquette, and C. Loup

Subjects
Physics, education.field_of_study, Cepheid variable, Astrophysics (astro-ph), Population, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Stellar classification, Spectral line, Stars, Space and Planetary Science, Long period, Asymptotic giant branch, Large Magellanic Cloud, education
Abstract

We present the first cross-identifications of sources in the near-infrared DENIS survey and in the micro-lensing EROS survey in a field of about 0.5 square degrees around the optical center (OC) of the Large Magellanic Cloud. We analyze the photometric history of these stars in the EROS data base and obtain light-curves for about 800 variables. Most of the stars are long period variables (Miras and Semi-Regulars), a few Cepheids are also present. We also present new spectroscopic data on 126 asymptotic giant branch stars in the OC field, 30 previously known and 96 newly discovered by the DENIS survey. The visible spectra are used to assign a carbon- (C-) or oxygen-rich (O-rich) nature to the observed stars on the basis of the presence of molecular bands of TiO, VO, CN, C2. For the remaining of the stars we used the (J-Ks) color to determine whether they are O-rich or C-rich. Plotting Log(period) versus Ks we find three very distinct period-luminosity relations, mainly populated by Semi-Regular of type a (SRa), b (SRb) and Mira variables. Carbon-rich stars occupy mostly the upper part of these relations. We find that 65% of the asymptotic giant branch population are long period variables (LPVs)., Comment: 9 pages, 7 figures, 4 tables (2 via CDS), accepted by A&A journal

Published
2001
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13. Mass-losing AGB Stars in the LMC

Author

Jacco Th. van Loon, C. Loup, L.B.F.M. Waters, Patricia A. Whitelock, and Albert A. Zijlstra

Subjects
Physics, Stars, Astrophysics
Abstract

We show the results of an infrared study of a sample of heavily obscured AGB stars in the LMC. Both carbon-rich and oxygen-rich mass-losing AGB stars can be found at both high and low luminosities, but the percentage of carbon stars decreases with increasing luminosity. The optical depth of the circumstellar envelopes also decreases with increasing luminosity, while the mass-loss rates are (nearly) constant with luminosity. We also show tentative evidence for having found the first post-AGB stars in the LMC.

Published
2000
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14. Extended Dust Shells around Carbon Stars in the Infrared and in Optical Light

Author

Osamu Hashimoto, C. Loup, T. de Jong, L. B. F. M. Waters, and Hideyuki Izumiura

Subjects
Physics, Infrared, Astronomy, Circumstellar dust, Astrophysics, Carbon star, Cosmic dust
Abstract

We investigate the structure of extended dust shells around optical carbon stars in the far-infrared and in optical light. In the optical we have discovered that R Scl and U Ant are associated with circularly extended emission, the radii of which are about 20″ and 58″, respectively. The emission is probably scattered light of the central star by dust grains in their circumstellar shells. In the far-infrared we have discovered a double shell structure surrounding U Ant in high resolution IRAS images, which is direct evidence of a periodic change of mass-loss on a time-scale of the order of 104 years in the AGB evolution. Relating the two shells to two consecutive thermal pulses allows for a self-consistent determination of the interpulse period, core-mass, luminosity, and distance. Direct mapping of Y CVn at 90 and 160 μm with ISOPHOT on board ISO has revealed a very extended detached dust shell around this star. The mass-loss rate is found to have decreased drastically by two orders of magnitude 1.4×104 years ago, which should be an important clue to the understanding of J-type stars.

Published
2000
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15. Thermal Infrared Survey of LMC, SMC and Sagittarius Dwarf Galaxy

Author

H. U. Käufl, G. Wiedemann, C. Loup, L. B. F. M. Waters, A. A. Zijlstra, Eline Tolstoy, and H. G. Reimann

Subjects
Physics, Luminous infrared galaxy, Stars, Luminous blue variable, Star formation, Milky Way, Astronomy, Astrophysics, Galaxy, Dwarf spheroidal galaxy, Dwarf galaxy
Abstract

The ESO VLT with its suite of infrared instruments (e.g. ISAAC, VISIR) allows for an area-limited deep survey for infrared-bright point sources in nearby local group galaxies. Data in four colours can be collected: 3, 5, 10, and 20μm; the 10/20μm data can be complemented with TIMMI2, a new instrument presently under construction for ESO's 3.6m telescope on La Silla. The scientific result will be a complete catalogue of obscured Asymptotic Giant Branch Stars in the LMC, the SMC and the Sagittarius Dwarf Galaxy (SDG). Using mostly twilight time, such a survey can be done for an area of ≈ 100 □arcmin per year per galaxy. At 10μm the limiting flux is expected to be 2–3 orders of magnitude fainter than the IRAS point source catalogue. This catalogue would give the first coherent sample of AGB stars with precise distances and consequently absolute bolometric luminosities. It may lead to a substantially better understanding of the mass loss of AGB stars, an important, but as of today largely enigmatic phase of stellar evolution. As a byproduct many more IR-bright objects in the Magellanic Clouds, e.g. dust envelopes around normal stars, luminous blue variable stars (LBV) or compact obscured HII-regions, will be discovered. For the SDG no LBVs or YSOs are expected as it had no star formation for the past 5 Gyr.

Published
1999
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16. Near-Infrared Catalogue of the Magellanic Clouds: DENIS (Deep Near-IR Southern Sky Survey)

Author

H. J. Habing, N. Epchtein, Martin Groenewegen, C. Loup, and M. R. Cioni

Subjects
Physics, 010504 meteorology & atmospheric sciences, media_common.quotation_subject, Near-infrared spectroscopy, Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Sky, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, media_common
Abstract

We report here on a preliminary analysis of the DENIS new IR point source catalogue of the Magellanic Clouds. After subtracting the contribution of foreground stars we interpret the colour-colour diagrams and colour-magnitude diagrams that characterize the Asymptotic Giant Branch (AGB). The AGB stars cause a clear bump in the luminosity function and they are distributed in two distinct regions, according to the spectral type (C-rich and O-rich), in the colour-luminosity diagram.

Published
1999
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17. ISOCAM and DENIS Survey of 0.5 square degrees in the Bar of the LMC. Detection of the whole TP-AGB Star Population

Author

A. A. Zijlstra, Martin Groenewegen, J. Th. van Loon, N. R. Trams, Franz Kerschbaum, Christophe Alard, C. Loup, P. Fouque, E. Josselin, H. J. Habing, J. A. D. L. Blommaert, Maria-Rosa L. Cioni, and L.B.F.M. Waters

Subjects
Physics, education.field_of_study, Bar (music), Population, Asymptotic giant branch, Square (unit), Astrophysics, education
Abstract

We surveyed 0.5 square degrees in the Bar of the LMC with ISOCAM at 4.5 and 12 μm, and with DENIS in the I, J, and Ks bands. Our goal was to build a complete sample of Thermally-Pulsing AGB stars. Here we present the first analysis of 0.14 square degrees. In total we find about 300 TP-AGB stars. Among these TP-AGB stars, 9% are obscured AGB stars (high mass-loss rates); 9 of them were detected by IRAS, and only 1 was previously identified. Their luminosities range from 2 500 to 14 000 L⊙, with a distribution very similar to the one of optical TP-AGB stars (i.e. those with low mass-loss rates). Such a luminosity distribution, as well as the percentage of obscured stars among TP-AGB stars, is in very good agreement with the evolutionary models of Vassiliadis & Wood (1993) if most of the TP-AGB stars that we find have initial masses smaller than 1.5 to 2 M⊙.

Published
1999
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18. AGB Stars in the Large Magellanic Cloud

Author

C. Loup

Subjects
Physics, Stars, 010504 meteorology & atmospheric sciences, 0103 physical sciences, Astronomy, Astrophysics, Large Magellanic Cloud, 010303 astronomy & astrophysics, 01 natural sciences, 0105 earth and related environmental sciences, Luminosity, Luminosity function (astronomy)
Abstract

This paper reviews the luminosity distribution of AGB stars in the Large Magellanic Cloud. I briefly summarize the history and results of the previous surveys, and then present a first analysis of the DENIS survey in the IJKS bands, and ISOCAM observations at 4.5 and 12 μm.

Published
1999
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19. A 12CO ($J=1\rightarrow 0$) and ($J=2\rightarrow 1$) atlas of circumstellar envelopes of AGB and post-AGB stars

Author

C. Loup, Valentin Bujarrabal, C. Kahane, R. Lucas, and Roberto Neri

Subjects
Physics, Telescope, Stars, law, General Physics and Astronomy, High resolution, Astronomy, Astrophysics, Radius, law.invention
Abstract

We present the results of a 12 CO (J =1 !0) and (J =2 !1) survey on a sample of 46 objects classi- ed as AGB and post-AGB stars. We have obtained fully sampled high resolution maps of their 12 CO (J =1 !0) emission by combining visibilities from the IRAM inter- ferometer with short spacing observations from the IRAM 30 m telescope. Properties of their circumstellar envelopes like fluxes, radii, and positions are derived from model ts to the visibilities and compared to the results obtained from 12 CO (J =2 !1) maps observed at the IRAM 30 m telescope. From the 12 CO (J =1 !0) observations we have derived mass loss rates for 38 stars and estab- lished an empirical relation between the CO photodisso- ciation radius of an envelope and the measured radius in the (J =1 !0) emission.

Published
1998
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20. Infrared giants vs. supergiants

Author

C. Barnbaum, E. Josselin, L.-Å. Nyman, Alain Omont, C. Loup, and F. Sèvre

Subjects
Physics, Stars, Point source, General Physics and Astronomy, Flux, Astronomy, Astrophysics, Supergiant, Stellar classification, Low Mass, Chromosphere, Luminosity
Abstract

We report systematic observations of millimeter CO emission from a sample of 109 oxygen–rich evolved stars (AGB and supergiants), colour–selected from the IRAS Point Source Catalog . CO has been searched with good sensitivity in 81 sources (74% of the sample). CO is detected in 54 sources and a significant upper limit has been achieved in 27 sources. In our previous paper we reported on the statistical results of these observations. We showed that in almost 50% of the sources, the ratio of the IRAS flux to CO intensity, , is larger by a factor of 3 to more than 10 than what is expected according to the correlation found by Nyman et al. (1992). Supergiants only exhibit very high values (≳ 200). In most cases, the observed spread in the values of this ratio can be explained by a large range of luminosities. This leads to a new criterion to identify AGB stars: an object with must have a low mass progenitor. Here we study the correlations between and various physical properties of the sources. Most sources with high values of also have low galactic latitudes, small IRAS variability indices, and early spectral types (typically M1–M5). Conversely, there is no dependence on the IRAS colours, nor on the intensity of silicate emission. However, a few AGB stars exhibit large ; other factors than luminosity are required to explain these values. Different hypotheses, such as the possible presence of a chromosphere, a low 12 C abundance or a variable mass–loss rate, are examined. Considering the global high OH detection rate , we studied the correlations with CO and OH emission. The detection of OH seems to be a useful discriminator of mechanisms that enhance .

Published
1998
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21. Obscured AGB stars in the Magellanic Clouds

Author

Albert A. Zijlstra, C. Loup, Martin Groenewegen, and Laurentius Waters

Subjects
Photometry (optics), Physics, Stars, General Physics and Astronomy, Astronomy, Red supergiant, Astrophysics, Small Magellanic Cloud, Supergiant, Large Magellanic Cloud, Planetary nebula, Carbon star
Abstract

We have selected 198 IRAS sources in the Large Magellanic Cloud, and 11 in the Small Magellanic Cloud, which are the best candidates to be mass–loosing AGB stars (or possibly post–AGB stars). We used the catalogues of Schwering & Israel (1990) and Reid et al. (1990). They are based on the IRAS pointed observations and have lower detection limits than the Point Source Catalogue. We also made cross–identifications between IRAS sources and optical catalogues. Our resulting catalogue is divided in 7 tables. Table 1 lists optically known red supergiants and AGB stars for which we found an IRAS counterpart (7 and 52 stars in the SMC and LMC, respectively). Table 2 lists "obscured” (or "cocoon”) AGB stars or late–type supergiants which have been identified as such in previous works through their IRAS counterpart and JHKLM photometry (2 SMC and 34 LMC sources; no optical counterparts). Table 3 lists known planetary nebulae with an IRAS counterpart (4 SMC and 19 LMC PNe). Table 4 lists unidentified IRAS sources that we believe to be good AGB or post–AGB or PNe candidates (11 SMC and 198 LMC sources). Table 5 lists unidentified IRAS sources which could be any type of object (23 SMC and 121 LMC sources). Table 6 lists IRAS sources associated with foreground stars (29 SMC and 135 LMC stars). Table 7 lists ruled out IRAS sources associated with HII regions, hot stars, etc We show that the sample of IRAS AGB stars in the Magellanic Clouds is very incomplete. Only AGB stars more luminous than typically and with a mass-loss rate larger than typically /yr could be detected by the IRAS satellite. As a consequence, one expects to find very few carbon stars in the IRAS sample. We also expect that most AGB stars with intermediate mass–loss rates have not been discovered yet, neither in optical surveys, nor in the IRAS survey.

Published
1997
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23. Experimental Study of Mode II Fracture of Hybrid Composite and Metal-Wire Joints

Author

Young W. Kwon, D. C. Loup, W. A. Schultz, and E. A. Rasmussen

Subjects
Digital image correlation, Fracture toughness, Materials science, Transfer molding, Mechanics of Materials, Mechanical Engineering, Composite number, Fracture (geology), Fracture mechanics, Composite material, Vacuum assisted resin transfer molding, Safety, Risk, Reliability and Quality, Sandwich-structured composite
Abstract

In order to join a composite structure to a metallic structure, metal-wire mats were co-cured with composite laminas using the vacuum assisted resin transfer molding technique. Then, interface fracture toughness was measured for Mode II fracture for various lay-up and interface conditions. The study included interfaces of metal-wire to composite, composite to composite, and metal-wire to metal-wire. In addition, the lay-up orientations of metal-wire mats were varied between 0 deg and 90 deg. This study also examined the crack propagation from a composite to a metal/composite interface. During the test, the digital image correlation technique was applied to capture the strain field around the crack tip. The results suggested that a hybrid metal-wire/composite laminate would be effective to connect a composite structure to a metallic structure as long as some critical interface conditions were avoided.

Published
2011
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24. New Magellanic Cloud R Coronae Borealis and DY Per type stars from the EROS-2 database: the connection between RCBs, DYPers and ordinary carbon stars

Author

J. de Kat, Anaëlle Maury, Andrew Gould, Cristina Afonso, J. B. Marquette, M. Gros, C. Loup, N. Palanque-Delabrouille, O. Perdereau, P. Bareyre, J. P. Beaulieu, R. Ansari, Peter R. Wood, A. Milsztajn, Roger Ferlet, E. Maurice, Alfred Vidal-Madjar, C. Magneville, X. Charlot, E. Lesquoy, J. N. Albert, Éric Aubourg, P. Schwemling, Bertrand Goldman, P. Tisserand, P. Fouque, M. Moniez, Jeffrey A. Rich, J. F. Glicenstein, C. Coutures, Johannes Andersen, Michel Spiro, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), APC - Cosmologie, Physique Corpusculaire et Cosmologie - Collège de France (PCC), Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire d'Astrophysique de l'Observatoire Midi-Pyrénées (LATT), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Observatoire astronomique de Strasbourg (ObAS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), EROS-2, Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Pierre et Marie Curie - Paris 6 (UPMC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
FOS: Physical sciences, Astrophysics, stars: AGB and post-AGB, computer.software_genre, 01 natural sciences, Luminosity, 0103 physical sciences, Magellanic Clouds, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Physics, Database, 010308 nuclear & particles physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], White dwarf, Astronomy and Astrophysics, supergiants, Light curve, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Carbon star, Stars, Supernova, stars: carbon, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Spectral energy distribution, Supergiant, computer
Abstract

R Coronae Borealis stars (RCB) are a rare type of evolved carbon-rich supergiant stars that are increasingly thought to result from the merger of two white dwarfs, called the Double degenerate scenario. This scenario is also studied as a source, at higher mass, of type Ia Supernovae (SnIa) explosions. Therefore a better understanding of RCBs composition would help to constrain simulations of such events. We searched for and studied RCB stars in the EROS Magellanic Clouds database. We also extended our research to DY Per type stars (DYPers) that are expected to be cooler RCBs (T~3500 K) and much more numerous than their hotter counterparts. The light curves of ~70 millions stars have been analysed to search for the main signature of RCBs and DYPers: a large drop in luminosity. Follow-up optical spectroscopy was used to confirm each photometric candidate found. We have discovered and confirmed 6 new Magellanic Cloud RCB stars and 7 new DYPers, but also listed new candidates: 3 RCBs and 14 DYPers. We estimated a range of Magellanic RCB shell temperatures between 360 and 600 K. We confirm the wide range of absolute luminosity known for RCB stars, M_V~-5.2 to -2.6. Our study further shows that mid-infrared surveys are ideal to search for RCB stars, since they have thinner and cooler circumstellar shells than classical post-AGB stars. In addition, by increasing the number of known DYPers by ~400%, we have been able to shed light on the similarities in the spectral energy distribution between DYPers and ordinary carbon stars. We also observed that DYPer circumstellar shells are fainter and hotter than those of RCBs. This suggests that DYPers may simply be ordinary carbon stars with ejection events, but more abundance analysis is necessary to give a status on a possible evolutionnary connexion between RCBs and DYPers., 22 pages, 38 figures, Accepted for publication in A&A

Published
2009
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25. The beat Cepheids in the Magellanic Clouds: an analysis from the EROS-2 database

Author

O. Perdereau, Alfred Vidal-Madjar, Bertrand Goldman, C. Loup, C. Hamadache, P. Tisserand, J. N. Albert, P. Bareyre, Jean-Philippe Beaulieu, E. Lesquoy, J. R. Buchler, X. Charlot, J. F. Glicenstein, Marc Moniez, Ch. Coutures, L. Le Guillou, Nathalie Palanque-Delabrouille, C. Afonso, E. Maurice, Éric Aubourg, J. Rich, A. Schwarzenberg-Czerny, J. de Kat, A. Milsztajn, M. Gros, Reza Ansari, Johannes Andersen, Michel Spiro, J. Haissinski, C. Magneville, Anaëlle Maury, Roger Ferlet, R. Szabó, S. Belghith, J. B. Marquette, David S. Graff, Andrew Gould, Y. R. Rahal, Pascal Fouqué, Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), Department of Astronomy (Ohio State University), Ohio State University [Columbus] (OSU), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Observatoire astronomique de Strasbourg (ObAS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), EROS-2, Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), and Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES)

Subjects
010504 meteorology & atmospheric sciences, Cepheid variable, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Metallicity, Population, FOS: Physical sciences, Astrophysics, Cepheids, Gravitational microlensing, 01 natural sciences, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], 0103 physical sciences, Magellanic Clouds, education, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, Physics, education.field_of_study, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Light curve, Galaxy, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Variable star
Abstract

A number of microlensing dark-matter surveys have produced tens of millions of light curves of individual background stars. These data provide an unprecedented opportunity for systematic studies of whole classes of variable stars and their host galaxies. We aim to use the EROS-2 survey of the Magellanic Clouds to detect and study the population of beat Cepheids (BCs) in both Clouds. BCs pulsating simultaneously in the first overtone and fundamental modes (FO/F) or in the second and first overtone modes (SO/FO) are of particular interest. Using special software designed to search for periodic variables, we have scanned the EROS-2 data base for variables in the typical period range of Cepheids. Metallicities of FO/F objects were then calculated from linear nonadiabatic convective stellar models. We identify 74 FO/F BCs in the LMC and 41 in the SMC, and 173 and 129 SO/FO pulsators in the LMC and SMC, respectively; 185 of these stars are new discoveries. For nearly all the FO/F objects we determine minimum, mean, and maximum values of the metallicity. The EROS data have expanded the samples of known BCs in the LMC by 31%, in the SMC by 110%. The FO/F objects provide independent measures of metallicities in these galaxies. The mean value of metallicity is 0.0045 in the LMC and 0.0018 in the SMC., Comment: 10 pages, 7 figures, accepted for publication in A&A

Published
2009
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26. The EROS2 search for microlensing events towards the spiral arms: the complete seven season results

Author

Christophe Magneville, P. Bareyre, J. de Kat, Roger Ferlet, Y. R. Rahal, E. Maurice, N. Palanque-Delabrouille, C. Hamadache, L. Le Guillou, F. Derue, Cristina Afonso, B. Mansoux, P. Fouque, M. Gros, Anaëlle Maury, F. Couchot, X. Charlot, C. Loup, Alfred Vidal-Madjar, J. F. Glicenstein, Sohrab Rahvar, E. Lesquoy, Jean-Philippe Beaulieu, Bertrand Goldman, P. Tisserand, J. Haissinski, C. Coutures, A. Milsztajn, D. Graff, J. N. Albert, O. Perdereau, Éric Aubourg, J. B. Marquette, R. Ansari, Jeffrey A. Rich, M. Moniez, Johannes Andersen, Michel Spiro, Andrew Gould, Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de l'Observatoire Midi-Pyrénées (LATT), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), Department of Astronomy (Ohio State University), Ohio State University [Columbus] (OSU), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Department of Physics [Tehran], Sharif University of Technology [Tehran] (SUT), EROS-2, Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES)

Subjects
Milky Way, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Gravitational microlensing, 01 natural sciences, Galaxy: bulge, Galaxy: disk, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Bulge, 0103 physical sciences, Thick disk, 010303 astronomy & astrophysics, Galaxy: structure, Astrophysics::Galaxy Astrophysics, Physics, Spiral galaxy, Galaxy: microlensing, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Galactic Center, Astronomy and Astrophysics, Galactic plane, Astrophysics - Astrophysics of Galaxies, Stars, Galaxy: spiral arms, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Cosmology: dark matter, Astrophysics::Earth and Planetary Astrophysics
Abstract

The EROS-2 project has been designed to search for microlensing events towards any dense stellar field. The densest parts of the Galactic spiral arms have been monitored to maximize the microlensing signal expected from the stars of the Galactic disk and bulge. 12.9 million stars have been monitored during 7 seasons towards 4 directions in the Galactic plane, away from the Galactic center. A total of 27 microlensing event candidates have been found. Estimates of the optical depths from the 22 best events are provided. A first order interpretation shows that simple Galactic models with a standard disk and an elongated bulge are in agreement with our observations. We find that the average microlensing optical depth towards the complete EROS-cataloged stars of the spiral arms is $\bar{\tau} =0.51\pm .13\times 10^{-6}$, a number that is stable when the selection criteria are moderately varied. As the EROS catalog is almost complete up to $I_C=18.5$, the optical depth estimated for the sub-sample of bright target stars with $I_C.11\times 10^{-6}$) is easier to interpret. The set of microlensing events that we have observed is consistent with a simple Galactic model. A more precise interpretation would require either a better knowledge of the distance distribution of the target stars, or a simulation based on a Galactic model. For this purpose, we define and discuss the concept of optical depth for a given catalog or for a limiting magnitude., Comment: 22 pages submitted to Astronomy & Astrophysics

Published
2009
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27. Discovery of a peculiar Cepheid-like star towards the northern edge of the Small Magellanic Cloud

Author

M. Gros, J. B. Marquette, Y. R. Rahal, E. Maurice, David S. Graff, J. de Kat, Andrew Gould, J. N. Albert, Pascal Fouqué, Alfred Vidal-Madjar, E. Lesquoy, V. Doublier, Patrick Tisserand, J. F. Glicenstein, Ch. Coutures, C. Hamadache, R. Ansari, L. Le Guillou, Roger Ferlet, P. Bareyre, Éric Aubourg, Anaëlle Maury, A. Schwarzenberg-Czerny, M. Moniez, Johannes Andersen, Michel Spiro, J. Pritchard, X. Charlot, J. Haissinski, J. Rich, A. Milsztajn, P. François, C. Magneville, Jean-Philippe Beaulieu, Bertrand Goldman, C. Afonso, Nathalie Palanque-Delabrouille, S. Zylberajch, O. Perdereau, C. Loup, Institut d'Astrophysique de Paris (IAP), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de l'Accélérateur Linéaire (LAL), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), ANR-06-BLAN-0416,HOLMES,HOLMES (Hunting cOol Low Mass Extrasolar PlanetS)(2006), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
Proper motion, Cepheid variable, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Metallicity, FOS: Physical sciences, Astrophysics, Cepheids, 01 natural sciences, Galaxy: disk, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], 0103 physical sciences, Magellanic Clouds, 010303 astronomy & astrophysics, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Astrophysics (astro-ph), stars: peculiar, Astronomy and Astrophysics, Astrometry, Light curve, Radial velocity, Space and Planetary Science, Small Magellanic Cloud, Variable star
Abstract

For seven years, the EROS-2 project obtained a mass of photometric data on variable stars. We present a peculiar Cepheid-like star, in the direction of the Small Magellanic Cloud, which demonstrates unusual photometric behaviour over a short time interval. We report on data of the photometry acquired by the MARLY telescope and spectroscopy from the EFOSC instrument for this star, called EROS2 J005135-714459(sm0060n13842), which resembles the unusual Cepheid HR 7308. The light curve of our target is analysed using the Analysis of Variance method to determine a pulsational period of 5.5675 days. A fit of time-dependent Fourier coefficients is performed and a search for proper motion is conducted. The light curve exhibits a previously unobserved and spectacular change in both mean magnitude and amplitude, which has no clear theoretical explanation. Our analysis of the spectrum implies a radial velocity of 104 km s$^{-1}$ and a metallicity of -0.4$\pm$0.2 dex. In the direction of right ascension, we measure a proper motion of 17.4$\pm$6.0 mas yr$^{-1}$ using EROS astrometry, which is compatible with data from the NOMAD catalogue. The nature of EROS2 J005135-714459(sm0060n13842) remains unclear. For this star, we may have detected a non-zero proper motion for this star, which would imply that it is a foreground object. Its radial velocity, pulsational characteristics, and photometric data, however, suggest that it is instead a Cepheid-like object located in the SMC. In such a case, it would present a challenge to conventional Cepheid models., Comment: Correction of typos in the abstract

Published
2008
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28. R Coronae Borealis stars in the Galactic Bulge discovered by EROS-2

Author

Johannes Andersen, Michel Spiro, Bertrand Goldman, M. Gros, A. Milsztajn, J. N. Albert, Nathalie Palanque-Delabrouille, S. Zylberajch, L. Le Guillou, O. Perdereau, J. de Kat, Anaëlle Maury, P. Bareyre, E. Maurice, Patrick Tisserand, M. Moniez, C. Hamadache, Peter R. Wood, Jean-Philippe Beaulieu, Roger Ferlet, Éric Aubourg, Andrew Gould, J. B. Marquette, R. Ansari, C. Magneville, C. Afonso, J. Rich, Alfred Vidal-Madjar, Y. R. Rahal, Pascal Fouqué, J. F. Glicenstein, Ch. Coutures, X. Charlot, E. Lesquoy, J. Haissinski, C. Loup, Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Département de Physique des Particules (ex SPP) (DPhP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), APC - Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Service Détecteurs (SERVICE DéTECTEURS), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Services communs OMP (UMS 831), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), EROS-2, Département de Physique des Particules (ex SPP) (DPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Physique Corpusculaire et Cosmologie - Collège de France (PCC), Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-AstroParticule et Cosmologie (APC (UMR_7164)), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Services communs OMP - UMS 831 (UMS 831), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Toulouse III - Paul Sabatier (UT3), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Gravitational microlensing, 01 natural sciences, Luminosity, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Bulge, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Stellar evolution, Astrophysics::Galaxy Astrophysics, Physics, Spiral galaxy, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Astrophysics (astro-ph), Astronomy and Astrophysics, Stars, Space and Planetary Science, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, Variable star, Supergiant
Abstract

Rare types of variable star may give unique insight into short-lived stages of stellar evolution. The systematic monitoring of millions of stars and advanced light curve analysis techniques of microlensing surveys make them ideal for discovering also such rare variable stars. One example is the R Coronae Borealis (RCB) stars, a rare type of evolved carbon-rich supergiant. We have conducted a systematic search of the EROS-2 database for the Galactic catalogue Bulge and spiral arms to find Galactic RCB stars. The light curves of $\sim$100 million stars, monitored for 6.7 years (from July 1996 to February 2003), have been analysed to search for the main signature of RCB stars, large and rapid drops in luminosity. Follow-up spectroscopy has been used to confirm the photometric candidates. We have discovered 14 new RCB stars, all in the direction of the Galactic Bulge, bringing the total number of confirmed Galactic RCB stars to about 51. After reddening correction, the colours and absolute magnitudes of at least 9 of the stars are similar to those of Magellanic RCB stars. This suggests that these stars are in fact located in the Galactic Bulge, making them the first RCB stars discovered in the Bulge. The localisation of the 5 remaining RCBs is more uncertain: 4 are either located behind the Bulge at an estimated maximum distance of 14 kpc or have an unusual thick circumstellar shell; the other is a DY Per RCB which may be located in the Bulge, even if it is fainter than the known Magellanic DY Per. From the small scale height found using the 9 new Bulge RCBs, $61, Comment: 20 pages, 26 figures, Accepted in A&A

Published
2008
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29. The Master Catalogue of Stars Towards the Magellanic Clouds

Author

N. Delmotte, C. Loup, Maria-Rosa L. Cioni, F. Pierfederici, and Daniel Egret

Subjects
Stars, Computer science, Astronomy, Context (language use), European commission, Virtual observatory
Abstract

The Master Catalogue of stars towards the Magellanic Clouds (MC2) is a multi-wavelength reference catalogue. We performed a systematic cross-matching of the DENIS (3) Catalogue towards the Magellanic Clouds (DCMC) (1) with 2MASS (4) and the optical (GSC-II 1 , UCAC1 (6)) catalogues. It provides an unprecedented wealth of data on the stellar populations of the Magellanic Clouds (MCs). New cross-matching procedures for very large catalogues have been developed and detailed results on the astrometric and photometric accuracy of the cross-identified catalogues were derived. The cross-matching of large surveys is an essential tool to improve our understanding of their specific contents in the Virtual Observatory context. This study has been partly supported by astrovirtel 2 , a project that aims at improving access to astronomical archives as virtual telescopes, and funded by the European Commission under FP5 Contract No. HPRI-CT-1999-00081.

Published
2006
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30. Galactic Bulge Microlensing Optical Depth from EROS-2

Author

J. B. Marquette, L. Le Guillou, P. Bareyre, E. Maurice, C. Magneville, Y. R. Rahal, P. Tisserand, J. Rich, C. Hamadache, A. Milsztajn, J. N. Albert, Roger Ferlet, Bertrand Goldman, E. Lesquoy, David S. Graff, Johannes Andersen, Michel Spiro, Andrew Gould, Jean-Philippe Beaulieu, X. Charlot, C. Loup, J. Haissinski, Anaëlle Maury, Pascal Fouqué, J. F. Glicenstein, Ch. Coutures, Reza Ansari, O. Perdereau, L. Vigroux, C. Afonso, Marc Moniez, M. Gros, Nathalie Palanque-Delabrouille, S. Zylberajch, Alfred Vidal-Madjar, Éric Aubourg, J. de Kat, Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de l'Accélérateur Linéaire (LAL), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut d'Astrophysique de Paris (IAP), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), EROS, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)

Subjects
FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Gravitational microlensing, 01 natural sciences, Einstein radius, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Bulge, 0103 physical sciences, Optical depth (astrophysics), Galaxy:stellar contents, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Galaxy:bar, Physics, Cosmology:gravitational lensing, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Astrophysics (astro-ph), Astronomy and Astrophysics, Light curve, Galaxy:structure, Stars, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics
Abstract

We present a new EROS-2 measurement of the microlensing optical depth toward the Galactic Bulge. Light curves of $5.6\times 10^{6}$ clump-giant stars distributed over $66 \deg^2$ of the Bulge were monitored during seven Bulge seasons. 120 events were found with apparent amplifications greater than 1.6 and Einstein radius crossing times in the range $5 {\rm d}, Comment: accepted A&A, minor revisions

Published
2006
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31. The OGLE-II event sc5_2859 : a Classical Nova outburst?

Author

C. Afonso, J. F. Glicenstein, A. Gould, M. C. Smith, R. M. Wagner, J. N. Albert, J. Andersen, R. Ansari, É. Aubourg, P. Bareyre, J. P. Beaulieu, G. Blanc, X. Charlot, C. Coutures, R. Ferlet, P. Fouqué, B. Goldman, D. Graff, M. Gros, J. Haissinski, C. Hamadache, J. de Kat, L. LeGuillou, É. Lesquoy, C. Loup, C. Magneville, J. B. Marquette, É. Maurice, A. Maury, A. Milsztajn, M. Moniez, N. Palanque-Delabrouille, O. Perdereau, L. Prévot, Y. R. Rahal, J. Rich, M. Spiro, P. Tisserand, A. Vidal-Madjar, L. Vigroux, S. Zylberajch, Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Services communs OMP (UMS 831), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), EROS, Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Astronomy, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Services communs OMP - UMS 831 (UMS 831), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées

Subjects
stars : novae, cataclysmic variables, MACHO PROJECT, 010504 meteorology & atmospheric sciences, Event (relativity), GRAVITATIONAL LENSING EXPERIMENT, Gravitational lensing, FOS: Physical sciences, Astrophysics, Gravitational microlensing, 01 natural sciences, Galaxy : stellar contents, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], 0103 physical sciences, Galaxy:stellar contents, Emission spectrum, 010303 astronomy & astrophysics, BLACK-HOLES, 0105 earth and related environmental sciences, Physics, cataclysmic variables, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], MICROLENSING OPTICAL DEPTH, Astrophysics (astro-ph), Astronomy and Astrophysics, Light curve, DIFFERENCE IMAGE-ANALYSIS, CATALOG, Nova (rocket), GALACTIC BULGE FIELDS, Space and Planetary Science, stars : novae, novæ
Abstract

The OGLE-II event sc5_2859 was previously identified as the third longest microlensing event ever observed. Additional photometric observations from the EROS (Experience de Recherche d'Objets Sombres) survey and spectroscopic observations of the candidate star are used to test the microlensing hypothesis.The combined OGLE and EROS data provide a high quality coverage of the light curve. The colour of the sc5_2859 event is seen to change with time. A spectrum taken in 2003 exhibits a strong Halpha emission line. The additionnal data show that the OGLE-II sc5_2859 event is actually a classical nova outburst., Comment: Accepted for publication in Astronomy and Astrophysics

Published
2006
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32. Experimental Failure Mode Determination of GRP/PVC-Foam Sandwich T-Joints

Author

A.W.J. Gielen, Douglas C. Loup, and Wim Trouwborst

Subjects
Materials science, business.industry, Dynamic loading, Mechanical strength, Collapse (topology), Structural engineering, business, Focus (optics), Failure mode and effects analysis, Static loading
Abstract

Application of GRP/PVC-Foam sandwich structures on naval ships strongly depends on the mechanical strength and collapse behaviour of the joints of the structure. Quasi-static and dynamic experiments were executed to determine the failure modes and failure progression of T-joints. The results were used to determine the focus of the material tests, and to determine the main properties of failure models that were developed.

Published
2005
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33. An empirical formula for the mass-loss rates of dust-enshrouded red supergiants and oxygen-rich Asymptotic Giant Branch stars

Author

Albert A. Zijlstra, Jacco Th. van Loon, C. Loup, and Maria-Rosa L. Cioni

Subjects
Physics, Metallicity, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Effective temperature, Stellar classification, Luminosity, Stars, Space and Planetary Science, Asymptotic giant branch, Astrophysics::Solar and Stellar Astrophysics, Red supergiant, Astrophysics::Earth and Planetary Astrophysics, Large Magellanic Cloud, Astrophysics::Galaxy Astrophysics
Abstract

We present an empirical determination of the mass-loss rate as a function of stellar luminosity and effective temperature, for oxygen-rich dust-enshrouded Asymptotic Giant Branch stars and red supergiants. To this aim we obtained optical spectra of a sample of dust-enshrouded red giants in the Large Magellanic Cloud, which we complemented with spectroscopic and infrared photometric data from the literature. Two of these turned out to be hot emission-line stars, of which one is a definite B[e] star. The mass-loss rates were measured through modelling of the spectral energy distributions. We thus obtain the mass-loss rate formula log Mdot = -5.65 + 1.05 log(L / 10,000 Lsun) -6.3 log(Teff / 3500 K), valid for dust-enshrouded red supergiants and oxygen-rich AGB stars. Despite the low metallicity of the LMC, both AGB stars and red supergiants are found at late spectral types. A comparison with galactic AGB stars and red supergiants shows excellent agreement between the mass-loss rate as predicted by our formula and that derived from the 60 micron flux density for dust-enshrouded objects, but not for optically bright objects. We discuss the possible implications of this for the mass-loss mechanism., Accepted for publication in Astronomy and Astrophysics, 17 pages including figures

Published
2005

34. ESO-VLT and Spitzer spectroscopy of IRAS05328-6827: a massive young stellar object in the Large Magellanic Cloud

Author

Laurentius Waters, Greg Sloan, Sacha Hony, Martin Groenewegen, M. R. L. Cioni, Patricia A. Whitelock, Peter R. Wood, J. A. D. L. Blommaert, Jacco Th. van Loon, Mikako Matsuura, A. A. Zijlstra, C. Loup, and Joana M. Oliveira

Subjects
Physics, Metallicity, Young stellar object, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Spectral line, Space and Planetary Science, Spectral energy distribution, Astrophysics::Solar and Stellar Astrophysics, Water ice, Astrophysics::Earth and Planetary Astrophysics, Spectroscopy, Large Magellanic Cloud, Astrophysics::Galaxy Astrophysics
Abstract

We present the first thermal-infrared spectra of an extra-galactic Young Stellar Object (YSO), IRAS05328-6827 in the HII region LHA 120-N148 in the Large Magellanic Cloud. The observed and modelled spectral energy distribution reveals a massive YSO, M=20 Msun, which is heavily-embedded and probably still accreting. The reduced dust content as a consequence of the lower metallicity of the LMC allows a unique view into this object, and together with a high C/O ratio may be responsible for the observed low abundance of water ice and relatively high abundances of methanol and CO2 ices., Comment: Accepted for publication in MNRAS Letters. 5 pages, 5 figures

Published
2005
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35. Type Ia supernova rate at a redshift of ~ 0.1

Author

A. Milsztajn, F. Derue, G. Garavini, A. Kim, Tomas Dahlen, C. Magneville, Ariel Goobar, Gastón Folatelli, Alexis Amadon, P. Tisserand, C. Loup, E. Maurice, Nicholas A. Walton, C. Afonso, Y. R. Rahal, Guillermo A. Blanc, S. Nobili, D. Hardin, Heidi Jo Newberg, J. F. Glicenstein, L. Prevot, Johannes Andersen, Michel Spiro, Ch. Coutures, Nathalie Palanque-Delabrouille, Bertrand Goldman, C. Hamadache, Jean-Philippe Beaulieu, Anaëlle Maury, S. Zylberajch, P. Bareyre, Thierry Lasserre, L. LeGuillou, Roger Ferlet, O. Perdereau, J. N. Albert, Pascal Fouqué, J. B. Marquette, Xiaohui Fan, Alex Conley, C. Alard, R. Ansari, J. deKat, Alfred Vidal-Madjar, David S. Graff, J. Rich, M. Mouchet, Christophe Balland, Éric Aubourg, Nicolas Regnault, I. M. Hook, L. Vigroux, Pilar Ruiz-Lapuente, X. Charlot, M. Gros, Andrew Gould, Greg Aldering, Stephen M. Kent, M. Moniez, J. Haissinski, E. Lesquoy, Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Physique Corpusculaire et Cosmologie - Collège de France (PCC), Collège de France (CdF (institution))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Accélérateur Linéaire (LAL), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Pierre et Marie Curie - Paris 6 (UPMC), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Services communs OMP (UMS 831), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Théories (LUTH (UMR_8102)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire Leprince-Ringuet (LLR), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), EROS, Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Services communs OMP - UMS 831 (UMS 831), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Supernova, 010308 nuclear & particles physics, Monte Carlo method, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Type (model theory), 01 natural sciences, Redshift, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Space and Planetary Science, Rate measurement, 0103 physical sciences, 010303 astronomy & astrophysics
Abstract

We present the type Ia rate measurement based on two EROS supernova search campaigns (in 1999 and 2000). Sixteen supernovae identified as type Ia were discovered. The measurement of the detection efficiency, using a Monte Carlo simulation, provides the type Ia supernova explosion rate at a redshift ~ 0.13. The result is $0.125^{+0.044+0.028}_{-0.034-0.028} h_{70}^2$ SNu where 1 SNu = 1 SN / $10^{10} L_{sun}^B$ / century. This value is compatible with the previous EROS measurement (Hardin et al. 2000), done with a much smaller sample, at a similar redshift. Comparison with other values at different redshifts suggests an evolution of the type Ia supernova rate., Comment: Accepted for publication in Astronomy & Astrophysics (15 pages, 16 figures)

Published
2004
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36. On the usefulness of finding charts Or the runaway carbon stars of the Blanco & McCarthy field 37

Author

C. Loup, N. Delmotte, Françoise Genova, M. R. L. Cioni, and Daniel Egret

Subjects
Physics, Information retrieval, media_common.quotation_subject, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Field (computer science), Identification (information), Surprise, Space and Planetary Science, Sky, media_common
Abstract

We have been recently faced with the problem of cross--identifying stars recorded in historical catalogues with those extracted from recent fully digitized surveys (such as DENIS and 2MASS). Positions mentioned in the old catalogues are frequently of poor precision, but are generally accompanied by finding charts where the interesting objects are flagged. Those finding charts are sometimes our only link with the accumulated knowledge of past literature. While checking the identification of some of these objects in several catalogues, we had the surprise to discover a number of discrepancies in recent works.The main reason for these discrepancies was generally the blind application of the smallest difference in position as the criterion to identify sources from one historical catalogue to those in more recent surveys. In this paper we give examples of such misidentifications, and show how we were able to find and correct them.We present modern procedures to discover and solve cross--identification problems, such as loading digitized images of the sky through the Aladin service at CDS, and overlaying entries from historical catalogues and modern surveys. We conclude that the use of good finding charts still remains the ultimate (though time--consuming) tool to ascertain cross--identifications in difficult cases., Comment: 4 pages, 1 figure, accepted by A&A

Published
2003
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37. Limits on Galactic Dark Matter with 5 Years of EROS SMC Data

Author

C. Hamadache, L. Le Guillou, P. Fouque, Alfred Vidal-Madjar, Y. R. Rahal, L. Prevot, Andrew Gould, F. Couchot, R. Ansari, J. F. Glicenstein, Ch. Coutures, E. Maurice, P. Tisserand, Christophe Magneville, Thierry Lasserre, S. Zylberajch, David S. Graff, Jean-Philippe Beaulieu, É. Lesquoy, X. Charlot, Anaëlle Maury, J. Rich, C. Loup, C. Afonso, J. N. Albert, Roger Ferlet, Bertrand Goldman, M. Moniez, P. Bareyre, G. Blanc, J. Haissinski, A. Milsztajn, M. Gros, Éric Aubourg, J. B. Marquette, Nathalie Palanque-Delabrouille, O. Perdereau, J. de Kat, L. Vigroux, Johannes Andersen, Michel Spiro, Physique Corpusculaire et Cosmologie - Collège de France (PCC), Collège de France (CdF (institution))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), EROS, Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), and Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)

Subjects
Physics, education.field_of_study, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Dark matter, Population, Astrophysics (astro-ph), Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Gravitational microlensing, 01 natural sciences, Cosmology, Galactic halo, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Gravitational lens, Space and Planetary Science, 0103 physical sciences, Halo, Small Magellanic Cloud, education, 010303 astronomy & astrophysics
Abstract

Five years of EROS data towards the Small Magellanic Cloud have been searched for gravitational microlensing events, using a new, more accurate method to assess the impact of stellar blending on the efficiency. Four long-duration candidates have been found which, if they are microlensing events, hint at a non-halo population of lenses. Combined with results from other EROS observation programs, this analysis yields strong limits on the amount of Galactic dark matter made of compact objects. Less than 25% of a standard halo can be composed of objects with a mass between 2 10^-7 Msol and 1 Msol at the 95% C.L., 6 pages, 3 figures. Accepted for publication in A&A

Published
2003
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38. The Master Catalogue of stars towards the Magellanic Clouds. I. Multispectral surveys of the Large Magellanic Cloud

Author

F. Pierfederici, N. Delmotte, Daniel Egret, Maria-Rosa L. Cioni, and C. Loup

Subjects
Physics, Stars, Optical wavelength, Space and Planetary Science, Sky, Point source, media_common.quotation_subject, Astronomy, Astronomy and Astrophysics, Astrophysics, media_common
Abstract

The Master Catalogue of stars towards the Magellanic Clouds (MC2) is a multi-wavelength reference catalogue. The current paper presents the first results of the MC2 project. We started with a massive cross-identification of the two recently released near-infrared surveys: the DENIS Catalogue towards the Magellanic Clouds (DCMC) with more than 1.3 million sources identified in at least two of the three DENIS filters (I J Ks) and the 2nd Incremental Release of the 2MASS point source catalogue (J H Ks) covering the same region of the sky. Both point source catalogues provide an unprecedented wealth of data on the stellar populations of the Magellanic Clouds (MCs). The cross-matching procedure has been extended to optical wavelength ranges, including the UCAC1 (USNO) and GSC2.2 catalogues. New cross-matching procedures for very large catalogues have been developed and important results on the astrometric and photometric accuracy of the cross-identified catalogues were derived. The cross-matching of large surveys is an essential tool to improve our understanding of their specific contents. This study has been partly supported by the ASTROVIRTEL project that aims at improving access to astronomical archives as virtual telescopes.

Published
2002

39. An overview of the land subsidence phenomena occurring in Greece, triggered by the overexploitation of the aquifers for irrigation and mining purposes

Author

C. Loupasakis

Subjects
Environmental sciences, GE1-350, Geology, QE1-996.5
Abstract

Land subsidence caused by overexploitation of aquifers manifests with an increasing frequency in several regions of Greece. The first signs of land subsidence have been identified since 1965 at the west side of Thessaloniki (broader Kalochori village region), in the form of a progressive marine invasion. Since then several areas have been investigated and proved to be affected mainly by the overexploitation of the aquifers. The Multidisciplinary nature of the subsidence mechanism combining the geological, hydrogeological and morphological setting of the areas with the human activities and the land use data makes their study complicated and require the intervention of multiple scientific specialties. Furthermore, at several sites, beside ground truth data, the land subsidence trends and extends have been also identified via multi-temporal InSAR techniques, such as PSI and SBAS techniques. Among the sites to be presented in the current paper is the wider area of Kalochori village in the eastern part of Thessaloniki plain, the east and west Thessaly plain in central Greece and the region extending to the west–southwest of the Amyntaio opencast coalmine in West Macedonia.

Published
2020
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40. Cross-matching DENIS and 2MASS point sources toward the Magellanic Clouds

Author

Maria-Rosa L. Cioni, C. Loup, N. Delmotte, and Daniel Egret

Subjects
Physics, Stars, Cross matching, Point (typography), Point source, Sky, media_common.quotation_subject, Astrophysics, Virtual observatory, media_common
Abstract

The recent publications of the DENIS Catalogue towards the Magellanic Clouds (MCs) with more than 1.3 million sources identified in at least two of the three DENIS filters (I J K_s) and of the incremental releases of the 2MASS point source catalogues (J H K_s) covering the same region of the sky, provide an unprecedented wealth of data related to stellar populations in the MCs. In order to build a reference catalogue of stars towards the Magellanic Clouds, we have performed a cross-identification of these two catalogues. This implied developing new tools for cross-identification and data mining. This study is partly supported by the Astrovirtel program that aims at improving access to astronomical archives as virtual telescopes. The main goal of the present study is to validate new cross-matching procedures for very large catalogues, and to derive results concerning the astrometric and photometric accuracy of these catalogues. The cross-matching of large surveys is an essential tool to improve our understanding of their specific contents. This approach can be considered as a new step towards a Virtual Observatory.

Published
2001
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41. Blue irregular variable stars in the Small Magellanic Cloud from EROS2 : Herbig Ae/Be or classical Be stars ?

Author

Alfred Vidal-Madjar, F. Derue, Roger Ferlet, Marc Moniez, Bertrand Goldman, F. Bauer, S. Totor, C. Afonso, Jean-Christophe Hamilton, L. Prevot, J. Rich, C. Loup, David S. Graff, S. Zylberajch, W. J. de Wit, E. Maurice, Pascal Fouqué, J. F. Glicenstein, Ch. Coutures, Reza Ansari, F. Couchot, O. Perdereau, J. N. Albert, G. Blanc, Éric Aubourg, J. B. Marquette, J. P. Beaulieu, H. J. G. L. M. Lamers, J. Haissinski, Christophe Magneville, B. Mansoux, J. de Kat, Nathalie Palanque-Delabrouille, É. Lesquoy, N. Regnault, L. Vigroux, P. Bareyre, X. Charlot, M. Gros, P. Leisy, T. Lasserre, A. Milsztajn, Johannes Andersen, Michel Spiro, C. Alard, D. Hardin, Departement de recherche SPAtiale (DESPA), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Laboratoire de l'Accélérateur Linéaire (LAL), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Physique Corpusculaire et Cosmologie - Collège de France (PCC), Collège de France (CdF (institution))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), EROS, Lantz, Simone, and Fouqué, Pascal

Subjects
Physics, 010308 nuclear & particles physics, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Gravitational microlensing, 01 natural sciences, Accretion (astrophysics), Luminosity, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Stars, Gravitational lens, [PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Space and Planetary Science, 0103 physical sciences, Small Magellanic Cloud, Emission spectrum, Variable star, 010303 astronomy & astrophysics
Abstract

Using data from the EROS2 microlensing survey, we report the discovery of two blue objects with irregular photometric behaviour of $\Delta V \sim 0.1$-0.4 mag on time scales of 20 to 200 days. They show a bluer when fainter behaviour. Subsequent spectra taken with the ESO 3.6m telescope show spectral type B4eIII and B2eIV-V with strong $H \alpha$ emission. These objects resemble the Herbig AeBe but also classical Be stars. At this stage, it is not possible to distinguish unambiguously between pre-main sequence and classical Be nature. If we favour the pre-main sequence interpretation, they are more luminous than the luminosity upper limit for Galactic HAeBe stars. The same was found for the HAeBe candidates in the LMC. This might be due to a shorter accretion time scale ($\tau = M_*/\dot{M}$), or the smaller dust content during the pre-main sequence evolution of SMC and LMC stars., Comment: : 9 pages, LaTeX, 7 figures. Accepted for publications in AA

Published
2001

42. The peculiar cluster HS 327 in the Large Magellanic Cloud: can OH/IR stars and carbon stars be twins?

Author

Jacco Th. van Loon, C. Loup, Gerry Gilmore, Lex Kaper, J. A. D. L. Blommaert, A. A. Zijlstra, and Low Energy Astrophysics (API, FNWI)

Subjects
Physics, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Star (graph theory), Carbon star, Spectral line, Luminosity, Stars, Space and Planetary Science, Cluster (physics), Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Large Magellanic Cloud, Stellar evolution, Astrophysics::Galaxy Astrophysics
Abstract

The obscured OH/IR star IRAS05298-6957 in the LMC was recently noticed to be member of the small double cluster HS 327 that also contains a carbon star (van Loon et al., 1998, A&A 329, 169). Hence they are coeval and have (nearly) the same progenitor mass, which can only be understood if Hot Bottom Burning (HBB) has prevented IRAS05298-6957 from being a carbon star. We present extensive visual and near-IR photometric data for >10^4 stars in and around HS 327, and spectroscopic data for some of the brightest AGB stars amongst these. Colour-magnitude diagrams are used to estimate the age for the cluster and its members, and luminosities are derived for the stars for which spectra have been obtained. The age for IRAS05298-6957 and the carbon star is estimated to be about 200 Myr. This corresponds to a Main-Sequence progenitor mass of about 4.0 M_sun --- the first direct measurement of the lower mass threshold for HBB. This agrees with stellar evolution models that, however, fail to reproduce the low luminosity of the carbon star., 11 pages (better quality Figs 1b & 9 on request from jacco@ast.cam.ac.uk). Accepted for publication in Astronomy and Astrophysics Main Journal

Published
2001

43. Observation of microlensing toward the galactic spiral arms. EROS II 3 year survey

Author

Franz E. Bauer, A. Milsztajn, N. Regnault, A. Bouquet, Cristina Afonso, X. Charlot, T. Lasserre, J. Haissinski, J. Rich, A. Kim, F. Couchot, David S. Graff, Johannes Andersen, Michel Spiro, J. de Kat, Roger Ferlet, S. Zylberajch, Andrew Gould, C. Loup, D. Hardin, G. Blanc, Marc Moniez, J. P. Beaulieu, L. Vigroux, Christophe Magneville, E. Maurice, Éric Aubourg, J. B. Marquette, M. Gros, Jean-Christophe Hamilton, C. Alard, J. F. Glicenstein, C. Coutures, O. Perdereau, N. Palanque-Delabrouille, L. Le Guillou, P. Fouque, Bertrand Goldman, P. Bareyre, L. Prevot, Alfred Vidal-Madjar, F. Derue, E. Lesquoy, S. Char, B. Mansoux, Reza Ansari, J. N. Albert, Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Paris, Université Paris sciences et lettres (PSL), Physique Corpusculaire et Cosmologie - Collège de France (PCC), Collège de France (CdF (institution))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Departement de recherche SPAtiale (DESPA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Observatoire Astronomique de Marseille Provence (OAMP), Université de Provence - Aix-Marseille 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and EROS

Subjects
Physics, GALAXY: KINEMATICS AND DYNAMICS, Spiral galaxy, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, GRAVITATIONAL LENSING, Galactic plane, Gravitational microlensing, Galactic tide, Galaxy, Galactic halo, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Space and Planetary Science, Bulge, Galactic corona, Astrophysics::Earth and Planetary Astrophysics, GALAXY: STELLAR CONTENT, GALAXY: STRUCTURE, Astrophysics::Galaxy Astrophysics, GALAXY: BAR
Abstract

International audience; We present an analysis of the light curves of 9.1 million stars observed during three seasons by EROS (Expérience de Recherche d'Objets Sombres), in the Galactic plane away from the bulge. Seven stars exhibit luminosity variations compatible with gravitational microlensing effects due to unseen objects. The corresponding optical depth, averaged over four directions, is bar tau = 0.43 +/- 0.2\ x\ 10-6. While this value is compatible with expectations from simple Galactic models under reasonable assumptions on the target star distances, we find an excess of events with short timescales toward the direction closest to the Galactic centre. We discuss a possible interpretation involving the contribution of an elongated bar. This work is based on observations made with the MARLY telescope at the European Southern Observatory, La Silla, Chile.

Published
2001
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44. Targeting of a hydrophilic photosensitizer by use of internalizing monoclonal antibodies: A new possibility for use in photodynamic therapy

Author

M B, Vrouenraets, G W, Visser, C, Loup, B, Meunier, M, Stigter, H, Oppelaar, F A, Stewart, G B, Snow, and G A, van Dongen

Subjects
Immunoconjugates, Photosensitizing Agents, Porphyrins, Antibodies, Monoclonal, Mice, Nude, Iodine Radioisotopes, Mice, Photochemotherapy, Head and Neck Neoplasms, Isotope Labeling, Carcinoma, Squamous Cell, Tumor Cells, Cultured, Animals, Humans, Electrophoresis, Polyacrylamide Gel, Tissue Distribution, Chromatography, High Pressure Liquid, Neoplasm Transplantation
Abstract

Coupling of photosensitizers to tumor-selective monoclonal antibodies (MAbs) is an attractive option for improving the selectivity of photodynamic therapy (PDT). For this purpose, hydrophilic sensitizers would be most suitable because of their solubility in water. However, such sensitizers are known to be ineffective in PDT, probably because they cannot readily pass the cell membrane and reach the critical intracellular target. We used the model compound TrisMPyP-PhiCO(2)H, a hydrophilic porphyrin derivative, to test the hypothesis that hydrophilic photosensitizers might become of therapeutic value when directed into the tumor cell by use of internalizing MAbs. TrisMPyP-PhiCO(2)H was conjugated using a labile ester. Conjugates showed no impairment of integrity on SDS-PAGE, full stability in serum in vitro, and optimal immunoreactivity when the sensitizer:MAb ratio was/=3. At higher molar ratios, the solubility of the conjugates decreased. In vitro internalization experiments showed that TrisMPyP-PhiCONH-(125)I-cMAb U36 and TrisMPyPPhiCONH-(125)I-mMAb 425 conjugates were internalized by A431 cells, in contrast to TrisMPyP-PhiCONH-(125)I-mMAb E48 conjugates. Data on the in vitro efficacy of PDT with MAb-conjugated TrisMPyP-PhiCO(2)H showed that the internalizing cMAb U36 and mMAb 425 conjugates were phototoxic to A431 cells, while the non-internalizing E48 conjugate and the unconjugated sensitizer were not. Biodistribution data of conjugates with sensitizer:(125)I-cMAb U36 ratios varying from 1:1 to 3:1 in tumor-bearing nude mice revealed selective accumulation in the tumor. Conjugates with higher molar ratios were cleared more rapidly from the blood than the unconjugated (125)I-cMAb U36, resulting in lower tumor uptake but similar tumor-to-blood ratios. Our data suggest that hydrophilic photosensitizers might have therapeutic value when targeted to tumors by internalizing MAbs.

Published
2000

45. The DENIS Point Source Catalogue towards the Magellanic Clouds

Author

J. Borsenberger, Thierry Forveille, Francois Lacombe, C. Loup, Annie C. Robin, N. Epchtein, M. R. L. Cioni, E. Deul, Stefan Kimeswenger, Daniel Egret, Emmanuel Bertin, Stefan Wagner, Alain Omont, Gary A. Mamon, Daniel Rouan, Josef Hron, C. Alard, T. Le Bertre, B. de Batz, Francisco Garzón, Paolo Persi, Grégory Simon, Pascal Fouqué, D. Tiphène, M. Dennefeld, Isabelle Vauglin, G. Paturel, Harm J. Habing, Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire astronomique de Strasbourg (OAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Observatoire de Paris - Site de Paris (OP), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)

Subjects
stars, magellanic clouds -galaxies, Point source, Epoch (astronomy), media_common.quotation_subject, General Physics and Astronomy, FOS: Physical sciences, Astrophysics, photometry -galaxies, 01 natural sciences, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], 0103 physical sciences, Asymptotic giant branch, Large Magellanic Cloud, catalogs -surveys -galaxies, 010303 astronomy & astrophysics, media_common, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Near-infrared spectroscopy, Astrophysics (astro-ph), stellar content -infrared, Stars, 13. Climate action, Sky, Small Magellanic Cloud
Abstract

We have compiled the near infrared Point Source Catalogue (PSC) towards the Magellanic Clouds (MCs) extracted from the data obtained with the Deep Near Infrared Survey of the Southern Sky - DENIS (Epchtein et al. 1997). The catalogue covers an area of of 19.87* 16 square degrees centered on (RA, DEC)=(5h27m20s, -69o00'00'') for the Large Magellanic Cloud (LMC) and 14.7* 10 square degrees centered on (RA, DEC)=(h02m40s, -73o00'00'' for the Small Magellanic Cloud (SMC) at the epoch J2000. It contains about 1300000 sources towards the LMC and 300000 sources towards the SMC each detected in at least 2 of the 3 photometric bands involved in the survey (I, J, Ks). 70% of the detected sources are true members of the Magellanic Clouds, respectively and consist mainly of red giants, asymptotic giant branch stars and super-giants. The observations have all been made with the same instrument and the data have been calibrated and reduced uniformly. The catalogue provides a homogeneous set of photometric data., 1 figure changed, published

Published
2000
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46. An absolute calibration of DENIS (deep near infrared southern sky survey)

Author

E. Copet, G. Paturel, E. Galliano, Daniel Rouan, Annie C. Robin, P. Persi, Maria-Rosa L. Cioni, M. Schultheis, E. Deul, Alain Omont, Harm J. Habing, D. Tiphène, Daniel Egret, Emmanuel Bertin, Gary A. Mamon, C. Loup, L. Chevallier, Michel Dennefeld, Stefan Kimeswenger, Martin Cohen, S. Derriere, T. Forveille, I. Vauglin, Stefan Wagner, T. Le Bertre, Francois Lacombe, B. de Batz, Josef Hron, Francisco Garzón, S. Pau, Pascal Fouqué, G. Simon, Pierre-Alain Duc, J. Borsenberger, Christophe Alard, N. Epchtein, Departement de recherche SPAtiale (DESPA), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL), Observatoire astronomique de Strasbourg (ObAS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, INFRARED: GENERAL, media_common.quotation_subject, Detector, Near-infrared spectroscopy, Astrophysics::Instrumentation and Methods for Astrophysics, Vega, General Physics and Astronomy, Astrophysics, law.invention, Telescope, Atmosphere, Wavelength, INSTRUMENTATION: MISCELLANEOUS, Sky, law, [SDU]Sciences of the Universe [physics], Magnitude (astronomy), SURVEYS, media_common, Remote sensing
Abstract

International audience; An absolute calibration of the DENIS photometric system is presented. It includes the determination of the overall transmission profiles in the 3 bands, namely i, J and K_s, combining contributions from atmosphere, telescope mirrors, instrument lenses and dichroics, filters, and detectors. From these normalized profiles, isophotal and effective wavelengths are computed, using the same synthetic Vega spectrum as that used to support the absolute calibration of many other ground-based and spaceborne photometric systems. Flux densities at zero magnitude are derived and integrated to give in-band fluxes, which are used to compute theoretical zero-points and compare them to observed ones, yielding estimates of the overall throughput of the whole system.

Published
2000
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47. DENIS Survey of AGB and Tip-RGB Stars in the LMC Bar West and Optical Center Fields

Author

E. Bertin, C. Loup, P. Fouque, N. Epchtein, and P. A. Duc

Subjects
Red-giant branch, Physics, Distance modulus, Stars, Diagram, Astrophysics, Large Magellanic Cloud, Stellar classification, Bar (unit), Luminosity
Abstract

We have observed with the DENIS instrument two regions of 22’ × 23’, located in the Bar of the LMC, and overlapping the Bar West and Optical Center fields studied by Blanco et al. (1980, BMB) in a prism-objective survey. Observations were performed simultaneously in the I, J, and K S bands. There were 376 AGB stars identified in previous studies in these 2 fields. We typically find back 97% of them in the DENIS data. We show that the BMB’s M and C stars follow two different sequences in the (I–J,J–K S ) colour-colour diagram. For M stars, the [I–J] colour is an indicator of the M subtype, increasing from 0.9 to 1.8 as one goes from MO to M7 spectral types, while the [J–K S ] colour remains almost constant (from 1.0 to 1.35). Conversely, C stars are located on a “reddening” branch, with [J–K S ] ranging from 1.0 to about 2.2. M and C stars discovered by BMB have no or faint mass-loss. The (I–J,J–K S ) diagram allows to define a simple criterion to select stars of spectral types M and C. With this criterion, we find a total of 1177 new AGB and tip-RGB stars candidates, and have calculated the bolometric luminosities of all of them as well as previously known stars, assuming a distance modulus of 18.55. 90% of the new candidates are blue sources, not searched for in a complete way by BMB. Their luminosity distribution shows a very clear peak at M bol ≃ -3.5, that we interpret as the tip of the Red Giant Branch. A second group is formed by stars for which the BMB survey should have been complete (i.e. relatively red C stars and M stars with spectral type later than M5.5). We find, however, 23% and 38% more such stars than they do in the Bar West and Optical Center, respectively.

Published
1998
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48. The Two EROS 4k x 8k CCD Mosaic Cameras

Author

F. Bauer, J. De Kat, C. Afonso, E. Aubourg, S. Aune, P. Bareyre, A. Bouere, X. Charlot, C. Coutures, N. Delabrouille, G. Dispau, D. Eppelle, O. Gachelin, C. Gaucherel, J. F. Glicenstein, B. Goldman, M. Gros, D. Hardin, C. Jeanney, J. F. Lecointe, A. Le Coroller, E. Lesquoy, C. Magneville, A. Milsztajn, P. Perrin, M. Pinabiau, P. Rebourgeard, C. Renault, J. Rich, M. Spiro, R. Treillard, J. de Trogoff, N. Vignal, L. Vigroux, C. Walter, S. Zylberajch, J. N. Albert, R. Ansari, F. Couchot, C. Eder, O. Lodygensky, B. Mansoux, M. Moniez, O. Perdereau, G. Adrianzyk, J. P. Berger, J. C. Delclite, C. Figuiere, C. Guillaume, D. Kohler, D. Lacroix, A. Baranne, E. Maurice, J. P. Beaulieu, R. Ferlet, C. Loup, A. Vidal-Madjar, and J. Andersen

Subjects
Physics, Mosaic (geodemography), Remote sensing
Published
1998
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49. Obscured AGB Stars in the LMC

Author

C. Loup, Albert A. Zijlstra, Martin Groenewegen, Jacco Th. van Loon, Peter te Lintel Hekkert, L. B. F. M. Waters, Norman R. Trams, and Patricia A. Whitelock

Subjects
Physics, Stars, Asymptotic giant branch, Astronomy, Large Magellanic Cloud, Carbon star
Abstract

We present results of a study of obscured Asymptotic Giant Branch (AGB) stars in the Large and Small Magellanic Clouds (LMC and SMC). In contrast with optically bright AGB stars (e.g. Blanco et al. 1980; Costa & Frogel 1996 and references therein) our sample of IRAS detected stars (Reid 1991; Wood et al. 1992; Loup et al. 1997; Zijlstra et al. 1996; van Loon et al. 1997a) represents stars that are in the very last stage of their AGB evolution. Elsewhere in this volume, Groenewegen reviews the magellanic AGB stars, and Trams et al. present first ISO results. Here we present results obtained from ground based observations.

Published
1998
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50. AGB Stars and Supergiants in the Bar of the LMC

Author

Joris Blommaert, E. Josselin, Alain Omont, C. Loup, and Martin Groenewegen

Subjects
Physics, Stars, Infrared excess, Red supergiant, Astrophysics, Supergiant, Large Magellanic Cloud, Cosmology, Carbon star, Bar (unit)
Abstract

Up to now, the knowledge of AGB stars and red supergiants in the Large Magellanic Cloud (LMC) was based on: optical surveys (I ≲ 17): about 4500 evolved stars have been identified, with small infrared excess ([J-K] ≲ 2.5) indicating no or moderate mass-loss rates; about one-third are carbon stars. IRAS data (Schwering and Israel, 1990, A&AS 79, 105): about 50 obscured AGB stars have been discovered (Loup et al., 1997, to appear in A&AS), with much reddder colours ([J-K] ~ 3.0 to 7.0).

Published
1998
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