Search Publications
A classical approach to faint extragalactic source extraction from ISOCAM deep surveys. Application to the Hubble Deep Field
Abergel, A.; Bernard, J. -P.; Clements, D. L. +4 more
We have developed a general data reduction technique for ISOCAM data coming from various deep surveys of faint galaxies. In order to reach the fundamental limits of the camera (due to the background photon noise and the readout noise), we have devised several steps in the reduction processes that transform the raw data to a sky map which is then u…
A determination of the outflow speeds in the lower solar wind
Simnett, G. M.; Tappin, S. J.; Lyons, M. A.
The acceleration of the low-latitude solar wind, which comes from regions of the corona above large, closed magnetic loops, is a theoretical challenge. Until recently we have lacked direct measurements close to the Sun with which to constrain the theory. When a series of high-resolution coronagraph images is viewed in the form of a movie the conti…
Intensity oscillations in a sunspot plume
Fludra, A.
Observations of a sunspot plume (a compact feature, bright in the transition region line of O V 629.7 Angstroms at 2.2 x 10(5) K), seen above a sunspot in the active region AR8249, have been made with a 15-second time resolution with the Coronal Diagnostic Spectrometer on SOHO. Intensity of the O V 629.7 Angstroms line in the sunspot plume oscilla…
A deep 12 micron survey with ISO
Cesarsky, C.; Clements, D. L.; Reach, W. T. +4 more
We present the first results of a study of faint 12 mu m sources detected with the Infrared Space Observatory (ISO) in four deep, high galactic latitude fields. The sample includes 50 such sources in an area of 0.1 square degrees down to a 5sigma flux limit of ~ 500 mu Jy. From optical identifications based on the US Naval Observatory (USNO) catal…
The circumstellar environment of UX ORI
Prusti, T.; Thi, W. F.; Natta, A. +3 more
This paper presents new observations of UX Ori obtained with the millimeter interferometer of Plateau de Bure and with ISO. UX Ori is the prototype of a group of pre-main-sequence, intermediate-mass stars, often indicated as precursors of beta Pic. The interferometry observations at 1.2 and 2.6 mm show that UX Ori has a circumstellar disk, with ou…
Interstellar oxygen in the heliospheric interface: influence of electron impact ionization
Geiss, J.; Lallement, R.; Izmodenov, V. V.
A fraction of the interstellar atoms crosses the interface between the solar wind and the ionized component of the local interstellar medium (the heliospheric interface), and enters the heliosphere. The number of penetrating atoms depends on the strength of the atom-plasma interaction, i.e. on the atom type. In this paper we consider the penetrati…
Late A-type stars: new Strömgren photometric calibrations of absolute magnitudes from HIPPARCOS
Figueras, F.; Domingo, A.
Hipparcos trigonometric parallaxes have been used to derive a photometric absolute magnitude calibration of main-sequence late A-type stars in terms of Strömgren photometric indices - accounting for temperature, evolution and metallicity effects - and projected equatorial rotational velocities. The derived calibrations are valid for main-sequence …
Radiation scattering in the solar corona
Noci, G.; Maccari, L.
This paper discusses the scattering in the solar corona of the radiation emitted by the solar disk. We obtain expressions for the emissivity which permit to deduce the spectral characteristics of the scattered radiation. With these expressions, assuming a Maxwellian distribution for the velocities of the scattering ions and a simple spectral shape…
HST observations of Terzan 1: a second parameter globular cluster in the galactic bulge
Bica, E.; Barbuy, B.; Marconi, G. +3 more
Hubble Space Telescope observations in the F555W and F814W bands are presented of the bulge globular cluster Terzan 1. This highly obscured cluster has the smallest projected distance to the Galactic center among all known globulars. Its colour-magnitude diagram shows a red horizontal branch, which is typical of metal-rich clusters, combined to a …
IRAS04496-6958: A luminous carbon star with silicate dust in the Large Magellanic Cloud
Waters, L. B. F. M.; Blommaert, J. A. D. L.; Whitelock, Patricia A. +7 more
We describe ISO observations of the obscured Asymptotic Giant Branch (AGB) star IRAS04496-6958 in the Large Magellanic Cloud (LMC). This star has been classified as a carbon star. Our new ISOCAM CVF spectra show that it is the first carbon star with silicate dust known outside of the Milky Way. The existence of this object, and the fact that it is…