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The European Large Area ISO Survey - I. Goals, definition and observations
Elbaz, D.; Genzel, R.; Omont, A. +67 more
We describe the European Large Area ISO Survey (ELAIS). ELAIS was the largest single Open Time project conducted by ISO, mapping an area of 12deg2 at 15µm with ISOCAM and at 90µm with ISOPHOT. Secondary surveys in other ISO bands were undertaken by the ELAIS team within the fields of the primary survey, with 6deg2…
Infrared colours for Mira-like long-period variables found in the (M⊙<~10-7 Msolar yr-1) Hipparcos Catalogue
Feast, Michael; Whitelock, Patricia; Marang, Freddy
Near-infrared, JHKL, photometry is presented for 193 Mira and semi-regular variables that were observed by Hipparcos; periods, bolometric magnitudes and amplitudes are derived for 92 of them. Because of the way in which the Hipparcos targets were selected, this group of stars provides a useful data base of Miras with low mass-loss rates (M⊙
The age of the solar neighbourhood
Binney, James; Dehnen, Walter; Bertelli, Gianpaolo
High-quality Hipparcos data for a complete sample of nearly 12000 main-sequence and subgiant stars, together with Padua isochrones, are used to constrain the star formation history of the solar neigbourhood and the processes that stochastically accelerate disc stars. The velocity dispersion of a coeval group of stars is found to increase with time…
Non-parametric star formation histories for four dwarf spheroidal galaxies of the Local Group
Gilmore, Gerard; Valls-Gabaud, David; Hernandez, X.
We use recent Hubble Space Telescope colour-magnitude diagrams of the resolved stellar populations of a sample of local dSph galaxies (Carina, Leo I, Leo II and Ursa Minor) to infer the star formation histories of these systems, SFR(t). Applying a new variational calculus maximum likelihood method, which includes a full Bayesian analysis and allow…
Testing the connection between the X-ray and submillimetre source populations using Chandra
Kneib, J. -P.; Ivison, R. J.; Smail, Ian +8 more
The powerful combination of the Chandra X-ray telescope, the SCUBA submillimetre-wave camera and the gravitational lensing effect of the massive galaxy clusters A2390 and A1835 has been used to place stringent X-ray flux limits on six faint submillimetre SCUBA sources and deep submillimetre limits on three Chandra sources which lie in fields commo…
Quantitative analysis of WC stars: constraints on neon abundances from ISO-SWS spectroscopy
Hillier, D. John; Morris, Patrick W.; Crowther, Paul A. +3 more
Neon abundances are derived in four Galactic WC stars - γ2Vel (WR11, WC8+O7.5III), HD156385 (WR90, WC7), HD192103 (WR135, WC8) and WR146 (WC5+O8) - using mid-infrared fine-structure lines obtained with ISO-SWS. Stellar parameters for each star are derived using the non-local thermodynamic equilibrium model atmospheric code of Hillier &a…
The recent star formation history of the Hipparcos solar neighbourhood
Gilmore, Gerard; Valls-Gabaud, David; Hernandez, X.
We use data from the Hipparcos catalogue to construct colour-magnitude diagrams for the solar neighbourhood, which are then treated using advanced Bayesian analysis techniques to derive the star formation rate history, SFR(t), of this region over the last 3Gyr. The method we use allows the recovery of the underlying SFR(t) without the need of assu…
The European Large Area ISO Survey - II. Mid-infrared extragalactic source counts
McMahon, Richard G.; Serjeant, Stephen; Clements, David L. +20 more
We present preliminary source counts at 6.7 and 15µm from the preliminary analysis of the European Large Area ISO Survey, with limiting flux densities of ~2mJy at 15µm and ~1mJy at 6.7µm. We separate the stellar contribution from the extragalactic using identifications with automated plate measurement sources made with the likeli…
Hipparcos parallaxes for Mira-like long-period variables
Feast, Michael; Whitelock, Patricia
This paper concerns the calibration of the K period-luminosity relation for Mira variables using Hipparcos parallaxes. K magnitudes are available for 255 Mira-like variables which were observed by Hipparcos. Period-luminosity zero-points are evaluated for various subgroups of data. The best solution for oxygen-rich Miras, which uses 180 stars, omi…
Mira kinematics from Hipparcos data: a Galactic bar to beyond the Solar circle
Whitelock, Patricia A.; Feast, Michael W.
The space motions of Mira variables are derived from radial velocities, Hipparcos proper motions and a period-luminosity relation. The previously known dependence of Mira kinematics on the period of pulsation is confirmed and refined. In addition, it is found that Miras with periods in the range 145-200d in the general Solar neighbourhood have a n…