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The peculiar variable V838 Mon
Kimeswenger, S.; Lederle, C.; Schmeja, S. +1 more
V838 Mon underwent, after a first nova-like outburst in January and a usual decline, a second outburst after one month, and a third weak one again a month later. Moreover, a very small increase of the temperature at the beginning of April gives us a hint about a physical process with a period of one month. We obtained a BVRIC time-seque…
The percentage of stellar light re-radiated by dust in late-type Virgo Cluster galaxies
Tuffs, Richard J.; Popescu, Cristina C.
We show that the mean percentage of stellar light re-radiated by dust is ~30 per cent for the Virgo Cluster late-spirals measured with ISOPHOT by Tuffs et al. A strong dependence of this ratio with morphological type was found, ranging from typical values of ~15 per cent for early spirals to up to ~50 per cent for some late spirals. The extreme BC…
A new method for ISOCAM data reduction - II. Mid-infrared extragalactic source counts in the ELAIS Southern field
Pozzi, F.; Franceschini, A.; Serjeant, S. +5 more
We present the 15-µm extragalactic source counts from the Final Analysis Catalogue of the European Large Area ISO Survey (ELAIS) Southern hemisphere field S1, extracted using the Lari method. The large number of extragalactic sources (~350) detected over this area between about 0.5 and 100 mJy guarantee a high statistical significance of the…
Circumnuclear regions in barred spiral galaxies - II. Relations to host galaxies
Knapen, J. H.; Pérez-Ramírez, D.; Laine, S.
We present optical broad- and narrow-band imaging of a sample of a dozen barred galaxies. These images are analysed in conjunction with our previously published near-infrared imaging of their central regions and with literature values for, e.g. bar strengths and the total star formation activity of the galaxies. We present B, I and Hα images, and …
A Hubble Space Telescope lensing survey of X-ray-luminous galaxy clusters - II. A search for gravitationally lensed EROs *
Kneib, J. -P.; Ivison, R. J.; Smith, Graham P. +7 more
We present the results of a survey for extremely red objects (EROs) undertaken in the fields of 10 massive galaxy cluster lenses at , combining sensitive, high-resolution Hubble Space Telescope imaging with deep, half-arcsecond K -band imaging from UKIRT. We detect 60 EROs with , of which 26 have in a total image-plane survey area of 49arcmin…
K dwarfs and the chemical evolution of the solar cylinder
Chiappini, Cristina; Matteucci, Francesca; Flynn, Chris +1 more
K dwarfs have lifetimes older than the present age of the Galactic disc, and are thus ideal stars for investigating the chemical evolution of the disc. We have developed several photometric metallicity indicators for K dwarfs, based on a sample of accurate spectroscopic metallicities for 34 disc and halo G and K dwarfs. The photometric metalliciti…
Mass segregation in young compact star clusters in the Large Magellanic Cloud - I. Data and luminosity functions
de Grijs, R.; Gilmore, G. F.; Johnson, R. A. +1 more
We have undertaken a detailed analysis of HST/WFPC2 and STIS imaging observations, and of supplementary wide-field ground-based observations obtained with the ESO New Technology Telescope (NTT) of two young (~10-25Myr) compact star clusters in the LMC, NGC 1805 and 1818. The ultimate goal of our work is to improve our understanding of the degree o…
Echoes in X-ray binaries
Horne, Keith; O'Brien, K.; Chen, W. +3 more
We present a method of analysing the correlated X-ray and optical/UV variability in X-ray binaries, using the observed time delays between the X-ray driving light curves and their reprocessed optical echoes. This allows us to determine the distribution of reprocessing sites within the binary. We model the time-delay transfer functions by simulatin…
Mass segregation in young compact clusters in the Large Magellanic Cloud - III. Implications for the initial mass function
Santiago, B. X.; Mackey, A. D.; de Grijs, R. +4 more
The distribution of core radii of rich clusters in the Large Magellanic Cloud (LMC) systematically increases in both upper limit and spread with increasing cluster age. Cluster-to-cluster variations in the stellar initial mass function (IMF) have been suggested as an explanation. We discuss the implications of the observed degree of mass segregati…
The SCUBA 8-mJy survey - II. Multiwavelength analysis of bright submillimetre sources
Ivison, R. J.; Dunlop, J. S.; Serjeant, S. +13 more
We present the results of a multiwavelength study of the 19 most significant submillimetre (submm) sources detected in the SCUBA 8-mJy survey. As described in Scott et al. , this survey covers ~=260arcmin2 using the submillimetre camera SCUBA, to a limiting source detection limit S 850µm ~=8mJy. One advantage of this re…