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The massive stars in the R136 region of 30 Doradus.

Elson, Rebecca A. W.; Schade, David J.; Thomson, Robert C. +1 more

We present U and B photometry, based on Hubble Space Telescope observations, for 26 stars in the R136 region of the young cluster 30 Doradus in the Large Magellanic Cloud. It has been suggested that rich star clusters form through the coalescence of clumps, and it seems likely that the R136 region is such a clump. If it is in virial equilibrium th…

Resolution of the southern radio lobe of 3C 33 at 660 NM

Stiavelli, Massimo; Crane, Phillipe

An HST planetary camera image of the southern radio lobe of 3C 33 has revealed a strand of emission coincident with the peak in the radio emission at 2 and 6 cm. The detailed morphological similarity between the optical and radio data confirms beyond doubt the common origin of the radio and optical emission, and raises the question of the physical…

Deconvolution and photometry of Faint Object Camera images with point sources.

Mackay, C. D.; Schade, D. J.; Thomson, R. C. +2 more

The peculiar characteristics of images obtained with the Hubble Space Telescope have raised important questions concerning the proper method for processing data in which the point spread function is seriously distorted. In particular, there is considerable confusion over whether or not it is useful to deconvolve the images, and to what extent the …

How fast is the evolution of the diffuse ultraviolet cosmic background radiation ?

Stanek, Krzysztof Z.

Lyα absorption lines observed in Hubble Space Telescope UV spectra of 3C 273 have neutral hydrogen column densities comparable with those of z ~ 2 quasars. Assuming the standard pressure-confined model of Lyα clouds, we use this fact to determine the evolution of UV background radiation for z < 2. We find that to fit the data the UV background …