Search Publications
Isophotal Diameters of Galaxies at High Redshifts
Weedman, Daniel W.; Williams, Karen L.
New ultraviolet observations and archival spectra are presented for the bright disk of the galaxy NGC 4736 to derive the ultraviolet surface brightness profile. This is used to predict the appearance of such a galaxy at high redshift. The profiles in red light of 100 galaxies determined by S. Kent (1984) are used with assumed ultraviolet spectra t…
X-Ray Observations of the Supernova Remnant N103B in the Large Magellanic Cloud
Singh, K. P.; Westergaard, N. J.; Schnopper, H. W. +1 more
New X-ray observations of the supernova remnant N103B made using the European X-Ray Observatory satellite Exosat and the Einstein Observatory are reported. An X-ray map from Exosat obtained with three different filters corresponding to three different energy bands is presented. The analysis of the X-ray spectra indicates a thermal origin for X-ray…
The Stars with H alpha Missing
Downes, Ronald A.
During the course of a survey for ultraviolet-excess objects, a group of objects were found that spectroscopically resemble the subdwarf B stars, except for variable strength H-alpha absorption. The H-alpha line can have the nominal strength predicted from the other Balmer lines, or it can be completely absent. Observations reveal significant chan…