Title of article :
Non-confirmation of reported H I clouds without optical counterparts in the Hercules cluster
Author/Authors :
ONeil، K. T. نويسنده , , Hern?ndez، H. نويسنده , , Driel، W. van نويسنده , , Balkowski، C. نويسنده , , Duc، P.-A. نويسنده , , Iglesias-P?ramo، J. نويسنده , , Cayatte، V. نويسنده , , Dickey، J. M. نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2003
Abstract :
21 cm H I line observations were made with the Arecibo Gregorian telescope of 9 H I clouds in the Hercules Cluster which were reported as tentative detections in a VLA H I study of the cluster (Dickey 1997) and for which our deep CCD imaging failed to find any optical counterparts. No sensitive observations could be made of one of these (sw-174) due to the presence of a close-by strong continuum source. The other 8 tentative H I detections were not confirmed by the Arecibo H I measurements. The CCD images did reveal faint, low surface brightness counterparts near the centres of two other VLA H I sources invisible on the Palomar Sky Survey, sw-103 and sw-194.
Keywords :
Galaxy , magnetic fields , HII regions , stars , pulsars , general , Structure , ISM
Journal title :
Astronomy and Astrophysics
Journal title :
Astronomy and Astrophysics