Is there hydrogen gas in dwarf spheroidal galaxies?
Typically dwarf spheroidals are thought to have formed all of their stars in old and intermediate-aged bursts, and to be devoid of gas today. This is unlike transition galaxies and the gas rich dwarf irregular galaxies. Some 21 cm detections towards dwarf spheroidals with the correct radial velocities, e.g., Carignan et al. (1998) who find H I associated with the Sculptor dwarf spheroidal galaxy. Young noted that a wider field shows similar H I, suggestive of a high velocity cloud complex. Thus, perhaps Sculptor does not have H I. The image at right, of Sculptor Dwarf Spheroidal Galaxy (the cluster in the center), shows that extensive high velocity clouds are all around the relgion and perhaps not associated directly with Sculptor. For more information: • Blitz and Robishaw. ”Gas-Rich Dwarf Spheroidals.” The Astrophysical Journal, 541:675-687, 2000 October 1. • Carignan, Beaulieu, Ct, Demers, and Mateo. “Detection of HI Associated with the Sculptor Dwarf Spheroidal Galaxy.” The Astro
