Discovery of a Nearby Low-Surface-Brightness Spiral Galaxy

Abstract

During the course of a search for compact, isolated gas clouds moving with anomalous velocities in or near our own Galaxy (Braun and Burton 1998 A&A, in press), we have discovered, in the data of the Leiden/Dwingeloo survey (Hartmann and Burton 1997, Atlas of Galactic Neutral Hydrogen, CUP) of Galactic hydrogen, the HI signature of a large galaxy, moving at a recession velocity of 282 km/s, with respect to our Galaxy. Deep multicolor and spectroscopic optical observations show the presence of star formation in scattered HII regions; radio HI synthesis interferometry confirms that the galaxy is rich in HI and has the rotation signature of a spiral galaxy; a submillimeter observation failed to detect the CO molecule. The radio and optical evidence combined suggest its classification as a low-surface-brightness spiral galaxy. It is located in close spatial and kinematic proximity to the galaxy NGC 6946. The newly-discovered galaxy, which we call Cepheus 1, is at a distance of about 6 Mpc. It is probably to be numbered amongst the nearest few LSB spirals.

13 page LaTeX, requires aastex, 4 GIF figures. Accepted for publication in the AJ, January 1999

References in corpus (3)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• New HI-detected Galaxies in the Zone of Avoidance
• Galaxies Discovered Behind the Milky Way by the Dwingeloo Obscured Galaxies Survey

Cited by in corpus (8)

• Reionization and the abundance of galactic satellites
• Jet-Induced Emission-Line Nebulosity and Star Formation in the High-Redshift Radio Galaxy 4C41.17
• An all-sky study of compact, isolated high-velocity clouds
• An automated search for high-velocity clouds in the Leiden/Dwingeloo Survey
• H-alpha imaging of the Local Volume galaxies I. The NGC 6946 galaxy group
• Faint HI 21-cm Emission Line Wings at Forbidden-Velocities
• Mapping the submillimeter spiral wave in NGC 6946
• Hidden Figures in the Sky: Evolution of low-surface brightness galaxies from a hydro-dynamical perspective