Bibcode
del Rio, M. S.; Brinks, E.; Cepa, J.
Bibliographical reference
"IX Latin American Regional IAU Meeting, "Focal Points in Latin American Astronomy", held in Tonantzintla, Mexico, Nov 9-13, 1998, Eds: Aguilar, A.; Carramiñana, A.; Revista Mexicana de Astronomia y Astrofisica Serie de Conferencias, p. 121."
Advertised on:
7
2001
Citations
0
Refereed citations
0
Description
We present high resolution (15'' and 2.5 km/s) HI observations of the S0
gal axy NGC 404. We derive an HI mass of MHI = 6.7 ×
107 Msolar, in good agreement with previous
measurements. The HI is distributed in a broad annulus and extends out
to a diameter of 9', well beyond the optical diameter of 6'. The
velocity field is regular and shows, surprisingly, a declining rotation
curve. This decline is purely Keplerian, strongly suggesting that all
the mass is contained within the inner 200''.