Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-02-16
Astrophys.J. 622 (2005) L21-L24
Astronomy and Astrophysics
Astrophysics
Accepted by ApJL
Scientific paper
10.1086/429538
VIRGOHI21 is an HI source detected in the Virgo Cluster survey of Davies et al. (2004) which has a neutral hydrogen mass of 10^8 M_solar and a velocity width of Delta V_20 = 220 km/s. From the Tully-Fisher relation, a galaxy with this velocity width would be expected to be 12th magnitude or brighter; however deep CCD imaging has failed to turn up a counterpart down to a surface-brightness level of 27.5 B mag/sq. arcsec. The HI observations show that it is extended over at least 16 kpc which, if the system is bound, gives it a minimum dynamical mass of ~10^11 M_solar and a mass to light ratio of M_dyn/L_B > 500 M_solar/L_solar. If it is tidal debris then the putative parents have vanished; the remaining viable explanation is that VIRGOHI21 is a dark halo that does not contain the expected bright galaxy. This object was found because of the low column density limit of our survey, a limit much lower than that achieved by all-sky surveys such as HIPASS. Further such sensitive surveys might turn up a significant number of the dark matter halos predicted by Dark Matter models.
Boyce Peter
Davies Jonathan
Disney Michael
Driel Wim van
Garcia Diego
No associations
LandOfFree
A Dark Hydrogen Cloud in the Virgo Cluster does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A Dark Hydrogen Cloud in the Virgo Cluster, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Dark Hydrogen Cloud in the Virgo Cluster will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-83305