Astrophysics (Index)About

intergalactic HI cloud

(cloud of HI not within any galaxy)

The term intergalactic HI cloud has been used for a volume of observed neutral atomic hydrogen (HI) not associated with an observed galaxy. HI detected beyond the Milky Way generally indicates the presence of a galaxy, but galaxy formation is presumed to begin with star formation in some region of space without a galaxy, starting with such an extragalactic HI cloud. Thus any discovery of such a cloud generates interest as do any other signs of star formation at such a location. Such clouds have been discovered, but in some cases, a galaxy has subsequently been detected at the location, e.g., a relatively-dim dwarf galaxy.


(cloud type,hydrogen,gas,object type)
Further reading:
http://ui.adsabs.harvard.edu/abs/2004IAUS..217...26B/abstract
https://ui.adsabs.harvard.edu/abs/2000AJ....120.1342K/abstract
PrefixExample  
HIHI 1225+01 

Referenced by page:
cloud

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