We present Hubble Space Telescope ( HST ) and ground-based observations of a pair of galaxies at redshift 2.38 , which are collectively known as 2142 - 4420 B1 ( 24 ) .
The two galaxies are both luminous extremely red objects ( EROs ) , separated by 0.8″ .
They are embedded within a 100 kpc scale diffuse Ly \alpha nebula ( or blob ) of luminosity \sim 10 ^ { 44 } { erg s } ^ { -1 } .

The radial profiles and colors of both red objects are most naturally explained if they are young elliptical galaxies : the most distant yet found .
It is not , however , possible to rule out a model in which they are abnormally compact , extremely dusty starbursting disk galaxies .
If they are elliptical galaxies , their stellar populations have inferred masses of \sim 10 ^ { 11 } M _ { \sun } and ages of \sim 7 \times 10 ^ { 8 } years .
Both galaxies have color gradients : their centers are significantly bluer than their outer regions .
The surface brightness of both galaxies is roughly an order of magnitude greater than would be predicted by the Kormendy relation .
A chain of diffuse star formation extending 1″ from the galaxies may be evidence that they are interacting or merging .

The Ly \alpha nebula surrounding the galaxies shows apparent velocity substructure of amplitude \sim 700 { km s } ^ { -1 } .
We propose that the Ly \alpha emission from this nebula may be produced by fast shocks , powered either by a galactic superwind or by the release of gravitational potential energy .