We made C ^ { 18 } O ( 2–1 ) and CS ( 7–6 ) images of the protostellar envelope around B335 with a high spatial dynamic range from \sim 10000 to \sim 400 AU , by combining the Submillimeter Array and single-dish data .
The C ^ { 18 } O emission shows an extended ( \sim 10000 AU ) structure as well as a compact ( \sim 1500 AU ) component concentrated at the protostellar position .
The CS emission shows a compact ( \sim 900 AU ) component surrounding the protostar , plus a halo-like ( \sim 3000 AU ) structure elongated along the east-west direction .
At higher velocities ( | \Delta V| \gtrsim 0.3 km s ^ { -1 } ) , the CS emission is stronger and more extended than the C ^ { 18 } O emission .
Physical conditions of the envelope were examined through an LVG model .
At | \Delta V| \gtrsim 0.3 km s ^ { -1 } , the gas temperature is higher ( > 40 K ) than that at | \Delta V| \lesssim 0.3 km s ^ { -1 } , whereas the gas density is lower ( < 10 ^ { 6 } cm ^ { -3 } ) .
We consider that the higher-temperature and lower-density gas at | \Delta V| \gtrsim 0.3 km s ^ { -1 } is related to the associated outflow , while the lower-temperature and higher-density gas at | \Delta V| \lesssim 0.3 km s ^ { -1 } is the envelope component .
From the inspection of the positional offsets in the velocity channel maps , the radial profile of the specific angular momentum of the envelope rotation in B335 was revealed at radii from \sim 10 ^ { 4 } down to \sim 10 ^ { 2 } AU .
The specific angular momentum decreases down to the radius of \sim 370 AU , and then appears to be conserved within that radius .
A possible scenario of the evolution of envelope rotation is discussed .