We present the first interferometric evidence of CO ( 1-0 ) emission in the intragroup starburst ( IGS ) region of HCG 92 ( Stephan ’ s Quintet ) .
BIMA ’ s large primary beam covers fully both the IGS region and the dominant group member galaxy Seyfert NGC 7319 , as well as partially the intruder galaxy NGC 7318B .
CO emission of \lower 2.0 pt \hbox { $ \buildrel > \over { \sim } $ } 4 \sigma is detected in all of them .
The detection of the CO emission associated with the IGS is further supported by comparisons with observations in other wavebands ( e.g. , HI , mid-IR , H \alpha ) .
Assuming the standard conversion factor , 3.6–8.0 \times 10 ^ { 8 } ~ { } \hbox { M$ { } _ { \odot } $ } molecular gas is found to be associated with the IGS .
Confining to the region of the CO emission peak , a relatively high star-formation efficiency of 8.6 \hbox { L$ { } _ { \odot } $ } / \hbox { M$ { } _ { \odot } $ } is derived for the IGS , which is nearly comparable to that of local starburst galaxies ( e.g. , M82 ) .