A 2-hour service-mode SCUBA observation of the gravitationally-lensed Lyman break galaxy MS 1512–cB58 resulted in a 3 \sigma upper limit of 3.9 mJy at 850µm .
A comparison of this upper limit with values expected from rest-UV/optical measurements of extiction suggests that dust temperature ( T _ { d } ) and/or emissivity index ( \beta ) in cB58 may be substantially higher than is seen in local galaxies , or that the attenuation curve in cB58 may be even gentler than the already quite mild SMC dust law .
If dust temperature T _ { d } and emissivity index \beta in cB58 are similar to those seen in local IRAS-seleceted galaxies , then cB58 ’ s dust mass is M _ { d } \lesssim 10 ^ { 7.7 } M _ { \odot } and its star formation rate is SFR \lesssim 10 M _ { \odot } yr ^ { -1 } ( for q _ { 0 } =0.1 , H _ { 0 } =75 km s ^ { -1 } Mpc ^ { -1 } ) .
This SFR upper limit is lower than the star formation rate measured from H \alpha , thus giving further support to the notion that ( T _ { d } , \beta ) values in cB58 are higher than those seen in local galaxies .
It thus appears that our understanding of dust in this extensively studied Lyman break galaxy is poor , and observations at other wavelentghs are needed to better understand dust at high redshift .
Such observations can be provided by the upcoming SIRTF mission for which cB58 ’ s expected flux densities are calculated .