Using the Hubble Space Telescope /Wide Field Camera 3 imaging data and multi-wavelength photometric catalog , we investigated the dust temperature of passively evolving and star-forming galaxies at 0.2 < z < 1.0 in the CANDELS fields .
We estimated the stellar radiation field by low-mass stars from the stellar mass and surface brightness profile of these galaxies and then calculated their steady-state dust temperature .
At first , we tested our method using nearby early-type galaxies with the deep FIR data by the Herschel Virgo cluster survey and confirmed that the estimated dust temperatures are consistent with the observed temperatures within the uncertainty .
We then applied the method to galaxies at 0.2 < z < 1.0 , and found that most of passively evolving galaxies with M _ { star } > 10 ^ { 10 } M _ { \odot } have a relatively high dust temperature of T _ { dust } > 20 K , for which the formation efficiency of molecular hydrogen on the surface of dust grains in the diffuse ISM is expected to be very low from the laboratory experiments .
The fraction of passively evolving galaxies strongly depends on the expected dust temperature at all redshifts and increases rapidly with increasing the temperature around T _ { dust } \sim 20 K. These results suggest that the dust heating by low-mass stars in massive galaxies plays an important role for the continuation of their passive evolution , because the lack of the shielding effect of the molecular hydrogen on the UV radiation can prevent the gas cooling and formation of new stars .