Metals are thought to have profound effects on the internal structures of molecular clouds in which stars are born .
The absence of metals is expected to prevent gas from efficient cooling and fragmentation in theory .
However , this effect has not yet been observed at low metallicity environments , such as in the early Universe and local dwarf galaxies , because of the lack of high spatial resolution maps of gas .
We carried out ALMA observations of the carbon monoxide ( CO ) J =2-1 emission line at 1.4-parsec resolutions of a molecular cloud in DDO 70 at 7 % solar metallicity , the most metal-poor galaxy currently known with a CO detection .
In total , five clumps have been identified and they are found to follow more or less the Larson ’ s law .
Since the CO emission exists in regions with visual extinction A _ { V } around 1.0 , we converted this A _ { V } to the gas mass surface density using a gas-to-dust ratio of 4,594 \pm 2,848 for DDO 70 .
We found that the CO clumps in DDO 70 exhibit significantly larger ( on average four times ) sizes than those at the same gas mass surface densities in massive star-formation regions of the Milky Way .
The existence of such large clumps appears to be consistent with theoretical expectations that gas fragmentation in low metallicity clouds is suppressed .
While our observation is only for one cloud in the galaxy , if it is representative , the above result implies suppressed gas fragmentation during the cloud collapse and star formation in the early Universe .