Our universe's smallest galaxies hold the largest star factories.

Some of the biggest, most intense regions of star formation are found in the smallest of galaxies, and scientists believe this is because stars reaching the ends of their lives in the so-called dwarf galaxies are more likely to turn into black holes than explode in supernovas. The contrast is large enough, the team says, that dwarf galaxies experience a 10-million-year delay in blowing all their star-forming material away, a process usually dependent on the forces of supernovas. 

In other words, dwarf galaxies are able to hang onto their precious trove of star-forming molecular gas for longer, allowing star-forming regions to grow in size and intensity, and produce more stars. 

Examples of such huge star-forming regions in local dwarf galaxies include 30 Doradus (the Tarantula Nebula) in the Large Magellanic Cloud, located just about 160,000 light-years away, and Markarian 71 in the galaxy NGC 2366, located about 10 million light years away.

Star-forming regions can produce stars of all masses; they mostly yield smaller stars, but create a handful of massive stars, too. When these massive stars reach the end of their life after a few million years, their cores collapse to either form a neutron star or a stellar-mass black hole. In the former scenario, a star's outer layers rebound off the neutron star and explode as a supernova. In the latter case, however, almost an entire star falls into the resultant black hole with nary a whimper.

Source: www.space.com


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