Weblog
23 Might 2014

NASA/JPL-Caltech/College of Zurich
Normally in astronomy we examine objects by the quantity of sunshine they emit. Most common matter offers of sunshine in some kind or one other. Even the chilly interstellar medium will emit some mild at infrared or radio wavelengths. However one draw back of that is that the sunshine usually comes from the floor areas of an object. To check the inside of an object we usually have to make use of points of emitted mild from the floor to find out properties of the inside. For shiny objects like stars this works fairly properly, however for dim objects like darkish interstellar clouds that is extra of a problem.
Just lately a group with the Spitzer area telescope has used a special methodology. Spitzer is a delicate infrared telescope, and the group has been utilizing it to look at chilly, dense interstellar clouds by the infrared mild that passes via them. There may be a substantial amount of infrared mild within the universe, and when that ambient background mild passes via a darkish cloud we are able to decide issues like its density and composition from the sunshine they take in. Principally it’s a strategy to examine darkish clouds by the shadows they forged.
A few of the group’s outcomes had been not too long ago printed within the Astrophysical Journal Letters. One of many issues they’ve introduced is the darkest and densest interstellar cloud ever found. It has a mass of about 70,000 Suns, and is just 50 mild years throughout. This cloud might be within the earliest levels of collapsing right into a cluster of enormous and shiny stars (O-type stars). Gaining a greater understanding of dense clouds like this one will assist us perceive simply how such giant stars kind.