Massive black holes halt star birth in distant galaxies
This is the full press-release (sans contact details) for the new HerMES consortium Nature paper led by Dr Mat Page of MSSL. I’m putting the full one up for those interested, doing it as two separate posts to get the tl;dr one with the picture out. (PS, Can you tell I’m somewhat invested in the HerMES consortium?)
Astronomers, using the European Space Agency’s (ESA) Herschel Space Observatory, have shown that the number of stars that form during the early lives of galaxies may be influenced by the massive black holes at their hearts. This helps explain the link between the size of the central bulges of galaxies and the mass of their central black holes.
All large galaxies have a massive black hole at their centre, each millions of times the mass of a single star. For over a decade scientists have been puzzled as to why the masses of the black holes are linked to the size of the round central bulges at the hearts of galaxies. The suspicion has long been that the answer lies in the early lives of the galaxies, when the stars in the bulge were forming. To study this phase, astronomers need to look at very distant galaxies, so far away that we see them as they were billions of years ago.
Although the black holes themselves cannot be seen, the material closest to them can get incredibly hot, emitting large amounts of light over a very wide range of wavelengths, from radio waves to x-rays. The light from this super-heated material can be trillions of times as bright as the Sun, with brighter emissions indicating a more massive black hole. There are also strong flows of material (winds and jets) expelled from the region around the black hole.
The hot material near the black hole outshines almost all the light from rest of the host galaxy, except for the light with wavelengths just less than a millimetre. This sub-millimetre light is invisible to normal telescopes but is seen by the Herschel Space Observatory and indicates the rate at which stars are being formed in the galaxy.
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