Who Knew Blobs Could be So Interesting
Credit: Left panel: X-ray (NASA/CXC/Durham Univ./D.Alexander et al.); Optical (NASA/ESA/STScI/IoA/S.Chapman et al.); Lyman-alpha Optical (NAOJ/Subaru/Tohoku Univ./T.Hayashino et al.); Infrared (NASA/JPL-Caltech/Durham Univ./J.Geach et al.); Right, Illustration: NASA/CXC/M.Weiss
NASA’s Chandra X-ray Observatory has been studying 29 gigantic blobs of hydrogen gas to ascertain the source of the huge amount of energy needed to make these structures glow. These strange globules are called ‘Lyman-alpha blobs’ by astronomers because of the light they emit and are several hundred thousand light years across. It’s also thought that they are only seen when the Universe is approximately two billion years old, or about 15% of its current age.
The composite image above shows one of the largest blobs observed in this study. The glowing hydrogen gas in the blob is shown by a Lyman-alpha optical image (coloured yellow) from the National Astronomy Observatory of Japan’s Suburu telescope. There is a galaxy located within the blob that is visible in a broadband optical image (white) from the Hubble Space Telescope and also an infrared image from the Spitzer Space Telescope (red). The blue image from the Chandra X-ray Observatory shows evidence of a growing supermassive black hole in the centre of the galaxy. The energy from this active black hole is enought to light up and heat the gas in the blob. It’s also thought that radiation and winds from rapid star formation occuring in the galaxy have a similar effect. There is also evidence of another four active black holes in the blobs.
The image top right shows an artist’s impression of what a galaxy may look like inside a blob when looked at from fairly close range.
For the further information go and see Chandra.
