W.M. Keck Observatory | 2014 Nov 26
[img3="CXC: NGC 4151: An Active Black Hole in the "Eye of Sauron"A team of scientists, led by Dr. Sebastian Hoenig from the University of Southampton, has accurately measured the distance to the nearby NGC4151 galaxy, using the W. M. Keck Observatory Interferometer. The team employed a new technique they developed, which allows them to measure precise distances to galaxies tens of millions of light years away. The research was published today in the journal Nature.
Credit: X-ray: NASA/CXC/CfA/J.Wang et al.; Optical: Isaac Newton Group of Telescopes, La Palma/Jacobus Kapteyn Telescope, Radio: NSF/NRAO/VLA"]http://chandra.harvard.edu/photo/2011/n4151/n4151.jpg[/img3]
The new technique is similar to that used by land surveyors on earth, who measure both the physical and angular – or ‘apparent’ – size of a distant object, to calculate its distance from Earth.
Previous reported distances to NGC 4151, which contains a supermassive black hole, ranged from 4- to 29-megaparsecs, but using this new, more accurate method, the researchers calculated the distance to the supermassive black hole as 19 megaparsecs.
The galaxy NGC415 is dubbed the ‘Eye of Sauron’ by astronomers for the similarity to its namesake in the film trilogy The Lord of the Rings. As in the famous saga, a ring plays a crucial role in this new measurement. All big galaxies in the universe host a supermassive black hole in their center and in about 10 percent of all galaxies, these supermassive black holes are growing by swallowing huge amounts of gas and dust from their surrounding environments. In this process, the material heats up and becomes very bright — becoming the most energetic sources of emission in the universe known as active galactic nuclei (AGN). ...
Using supermassive black holes to measure cosmic distances
Niels Bohr Institute | University of Copenhagen | 2014 Nov 26
'Eye of Sauron' Provides New Way to Measure Galaxy Distances
University of Southampton, UK | 2014 Nov 27
A dust-parallax distance of 19 megaparsecs to the supermassive black hole in NGC 4151 - Sebastian F. Hönig et al
- Nature 515(7528) 528 (27 Nov 2014) DOI: 10.1038/nature13914
