by bystander » Mon Dec 25, 2017 11:50 pm
Hubble and HAWK-I explore a cluster with the mass of two quadrillion Suns
ESO &
ESA Hubble Picture of the Week | 2017 Dec 25
This image shows something spectacular: a galaxy cluster so massive that it is warping the space around it! The cluster, whose heart is at the centre of the frame, is named
RCS2 J2327, and is one of the most massive clusters known as its distance or beyond.
Massive objects such as RCS2 J2327 have such a strong influence on their surroundings that they actually warp the space around them — this effect is known as
gravitational lensing, and can cause light from more distant objects to be bent, distorted, and amplified, allowing us to see galaxies that would otherwise be far too distant for us to detect. Gravitational lensing is one of the predictions of Albert Einstein's
General Theory of Relativity and can be observed in three different regimes:
strong lensing,
weak lensing, and
microlensing. Unlike strong lensing, which produces stunning images of distorted galaxies, sweeping arcs, and phenomena known as
Einstein rings, weak gravitational lensing is mostly studied statistically — but offers a way to measure the masses of cosmic objects, as shown here.
This image is a composite of observations from the
HAWK-I instrument on ESO’s
Very Large Telescope and the NASA/ESA
Hubble Space Telescope’s
Advanced Camera for Surveys, and demonstrates an impressively detailed collaborative approach to studying weak lensing in the cosmos. The study found RCS2 J2327 to contain the mass of two quadrillion Suns!
The diffuse blue and white image is a mass map, showing the amount of mass thought to be contained within each part of the cluster. The creation of the map was only possible due to the exact measurements on the amount of gravitational lensing in the different areas of the cluster.
[size=125][b][i]Hubble and HAWK-I explore a cluster with the mass of two quadrillion Suns[/i][/b][/size]
[url=http://www.eso.org/public/images/comparisons/potw1752a/][b]ESO[/b][/url] & [url=https://www.spacetelescope.org/images/comparisons/potw1752a/][b]ESA Hubble[/b][/url] Picture of the Week | 2017 Dec 25
[quote]
[float=left][size=85][c][imghover=https://cdn.spacetelescope.org/archives/images/screen/potw1752b.jpg]https://cdn.spacetelescope.org/archives/images/screen/potw1752a.jpg[/imghover][b][i]Credit: ESO, ESA/Hubble & NASA[/i][/b][/c][hr][/hr][/size][/float]This image shows something spectacular: a galaxy cluster so massive that it is warping the space around it! The cluster, whose heart is at the centre of the frame, is named [url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=RCS+J2327-0204]RCS2 J2327[/url], and is one of the most massive clusters known as its distance or beyond.
Massive objects such as RCS2 J2327 have such a strong influence on their surroundings that they actually warp the space around them — this effect is known as [url=https://en.wikipedia.org/wiki/Gravitational_lens]gravitational lensing[/url], and can cause light from more distant objects to be bent, distorted, and amplified, allowing us to see galaxies that would otherwise be far too distant for us to detect. Gravitational lensing is one of the predictions of Albert Einstein's [url=https://en.wikipedia.org/wiki/General_relativity]General Theory of Relativity[/url] and can be observed in three different regimes: [url=https://en.wikipedia.org/wiki/Strong_gravitational_lensing]strong lensing[/url], [url=https://en.wikipedia.org/wiki/Weak_gravitational_lensing]weak lensing[/url], and [url=https://en.wikipedia.org/wiki/Gravitational_microlensing]microlensing[/url]. Unlike strong lensing, which produces stunning images of distorted galaxies, sweeping arcs, and phenomena known as [url=https://en.wikipedia.org/wiki/Einstein_ring]Einstein rings[/url], weak gravitational lensing is mostly studied statistically — but offers a way to measure the masses of cosmic objects, as shown here.
This image is a composite of observations from the [url=http://www.eso.org/public/teles-instr/paranal-observatory/vlt/vlt-instr/hawk-i/]HAWK-I[/url] instrument on ESO’s [url=http://www.eso.org/public/teles-instr/paranal-observatory/vlt/]Very Large Telescope[/url] and the NASA/ESA [url=https://www.spacetelescope.org/]Hubble Space Telescope[/url]’s [url=http://spacetelescope.org/about/general/instruments/acs/]Advanced Camera for Surveys[/url], and demonstrates an impressively detailed collaborative approach to studying weak lensing in the cosmos. The study found RCS2 J2327 to contain the mass of two quadrillion Suns!
The diffuse blue and white image is a mass map, showing the amount of mass thought to be contained within each part of the cluster. The creation of the map was only possible due to the exact measurements on the amount of gravitational lensing in the different areas of the cluster. [/quote]