CXC: Most Massive Galaxy Cluster in Distant Universe

[bystander]

Chandra Weighs Most Massive Galaxy Cluster in Distant Universe
NASA | MSFC | SAO | Chandra X-ray Observatory | 2014 Dec 18

[c]Credit: X-ray: NASA/CXC/INAF/P.Tozzi, et al; Optical:
NAOJ/Subaru and ESO/VLT; Infrared: ESA/Herschel[/c]

Using NASA's Chandra X-ray Observatory, astronomers have made the first determination of the mass and other properties of a very young, distant galaxy cluster.

The Chandra study shows that the galaxy cluster, seen at the comparatively young age of about 800 million years, is the most massive known cluster with that age or younger. As the largest gravitationally- bound structures known, galaxy clusters can act as crucial gauges for how the Universe itself has evolved over time.

The galaxy cluster was originally discovered using ESA’s XMM-Newton observatory and is located about 9.6 billion light years from Earth. Astronomers used X-ray data from Chandra that, when combined with scientific models, provides an accurate weight of the cluster, which comes in at a whopping 400 trillion times the mass of the Sun. Scientists believe the cluster formed about 3.3 billion years after the Big Bang.

The cluster is officially named XDCP J0044.0-2033, but the researchers have nicknamed it “Gioiello”, which is Italian for “jewel”. They chose this name because an image of the cluster contains many sparkling colors from the hot, X-ray emitting gas and various star-forming galaxies within the cluster. Also, the research team met to discuss the Chandra data for the first time at Villa il Gioiello, a 15th century villa near the Observatory of Arcetri, which was the last residence of prominent Italian astronomer Galileo Galilei. ...

Chandra deep observation of XDCP J0044.0-2033, a massive galaxy cluster at z>1.5 - P. Tozzi et al

• arXiv.org > astro-ph > arXiv:1412.5200 > 16 Dec 2014

[BDanielMayfield]

At 400 trillion suns, that jewel has an awful lot of carats.

[Ann]

I was a bit confused when it comes to the age of the cluster.

The Chandra study shows that the galaxy cluster, seen at the comparatively young age of about 800 million years

Scientists believe the cluster formed about 3.3 billion years after the Big Bang.

Does that mean that the cluster formed 3.3 billion years ago, but the Chandra study shows what the cluster looked like when it had existed for 800 millions years?

Ann

[rstevenson]

I was a bit confused when it comes to the age of the cluster.

The Chandra study shows that the galaxy cluster, seen at the comparatively young age of about 800 million years

Scientists believe the cluster formed about 3.3 billion years after the Big Bang.

Does that mean that the cluster formed 3.3 billion years ago, but the Chandra study shows what the cluster looked like when it had existed for 800 millions years?

If the cluster formed 3.3 billion years after the Big Bang (not 3.3 billion years ago), and this image shows what it looked like when it was about 800 million years old, then it's about 4.1 billion years after the Big Bang in this image.

That adds up, since they also say it is about 9.6 billion light years from us, so 9.6 + 4.1 = 13.7 billion years, or very nearly the age of the universe. (I know you know, Ann, but I'll say for completeness: that looks like I just added a distance measure to a time measure, but light travels one light-year in a year in a vacuum, so it's easy to slip back and forth between the two aspects of time and distance.)

Rob

[Ann]

Thanks, Rob!

Ann