(Press-News.org) PGC 6240 is an elliptical galaxy that resembles a pale rose in the sky, with hazy shells of stars encircling a very bright centre. Some of these shells are packed close to the centre of the galaxy, while others are flung further out into space. Several wisps of material have been thrown so far that they appear to be almost detached from the galaxy altogether.
Astronomers have studied PGC 6240 in detail due to this structure, and also because of its surrounding globular clusters — dense, tightly packed groups of gravitationally bound stars that orbit galaxies. Over 150 of these clusters orbit our own galaxy, the Milky Way, all composed of old stars.
All the globular clusters around a certain galaxy form at approximately the same time, giving them all the same age. This is echoed within the clusters — all the stars within a single cluster form at around the same time, too. Because of this, most galaxies have cluster populations of pretty similar ages, both in terms of overall cluster, and individual stars. However, PGC 6240 is unusual in that its clusters are varied — while some do contain old stars, as expected, others contain younger stars which formed more recently.
The most likely explanation for both the galaxy's stacked shell structure and the unexpectedly young star clusters is that PGC 6240 merged with another galaxy at some point in the recent past. Such a merger would send ripples through the galaxy and disrupt its structure, forming the concentric shells of material seen here. It would also ignite a strong burst of star formation in the galaxy, which would then trigger similar activity in nearby space — leading to the creation of new, younger globular clusters around PGC 6240.
PGC 6240 is an elliptical galaxy in the southern constellation of Hydrus (The Water Snake). Also visible in this region are numerous background galaxies, speckled across the sky behind PGC 6240. Even though these bodies are at such vast distances from us, it is possible to make out the structure of many of the galaxies, especially the small spirals that stand out colourfully against the dark sky.
A version of this image was entered into the Hubble's Hidden Treasures image processing competition by contestant Judy Schmidt.
INFORMATION:
Notes
[1] Hidden Treasures is an initiative to invite astronomy enthusiasts to search the Hubble archive for stunning images that have never been seen by the general public. The competition is now closed, and the list of winners is available here: http://www.spacetelescope.org/announcements/ann1211.
More information
The Hubble Space Telescope is a project of international cooperation between
ESA and NASA.
Links
Images of Hubble - http://www.spacetelescope.org/images/archive/category/spacecraft/
Hubble's Hidden Treasures - http://www.spacetelescope.org/projects/hiddentreasures/contest/
Contacts
Nicky Guttridge
Hubble/ESA
Garching, Germany
Tel: +44-75-1231-8322
Email: nguttrid@partner.eso.org
Soft shells and strange star clusters
2013-10-10
ELSE PRESS RELEASES FROM THIS DATE:
Direct 'writing' of artificial cell membranes on graphene
2013-10-10
Writing in Nature Communications, researchers at The University of Manchester led by Dr Aravind Vijayaraghavan, and Dr Michael Hirtz at the Karlsruhe Institute of Technology (KIT), have demonstrated that membranes can be directly 'written' on to a graphene surface using a technique known as Lipid Dip-Pen Nanolithography (L-DPN).
The human body contains 100 trillion cells, each of which is enveloped in a cell membrane which is essentially a phospholipid bi-layer membrane. These cell membranes have a plethora of proteins, ion channels and other molecules embedded in them, ...
Look out above! Experiment explores innate visual behavior in mice
2013-10-10
When you're a tiny mouse in the wild, spotting aerial predators—like hawks and owls—is essential to your survival. But once you see an owl, how is this visual cue processed into a behavior that helps you to avoid an attack? Using an experimental video technique, researchers at the California Institute of Technology (Caltech) have now developed a simple new stimulus with which they can spur the mouse's escape plans. This new stimulus allows the researchers to narrow down cell types in the retina that could aid in the detection of aerial predators.
"The mouse has recently ...
Super-enhancers seen as 'Rosetta Stone' for dialog between genes and disease
2013-10-10
CAMBRIDGE, Mass. (October 10, 2013) – Having recently discovered a set of powerful gene regulators that control cell identity in a few mouse and human cell types, Whitehead Institute scientists are now showing that these regulators—which they named "super-enhancers"—act across a vast array of human cell types and are enriched in mutated regions of the genome that are closely associated with a broad spectrum of diseases.
The findings, published online today by the journal Cell, suggest that these super-enhancers, first described in Cell several months ago by Whitehead ...
Genes predispose some people to focus on the negative
2013-10-10
A new study by a University of British Columbia researcher finds that some people are genetically predisposed to see the world darkly.
The study, published in Psychological Science, finds that a previously known gene variant can cause individuals to perceive emotional events—especially negative ones – more vividly than others.
"This is the first study to find that this genetic variation can significantly affect how people see and experience the world," says Prof. Rebecca Todd of UBC's Dept. of Psychology. "The findings suggest people experience emotional aspects of ...
Scientists find potential new targets for anti-inflammatory therapies
2013-10-10
LA JOLLA, CA -- October 9, 2013 -- A team led by scientists at The Scripps Research Institute (TSRI) has identified key signaling proteins in the inflammation process that contribute to the development of inflammatory diseases such as rheumatoid arthritis, psoriasis, sepsis and inflammatory bowel diseases. The finding highlights possible new ways of treating these inflammation disorders, which sicken or kill millions of people around the world each year.
"We hope our approach will lead to the development of drugs that augment current anti-inflammatory strategies," said ...
Gene movements observed in vivo
2013-10-10
This new method will be a great step forwards to understanding the resulting processes that control gene regulation.
These results were published on October 6, 2013 on the website of the review Nature Structural & Molecular Biology.
In the cell nucleus, DNA is highly dynamic and changes its spatial configuration, in the same way as during the process of cell division. We already know that the spatial configuration of DNA determines whether the genes are active or inactive, in other words whether they are capable of expression. In this study, the researchers attempted ...
Correcting emotional misunderstandings
2013-10-10
When we are sad the world seemingly cries with us. On the contrary, when we are happy everything shines and all around people's faces seem to rejoyce with us. These projection mechanisms of one's emotions onto others are well known to scientists, who believe they are at the core of the ability to interpret and relate to others. In some circumstances, however, this may lead to gross mistakes (called egocentricity bias in the emotional domain EEB), to avoid them cerebral mechanisms are activated about which still little is known.
Giorgia Silani, a neuroscientist at SISSA, ...
Weight loss through the use of intestinal barrier sleeves
2013-10-10
Bariatric surgeries, such as a gastric bypass, are currently the most effective anti-obesity therapies. They also lead to a reduced insulin resistance. However, the pitfall of these surgical interventions is that they are highly invasive and often permanent procedures. An international team of scientists led by Dr. Kirk Habegger, Metabolic Disease Institute, University of Cincinnati, and Prof. Dr. Matthias Tschöp, Scientific Director of the Helmholtz Diabetes Center (HDC) at the Helmholtz Zentrum München (HMGU), Partner of the German Center for Diabetes Research (DZD), ...
Malaria, toxoplasmosis: Toward new lines of research?
2013-10-10
This work, published on 10th October on the website of Nature Communications, concerns the role of one protein which is common to these parasites. Called AMA1, it has been at the heart of many years' research on upgrading treatments, such as trying out vaccination against malaria. However, the present authors have reservations about the success of therapeutic strategies which rely solely on the blockage of AMA1, by demonstrating that the malaria and toxoplasmosis parasites, without the protein, can develop normally.
With 1 million victims every year, malaria is the most ...
I'm ok, you're not ok
2013-10-10
This news release is available in German. Egoism and narcissism appear to be on the rise in our society, while empathy is on the decline. And yet, the ability to put ourselves in other people's shoes is extremely important for our coexistence. A research team headed by Tania Singer from the Max Planck Institute for Human Cognitive and Brain Sciences has discovered that our own feelings can distort our capacity for empathy. This emotionally driven egocentricity is recognised and corrected by the brain. When, however, the right supramarginal gyrus doesn't function properly ...