* Astronomy

Blobrana · L

RE: ESO 137-001

Blobrana · L

Life Is Too Fast, Too Furious for This Runaway Galaxy

Our spiral-shaped Milky Way galaxy lives in a comparatively quiet backwater region of the universe. This is not the case for galaxies crammed together inside huge clusters. As they zip around within a cluster, gas can be pulled from their disks due to a process called ram pressure stripping. Galaxy ESO 137-001 is one example. The star-city looks like it is "leaking" as it plunges through the Norma galaxy cluster.
Read more

Blobrana · L

Nearby Galaxy shows spectacular X-ray tails with embedded active star formation

In one of the nearest giant clusters of galaxies, Abell 3627, astronomers have reported finding a galaxy with two distinct tails of gas. Of particular significance, there are unambiguous signs of current star formation in this gas tail, providing the first evidence that star formation can actively take place in the cold intergalactic medium. These results challenge ideas based on the current computer simulations and modelling.
Read more

Blobrana · L

"Crazy" and "cool" are two of the words Michigan State University astronomer Megan Donahue uses to describe the two distinct "tails" found on a long tail of gas that is believed to be forming stars where few stars have been formed before.
Donahue was part of an international team of astronomers that viewed the gas tail with a very long, new observation made by the Chandra X-ray Observatory and detailed it in a paper published this month in the publication Astrophysical Journal.
Read more

Blobrana · L

ESO 137-001: Two Tails to Tell

Two spectacular tails of X-ray emission have been seen trailing behind a galaxy using the Chandra X-ray Observatory. A composite image of the galaxy cluster Abell 3627 shows X-rays from Chandra in blue, optical emission in yellow and emission from hydrogen light -- known to astronomers as "H-alpha" -- in red. The optical and H-alpha data were obtained with the Southern Astrophysical Research (SOAR) Telescope in Chile.
At the front of the tail is the galaxy ESO 137-001. The brighter of the two tails has been seen before and extends for about 260,000 light years. The detection of the second, fainter tail, however, was a surprise to the scientists.
Read more

Credit X-ray: NASA/CXC/UVa/M. Sun, et al; H-alpha/Optical: SOAR (UVa/NOAO/UNC/CNPq-Brazil)/M.Sun et al.

Position(2000): RA 16h 13m 25.59s, Dec -60° 45' 43.10

Blobrana · L

ESO 137-001 is a member of Abell Cluster 3627a swarm of galaxies 65 Megaparsecs (212 million light years) from Earth. ESO 137-001 stands out among other galaxies in the cluster because it has a gigantic comet-like tail peppered with young stars.

"We call them orphan stars, because they are separating from their parent" - Megan Donahue, Michigan State University.

Read more

Blobrana · L

The stars' youth means they cannot have formed in a galaxy. Instead, they must have formed in the cloud itself, which was ripped out of ESO 137-001 by so-called ram pressure, when the galaxy plunged through a zone of high-temperature gas within the Abell 3627 cluster. That also means much of the raw material for new stars was removed from the galaxy itself, severely inhibiting its own ability to form stars.

"Our observations have revealed a new mechanism for populating intergalactic space with stars" - Michigan State University astronomer and co-author Mark Voit.

Source

Position (J2000): RA 16h 12m 39.43s | Dec 60° 47' 02.71''

ESO 137-001.kmz
Google Sky file

-- Edited by Blobrana at 14:51, 2008-01-12

Blobrana · L

Galaxy sports vast comet-like tail
Orphaned stars are being born in a vast tail of material stretching behind a faraway galaxy, astronomers said today.
The finding is evidence that orphaned stars those not orbiting the centre of a galaxy in normal fashion are much more common than thought.
The feature extends for more than 200,000 light-years and was created as gas was stripped from the galaxy. For comparison, our solar system is about 26,000 light-years from the centre of the Milky Way, and we're said to be in the galactic outskirts.

Source

Blobrana · L

Orphan Stars Found in Long Galaxy Tail


Credit: X-ray: NASA/CXC/MSU/M.Sun et al; H-alpha/Optical: SOAR (MSU/NOAO/UNC/CNPq-Brazil)/M.Sun et al.
JPEG (273 kb)	Tiff (4.8 MB)	PS (6.6 MB)

This composite image of X-ray and optical light shows a tail that has been created as a galaxy plunges into a cluster, shedding material and forming stars behind it. In this image, X-rays from NASA's Chandra X-ray Observatory (blue) are seen to extend for over 200,000 light years behind the galaxy called ESO 137-001. Emission from hydrogen light (red), known to astronomers as "H-alpha", and the continuum of optical light (white) were gathered from the Southern Astrophysical Research telescope (SOAR) in Chile.

X-ray & H-alpha

The tail was created as gas was stripped from ESO 137-001 as it descends toward the centre of Abell 3627, a giant cluster of galaxies. The tail in X-rays reveals multimillion-degree gas from the cluster and the H-alpha radiation, which stretches for about 130,000 light years, is much cooler gas. Evidence for star formation in this tail includes 29 regions of ionised hydrogen that are glowing in H-alpha, from the light of newly formed stars. These regions are all downstream of the galaxy, located in or near the tail. The researchers believe the stars formed in the tail within the last 10 million years or so. Two Chandra X-ray sources near these regions represent extra evidence for star formation activity.

Read more