Starship Asterisk*

by **geckzilla** » Sun Oct 06, 2013 11:19 pm

BillBixby wrote:Today's picture and discussion sure looks like yesterday's news. I am looking forward to this government shutdown fiasco ending.

Yeah, it's fixed now. Not sure how that happened.

by **Boomer12k** » Sun Oct 06, 2013 11:09 pm

Sooooo......The FIREWORKS GALAXY?????

:---[===] *

by **Anthony Barreiro** » Sun Oct 06, 2013 10:27 pm

APOD Robot wrote:Active galaxy NGC 1275 is the central, dominant member of the large and relatively nearby Perseus Cluster of Galaxies. ... Also known as Perseus A, NGC 1275 spans over 100,000 light years and lies about 230 million light years away.

I wouldn't usually consider something at a distance of 230 million light years "relatively nearby", but I guess if we're talking about galaxy clusters that would be an accurate statement. Guy Ottewell's Astronomical Companion shows only 16 galaxy clusters within 1.5 billion light years of Earth, nine of which appear to be as close as or closer than the Perseus cluster. Space is big.

by **BillBixby** » Sun Oct 06, 2013 8:42 pm

Today's picture and discussion sure looks like yesterday's news. I am looking forward to this government shutdown fiasco ending.

by **LocalColor** » Sun Oct 06, 2013 3:23 pm

Beyond wrote:Yes, it certainly is wild looking for a galaxy. From that picture, i would never have guessed it to actually be a galaxy. Space can be very strange

I agree, very wild.

Thank you APOD.

by **neufer** » Sun Oct 06, 2013 11:27 am

Ann wrote:
I'm wondering about the colors of the picture and the filters that were used to obtain it. The red filaments can definitely be assumed to be Ha. Other galaxies have outflows of Ha, most notably M82 and M106. So I'm going to assume that the red outflows are Ha emission from ionized gas outflows. What are the blue outflows, though? I haven't seen blue outflows like the ones in NGC 1275 in a color picture of any other galaxy.

http://en.wikipedia.org/wiki/NGC_1275 wrote:
<<NGC 1275 (also known as Perseus A or Caldwell 24) is a type 1.5 Seyfert galaxy located around 237 million light-years away in the direction of the constellation Perseus. NGC 1275 corresponds to the radio galaxy Perseus A and is situated near the centre of the large Perseus Cluster of galaxies.

NGC 1275 consists of two galaxies, a central type-cD galaxy in the Perseus Cluster, and a so-called "high velocity system" (HVS) which lies in front of it. The HVS is moving at 3000 km/s towards the dominant system, and is believed to be merging with the Perseus Cluster. The HVS is not affecting the cD galaxy as it lies at least 200 thousand light years from it.

The central cluster galaxy contains a massive network of spectral line emitting filaments, which apparently are being dragged out by rising bubbles of relativistic plasma generated by the central active galactic nucleus. Long gaseous filaments made up of threads of gas stretch out beyond the galaxy, into the multimillion-degree, X-ray–emitting gas that fills the cluster. The amount of gas contained in a typical thread is approximately one million times the mass of our own Sun. They are only 200 light-years wide, are often very straight, and extend for up to 20,000 light-years.

The existence of the filaments poses a problem. As they are much cooler than the surrounding intergalactic cloud, how have they persisted for perhaps 100 million years? Why haven’t they warmed, dissipated or collapsed to form stars? One possibility is that weak magnetic fields (about one-ten-thousandth the strength of Earth’s field) exert enough force on the ions within the threads to keep them together.>>

by **Ann** » Sun Oct 06, 2013 10:44 am

It's a great picture and a fascinating galaxy.

As usual, I'm wondering about the colors of the picture and the filters that were used to obtain it. The red filaments can definitely be assumed to be Ha. Other galaxies have outflows of Ha, most notably M82 and M106.

So I'm going to assume that the red outflows are Ha emission from ionized gas outflows. What are the blue outflows, though? I haven't seen blue outflows like the ones in NGC 1275 in a color picture of any other galaxy.

According to Hubblesite, NGC 1275 was imaged by Hubble through the following filters: F435W (B), F550M (V), and F625W (r). The wideband red filter would detect the Ha emission, but what about the blue filaments? The blue filter is a wideband one, and it might possibly detect near ultraviolet light, too. Could the filter have detected ultraviolet emission of some sort? Or are we just seeing the light of young blue clusters?

Ann

by **Beyond** » Sun Oct 06, 2013 4:09 am

Yes, it certainly is wild looking for a galaxy. From that picture, i would never have guessed it to actually be a galaxy. Space can be very strange

by **APOD Robot** » Sun Oct 06, 2013 4:02 am

Hubble Remix: Active Galaxy NGC 1275

Explanation: Active galaxy NGC 1275 is the central, dominant member of the large and relatively nearby Perseus Cluster of Galaxies. Wild-looking at visible wavelengths, the active galaxy is also a prodigious source of x-rays and radio emission. NGC 1275 accretes matter as entire galaxies fall into it, ultimately feeding a supermassive black hole at the galaxy's core. This color composite image, recreated from archival Hubble Space Telescope data, highlights the resulting galactic debris and filaments of glowing gas, some up to 20,000 light-years long. The filaments persist in NGC 1275, even though the turmoil of galactic collisions should destroy them. What keeps the filaments together? Observations indicate that the structures, pushed out from the galaxy's center by the black hole's activity, are held together by magnetic fields. Also known as Perseus A, NGC 1275 spans over 100,000 light years and lies about 230 million light years away.

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