APOD: Filaments of Active Galaxy NGC 1275 (2017 Apr 05)

[APOD Robot]

Filaments of Active Galaxy NGC 1275

Explanation: What keeps these filaments attached to this galaxy? The filaments persist in NGC 1275 even though the turmoil of galactic collisions should destroy them. First, 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 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. 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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[neufer]

https://pbs.twimg.com/profile_images/75 ... 00x400.jpg

[Guest]

I would like to propose an informal name for this galaxy: "the star child". Can you see the left leg descending toward the bottom of the screen, two arms extending toward the left, right above left, and the dome of the cranium delicately enclosing the galactic core?

[Boomer12k]

A galaxy in shock.... poor thing....

Hmmm... Magnetic Fields... OK... held in place like the Prominences of The Sun....and evidently strong enough not to be too disturbed or disrupted by mergers...

:---[===] *

[MikeA]

I'm noticing a faint donut shape around the smaller elliptical bottom right .... ??

[Ann]

Click to view full size image

NGC 1275. Source:
https://www.spacetelescope.org/news/heic0817/

Today's APOD is a very interesting portrait of a fascinating active galaxy. It looks different than the most common Hubble pictures of NGC 1275, of which one can be seen (at fairly low resolution) at left. For example, there is just a little bit of red in the APOD, which can indeed be due to bright ionized hydrogen.

Click to view full size image

NGC 1275 in the Perseus Cluster.
Photo: R. Jay GaBany.

NGC really "sticks out like a sore thumb" in the Perseus Cluster! NGC 1275 is a giant elliptical galaxy like several others in the cluster, but it is an elliptical galaxy with a twist - an elliptical galaxy in the process of merging with a spiral galaxy.

Click to view full size image

In the galaxy cluster NGC 1275, bubbles appear to be generated by high-speed
jets blasting away from the vicinity of the giant galaxy's supermassive black hole.
Individual bubbles seen in the inner regions expand and merge to create
vast plumes at larger distances.
Credit: NASA/CXC/IoA/J.Sanders et al.

One intriguing fact about active galaxies with jets is that they are almost always merging with another galaxy, or else they have recently undergone such a merger.

ESA/HEIC wrote:
In the most extensive survey of its kind ever conducted, a team of scientists have found an unambiguous link between the presence of supermassive black holes that power high-speed, radio-signal-emitting jets and the merger history of their host galaxies. Almost all of the galaxies hosting these jets were found to be merging with another galaxy, or to have done so recently. The results lend significant weight to the case for jets being the result of merging black holes and will be presented in the Astrophysical Journal.

Well, NGC 1275 is most definitely merging, and it is indeed a radio galaxy.

Philip Ball of Nature wrote:
An immense black hole 250 million light years away is blowing the lowest B flat ever heard.

It sits at the hub of a giant galaxy called NGC 1275, in the Perseus cluster of galaxies. The satellite-borne Chandra X-ray Observatory has spotted ripples in the gas dispersed throughout the cluster.

These ripples of high- and low-density gas are like sound waves in air. But their frequency is far lower than the deepest sound audible to the human ear. A keyboard capable of producing the note would have 57 octaves below middle C and would have a keyboard more than 15 metres long.

So does NGC 1275 produce jets? Yes, it would seem so, according to the caption to the NASA/CXC/IoA/J.Sanders et al. picture of NGC 1275. It said, In the galaxy cluster NGC 1275, bubbles appear to be generated by high-speed jets blasting away from the vicinity of the giant galaxy's supermassive black hole.

So I guess that NGC 1275 is one of those galaxies with jets! It is perhaps good for us that the nearest merging galaxy with jets, NGC 5128 or Cen A, is fairly small stuff compared with a galaxy like NGC 1275.

Ann

[Tom Fleming]

For reference on the image: There are two stars of similar brightness flanking the galaxy at the Three and Nine O'clock positions. Slightly tilted from that reference, there appears to be a dark line (not absorption but a lack of light) one each side of the galaxy. Is this an artifact of image processing or is there some other explanation?

[tomatoherd]

Today's image is mirror-image of the two links here in the discussion, one of which is the "Perseus cluster..." link in the third sentence. I can understand rotation of images, since there is no "up" in space, but is flipping back and forth from mirror to reality acceptable practice??

[Coil_Smoke]

If You Look Real Close ...

[Case]

For reference on the image: There are two stars of similar brightness flanking the galaxy at the Three and Nine O'clock positions. Slightly tilted from that reference, there appears to be a dark line (not absorption but a lack of light) one each side of the galaxy. Is this an artifact of image processing or is there some other explanation?

Well spotted! Further brightness tweaking reveals that it appears to be a seam where two images are stitched together, as it is in the background from left to right. Perhaps it is tilted 3.5° because of multiple layers of images and the base image had a sightly different orientation? Notice the mouse-over for the second image on this HH-page is similarly tilted.

[Ann]

I'm noticing a faint donut shape around the smaller elliptical bottom right .... ??

That is barred galaxy that has mostly lost all of its features except its bar.

Click to view full size image

The Large Magellanic Cloud.
Photo: Eckhard Slawik.

Consider the Large Magellanic Cloud. Practically everyone is most interest in the Tarantula Nebula when it comes to the LMC, but it is really the bar that is the LMC:s most stable and long-lasting feature. If the LMC were to "run out of gas" by some means - by having it stolen by the Milky Way? - so that its star formation stopped, most of the galaxy's blue features would simply fade away and become insignificant. What would be left is the bar.

Click to view full size image

NGC 1073.
Photo: NASA/ESA/Hubble.

Most barred galaxies have what the LMC lacks, namely a bright nucleus and a set of spiral arms. Many also have a ring. Consider NGC 1073. It has a bright nucleus and a ring surrounding the bar. (The ring may be two overlapping spiral arms, but never mind.) If you compare the picture of the LMC with the picture of NGC 1073, you can see that the LMC also seems to have the beginnings of ring fragments at the ends of its bar.

Click to view full size image

NGC 936. Source:
https://skyserver.sdss.org/dr12/en/tool ... page1.aspx

When a galaxy runs out of gas, which often happens to galaxies in dense clusters, star formation will come to an end, the brightest stars will disappear and die, and the overall populations will become ever more yellow. Also the the interesting features of the galaxy - the spiral arms, the dust lanes - will become ever more blurred and muted. But the brightest, most well-established features will remain the longest - such as the galactic bar, and even some hints of a ring. The ring will typically be brightest near the ends of the bar, as is the case in NGC 936.

So I'd say that the elongated, "donut-shaped" galaxy at bottom left in the APOD is a barred galaxy that has lost almost all of its features. Like the LMC, it may never have had a bright nucleus. It did have a ring, and we can actually still see a faint ring. And we can see typical bar-end enhancements, which seem to make the bar flare out at both ends.

Ann

[Fred the Cat]

Do you suppose there is a catalogue of the most precisely face-on galaxies so far discovered? I'd be curious how face-on this one is though, exactly how face-on it is may be difficult to determine. Or easy if the type or intensity of EM radiation detected gives an indication.

I know some worry about being right in the line-of-sight but do we know how it would appear visually?

[Ann]

Do you suppose there is a catalogue of the most precisely face-on galaxies so far discovered? I'd be curious how face-on this one is though, exactly how face-on it is may be difficult to determine. Or easy if the type or intensity of EM radiation detected gives an indication.

I know some worry about being right in the line-of-sight but do we know how it would appear visually?

I would assume that the blazars are pretty much face-on galaxies. At the very least, their jets are believed to be aimed pretty much straight at us!

Wikipedia wrote:
A blazar is a very compact quasar (quasi-stellar radio source) associated with a presumed supermassive black hole at the center of an active, giant elliptical galaxy. Blazars are among the most energetic phenomena in the universe and are an important topic in extragalactic astronomy.[1]
...
Blazars emit a relativistic jet that is pointing in the general direction of the Earth. The jet's path corresponds with our line of sight, which accounts for the rapid variability and compact features of both types of blazars. Many blazars have apparent superluminal features within the first few parsecs of their jets, probably due to relativistic shock fronts.[2]

Ann

[MarkBour]

For reference on the image: There are two stars of similar brightness flanking the galaxy at the Three and Nine O'clock positions. Slightly tilted from that reference, there appears to be a dark line (not absorption but a lack of light) one each side of the galaxy. Is this an artifact of image processing or is there some other explanation?

Well spotted! Further brightness tweaking reveals that it appears to be a seam where two images are stitched together, as it is in the background from left to right. Perhaps it is tilted 3.5° because of multiple layers of images and the base image had a sightly different orientation? Notice the mouse-over for the second image on this HH-page is similarly tilted.

At a similar angle are some extra lines through the two foreground stars most nearly below that region. They blend in with the diffraction spikes, but not quite.

[Ann]

Click to view full size image

An artist's impression of 3C321 shows the main galaxy and the companion galaxy.
A jet of particles generated by a supermassive black hole at the center of the main
galaxy is striking the companion galaxy. The jet is disrupted and deflected by this
impact. NASA/CXC/M. Weiss

By the way, jets from a galaxy can hit you!

Space.com wrote:
For the first time astronomers have witnessed a supermassive black hole blasting its galactic neighbor with a deadly beam of energy.

The "death star galaxy," as NASA astronomers called it, could obliterate the atmospheres of planets but also trigger the birth of stars in the wake of its destructive beam. Fortunately, the cosmic violence is a safe distance from our own neck of the cosmos.

Ann

[sallyseaver]

Click to view full size image

NGC 1275. Source:
https://www.spacetelescope.org/news/heic0817/

Today's APOD is a very interesting portrait of a fascinating active galaxy. It looks different than the most common Hubble pictures of NGC 1275, of which one can be seen (at fairly low resolution) at left. For example, there is just a little bit of red in the APOD, which can indeed be due to bright ionized hydrogen.

NGC 1275 in the Perseus Cluster.
Photo: R. Jay GaBany.[/size][/c][/float] NGC really "sticks out like a sore thumb" in the Perseus Cluster! NGC 1275 is a giant elliptical galaxy like several others in the cluster, but it is an elliptical galaxy with a twist - an elliptical galaxy in the process of merging with a spiral galaxy.

Ann

Ann, thank you for the context of the other images and a discussion of the possible activity going on in the complex area of space imaged in the APOD image April 5, 2017 image of NGC1275.

Sally