Explanation: Enigmatic spiral galaxy NGC 1097 shines in southern skies, about 45 million light-years away in the chemical constellation Fornax. Its blue spiral arms are mottled with pinkish star forming regions in this colorful galaxy portrait. They seem to have wrapped around a small companion galaxy below and left of center, about 40,000 light-years from the spiral's luminous core. That's not NGC 1097's most peculiar feature, though. The very deep exposure hints of faint, mysterious jets, most easily seen to extend well beyond the bluish arms toward the lower right. In fact, four faint jets are ultimately recognized in optical images of NGC 1097. The jets trace an X centered on the galaxy's nucleus, but probably don't originate there. Instead, they could be fossil star streams, trails left over from the capture and disruption of a much smaller galaxy in the large spiral's ancient past. A Seyfert galaxy, NGC 1097's nucleus also harbors a supermassive black hole.
Oh, interesting. Even before reading the description I was dubious about naming them jets. If it is more likely that they are star streams with a coincidentally jet-shaped pattern, is it really appropriate to call them jets?
Just call me "geck" because "zilla" is like a last name.
Geckzilla quetions calling them jets: "is it really appropriate to call them jets?" Vapor trails might do as well since they lines of faint stars presumably formed eons ago from tidal tails of small galaxies which interacted with NGC 1097. These jets though are pretty hard to see in the colored images but show up readily in the old black and white images. Good ole faint stars are the kinds we all like the most...kinda reminds you of home and mom & dad.
geckzilla wrote:
Oh, interesting. Even before reading the description I was dubious about naming them jets. If it is more likely that they are star streams with a coincidentally jet-shaped pattern, is it really appropriate to call them jets?
Geckzilla quetions calling them jets: "is it really appropriate to call them jets?" Vapor trails might do as well since they lines of faint stars presumably formed eons ago from tidal tails of small galaxies which interacted with NGC 1097. These jets though are pretty hard to see in the colored images but show up readily in the old black and white images. Good ole faint stars are the kinds we all like the most...kinda reminds you of home and mom & dad.
I was waiting to see if anyone commented on the one in the 3 o'clock position that seems to make a 90' turn. I thought that was a bit strange. What in space makes right angles?
Wow that has gotta be the deepest image of this amazing galaxy!!! I have never seen hints of tidal arms at the edges and starforming complexes extending quite far from the main disk!
The "jets" were the interpretation when they were first discovered but in the past decade have been found to be tidal streams caused by interactions with previous companions that got too close and were presumably cannibalised.
Beyond wrote:
I was waiting to see if anyone commented on the one in the 3 o'clock position that seems to make a 90' turn. I thought that was a bit strange. What in space makes right angles?
Are you talking about the line artifact
(like the one in the upper left corner?)
Beyond wrote:
I was waiting to see if anyone commented on the one in the 3 o'clock position that seems to make a 90' turn. I thought that was a bit strange. What in space makes right angles?
Are you talking about the line artifact
(like the one in the upper left corner?)
Hmm... i don't see anything in the upper left corner. In your picture it's labeled Jet 2.
Beyond wrote:
I was waiting to see if anyone commented on the one in the 3 o'clock position that seems to make a 90' turn. I thought that was a bit strange. What in space makes right angles?
Are you talking about the line artifact
(like the one in the upper left corner?)
Hmm... i don't see anything in the upper left corner. In your picture it's labeled Jet 2.
I frankly can't spot jets 3 and 4 in today's APOD, but jets 1 and 2 are obvious. They look neutral-colored to me. If they are made of stars, they must be either old or intermediately-aged stars, likely slightly (but not much) redder than the Sun.
Martin Pugh's beautiful image shows two blue spiral arms (and a lot of blue fluff around the companion galaxy). There is a lot of star formation here.
But look at the inter-arm regions of the galaxy. There is an extensive, although faint, disk here made up of old or intermediately-aged stars. (And there is dark matter, dust and planets here too, of course, but that's beside the point here.)
In fact, I'd say that the disk away from the spiral arms and star formation regions looks very slightly reddish. To me, jets 1 and 2 seem to be basically the same color as the non-starforming disk. To me that suggests that jets 1 and 2 may be made up of relatively old, faint stars.
Zoom into Markarian 739, a nearby galaxy hosting two monster black holes.
Using NASA's Swift and Chandra, astronomers have shown that both black holes
are producing energy as gas falls into them. The object is only the second-known
binary active galactic nucleus within half-a-billion light-years. (Animation begins
with visible light view of Markarian 739 and transitions into an artistic rendering
of the two black holes. Credit: NASA's Goddard Space Flight Center)
Nearby Galaxy Boasts Two Monster Black Holes, Both Active
NASA Swift, 06.10.11
<<A study using NASA's Swift satellite and the Chandra X-ray Observatory has found a second supersized black hole at the heart of an unusual nearby galaxy already known to be sporting one. The galaxy, which is known as Markarian 739 or NGC 3758, lies 425 million light-years away toward the constellation Leo. Only about 11,000 light-years separate the two cores, each of which contains a black hole gorging on infalling gas. The study will appear in a forthcoming issue of The Astrophysical Journal Letters.
"At the hearts of most large galaxies, including our own Milky Way, lies a supermassive black hole weighing millions of times the sun's mass," said Michael Koss, the study's lead author at NASA's Goddard Space Flight Center in Greenbelt, Md., and the University of Maryland in College Park (UMCP). "Some of them radiate billions of times as much energy as the sun."
Astronomers refer to galaxy centers exhibiting such intense emission as active galactic nuclei (AGN). Yet as common as monster black holes are, only about one percent of them are currently powerful AGN. Binary AGN are rarer still: Markarian 739 is only the second identified within half a billion light-years.
Since 2004, the Burst Alert Telescope (BAT) aboard Swift has been mapping high-energy X-ray sources all around the sky. The survey is sensitive to AGN up to 650 million light-years away and has uncovered dozens of previously unrecognized systems. Follow-up studies by Koss and colleagues published in 2010 reveal that about a quarter of the Swift BAT AGN were either interacting or in close pairs, with perhaps 60 percent of them poised to merge in another billion years. "If two galaxies collide and each possesses a supermassive black hole, there should be times when both black holes switch on as AGN," said coauthor Richard Mushotzky, professor of astronomy at UMCP. "We weren't seeing many double AGN, so we turned to Chandra for help."
For decades, astronomers have known that the eastern nucleus of Markarian 739 contains a black hole that is actively accreting matter and generating prodigious energy. The Chandra study shows that its western neighbor is too. This makes the galaxy one of the nearest and clearest cases of a binary AGN. The distance separating the two black holes is about a third of the distance separating the solar system from the center of our own galaxy. The dual AGN of Markarian 739 is the second-closest known, both in terms of distance from one another and distance from Earth. However, another galaxy known as NGC 6240 holds both records.
How did the second AGN remain hidden for so long? "Markarian 739 West shows no evidence of being an AGN in visible, ultraviolet and radio observations," said coauthor Sylvain Veilleux, a professor of astronomy at UMCP. "This highlights the critical importance of high-resolution observations at high X-ray energies in locating binary AGN.">>
My question is, 'Why are the 'jets' straight when the arms of the galaxy show definate evidence of rotational forces? One would have thought that if the jets wee associated with the galaxy they too would show rotational forces. To me at least it simple doesn't make sense that straight jet lies can come out of an object that is rotating.
Historycalling wrote:My question is, 'Why are the 'jets' straight when the arms of the galaxy show definate evidence of rotational forces? One would have thought that if the jets wee associated with the galaxy they too would show rotational forces. To me at least it simple doesn't make sense that straight jet lies can come out of an object that is rotating.
There are no "rotational forces" in a galaxy. There are only billions of individual stars, and gravitationally bound clumps of gas and dust, which are orbiting the galaxy's center of mass. Material that is dragged out of the galaxy is no longer in a closed orbit. It may move nearly straight, or appear slightly curved, depending on its velocity and our point of view.
Chris
*****************************************
Chris L Peterson
Cloudbait Observatory https://www.cloudbait.com
One of the jets of NGC 1097 (at about 3 o'clock) appears to turn suddenly at right angles. This could simply be a remnant bow shock.
Compare the "broken jet" of NGC 1097 with this umbrella-shaped jet of NGC 4651. The jet of NGC 4651 is clearly a star stream made up of relatively old star, and it ends abruptly in a large bow shock.
I don't think the shells and various shapes formed by galaxy mergers can really be called bow shocks. It just happens to be shaped similarly in that one instance for NGC 4651 but the reason for it forming is completely different.
Just call me "geck" because "zilla" is like a last name.
It looks to me like a lot of gas and dust are being pulled into the center of the galaxy. Indeed there is a ring around the central object that may well be an accretion disk. This movement of mass from the outer reaches of the bar towards the center may well be behind the phenomenon of jets 1 and 3. Perhaps the jets are due to the same mechanism that creates them for young stars. Of course, that implies that the central object is young.
FWIW - I see this as being the later stages of a galactic merger. Early on a bridge forms between the cores of the galaxies. If the bridge is big enough, a new core starts to build up in its center, and brings the former galaxies into orbit around itself. The really wild thing is that the central objects in the galaxies somehow get disrupted as this happens, and their stuffs gets pulled in towards the new central object. I'm OK with the central objects not being black holes, but even so the loss of something that has millions of solar masses needs a coherent explanation, and I do not have that yet. Maybe the formation of a line of mass heading to the new center weakens the gravitational gradient and a very quick flow of mass results. Whatever happens, it must be quick since otherwise it would be easily observed. (Maybe some very odd looking collisions are undergoing the process. I'm just not sure.) In any case, the would explain the ongoing flow of mass to the center and therefore the jets.
Jets 2 and 4 appear to not be connected, BTW. They appear to be older jets, created before something caused the orientation of the central object to change. (Perhaps a sudden influx of mass from somewhere did that. It does dovetail with my ideas nicely.)
ems57fcva wrote:It looks to me like a lot of gas and dust are being pulled into the center of the galaxy. Indeed there is a ring around the central object that may well be an accretion disk.
Nope. There is no mechanism to pull anything into the center. And an accretion disc around a central massive black hole would be too small to see at this scale by orders of magnitude- smaller than one pixel.
Chris
*****************************************
Chris L Peterson
Cloudbait Observatory https://www.cloudbait.com
ems57fcva wrote:It looks to me like a lot of gas and dust are being pulled into the center of the galaxy. Indeed there is a ring around the central object that may well be an accretion disk.
Nope. There is no mechanism to pull anything into the center. And an accretion disc around a central massive black hole would be too small to see at this scale by orders of magnitude- smaller than one pixel.
That ring has all of the hallmarks of an accretion disk in so far as I am concerned. What makes an accretion disk? Is it not the angular momentum of a large enough amount of gas and dust getting squeezed together as it heads into a central object? And just look at the dust lanes, how they turn into that ring! It speaks to me of infalling gas and dust being sent into a large orbit around the central object.
I will not say that your comment about the usual accretion disk is much off-base however. If it is an accretion disk, then oh-my-God the amount of matter that must be moving towards the central object to create it! It fits my paradigm, but even in that case it is very mind-boggling. I wonder what measurements can be made that could make (or break) my point. If there are massive amounts of gas on the move there (albeit without all that much speed given how far from the central object the ring structure is), there should be some was to say if it really is infalling and at what rate.
ems57fcva wrote:It looks to me like a lot of gas and dust are being pulled into the center of the galaxy. Indeed there is a ring around the central object that may well be an accretion disk.
Nope. There is no mechanism to pull anything into the center. And an accretion disc around a central massive black hole would be too small to see at this scale by orders of magnitude- smaller than one pixel.
That ring has all of the hallmarks of an accretion disk in so far as I am concerned. What makes an accretion disk? Is it not the angular momentum of a large enough amount of gas and dust getting squeezed together as it heads into a central object? And just look at the dust lanes, how they turn into that ring! It speaks to me of infalling gas and dust being sent into a large orbit around the central object.
I will not say that your comment about the usual accretion disk is much off-base however. If it is an accretion disk, then oh-my-God the amount of matter that must be moving towards the central object to create it! It fits my paradigm, but even in that case it is very mind-boggling. I wonder what measurements can be made that could make (or break) my point. If there are massive amounts of gas on the move there (albeit without all that much speed given how far from the central object the ring structure is), there should be some was to say if it really is infalling and at what rate.
Dude, it's just a galaxy. Accretion discs are too small to ever image directly. Go ahead and search for pictures. You won't find anything but concept art.
Just call me "geck" because "zilla" is like a last name.
The Jets of NGC 1097
Are you talking about the line artifact
