APOD: M86 in the Central Virgo Cluster (2018 Aug 14)

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APOD: M86 in the Central Virgo Cluster (2018 Aug 14)

Post by APOD Robot » Tue Aug 14, 2018 4:11 am

[img]https://apod.nasa.gov/apod/calendar/S_180814.jpg[/img] M86 in the Central Virgo Cluster

Explanation: Is there a bridge of gas connecting these two great galaxies? Quite possibly, but it is hard to be sure. M86 on the upper left is a giant elliptical galaxy near the center of the nearby Virgo Cluster of galaxies. Our Milky Way Galaxy is falling toward the Virgo Cluster, located about 50 million light years away. To the lower right of M86 is unusual spiral galaxy NGC 4438, which, together with angular neighbor NGC 4435, are known as the Eyes Galaxies (also Arp 120). Featured here is one of the deeper images yet taken of the region, indicating that red-glowing gas surrounds M86 and seemingly connects it to NGC 4438. The image spans about the size of the full moon. It is also known, however, that cirrus gas in our own Galaxy is superposed in front of the Virgo cluster, and observations of the low speed of this gas seem more consistent with this Milky Way origin hypothesis. A definitive answer may come from future research, which may also resolve how the extended blue arms of NGC 4435 were created.

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Ann
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Re: APOD: M86 in the Central Virgo Cluster (2018 Aug 14)

Post by Ann » Tue Aug 14, 2018 4:50 am

This is a fantastic picture, and it raises so many questions! Why is elliptical galaxy M86 surrounded by a huge cloud of glowing hydrogen? Did it have an outburst of some sort, maybe triggered by a close encounter with NGC 4438? And how did NGC 4438 and NGC 4435 get entangled that way?

Questions, questions! All that is certain is that this is a brilliant picture! Congrats and thanks, Mark Hanson! :D :clap: :D

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Re: APOD: M86 in the Central Virgo Cluster (2018 Aug 14)

Post by peterfergusson1@hotmail.com » Tue Aug 14, 2018 6:35 am

THIS picture does not look correct,as would be many others.The telescopes are made to be getting above earths atmosphere,you show star-light in this picture with radeance lines protruding from the Virgo cluster,that should be completely free of Atmosphere,is this a trick sometimes i wonder,something the public does not pick up,but accepts whats there,arr saw the mistake,mmmm,depending on where this was taken,it might on ground opticle telescopes can;t get through earths murky atmosphere quite so easily,no matter how close they get,and in talking of LY ,that is just a human trying to be superhuman,Not Likely.Ps (Light Years)

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Re: APOD: M86 in the Central Virgo Cluster (2018 Aug 14)

Post by saturno2 » Tue Aug 14, 2018 11:15 am

Very interesting image, in special the colors

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Re: APOD: M86 in the Central Virgo Cluster (2018 Aug 14)

Post by Locutus76 » Tue Aug 14, 2018 1:05 pm

extended blue arms of NGC 4435 were created.
Shouldn’t that be the extended blue arms of NGC 4438? Based on the labeled image from the creator.

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Re: APOD: M86 in the Central Virgo Cluster (2018 Aug 14)

Post by neufer » Tue Aug 14, 2018 1:08 pm

https://en.wikipedia.org/wiki/86_(term) wrote:
<<When used as a verb, eighty-six, eighty-sixed, 86, 86ed, or 86'd is American English slang for getting rid of something, ejecting someone, or refusing service.

According to Merriam-Webster's Dictionary, "86" is a slang term that is used in the American popular culture as a transitive verb in the food service industry as a term to describe an item no longer available on the menu. The Merriam Webster dictionary suggests the term may be associated with the word "nix" ("no" or a more general prohibition). "Nix" is related to the word "Nichts", which means "nothing" in the German language.

The term is part of restaurant slang, seen among restaurant workers in the 1930s, where 86 meant "we're all out of it." Walter Winchell published examples of similar restaurant slang in his newspaper column in 1933, which he presented as part of a "glossary of soda-fountain lingo."

Several possible origins of the term 86 have been suggested, all dated before the 1950s: United States Navy decommissioning: One possible origin is from the U.S. Navy's Allowance Type (AT) coding system used for logistics. The allowance type code is a single digit that identifies the reason that material is being carried in stock. Throughout the life-cycle of a warship, many pieces of equipment are upgraded or replaced, requiring onboard spare parts to be disposed of, and the code is AT-6 for parts designated for disposal. Following World War II, there were a great number of warships being decommissioned, sold, scrapped, or deactivated and placed in reserve (commonly referred to as "mothballed"). During this process, labor workers would bring up spare parts from the storerooms and the supply clerk would tell them the AT code. Anything to be disposed of was referred to as AT-6— which is pronounced the same as "86".
  • 1947: In the song "Boogie Woogie Blue Plate" by Louis Jordan, one line is "86 on the cherry pies" as one of many examples of short-order restaurant lingo.

    1957: The main character in Gore Vidal's play Visit to a Small Planet uses the command "86" numerous times to destroy things.

    1973: Thomas Pynchon used the term "86" in Gravity's Rainbow: "They did finally 86 him out of Massachusetts Bay Colony."
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Re: APOD: M86 in the Central Virgo Cluster (2018 Aug 14)

Post by Chris Peterson » Tue Aug 14, 2018 1:41 pm

peterfergusson1@hotmail.com wrote:
Tue Aug 14, 2018 6:35 am
THIS picture does not look correct,as would be many others.The telescopes are made to be getting above earths atmosphere,you show star-light in this picture with radeance lines protruding from the Virgo cluster,that should be completely free of Atmosphere,is this a trick sometimes i wonder,something the public does not pick up,but accepts whats there,arr saw the mistake,mmmm,depending on where this was taken,it might on ground opticle telescopes can;t get through earths murky atmosphere quite so easily,no matter how close they get,and in talking of LY ,that is just a human trying to be superhuman,Not Likely.Ps (Light Years)
Telescopes don't get above Earth's atmosphere unless they are actually in space, like the Hubble Telescope. This image was made from the ground, looking through the atmosphere. And even in space, you can have spikes around stars. That is caused by the diffraction of light around the vanes that hold the secondary mirror in front of the primary mirror.
Chris

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Re: APOD: M86 in the Central Virgo Cluster (2018 Aug 14)

Post by ems57fcva » Tue Aug 14, 2018 2:57 pm

I have noticed bridges between the cores of interacting galaxies, and even suspect the merging galaxies become barred spiral galaxies with center of the bridge turning into a new common core when that happens.

In any case, the "bridge" in this picture has nothing to do with those bridges. Bridges between galaxies are usually bright and smooth, being composed of gas, dust, and stars pulled out from the galaxies, with dust lanes showing where the currents in the bridge are going. See https://apod.nasa.gov/apod/ap151209.html for an example. (Be aware that the bridge is behind a sprial arm of the galaxy on the right at first.) In this APOD, the "bridge" is red, diffuse, and braided. So I agree with this being Milky Way cirrus clouds back-lit by the galaxies.

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Re: APOD: M86 in the Central Virgo Cluster (2018 Aug 14)

Post by Ann » Tue Aug 14, 2018 3:03 pm

ems57fcva wrote:
Tue Aug 14, 2018 2:57 pm
I have noticed bridges between the cores of interacting galaxies, and even suspect the merging galaxies become barred spiral galaxies with center of the bridge turning into a new common core when that happens.

In any case, the "bridge" in this picture has nothing to do with those bridges. Bridges between galaxies are usually bright and smooth, being composed of gas, dust, and stars pulled out from the galaxies, with dust lanes showing where the currents in the bridge are going. See https://apod.nasa.gov/apod/ap151209.html for an example. (Be aware that the bridge is behind a sprial arm of the galaxy on the right at first.) In this APOD, the "bridge" is red, diffuse, and braided. So I agree with this being Milky Way cirrus clouds back-lit by the galaxies.
I agree that the apparent bridge between M86 and NGC 4438 may well be a foreground feature in the Milky Way. But that ginormous Hα halo around M86 must be a "real" feature, and it sure looks amazing to me.

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Re: APOD: M86 in the Central Virgo Cluster (2018 Aug 14)

Post by ems57fcva » Tue Aug 14, 2018 7:46 pm

Ann wrote:
Tue Aug 14, 2018 3:03 pm
ems57fcva wrote:
Tue Aug 14, 2018 2:57 pm
I have noticed bridges between the cores of interacting galaxies, and even suspect the merging galaxies become barred spiral galaxies with center of the bridge turning into a new common core when that happens.

In any case, the "bridge" in this picture has nothing to do with those bridges. Bridges between galaxies are usually bright and smooth, being composed of gas, dust, and stars pulled out from the galaxies, with dust lanes showing where the currents in the bridge are going. See https://apod.nasa.gov/apod/ap151209.html for an example. (Be aware that the bridge is behind a sprial arm of the galaxy on the right at first.) In this APOD, the "bridge" is red, diffuse, and braided. So I agree with this being Milky Way cirrus clouds back-lit by the galaxies.
I agree that the apparent bridge between M86 and NGC 4438 may well be a foreground feature in the Milky Way. But that ginormous Hα halo around M86 must be a "real" feature, and it sure looks amazing to me.

Ann
All that I see is more galactic cirrus surrounding the whitish stellar halo of M86. At the 6 o'clock position you can see where a thicker piece of cirrus is visible in front of the outer parts of M86. What I think is going on is that the relatively diffuse cirrus light is being overwhelmed by the light from M86 in the central area, and that is why it appears as a halo around the galaxy.

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Re: APOD: M86 in the Central Virgo Cluster (2018 Aug 14)

Post by Ann » Tue Aug 14, 2018 11:12 pm

ems57fcva wrote:
Tue Aug 14, 2018 7:46 pm
Ann wrote:
Tue Aug 14, 2018 3:03 pm
ems57fcva wrote:
Tue Aug 14, 2018 2:57 pm
I have noticed bridges between the cores of interacting galaxies, and even suspect the merging galaxies become barred spiral galaxies with center of the bridge turning into a new common core when that happens.

In any case, the "bridge" in this picture has nothing to do with those bridges. Bridges between galaxies are usually bright and smooth, being composed of gas, dust, and stars pulled out from the galaxies, with dust lanes showing where the currents in the bridge are going. See https://apod.nasa.gov/apod/ap151209.html for an example. (Be aware that the bridge is behind a sprial arm of the galaxy on the right at first.) In this APOD, the "bridge" is red, diffuse, and braided. So I agree with this being Milky Way cirrus clouds back-lit by the galaxies.
I agree that the apparent bridge between M86 and NGC 4438 may well be a foreground feature in the Milky Way. But that ginormous Hα halo around M86 must be a "real" feature, and it sure looks amazing to me.

Ann
All that I see is more galactic cirrus surrounding the whitish stellar halo of M86. At the 6 o'clock position you can see where a thicker piece of cirrus is visible in front of the outer parts of M86. What I think is going on is that the relatively diffuse cirrus light is being overwhelmed by the light from M86 in the central area, and that is why it appears as a halo around the galaxy.
To me it is too much of a coincidence that a bright reddish halo that is clearly surrounding M86 would be a foreground feature in the Milky Way. I can see only two possibilities for the existence of such an obvious halo, either that it is real or that it is a processing artifact. It does seem as if all or most of the galaxies in the picture do show a reddish halo, if you look closely. However, the halo of M86 is far bigger and much redder than the halos around the other galaxies.

Perhaps Mark Hanson can chime in here?

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Re: APOD: M86 in the Central Virgo Cluster (2018 Aug 14)

Post by ems57fcva » Wed Aug 15, 2018 4:06 am

Ann wrote:
Tue Aug 14, 2018 11:12 pm
ems57fcva wrote:
Tue Aug 14, 2018 7:46 pm
Ann wrote:
Tue Aug 14, 2018 3:03 pm

I agree that the apparent bridge between M86 and NGC 4438 may well be a foreground feature in the Milky Way. But that ginormous Hα halo around M86 must be a "real" feature, and it sure looks amazing to me.

Ann
All that I see is more galactic cirrus surrounding the whitish stellar halo of M86. At the 6 o'clock position you can see where a thicker piece of cirrus is visible in front of the outer parts of M86. What I think is going on is that the relatively diffuse cirrus light is being overwhelmed by the light from M86 in the central area, and that is why it appears as a halo around the galaxy.
To me it is too much of a coincidence that a bright reddish halo that is clearly surrounding M86 would be a foreground feature in the Milky Way. I can see only two possibilities for the existence of such an obvious halo, either that it is real or that it is a processing artifact. It does seem as if all or most of the galaxies in the picture do show a reddish halo, if you look closely. However, the halo of M86 is far bigger and much redder than the halos around the other galaxies.

Perhaps Mark Hanson can chime in here?

Ann
Look more closely at that "halo", and you will see that it has the same clumpiness as the "bridge" does. So I am quite convinced from that observation that the red halo is just local galactic cirrus.

Even so, you are right that it would be an interesting coincidence to have the cirrus exactly around the M86 and nowhere else. My explanation is that this is an artifact of how the picture was processed: First you have that "bridge" which appears to be a thicker and more visible piece of cirrus. At M86, the brightness of the galaxy is backlighting the cirrus so that it is more visible at and near the galaxy. Closer to the center of M86, the light from the galaxy overwhelms the cirrus light, and father away from M86 there is insufficient scattering of the light from M86. Hence the appearance of a halo is present even though the cirrus must be far more extensive than what is visible.

I can only guess at how this effect was achieved. Certainly steps were taken to bring out dim red features. It seems that the intent was to bring out the "bridge" and the "halo" appeared as a side-effect.

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Re: APOD: M86 in the Central Virgo Cluster (2018 Aug 14)

Post by neufer » Wed Aug 15, 2018 11:28 am

https://en.wikipedia.org/wiki/Messier_86 wrote:
<<Messier 86 (also known as M86 or NGC 4406) is an elliptical or lenticular galaxy in the constellation Virgo. It was discovered by Charles Messier in 1781. M86 lies in the heart of the Virgo Cluster of galaxies and forms a most conspicuous group with another large galaxy known as Messier 84. It displays the highest blue shift of all Messier objects, as it is approaching the Milky Way at 244 km/s. This is due to its falling towards the center of the Virgo cluster from the opposite side, which causes it to move in the direction of the Milky Way.

Messier 86 is linked by several filaments of ionized gas to the severely disrupted spiral galaxy NGC 4438 and shows some gas and interstellar dust that may have been stripped of it like the one present in those filaments. It is also suffering ram-pressure stripping as it moves at high speed through Virgo's intracluster medium, losing its interstellar medium and leaving behind a very long trail of X ray-emitting hot gas that has been detected with the help of the Chandra space telescope.>>
http://iopscience.iop.org/article/10.1086/593300/fulltext/ wrote:
A Spectacular Hα Complex in Virgo: Evidence for a Collision between M86 and NGC 4438 and Implications for the Collisional ISM Heating of Ellipticals
Jeffrey D. P. Kenney, Tomer Tal, Hugh H. Crowl, John Feldmeier, and George H. Jacoby

The Astrophysical Journal 687 (2008) L69

ABSTRACT: Deep wide-field Hα+[N ii] imaging around the Virgo Cluster giant elliptical galaxy M86 reveals a highly complex and disturbed ISM/ICM. The most striking feature is a set of Hα filaments which clearly connect M86 with the nearby disturbed spiral NGC 4438 (23' = 120 kpc projected away), providing strong evidence for a previously unrecognized collision between them. Spectroscopy of selected regions shows a fairly smooth velocity gradient between M86 and NGC 4438, consistent with the collision scenario. Such a collision would impart significant energy into the ISM of M86, probably heating the gas and acting to prevent the gas from cooling to form stars. We propose that cool gas stripped from NGC 4438 during the collision and deposited in its wake is heated by shocks, ram pressure drag, or thermal conduction, producing most of the Hα filaments. Some Hα filaments are associated with the well-known ridge of bright X-ray emission to the NW of the nucleus, suggesting that the collision is responsible for peculiarities of M86 previously ascribed to other effects. M86 is radio-quiet; thus AGN heating is unlikely to play a significant role. The M86 system has implications for understanding the role of gravitational interactions in the heating of the ISM in ellipticals, and how collisions in clusters transform galaxies.
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Re: APOD: M86 in the Central Virgo Cluster (2018 Aug 14)

Post by neufer » Wed Aug 15, 2018 12:06 pm

https://en.wikipedia.org/wiki/Eyes_Galaxies wrote:
<<The Eyes Galaxies (NGC 4435-NGC 4438) are a pair of galaxies about 52 million light-years away in the constellation Virgo. The pair are members of the string of galaxies known as Markarian's Chain.

NGC 4438 is the most curious interacting galaxy in the Virgo Cluster, due to the uncertainty surrounding the energy mechanism that heats the nuclear source; this energy mechanism may be a starburst region, or a black hole-powered active galactic nucleus (AGN). Both hypotheses are currently under investigation by astronomers.

This galaxy shows a highly distorted disk, including long tidal tails due to the gravitational interactions with other galaxies in the cluster and its companion. The aforementioned features explain why sources differ to classify it as a lenticular or spiral galaxy. NGC 4438 also shows signs of a past, extended, - but modest - starburst, a considerable deficiency of neutral hydrogen, as well as a displacement of the components of its interstellar medium - atomic hydrogen, molecular hydrogen, interstellar dust, and hot gas - in the direction of NGC 4435. This observation suggests both a tidal interaction with NGC 4435 and the effects of ram-pressure stripping as NGC 4438 moves at high speed through Virgo's intracluster medium, increased by the encounter between both galaxies.

While there is evidence to suggest that the environmental damage to the interstellar medium of NGC 4438 may have been caused by an off-center collision with NGC 4435 millions of years ago, a recent discovery of several filaments of ionized gas link NGC 4438 with the large neighboring elliptical galaxy Messier 86, in addition to a discovery of gas and dust within M86 that may have been stripped from NGC 4438 during a past encounter between the two. Given the high density of galaxies in the center of the Virgo galaxy cluster, it is possible that the three galaxies, NGC 4435, NGC 4438, and M86, have had past interactions.

In the 2014 film Interstellar, "NGC 4438" along with specific observation data can be seen in Murphy Cooper (Jessica Chastain)'s notepad during the film's climactic sequence. As the presence of a supermassive black hole in the AGC of NGC 4438 is one of two leading theories, the galaxy is potentially that accessed by the wormhole in the film.>>
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Re: APOD: M86 in the Central Virgo Cluster (2018 Aug 14)

Post by RJN » Thu Aug 16, 2018 2:14 pm

Locutus76 wrote:
Tue Aug 14, 2018 1:05 pm
extended blue arms of NGC 4435 were created.
Shouldn’t that be the extended blue arms of NGC 4438? Based on the labeled image from the creator.
Yes. This has now been fixed on the main NASA APOD. My apologies for the oversight.

- RJN