galactic disk

NGC 660. A rare galaxy type, polar ring galaxies have a substantial population of stars, gas, and dust orbiting in rings nearly perpendicular to the plane of a flat galactic disk. Only about a dozen of such galaxies have been discovered

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NGC 660 is featured in this cosmic snapshot. Over 40 million light-years away and swimming within the boundaries of the constellation Pisces, NGC 660’s peculiar appearance marks it as a polar ring galaxy. A rare galaxy type, polar ring galaxies have a substantial population of stars, gas, and dust orbiting in rings strongly tilted from the plane of the galactic disk. The bizarre-looking configuration could have been caused by the chance capture of material from a passing galaxy by a disk galaxy, with the captured debris eventually strung out in a rotating ring. The violent gravitational interaction would account for the myriad pinkish star forming regions scattered along NGC 660’s ring. The polar ring component can also be used to explore the shape of the galaxy’s otherwise unseen dark matter halo by calculating the dark matter's gravitational influence on the rotation of the ring and disk. Broader than the disk, NGC 660’s ring spans over 50,000 light-years.

Image Credit & Copyright: CHART32 Team,Processing - Johannes Schedler

Time And Space

tbh i love swtor

we can fly through space and shot at things with deadly lasers we can see incrediy advanced artificial intelligences we can communicate with others via headset or com link across the galactic disk with like zero delay we can use super-heated plasma as swords we can communicate nearly without problems with all sorts of weird aliens we can even-

oh messages? oh nah pls look for a 17th century mailbox for those

Large spiral galaxy NGC 891 spans about 100 thousand light-years and is seen almost exactly edge-on from our perspective. In fact, about 30 million light-years distant in the constellation Andromeda, NGC 891 looks a lot like our Milky Way. At first glance, it has a flat, thin, galactic disk of stars and a central bulge cut along the middle by regions of dark obscuring dust. But remarkably apparent in NGC 891's edge-on presentation are filaments of dust that extend hundreds of light-years above and below the center line. The dust has likely been blown out of the disk by supernova explosions or intense star formation activity. Fainter galaxies can also be seen near the edge-on disk in this deepportrait of NGC 891.

For image credit and copyright guidance, please visit the image websitehttp://antwrp.gsfc.nasa.gov/apod/ap170112.html

Time And Space

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Monstrous cosmic gas cloud set to ignite the Milky Way

“The gravitational interactions are particularly interesting, because whenever you have three bodies interacting, two often become more tightly bound while the third gets a “kick,” potentially ejecting it. This is how we use planets to assist spacecrafts in their journey towards the outer Solar System, and the same principle can allow gas clouds to be ejected from our own galaxy. In one very particular, peculiar case, however, a gas cloud in our own galaxy almost got kicked out, but not quite.”

Give a planet a kick, and it goes into a more distant orbit around our star. Give it a hard enough kick, and it will reach escape velocity, leaving our Solar System forever. But if you gave it an almost hard enough kick, it would travel extremely far from the Sun, but it would eventually boomerang back towards the inner Solar System, with potentially disastrous, disruptive consequences. This applies to any system (not just the Solar System), including our own galaxy. In the Milky Way’s outskirts, there are high-velocity gas clouds, including one — the Smith Cloud — that’s moving towards us at a breakneck pace. Thanks to data from the Hubble Space Telescope, Andrew Fox and his team have just uncovered that this cloud came from our Milky Way, was almost ejected into intergalactic space, but is now on its way back, where in 30 million years it will collide with our galactic disk. The 11,000 light year-long cloud is expected to produce over 2 million new stars when it does.

50,000 Years

Here’s something that bugs me slightly about the timing of Reaper invasions.

They’re supposedly every 50,000 years. The galactic disk is, roughly speaking, ~100,000 light years in diameter. (Obligatory note: actual estimates vary between - don’t quote me on this! - 90-120 kLY, due to practical difficulties associated with doing the observations *from the inside the same disk*. But, 100K is a reasonable round-number ballpark.)

This means that the light from the last invasion hasn’t had time to completely-leave the disc yet. So, with a sufficiently-good telescope, it is possible to observe the previous invasion and - perhaps - learn from it.

Granted such a telescope would have to be a) huge, b) presumably space-based and c) frighteningly-expensive to build. (The minimum specs would be an instrument able to resolve a ~2Km Reaper from distances greater than 50 kLY. Given that they’re basically black in colour, the limiting magnitude must have to be something impressive too.) But, there’s nothing physically-impossible about it. And the Reapers were impressively-paranoid about everything else. I mean, Vigil even suggests that they cleaned up after themselves to hide the evidence of their presence.

The light-travel-time issue just seems like an odd thing for them to have missed. I suppose to some extent, their hands (tentacles?) might be forced by the development-time issue for subsequent organic civilisations. But again, it seems unlikely that this is always every 50,000 years. Are organics really that regular?

FLY-BY OF A SCHWARZSCHILD BLACK HOLE
What you’re seeing is a sequence of “Einstein Rings" 

Einstein Ring is a term from observational astronomy. It’s an artifact of the gravitational lensing of light (from a star or galaxy) by a massively massive astronomical object (like a black hole or another galaxy).

In order for an Einstein Ring to appear, all three—the light source, the massive lens, and the observer—must all be aligned. In other words, it occurs when the object that you’re seeing as an Einstein ring is directly behind the object that is the gravitational lens.

Gravitational lensing is predicted by Albert Einstein’s theory of general relativity. Instead of light from a source traveling in a straight line (in three dimensions), it is bent by the presence of a massive body, which distorts spacetime.

The animation above is

a simulation depicting a zoom-in on a Schwarzschild black hole in front of the Milky Way.

  • The first Einstein ring corresponds to the most distorted region of the picture and is clearly depicted by the galactic disc.
  • The zoom then reveals a series of 4 extra rings, increasingly thinner and closer to the black hole shadow. They are easily seen through the multiple images of the galactic disk.
The odd-numbered rings correspond to [images of objects] which are behind the black hole (from the observer’s point of view);  they correspond here to the bright yellow region of the galactic disc (close to the galactic center).

The even-numbered rings correspond to images of objects which are behind the observer.  These objects appear bluer since the corresponding part of the galactic disc is thinner and hence dimmer.  [WP]

SOURCE:  Einstein ring - Wikipedia).
The animation was created by Wikipedia contributor Urbane Legend.

Sharp telescopic views of NGC 3628 show a puffy galactic disk divided by dark dust lanes. Of course, this deep portrait of the magnificent, edge-on spiral galaxy puts some astronomers in mind of its popular moniker, the Hamburger Galaxy.

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It is one of the most massive galaxies known. A mere 46 million light-years distant, spiral galaxy NGC 2841 can be found in the northern constellation of Ursa Major. This sharp view of the gorgeous island universe shows off a striking yellow nucleus and galactic disk. Dust lanes, small, pink star-forming regions, and young blue star clusters are embedded in the patchy, tightly wound spiral arms. In contrast, many other spirals exhibit grand, sweeping arms with large star-forming regions. NGC 2841 has a diameter of over 150,000 light-years, even larger than our own Milky Way and captured by this composite image merging exposures from the orbiting 2.4-meter Hubble Space Telescope and the ground-based 8.2-meter Subaru Telescope. X-ray images suggest that resulting winds and stellar explosions create plumes of hot gas extending into a halo around NGC 2841.

Object Names: NGC 2841

Image Type: Astronomical

Credit: Hubble Space Telescope, Subaru Telescope

Composition And Copyright: Roberto Colombari

Time And Space

NGC 4651: The Umbrella Galaxy

Spiral galaxy NGC 4651 is a mere 62 million light-years distant, toward the well-groomed northern constellation Coma Berenices. About the size of our Milky Way, this island universe is seen to have a faint umbrella-shaped structure that seems to extend some 100 thousand light-years beyond the bright galactic disk. The giant cosmic umbrella is now known to be composed of tidal star streams - extensive trails of stars gravitationally stripped from a smaller satellite galaxy. The small galaxy was eventually torn apart in repeated encounters as it swept back and forth on eccentric orbits through NGC 4651.

Image Credit & Copyright: R Jay Gabany (Blackbird Observatories)
Collaboration: C.Foster (Australian Astronomical Obs.), H.Lux (U. Nottingham, Oxford),
A.Romanowsky (San Jose State, UCO), D.Martínez-Delgado (Heidelberg), et al.

NGC 660. A rare galaxy type, polar ring galaxies have a substantial population of stars, gas, and dust orbiting in rings nearly perpendicular to the plane of a flat galactic disk. Only about a dozen of such galaxies have been discovered

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Polar ring galaxy NGC 660

NGC 660 is featured in this cosmic snapshot, a sharp composite of broad and narrow band filter image data from the Gemini North telescope on Mauna Kea. Over 20 million light-years away and swimming within the boundaries of the constellation Pisces, NGC 660’s peculiar appearance marks it as a polar ring galaxy. A rare galaxy type, polar ring galaxies have a substantial population of stars, gas, and dust orbiting in rings nearly perpendicular to the plane of the galactic disk. The bizarre-looking configuration could have been caused by the chance capture of material from a passing galaxy by a disk galaxy, with the captured debris eventually strung out in a rotating ring. The violent gravitational interaction would account for the myriad pinkish star forming regions scattered along NGC 660’s ring.The polar ring component can also be used to explore the shape of the galaxy’s otherwise unseen dark matter halo by calculating the dark matter's gravitational influence on the rotation of the ring and disk. Broader than the disk, NGC 660’s ring spans over 50,000 light-years.

Image credit: Gemini Observatory, AURA, Travis Rector (Univ. Alaska Anchorage)

You’re Tearing it Apart

These four spiral galaxies in NGC 4410 display an extraordinary cosmic spectacle, each generating immense tidal forces that rip each other apart as they pass close to each other. The galactic disks and spiral arms stretch apart while stellar filaments swirl into the intergalactic medium as the galaxies entwine in a dance of staggering proportions.

Image Credit: Canada-France-Hawaii Telescope/Coelum

Polar ring galaxy NGC 2685

NGC 2685 is a confirmed polar ring galaxy - a rare type of galaxy with stars, gas and dust orbiting in rings perpendicular to the plane of a flat galactic disk. The bizarre configuration could be caused by the chance capture of material from another galaxy by a disk galaxy, with the captured debris strung out in a rotating ring. Still, observed properties of NGC 2685 suggest that the rotating ring structure is remarkably old and stable. In this sharp view of the peculiar system also known as Arp 336 or the Helix galaxy, the strange, perpendicular rings are easy to trace as they pass in front of the galactic disk, along with other disturbed outer structures. NGC 2685 is about 50,000 light-years across and 40 million light-years away in the constellation Ursa Major.

Image credit & copyright: Ken Crawford

NGC 4651: The Umbrella galaxy

Spiral galaxy NGC 4651 is a mere 62 million light-years distant, toward the well-groomed northern constellation Coma Berenices. About the size of our Milky Way, this island universe is seen to have a faint umbrella-shaped structure that seems to extend (left) some 100 thousand light-years beyond the bright galactic disk. The giant cosmic umbrella is now known to be composed of tidal star streams - extensive trails of stars gravitationally stripped from a smaller satellite galaxy. The small galaxy was eventually torn apart in repeated encounters as it swept back and forth on eccentric orbits through NGC 4651. In fact, the picture insert zooms in on the smaller galaxy’s remnant core, identified in an extensive exploration of the system, using data from the large Subaru and Keck telescopes on Mauna Kea. Work begun by a remarkable collaboration of amateur and professional astronomers to image faint structures around bright galaxies suggests that even in nearby galaxies, tidal star streams are common markers of such galactic mergers. The result is explained by models of galaxy formation that also apply to our own Milky Way.

Image credit & copyright: R Jay Gabany (Blackbird Observatories) 
Collaboration: C.Foster (Australian Astronomical Obs.), H.Lux (U. Nottingham, Oxford), A.Romanowsky (San Jose State, UCO), D.Martínez-Delgado (Heidelberg), et al.

Massive nearby spiral galaxy NGC 2841

It is one of the more massive galaxies known. A mere 46 million light-years distant, spiral galaxy NGC 2841 can be found in the northern constellation of Ursa Major. This sharp view of the gorgeous island universe shows off a striking yellow nucleus and galactic disk. Dust lanes, small, pink star-forming regions, and young blue star clusters are embedded in the patchy, tightly wound spiral arms.In contrast, many other spirals exhibit grand, sweeping arms with large star-forming regions. NGC 2841 has a diameter of over 150,000 light-years, even larger than our own Milky Way and captured by this composite image merging exposures from the orbiting 2.4-meter Hubble Space Telescope and the ground-based 8.2-meter Subaru Telescope. X-ray images suggest that resulting winds and stellar explosions create plumes of hot gas extending into a halo around NGC 2841.

Image credit: Hubble, Subaru; Composition & Copyright: Robert Gendler

(NASA)  Edge-on NGC 3628
Image Credit & Copyright: Alessandro Falesiedi

Sharp telescopic views of magnificent edge-on spiral galaxy NGC 3628 show a puffy galactic disk divided by dark dust lanes. Of course, this deep galactic portrait puts some astronomers in mind of its popular moniker, The Hamburger Galaxy. The tantalizing island universe is about 100,000 light-years across and 35 million light-years away in the northern springtime constellation Leo. NGC 3628 shares its neighborhood in the local Universe with two other large spirals M65 and M66 in a grouping otherwise known as the Leo Triplet. Gravitational interactions with its cosmic neighbors are likely responsible for the extended flare and warp of this spiral’s disk.

Sculptor Galaxy NGC 134 : NGC 134 is probably not the best known spiral galaxy in the constellation Sculptor. Still, the tantalizing island universe is a clearly a telescopic treasure in southern skies. It shares a bright core, clumpy dust lanes, and loosely wrapped spiral arms with spiky foreground stars of the Milky Way and the more diminutive galaxy NGC 131 in this sharp cosmic vista. From a distance of about 60 million light-years, NGC 134 is seen tilted nearly edge-on. It spans some 150,000 light-years, making it even larger than our own Milky Way galaxy. NGC 134’s warped disk and faint extensions give the appearance of past gravitational interactions with neighboring galaxies. Like the much closer and brighter Sculptor galaxy NGC 253, tendrils of dust appear to rise from a galactic disk sprinkled with blue star clusters and pinkish star forming regions. via NASA

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The tail of the Hamburger Galaxy

Sharp telescopic views of NGC 3628 show a puffy galactic disk divided by dark dust lanes. Of course, this deep portrait of the magnificent, edge-on spiral galaxy puts some astronomers in mind of its popular moniker, the Hamburger Galaxy. It also reveals a small galaxy nearby, likely a satellite of NGC 3628, and a faint but extensive tidal tail. The tantalizing island universe itself is about 100,000 light-years across and 35 million light-years away in the northern springtime constellation Leo. Its drawn out tail stretches for about 300,000 light-years, even beyond the left edge of the wide frame. NGC 3628 shares its neighborhood in the local Universe with two other large spirals M65 and M66 in a grouping otherwise known as the Leo Triplet. Gravitational interactions with its cosmic neighbors are likely responsible for creating the tidal tail, as well as the extended flare and warp of this spiral’s disk.

Image credit & copyright: Martin Pugh