Other Galaxies

NGC 4651: The Umbrella Galaxy NASA - July 2, 2014

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.

Barred Spiral Galaxy NGC 6217 NASA - December 28, 2009

Many spiral galaxies have bars across their centers. Even our own Milky Way Galaxy is thought to have a modest central bar. Prominently barred spiral galaxy NGC 6217, pictured above, was captured in spectacular detail in this recently released image taken by the newly repaired Advanced Camera for Surveys on the orbiting Hubble Space Telescope. Visible are dark filamentary dust lanes, young clusters of bright blue stars, red emission nebulas of glowing hydrogen gas, a long bright bar of stars across the center, and a bright active nucleus that likely houses a supermassive black hole. Light takes about 60 million years to reach us from NGC 6217, which spans about 30,000 light years across and can be found toward the constellation of the Little Bear (Ursa Minor).

Messier 63: The Sunflower Galaxy
NASA - April 17, 2008

Sunflower Galaxy  Wikipedia

Messier 63 (also known as M63, NGC 5055, or the Sunflower Galaxy) is a spiral galaxy in the constellation Canes Venatici consisting of a central disc surrounded by many short spiral arm segments. M63 is part of the M51 Group, a group of galaxies that also includes M51 (the 'Whirlpool Galaxy'). M63 was discovered by Pierre Méchain on June 14, 1779. The galaxy was then listed by Charles Messier as object 63 in the Messier Catalogue. In the mid-19th century, Lord Rosse identified spiral structures within the galaxy, making this one of the first galaxies in which such structure was identified. In 1971, a supernova with a magnitude of 11.8 appeared in one of the arms of M63.

The "Galactic Mask" Unveiled Thunderbolts - March 12, 2008

NASA scientists tell us that two "colliding galaxies" in the constellation Canis Major are responsible for the amazing, mask-like structure shown here. But experts in plasma discharge might suggest a different conclusion. In a supposedly expanding universe still rushing outward from the Big Bang, one would think that the vast reaches of space are an unlikely place for "fender-benders." Yet the word "collision" is extremely common in scientific press releases these days, as astronomers grasp for explanations of galactic events in faraway places. It is gaseous collisions that generate the X-rays, radio waves, and synchrotron radiation detected throughout the cosmos, they tell us.

The picture above shows the galaxies NGC 2207 and IC 2163 in the constellation Canis Major in what astronomers are calling a "cosmic smash up." The structure's unique appearance has led investigators to dub it “The Galactic Mask”. They say the mask's “eyes” are the galactic cores, and its "feathers" are the galaxies' star-filled spiral arms.

Vassar College astronomer Debra Elmegreen, the lead author of a paper on the observations, said of the image: "This is the most elaborate case of beading we've seen in galaxies..."They are evenly spaced and sized along the arms of both galaxies."

MSNBC's Cosmic Log website, describing the scientists' observations, tells us that the bead-like structure of the spiral arms is caused by "gravitational pressures (squeezing) gas and dust into new clusters of stars." The website also reports: 'There’s one particularly bright bead on the left side of the mask -- so bright it accounts for 5 percent of the total infrared emissions coming from both galaxies... Elmegreen's team thinks the stars in this dense, dusty cluster might have merged to become a black hole. To form a black hole that's outside the disk of the galaxy is a real surprise, if in fact that's what it is, said one of the research team's co-authors.

Experts in plasma discharge phenomena will use a much different language to describe the image. For decades, advanced research into plasma discharge instabilities has documented formations precisely matching galactic structures seen in space. As noted in an earlier TPOD, 'Plasma Galaxies,' plasma scientist Anthony Perratt, using particle-in-cell computer simulations, has demonstrated the evolution of galactic structures under the influence of electric currents. Through the "pinch effect", parallel currents converge to produce spiraling structures. Dual, interacting currents can, in fact, present an appearance surprisingly similar to that of the twin eyes in the 'Galactic Mask' seen above.

To see the connection between plasma experiments and plasma formations in space, it is essential to understand the scalability of plasma phenomena. Under similar conditions, plasma discharge will produce the same formations irrespective of the size of the event. The same basic patterns will be seen at laboratory, planetary, stellar, and galactic levels. Duration is proportional to size as well. A spark that lasts for microseconds in the laboratory may continue for years at planetary or stellar scales, or for millions of years at galactic or intergalactic scales.

Laboratory discharge experiments have documented all of the features of the "Galactic Mask" above. Indeed, the very words used in the article could have been taken from the lexicon of plasma scientists describing plasma discharge instabilities: 'string of pearls,' beads on a string, feathers, and mask. In plasma discharge terms, the evenly spaced beading along spiraling arms is a perfect example, but of the 'Z-pinch effect' that, in plasma cosmology, gives birth to stars. In a more familiar setting, the same plasma pinch produces the oft-observed beading of lightning.

On the other hand gravitational pressure supplemented by imagined black holes placed wherever energies are too high to be explained through old-fashioned gravity, can offer almost nothing to test scientifically. How, then, can the theories ever fail? The explanatory power of plasma discharge becomes even more interesting when one begins to consider new evidence that our early ancestors witnessed strikingly similar high-energy plasma discharge in the terrestrial sky. The rock art images above are from North America (first row) and Easter Island (second row). Innumerable counterparts occur around the world - all presenting a common pattern that would seem to mock natural experience: disembodied, often 'hairy eyes' presented in a consistently 'non-human' form.

The pictures are not random, either in their geographic positioning, or in their depictions of detail. And in almost every instance they sit alongside equally enigmatic carvings of other well-defined motifs, all chronicled through cross cultural comparison, and now posing a grand mystery yet to be unraveled by rock art specialists. When seen from a larger perspective, three independent lines of evidence – galactic structure, plasma experiments, and images carved on stone – converge to tell the same story.

M74: The Perfect Spiral
NASA - December 1, 2007

If not perfect, then this spiral galaxy is at least one of the most photogenic. An island universe of about 100 billion stars, 32 million light-years away toward the constellation Pisces, M74 presents a gorgeous face-on view. Classified as an Sc galaxy, the grand design of M74's graceful spiral arms are traced by bright blue star clusters and dark cosmic dust lanes. Constructed from image data recorded in 2003 and 2005, this sharp composite is from the Hubble Space Telescope's Advanced Camera for Surveys. Spanning about 30,000 light-years across the face of M74, it includes exposures recording emission from hydrogen atoms, highlighting the reddish glow of the galaxy's large star-forming regions.

Messier 74 or NGC 628 is a face-on spiral galaxy in the constellation Pisces  Wikipedia

Messier 74 (also known as NGC 628) is a face-on spiral galaxy in the constellation Pisces. It is at a distance of about 32 million light-years away from Earth. The galaxy contains two clearly defined spiral arms and is therefore used as an archetypal example of a Grand Design Spiral Galaxy. The galaxy's low surface brightness makes it the most difficult Messier object for amateur astronomers to observe. However, the relatively large angular size of the galaxy and the galaxy's face-on orientation make it an ideal object for professional astronomers who want to study spiral arm structure and spiral density waves. It is estimated that M74 is home to about 100 billion stars.

The Closest Galaxy: Canis Major Dwarf NASA - November 4, 2007

What is the closest galaxy to the Milky Way? The new answer to this old question is the Canis Major dwarf galaxy. For many years astronomers thought the Large Magellan Cloud (LMC) was closest, but its title was supplanted in 1994 by the Sagittarius dwarf galaxy. Recent measurements indicate that the Canis Major dwarf is only 42,000 light years from the Galactic center, about three quarters of the distance to the Sagittarius dwarf and a quarter of the distance to the LMC. The discovery was made in data from the 2MASS-sky survey, where infrared light allows a better view through our optically opaque Galactic plane. The labeled illustration above shows the location of the newly discovered Canis Major dwarf and its associated tidal stream of material in relation to our Milky Way Galaxy. The Canis Major dwarf and other satellite galaxies are slowly being gravitationally ripped apart as they travel around and through our Galaxy.

I Zwicky 18 - The Case of the Aging Galaxy

NASA - October 17, 2007

How old is this galaxy? The galaxy on the left, I Zwicky 18, was once thought to be one of the youngest galaxies on record since its bright stars indicated an age of only 500 million years. The galaxy was also intriguing because it resembled galaxies forming in the very early universe, but mysterious since it is so nearby -- only 59 million light years away -- and surrounded by galaxies that are significantly older. Recent images of I Zwicky 18 by the Hubble Space Telescope have helped resolve this mystery, discovering a population of old faint stars intermixed with the bright star population. Therefore I Zwicky 18 is now thought to be just as old as its neighbors, roughly 10 billion years old, but with an intense episode of relative new star formation. Possibly the trigger for this recent episode of bright star formation is the changing gravitational influence of I Zwicky 18's smaller companion galaxy, visible at the upper right.

Barred Spiral Galaxy M95 NASA - March 14, 2007

Why do some spiral galaxies have a ring around the center? First and foremost, M95 is one of the closer examples of a big and beautiful barred spiral galaxy. Visible in the above recent image from the CFHT telescope in Hawaii, USA, are sprawling spiral arms delineate by open clusters of bright blue stars, lanes of dark dust, the diffuse glow of billions of faint stars, and a short bar across the galaxy center. What intrigues many astronomers, however, is the circumnuclear ring around the galaxy center visible just outside the central bar. Recent images by the Chandra X-ray Observatory have shown that X-ray light surrounding the ring is likely emission from recent supernovas. Although the long term stability of the ring remains a topic of research, recent observations indicate its present brightness is at least enhanced by transient bursts of star formation. M95, also known as NGC 3351, spans about 50,000 light-years and can be seen with a small telescope toward the constellation of the Lion (Leo).

Distorted galaxy NGC 2442 NASA March 15, 2007

Distorted galaxy NGC 2442 can be found in the southern constellation of the flying fish, (Pisces) Volans. Located about 50 million light-years away, the galaxy's two spiral arms extending from a pronounced central bar give it an ominous hook-shaped appearance. This striking color image also shows obscuring dust lanes, young blue star clusters and reddish star forming regions surrounding a core of yellowish light from an older population of stars. But the star forming regions seem more concentrated along the drawn-out northern (top) spiral arm. The distorted structure is likely the result of a close encounter with a smaller galaxy located just outside this telescopic field of view. The picture spans about 1/6 of a degree, or 150,000 light years at the estimated distance of NGC 2442.

Sombrero Galaxy
NASA - February 16, 2007

Sombrero Galaxy Wikipedia

The Sombrero Galaxy (also known as Messier Object 104, M104 or NGC 4594) is an unbarred spiral galaxy in the constellation Virgo located 28 million light-years (8.6 Mpc) from Earth. It has a bright nucleus, an unusually large central bulge, and a prominent dust lane in its inclined disk. The dark dust lane and the bulge give this galaxy the appearance of a sombrero. Astronomers initially thought that the halo was small and light, indicative of a spiral galaxy, but Spitzer found that the halo around the Sombrero Galaxy is larger and more massive than previously thought, indicative of a giant elliptical galaxy. The galaxy has an apparent magnitude of +9.0, making it easily visible with amateur telescopes, and it's considered by some authors to be the brightest galaxy within a radius of 10 megaparsecs of the Milky Way. The large bulge, the central supermassive black hole, and the dust lane all attract the attention of professional astronomers.

M64: The Black Eye Galaxy NASA - August 2, 2007

This bright, beautiful spiral galaxy is Messier 64, sometimes known as the Black Eye Galaxy. M64 lies about 17 million light-years distant in the otherwise well-groomed northern constellation Coma Berenices. The dark clouds along the near-side of M64's central region that give the galaxy its black-eye appearance are enormous obscuring dust clouds associated with star formation, but they are not the galaxy's only peculiar feature. Observations show that M64 is actually composed of two concentric, counter-rotating systems of stars, one in the inner 3,000 light-years and another extending to about 40,000 light-years and rotating in the opposite direction. The dusty black eye and bizarre rotation is likely the result of a merger of two different galaxies.