APOD: M83: The Thousand-Ruby Galaxy (2015 Oct 08)

[APOD Robot]

M83: The Thousand-Ruby Galaxy

Explanation: Big, bright, and beautiful, spiral galaxy M83 lies a mere twelve million light-years away, near the southeastern tip of the very long constellation Hydra. Prominent spiral arms traced by dark dust lanes and blue star clusters lend this galaxy its popular name, The Southern Pinwheel. But reddish star forming regions that dot the sweeping arms highlighted in this sparkling color composite also suggest another nickname, The Thousand-Ruby Galaxy. About 40,000 light-years across, M83 is a member of a group of galaxies that includes active galaxy Centaurus A. In fact, the core of M83 itself is bright at x-ray energies, showing a high concentration of neutron stars and black holes left from an intense burst of star formation. This sharp composite color image also features spiky foreground Milky Way stars and distant background galaxies. The image data was taken from the Subaru Telescope, the European Southern Observatory's Wide Field Imager camera, and the Hubble Legacy Archive.

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[Beyond]

It's amazing what one can find out at this site. I never knew Hercules had a twin brother.

[Ann]

It's amazing what one can find out at this site. I never knew Hercules had a twin brother.

Oh yes. And if I remember correctly wihout googling, Iphicles (makes me think of icicles) was nowhere near as strong and brave as Heracles (Hercules), and his father wasn't Zeus, either.

Back to the APOD. I'm always glad to see a galaxy picture by Robert Gendler.

The full resolution of today's APOD shows very clearly what parts of M83 were imaged by the Hubble telescope, and what parts weren't. It's a pity that not all of the galaxy could be imaged with the resolution that only Hubble can achieve in RBG, but on the other hand it is good that the missing pieces could be filled out, albeit at a lower resolution, by other telescopes.

Ann

[Boomer12k]

A beautiful gem indeed... I am thinking several mergers, as there are whispy sections that are chppy and not filled in and consistent. Not settled... Boy, is it an active star former....wow.


:---(===) *

[Richard Melton]

Why is the center of galaxies bright yellow?

[Ann]

Why is the center of galaxies bright yellow?

The short answer is that stars congregate at the center of galaxies, because of their mutual gravity. Also there is generally little gas and dust near the center, so few new stars are born there. The stars in the center of galaxies are typically old, and populations of old stars are yellower than the Sun. That is because most of the light of populations of old stars is emitted by yellow-colored red giant stars of spectral class K. Examples of such stars are Dubhe, one of the pointer stars of the Big Dipper, and Pollux, one of the two bright stars of Gemini. The picture shows Pollux on the left and bluer Castor at right.

Ann

[starsurfer]

Magnificent image of a magnificent galaxy! Rob Gendler is an expert at blending together data from multiple sources! Something I find curious is that this image includes both real diffraction spikes as well as fake diffraction spikes, which I now know are sometimes necessary. Isn't this galaxy also similar to NGC 6946 in that it has had lots of supernovae?

[rgendler]

Below is a link to a much higher resolution image of only the HST data. (6000 X 6659 pixels)

http://www.robgendlerastropics.com/M83-New-HST-LL.html

[saturno2]

Very interesting

[FLPhotoCatcher]

Most galaxies have super massive black holes in their centers, with jets jetting out both sides of them. Does this one have a super massive black hole in it? It doesn't seem to have a jet.
Would a jet from its center have any effect on earth?

[Chris Peterson]

Most galaxies have super massive black holes in their centers, with jets jetting out both sides of them. Does this one have a super massive black hole in it? It doesn't seem to have a jet.
Would a jet from its center have any effect on earth?

Most galaxies have central black holes, but only a small percentage are active at any time- jets are the exception, not the rule.

M83 is famous for having a double nucleus, attributed to a lopsided distribution of stars around a central supermassive black hole. (It might also have a pair of supermassive black holes, but that isn't the general consensus.)

In any case, there's nothing that can happen in another galaxy that would have any significant impact on Earth. That requires something quite close, inside our own galaxy.

[neufer]

there's nothing that can happen in another galaxy that would have any significant impact on Earth.
That requires something quite close, inside our own galaxy.

• Which is not to say that every galaxy gets along with all it's neighbors:

[b][color=#FF00FF]Credit: X-ray: NASA/CXC/CfA/D.Evans et al.[/color]; [color=#FF4040]Optical/UV: NASA/STScI[/color]; [color=#0000FF]Radio: NSF/VLA/CfA/D.Evans et al., STFC/JBO/MERLIN[/color][/b]

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<<This composite image shows the jet from a black hole at the center of a galaxy striking the edge of another galaxy, the first time such an interaction has been found. In the image, data from several wavelengths have been combined. X-rays from Chandra (colored purple), optical and ultraviolet (UV) data from Hubble (red and orange), and radio emission from the Very Large Array (VLA) and MERLIN (blue) show how the jet from the main galaxy on the lower left is striking its companion galaxy to the upper right. The jet impacts the companion galaxy at its edge and is then disrupted and deflected, much like how a stream of water from a hose will splay out after hitting a wall at an angle.

Each wavelength shows a different aspect of this system, known as 3C321. The Chandra X-ray image provides evidence that each galaxy contains a rapidly growing supermassive black hole at its center. Hubble's optical light images (orange) show the glow from the stars in each galaxy. A bright spot in the VLA and MERLIN radio image shows where the jet has struck the side of the galaxy - about 20,000 light years from the main galaxy - dissipating some of its energy. An even larger "hotspot" of radio emission detected by VLA (seen in an image with a much larger field-of-view) reveals that the jet terminates much farther away from the galaxy, at a distance of about 850,000 light years away. The Hubble UV image shows large quantities of warm and hot gas in the vicinity of the galaxies, indicating the supermassive black holes in both galaxies have had a violent past. Faint emission from Chandra, Hubble and Spitzer, not shown in this image, indicate that the galaxies are orbiting in a clockwise direction, implying that the companion galaxy is swinging into the path of the jet.

Since the Chandra data shows that particle acceleration is still occurring in this hotspot, the jet must have struck the companion galaxy relatively recently, less than about a million years ago (i.e. less than the light travel time to the hotspot). This relatively short cosmic time frame makes this event a very rare phenomenon.

This "death star galaxy" will produce large amounts of high-energy radiation, which may cause severe damage to the atmospheres of any planets in the companion galaxy that lie in the path of the jet. From the Earth we look down the barrel of jets from supermassive black holes, however these so-called "blazars" are at much safer distances of millions or billions of light years.>>

[Ann]

Click to view full size image

Like you said, Art.
3C 321 is the kind of galactic super-bully that you wouldn't want for a neighbour!!!

Ann