APOD: M82: Galaxy with a Supergalactic Wind (2012 Mar 26)

[APOD Robot]

M82: Galaxy with a Supergalactic Wind

Explanation: What's lighting up the Cigar Galaxy? M82, as this irregular galaxy is also known, was stirred up by a recent pass near large spiral galaxy M81. This doesn't fully explain the source of the red-glowing outwardly expanding gas, however. Recent evidence indicates that this gas is being driven out by the combined emerging particle winds of many stars, together creating a galactic superwind.. The above photographic mosaic highlights a specific color of red light strongly emitted by ionized hydrogen gas, showing detailed filaments of this gas. The filaments extend for over 10,000 light years. The 12-million light-year distant Cigar Galaxy is the brightest galaxy in the sky in infrared light, and can be seen in visible light with a small telescope towards the constellation of the Great Bear (Ursa Major).

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[TrinitySite 555]

The pitcures and discussion reference M82 and the Superwind was very informative today. However, it gave me some pause when it discussed the "close brush" with it's neighbor, M81. Does anyone know what the distance is that separates these two?

[neufer]

[size=175][color=#0000FF]Eta Carinae [/color][/size][url=http://en.wikipedia.org/wiki/Wolf-Rayet_star][size=175]Wolf-Rayet star[/size][/url]

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[copper5817]

It kinda looks like the "supergalactic wind" is just a nebula which as far closer to us than the galaxy and just happens to be in the same sightline...

[rstevenson]

According to this Wikipedia page, the apparent visual separation is about 130,000 light years, but the actual distance between them is more like 300,000 light years. Their most recent "close brush" happened about 200 Myr ago, more or less.

Rob

[neufer]

Huge Gamma Ray Bubbles Found Around Milky Way

Explanation: Did you know that our Milky Way Galaxy has huge bubbles emitting gamma rays from the direction of the galactic center? Neither did anybody. As the data from the Earth-orbiting Fermi satellite began acuminating over the past two years, however, a large and unusual feature toward our Galaxy's center became increasingly evident. The two bubbles are visible together as the red and white spotted oval surrounding the center of the above all sky image, released yesterday. The plane of our Galaxy runs horizontally across the image center. Assuming the bubbles emanate from our Galaxy's center, the scale of the bubbles is huge, rivaling the entire Galaxy in size, and spanning about 50,000 light years from top to bottom. Earlier indications of the bubbles has been found on existing all sky maps in the radio, microwave, and X-ray. The cause of the bubbles is presently unknown, but will likely be researched for years to come.

[neufer]

[b][color=#FF0000]M82's infrared appearance in the Spitzer Space Telescope[/color] Credit: C. Engelbracht (Steward Obs.), et al. JPL, Caltech, NASA[/b]

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Smoke from the Cigar Galaxy

<<Explanation: Very bright in infrared light, well-known starburst galaxy M82's popular name describes its suggestive shape seen at visible wavelengths - The Cigar Galaxy. Ironically, M82's fantastic appearance in this Spitzer Space Telescope image really is due to cosmic "smoke" - the infrared emission of exented dust features blown by stellar winds from M82's luminous, central star forming regions. The false-color view highlights a component of dust emission from complex carbon molecules called polycyclic aromatic hydrocarbons or PAHs. PAHs are also seen in star forming regions throughout our own, much calmer, Milky Way Galaxy and are products of combustion on planet Earth. Likely triggered by interactions with nearby galaxy M81, M82's intense star formation activity appears to be blowing out immense clouds of dust and PAHs extending nearly 20,000 light-years both above and below the galactic plane. M82 is about 12 million light-years away in the constellation Ursa Major. >>

[orin stepanek]

Interesting looking galaxy; but not very pretty! It's kind of like the ugly duckling of galaxies! Maybe it will evolve into a beautiful swan!

[neufer]

Interesting looking galaxy; but not very pretty!

It's kind of like the ugly duckling of galaxies!

Maybe it will evolve into a beautiful swan!

[b][size=150][color=#0000FF]Swan galaxiid[/color]; credit: A. Sanger.[/size][/b]

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• Swan galaxias

<<The decline in populations of Swan galaxiids (Galaxias fontanus) has been attributed to predation by introduced fish such as brown trout and redfin perch. The endemic Swan galaxiid also has a fairly restricted, natural range, only being found in the Swan and Macquarie river tributaries on Tasmania's east coast. Any changes to its habitat could have a disastrous effect on the fish.

To prevent the Swan galaxiid being eaten to extinction by these introduced predators, since 1989 the Inland Fisheries Commission has been relocating them to areas where these predators do not occur. Sites chosen usually have natural barriers, such as waterfalls, to prevent the trout and perch from reaching them. Provided people do not interfere by introducing exotic fish to these particular sites the Swan galaxiid has a good chance of survival.>>

[neptunium]

Could M82 be a spiral galaxy of some sort but classified as irregular due to its texture and shape? It seems to me that this galaxy is seen more edge-on.

[Sandstone]

<<The decline in populations of Swan galaxiids (Galaxias fontanus) has been...

Neufer,

From where do these gems of thought and wondrous information spring forth???

[bub4280]

Those Clouds take a shape similar to suspected dark matter lobes.

[jisles]

The galaxy is not 'towards' the constellation Ursa Major. APOD captions regularly make this mistake. It's IN the constellation Ursa Major. Constellations comprise everything within an irregularly-outlined cone, stretching to infinity, whose apex is at the observer's eye. I love APOD though!

[Beyond]

<<The decline in populations of Swan galaxiids (Galaxias fontanus) has been...

Neufer,

From where do these gems of thought and wondrous information spring forth???

Oh my

[ta152h0]

Apparently Mr jisles is another nit picker who gives a candela... pass the ice cold one around ...

[neufer]

<<The decline in populations of Swan galaxiids (Galaxias fontanus) has been...

Neufer,

From where do these gems of thought and wondrous information spring forth???

Oh my

I'll have you know, Beyond, that Swan galaxiids are NOT related to candiru

[Beyond]

Only ifin i's wants to.

[Sandstone]

The galaxy is not 'towards' the constellation Ursa Major. APOD captions regularly make this mistake. It's IN the constellation Ursa Major. Constellations comprise everything within an irregularly-outlined cone, stretching to infinity, whose apex is at the observer's eye. I love APOD though!

Hmmmm... and how does one define "cone", then?

[Chris Peterson]

The galaxy is not 'towards' the constellation Ursa Major. APOD captions regularly make this mistake. It's IN the constellation Ursa Major. Constellations comprise everything within an irregularly-outlined cone, stretching to infinity, whose apex is at the observer's eye. I love APOD though!

Hmmmm... and how does one define "cone", then?

Good point... my dictionary includes

a solid bounded by a circular or other closed plane base and the surface formed by line segments joining every point of the boundary of the base to a common vertex

which suggests to me that the usage given by jisles is acceptable.

[TNT]

The galaxy is not 'towards' the constellation Ursa Major. APOD captions regularly make this mistake. It's IN the constellation Ursa Major. Constellations comprise everything within an irregularly-outlined cone, stretching to infinity, whose apex is at the observer's eye. I love APOD though!

That seems correct to me. If an object is said to be in a certain area, wouldn't it also be seen towards that area? And where are you getting an irregularly outlined cone? It would be more logical to say that it is an irregularly shaped figure or plane, as it appears two-dimensional. I don't think I've even seen an irregularly outlined cone before.

[Chris Peterson]

The galaxy is not 'towards' the constellation Ursa Major. APOD captions regularly make this mistake. It's IN the constellation Ursa Major. Constellations comprise everything within an irregularly-outlined cone, stretching to infinity, whose apex is at the observer's eye. I love APOD though!

That seems correct to me. If an object is said to be in a certain area, wouldn't it also be seen towards that area? And where are you getting an irregularly outlined cone? It would be more logical to say that it is an irregularly shaped figure or plane, as it appears two-dimensional. I don't think I've even seen an irregularly outlined cone before.

As I noted, a cone is not limited to a solid with a circular base- the base can be any polygon, and calling that shape "an irregularly outlined cone" seems clear enough. Technically, an object is always "in" a constellation, not "towards" it. And that means that the object lies in the volume defined by the so-called irregularly outlined cone. Personally, I don't have much problem with a caption that says something is "towards" a constellation, but that usage isn't very conventional.

[Sandstone]

On "Maxwell Smart", the "Cone of Silence" was clearly dome shaped.

[Beyond]

And it worked so well that they couldn't hear each other

[Chris Peterson]

I've scoured the finest mathematical resources known to humanity, and a cone is... well... a cone. You know, one of those round pointy things.

The error you made was in scouring "mathematical resources". The APOD caption isn't a mathematical discourse, nor are the discussions here. And a quick perusal of ordinary English language dictionaries will immediately reveal that a cone can be something other than "one of those round pointy things".

[neufer]

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The galaxy is not 'towards' the constellation Ursa Major. APOD captions regularly make this mistake.
It's IN the constellation Ursa Major. Constellations comprise everything within an irregularly-outlined cone, stretching to infinity, whose apex is at the observer's eye. I love APOD though!

That seems correct to me. If an object is said to be in a certain area, wouldn't it also be seen towards that area?

Most non-astronomers would have a good idea of what 'towards' the constellation Ursa Major or Big Dipper generally means.

However, few would know, off hand, what constitutes the gerrymandered district "IN the constellation Ursa Major."