An Orion Deep Field (APOD 15 Oct 2006)

[harry]

Hello All

An Orion Deep Field

15th Oct 2006
http://antwrp.gsfc.nasa.gov/apod/ap061015.html
It makes the statement of deep field.

I thought deep field meant billions of light years deep into space.

Adrift 1,500 light-years away in one of the night sky's most recognizable constellations, the glowing Orion Nebula and the dark Horsehead Nebula are contrasting cosmic vistas

Regardless, the APOD image is fantastic and the parts within and the associated objects are worth discussing. Wow! what an IMAGE.

The Great Nebula in Orion
http://antwrp.gsfc.nasa.gov/apod/ap020213.html

Search results for the Orion Nebulae
http://antwrp.gsfc.nasa.gov/cgi-bin/apo ... ion+Nebula

Orion: The Big Picture
http://antwrp.gsfc.nasa.gov/apod/ap971201.html

The Horsehead Nebula
http://antwrp.gsfc.nasa.gov/apod/ap011216.html
http://astro.nineplanets.org/twn/b33x.html

The Orion Cloud and Association
http://www.seds.org/messier/more/oricloud.html

Reflections on the 1970s
http://antwrp.gsfc.nasa.gov/apod/ap031002.html


The Flame Nebula in Infrared
http://antwrp.gsfc.nasa.gov/apod/ap990713.html

Orion's Belt Stars

http://www.gb.nrao.edu/~rmaddale/Educat ... /belt.html

One of the most obvious features people see in Orion is the three stars that make up what most people consider the belt of the giant. Mintaka , the westernmost star in the belt, comes from the Arabic word for belt. Alnilam, the center star in the belt, means "a belt of pearls". And Alnitak, the eastern-most star, means the girdle. All three are at the same distance from us and, with Rigel, Saiph, and Meissa, probably formed at about the same time some ten million years ago from the molecular clouds astronomers have found in Orion.

[astro_uk]

Deep in astronomy terms usually just means deep as in exposure time. So a deep exposure is one with a lot of exposure time. It just means you can see fainter objects.

[FieryIce]

Deep in astronomy terms usually just means deep as in exposure time. So a deep exposure is one with a lot of exposure time. It just means you can see fainter objects.

Astro I think there is an error in what you are professionally implying about “deep”, whereas, Harry’s notion is closer to the truth.

Adding images together like this is common in astronomical imaging. If you take, for example, 10 images with exposure times of 10 seconds each and then add them all together, it produces one image equal to an exposure time of 100 seconds.
The advantage of doing it this way has to do with the way images are produced by a CCD detector. CCD's produce more noise or 'grain' to an image if you just let them sit there collecting light. Less grainy images are obtained if you just add a bunch of shorter exposures together. With each image added, the light from the galaxies increases by the amount that the image was exposed, but the graininess increases by a lesser amount (the square root of the number of images for those technically motivated).
The result is an image that is sharper and has more detail.

Where Did Hubble Look?
Half way down that page, titled "Where Did Hubble Look?"

Edited to add:

Called Hubble Ultra Deep Field (HUDF), the million-second-long exposure...This Historic new view is actually two separate images taken by Hubble's Advance Camera for Surveys (ACS) and the Near Infrared Camera and Multi-object Sectrometer (NICMOS).

Hubble's Deepest View Ever of the Universe Unveils Earliest Galaxies

[astro_uk]

I wasn't implying anything, I was describing the semantics of what "deep" means to astronomers. We use deep to mean any observation that has a very faint magnitude limit, so the HST in certain filters can observe to a magnitude limit of around 29, in many hours or days of exposure. That is you can just detect an object above the background if it has a magnitude of 29 contained within some region (usually something like the psf of the instrument).

Now the choice of what constitutes a deep observation is arbitrary. For the HST it is usually an observation that takes days of observing, like the UDF. But for ground based instruments, generally you never get enough time to get anywhere near as deep as the HST, so in this case, on something like Gemini a single 2-hour exposure gets called deep by some people.

The fact that you go "deep" means that you can see distant galaxies that you wouldnt have. But you can still do deep observations of nearby objects, you just see fainter parts (like the outer reaches of nearby galaxies). It may be that the use of deep started out to imply reaching greater distances, but that is not the common meaning today.

[harry]

Hello All

Sounds heavy to me.

I noticed the link by fieryIce

http://hubblesite.org/newscenter/newsde ... s/2004/07/

Hubble's Deepest View Ever of the Universe Unveils Earliest Galaxies

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View all images

Astronomers at the Space Telescope Science Institute today unveiled the deepest portrait of the visible universe ever achieved by humankind. Called the Hubble Ultra Deep Field (HUDF), the million-second-long exposure reveals the first galaxies to emerge from the so-called "dark ages," the time shortly after the big bang when the first stars reheated the cold, dark universe. The new image should offer new insights into what types of objects reheated the universe long ago.

What hog wash

It does not reveal the early universe. It makes an assumption that the Big Bang is correct and adds an opinion without evidence, particulary when the observation image is present.

If you look at the image you see all galaxies in deep field. Many different forms young and old and different shapes and sizes.

[craterchains]

In football "go deep" means DISTANCE.

Norval

[Dr. Skeptic]

It does not reveal the early universe. It makes an assumption that the Big Bang is correct and adds an opinion without evidence, particulary when the observation image is present.

If you look at the image you see all galaxies in deep field. Many different forms young and old and different shapes and sizes.

What about the observable differences in the deep field compared to the near-by universe?

[astro_uk]

Well spotted craterchains, but this was a discussion about the use of the word in astronomy.

To follow up Dr. Skeptic, here is another article that Harry will hate.

http://space.com/scienceastronomy/06101 ... alaxy.html

A series of smaller galaxies merging to form a larger one at a redshift of about 2.2.

[iamlucky13]

What hog wash

It does not reveal the early universe. It makes an assumption that the Big Bang is correct and adds an opinion without evidence, particulary when the observation image is present.

While true, it is important to note that the findings are consistent with the Big Bang Theory, although if I remember right, the ultra-deep field did challenge some sub-theories about the formation of galaxies in the early universe.

Million second long exposure. Wow. That's something like 12 days. There's only a limited direction in the sky Hubble can look for an observation like that or it will be interrupted by glare from the sun, earth, or moon.

[harry]

Hello All

Ok, lets get something correct. I do not hate.
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Re: link

http://space.com/scienceastronomy/06101 ... alaxy.html

Hubble photographed the Spiderweb Galaxy [image], officially MRC 1138-262. It is 10.6 billion light-years away. The light we see from it emanated when the universe was only a couple billion years old.

What do you expect a BB peerson to say?

They assume the BB theory is correct and jump to conclusions.

What I see in the image is a process thats been ongoing endlessly.

Evolution and recycling is an ongoing process.

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Big Bang Expansion
http://antwrp.gsfc.nasa.gov/apod/ap060323.html

Have a look at the image and tell me the error.

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http://www.smh.com.au/news/science/big- ... 22240.html
Big bang: NASA gets to the heart of all matter

SCIENTISTS examining the oldest light in the universe say they have found evidence that matter expanded at an almost inconceivable rate after the big bang, creating conditions that led to the formation of the first stars.

Light from the big bang's afterglow shows that the universe grew from the size of a marble to an astronomical size in just a trillionth of a second after its birth 13.7 billion years ago, researchers from Johns Hopkins and Princeton universities say.

It is statements like the one above, that I think NASA is in La La land.
They make their model work by making fantasy statements that are not real or practical.


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http://asterisk.apod.com/pos ... ply&t=8487

Large scale structure of the universe.

Read the first page.

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http://hubblesite.org/newscenter/newsde ... s/2006/44/

Tracing the Evolution of the First Galaxies in the Universe

These BB people have money to burn.

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Astro , in your position you should be looking at all aspects and evidence supporting models that work.

[Dr. Skeptic]

Quote:
SCIENTISTS examining the oldest light in the universe say they have found evidence that matter expanded at an almost inconceivable rate after the big bang, creating conditions that led to the formation of the first stars.

Light from the big bang's afterglow shows that the universe grew from the size of a marble to an astronomical size in just a trillionth of a second after its birth 13.7 billion years ago, researchers from Johns Hopkins and Princeton universities say.


It is statements like the one above, that I think NASA is in La La land.
They make their model work by making fantasy statements that are not real or practical.

Agreed, there are inconsistencies in the BB theory. But for every one inconsistencies in the BB theory there no less than ten inconsistencies for any of the steady state theories.
It is more practical to "fix" the BBT - the steady state theories cannot be fixed.

...by making fantasy statements that are not real or practical. ...

Harry, isn't this what we keep telling you?

[harry]

Hello All

Dr Skeptic said

Agreed, there are inconsistencies in the BB theory. But for every one inconsistencies in the BB theory there no less than ten inconsistencies for any of the steady state theories.
It is more practical to "fix" the BBT - the steady state theories cannot be fixed.

At this moment the BBT is under fire. Let us wait until the dust settles and see if the BB model is still standing.

This may take sometime.