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View Full Version : The HST's EXTREME Deep Field



Cougar
2012-Sep-26, 12:23 AM
I'm surprised no one has posted about this yet. This image is amazing. (http://hubblesite.org/newscenter/archive/releases/2012/37/image/a/) It's the Ultra Deep Field with a lot more time layered on, giving it a lot more clarity. And depth. And apparently they threw in time on the Wide Field Camera 3, which extends the image into the near-infrared. Look at the variations in galaxy morphologies!

Cougar
2012-Sep-26, 12:58 AM
I noticed this odd lineup of... galaxies (?) seen in the Ultra Deep Field (lower left) now has a red "companion" in the Extreme Deep Field.

This little configuration was strange enough, now this. Is the red object far in the background of the white and blue structures?

Swift
2012-Sep-26, 01:35 AM
Those kinds of images blow me away. That is a tiny, tiny patch of the sky and those are all GALAXIES! The Universe is really freaking big!

John Jaksich
2012-Sep-26, 02:32 PM
I noticed this odd lineup of... galaxies (?) seen in the Ultra Deep Field (lower left) now has a red "companion" in the Extreme Deep Field.

This little configuration was strange enough, now this. Is the red object far in the background of the white and blue structures?

That is truly a nice post!---Thanks

George
2012-Sep-28, 02:13 AM
I'm surprised no one has posted about this yet. This image is amazing. (http://hubblesite.org/newscenter/archive/releases/2012/37/image/a/) It's the Ultra Deep Field with a lot more time layered on, giving it a lot more clarity. And depth. And apparently they threw in time on the Wide Field Camera 3, which extends the image into the near-infrared. Look at the variations in galaxy morphologies!Nice!

Looks like the universe just gained about 50 billion galaxies, up from 125 billion.

[Based on the ~5,500 galaxies in the 4.6 sq. arcminute field. http://www.nasa.gov/mission_pages/hubble/science/xdf.html ]

Jerry
2012-Sep-29, 03:07 AM
I noticed this odd lineup of... galaxies (?) seen in the Ultra Deep Field (lower left) now has a red "companion" in the Extreme Deep Field.

This little configuration was strange enough, now this. Is the red object far in the background of the white and blue structures?
Usually a red spotted with a bunch of blues is a deep background galaxy but it can also be a highly reddened dusty star.

kzb
2012-Oct-01, 05:11 PM
Nice!

Looks like the universe just gained about 50 billion galaxies, up from 125 billion.

[Based on the ~5,500 galaxies in the 4.6 sq. arcminute field. http://www.nasa.gov/mission_pages/hubble/science/xdf.html ]

Looking at the photographic representation of the field of view on that site, the image would be about half a millimetre across at arm's length. In other words, a large full-stop (or period in US-parlance) held at arm's length. That's a smaller field of view than looking through a drinking straw!

What comes after "Extreme" deep field? Ultra-Extreme?

antoniseb
2012-Oct-01, 05:23 PM
... That's a smaller field of view than looking through a drinking straw!

What comes after "Extreme" deep field? Ultra-Extreme?

1. Yes! Unless your arms are more than ten meters long.
2. :) We can only guess. Perhaps "Extra Extreme Deep Field", "Yet More Extreme Deep Field", or "Abbott and Costello Meet the Deep Field". New more superlative designations are wide open naming-wise.

George
2012-Oct-03, 04:22 AM
Looking at the photographic representation of the field of view on that site, the image would be about half a millimetre across at arm's length. In other words, a large full-stop (or period in US-parlance) held at arm's length. That's a smaller field of view than looking through a drinking straw! Yes, but it is easier to count ~ 5,500 galaxies in this one than it is to count ~ 10,000 in the HUDF, though I haven't heard if anyone has bothered to do an accurate count of them, oddly enough.

If we assume a little over 100 billion (1E11) stars per galaxy, then with the count now at about 175 billion galaxies, we are at rougly 2E22 stars in the observeable universe, and 2E22 is a number I can remember -- two times easier than having to multiply the two quantities in my head, too. It also "eschews obfuscation" with the avoidance of the use of the "billion" term.


What comes after "Extreme" deep field? Ultra-Extreme?They seem to be climbing up the spectrum. From ultra (violet) to extreme ultra (violet), so I am guessing the next one should be the Hubble X-UDF image. ;)

I hope they do it [a smaller and more robust image]; it is easier and more fun to count a smaller number of galaxies that yield a larger number of galaxies. :)

Shaula
2012-Oct-03, 07:04 AM
They should have kept things simple and used the radio band designators:
Deep field
Very deep field
Ultra deep field
Super deep field
Extremely deep field
Terrifically deep field

By jumping to extreme they have messed up their potential for expansion. And annoyed radio geeks.

kzb
2012-Oct-03, 11:22 AM
George wrote:
Yes, but it is easier to count ~ 5,500 galaxies in this one than it is to count ~ 10,000 in the HUDF, though I haven't heard if anyone has bothered to do an accurate count of them, oddly enough.

It's such a tiny proportion of the sky, that you could argue that it is dangerous, statistically, to use that as the sole sample. To do statistically robust head counts we need several other extreme deep field images in other directions.

antoniseb
2012-Oct-03, 12:29 PM
... It's such a tiny proportion of the sky, that you could argue that it is dangerous, statistically, to use that as the sole sample. To do statistically robust head counts we need several other extreme deep field images in other directions.

While I would like to see several other regions get the Extreme Deep Field level of observation, I think that it isn't "dangerous" to report what we find in this and the Southern one before other ones are made. Scientists know the limitations of the circumstances of the observations, and data at the edge of observational capability shouldn't be suppressed.

George
2012-Oct-03, 08:58 PM
While I would like to see several other regions get the Extreme Deep Field level of observation, I think that it isn't "dangerous" to report what we find in this and the Southern one before other ones are made. Scientists know the limitations of the circumstances of the observations, and data at the edge of observational capability shouldn't be suppressed. Yep.

There are a few interesting notes to support the better than average 2e22 assesment. The original Hubble image (pre Ultra) came with the logical statistical questions raised. So they took a southern hemisphere image, and got a similar result. [I don't think they did a southern HUDF image, however.] The isotropy of the CMB and the ability to image close to the earliest galaxy periods suggest that there should not be a lot of variation in galaxtic counts per unit area. The EUDF should raise the count since the more faint galaxies become visible and increase the count. The increase wasn't that significant, though I didn't notice what magnitude improvement exists in the image between ultra and extreme. [I think the Hubble limit is still around 31 mag., though this is a number from several years ago, possibly before the gear exchange.]

Is my view reasonable? Perhaps I just like 2e22 2 much.

George
2012-Oct-03, 09:05 PM
They should have kept things simple and used the radio band designators:
Deep field
Very deep field
Ultra deep field
Super deep field
Extremely deep field
Terrifically deep field

Was there a Very Deep Field?

I like 'em. Would Terrifyingly Deep be next?

The Hubble is lilkely limited by redshift beyond this level, right? With the James Webb, we can start all over again. :)

The bottom turtle can't be too far off.