Theoretical Astrophysicist, Ethan Siegel PhD : This is what your Universe looks like!

Recently, a stroll across the internet brought me to the webpage of a very fascinating and thought provoking scientist. Please click on the link below to see the images and additional information.

http://scienceblogs.com/startswithabang/2012/03/this_is_what_your_universe_loo.php

~Posted with permission~

"This is what your Universe looks like!
Category: Astronomy • Galaxies
Posted on: March 21, 2012 4:31 PM, by Ethan Siegel

"When you look out into the darkness of a moonless, unpolluted night sky, you'll of course notice that it's full of stars, planets, and the occasional extended object.

But you'll also notice that there are plenty of regions that -- other than a few stars -- don't really have very much going on. One such region, visible in the southern skies pretty much year-round, is the constellation of Sextans.

A region of space where there isn't very much going on -- no bright stars, no planets, no close, extended galaxies or nebulae -- is ideal for looking out, deeply, into the Universe.

You may remember, very famously, that the Hubble Space Telescope has done that a number of times, producing images such as the magnificent Hubble Ultra-Deep Field, an image which contains around 10,000 galaxies!



And that, well, that's a lot. But is that the record?

If it was, it certainly isn't anymore! Because that region of space I showed you, above, in the constellation of Sextans? The European Southern Observatory has -- with their VISTA telescope -- created the deepest wide-field image of all-time, containing over 200,000 galaxies!

The ESO has released a couple of videos, where you can see exactly where on the sky this region is, and zoom in a bit on some of these 200,000+ galaxies. In the video below, the full region of the survey -- known as UltraVISTA, of the COSMOS field -- is visible at about 0:31 into the clip.



(Video credit: ESO/A. Fujii/Digitized Sky Survey 2/UltraVISTA teamESO; music by John Dyson.)

Of course, they've also created an interactive, zoomable version of this survey..."

"...Remember, as we did this, that the only remarkable thing about this patch of space is how unremarkable it was! With the exception of two or three faint stars, every dot of light in this image is a galaxy, containing hundreds of billions (or more) of stars! And by doing this to the entire image, we can determine that there are more than 200,000 galaxies in this space."

~*~

About Ethan Siegel:

Ethan fell in love with learning about how and why the Universe works the way it does at a very young age, and has spent his entire adult life pursuing that end. He received his B.A. in Physics, Classics, and the Integrated Science Program from Northwestern in 2000, and his Ph.D. in theoretical cosmology from Florida in 2006. He has a myriad of scientific publications and has been doing science writing since January, 2008.

Please take a look at his website and prepare to learn some incredible information!

http://scienceblogs.com/startswithabang/

Thank you for that post Jackie, and thank you also Dr. Siegel for the original post on your site. That’s a lot of stars in one image!!

I’m wondering, Dr. Siegel, whether you have a fairly good idea of the layout of the black holes at the center of our galaxy. I would be keenly interested in seeing a diagram of how they are placed, and their orbits, etc.

Copernicus

Hey Copernicus ~*~

I sent your question to Ethan, and he sent a reply to you as follows:

"...I wrote a post on our galaxy's largest black hole: the multi-million solar mass behemoth at the center of our galaxy!

http://scienceblogs.com/startswithabang/2010/12/dont_believe_in_black_holes_th.php

We can detect this black hole by the orbit of the stars that go around it; via Kepler's laws we can deduce the black hole's mass, and by the complete absence of light in any portion of the electromagnetic spectrum, there's no alternative explanation to "black hole" for this object..."

Thanks to Dr. Siegel - and thanks to you, Copernicus, for the great question!!!

Thank you once again Jackie!!

And thank you for the quick reply, Dr. Siegal. Your article does a fine job of answering my questions to you about the black hole at the center of our galaxy. From the animation, I think that S2 would be near the apogee of its orbital path this year. I assume that Sgr A would be the actual position of the black hole?

C