liveblogging the high redshift universe II

extremely high redshift galaxies found

Garth Illingworth gave a talk this morning, the first of two, on new extremely high redshift galaxies found in the Ultra Deep Field using combined ACS, NICMOS and Spitzer data.
Second talk tomorrow by Rychard Bouwens on unpublished candidates.

So... the press release claim of the week is that A1689-zD1 a lensed galaxy by the cluster Abel 1689 is at redshift greater than 7.
Estimated redshift is 7.6, which has the galaxy formed within 700 million years of the Big Bang. Galaxy was lensed by a factor of about 10 by the foreground cluster.


i-989123ef428218aace4fcb8b29598982-A1689-lil.jpg
click for high res image

Another published galaxy in the Ultra Deep Field (unlensed) is estimated at redshift 7.4, and if its redshift, when finally established by spectra, is found to be less than 7 then Garth owes me, and about 70 other people, a nice cold beer.

Rumour is that tomorrow we will get the rundown on 8 more candiate objects which appear to be galaxies with redshifts between 7 and 10.
That is enough to get a luminosity function at redshift > 7, a measure of the volume density of luminous (> 0.3 L* or roughly brighter than the Milky Way, in the ultra-violet) galaxies at this early time.
Data are already good enough to establish that the luminosity density at z>7 is significantly lower than at z>6, which is not surprising, it is hard to get enough stuff together that quickly to make a respectable galaxy.


i-65d669e924f6fd6602db1352c5805797-cosmic-lil.jpg

click for high res image

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"Redshift" is a term that astronomers use a lot. This is particularly true if they are extragalactic astronomers or (especially) cosmologists, but even galactic astronomers use it, and it is absolutely central to the method use to discover most of the extrasolar planets known today.
"It's the great mystery of human life that old grief passes gradually into quiet, tender joy. The mild serenity of age takes the place of the riotous blood of youth.
One of my favorite places on the net to find really goofy bad math is Answers in Genesis. When I'm trying to avoid doing real work, I like to wander over there and look at the crazy stuff that people will actually take seriously in order to justify their religion.
Last week, we began talking about understanding the size of the Universe, and we continued this week with some information

Thank you, Steinn Sigur�sson. That was wonderful!

Now, as I'm tied up trying to edit down 125 pages of draft paper to 4 pages of submittable to "Nature" paper, who wants to write the great Science Fiction novel set in a galaxy formed within 700 million years of the Big Bang?

Dave Brin? Greg Bear? Greg Benford? Iain M. Banks? Stephen Baxter?

And that's just the plausible B's.

Remember, superscientists Carl Sagan and Kip S. Thorne both got film deals with Lynda Obst, the latter [Interstellar (2009)] having Steven Spielberg attached. And superscientist Stephen Hawking got to appear in the Errol Morris adaptation of A Brief History of Time (1991), which yielded the anomaly of "the book based on the movie based on the book."

Hint: the Writers Guild strike is over. Think Feature Film. Think miniseries. Think Franchise.

I'll take an "from an idea by" credit, please.

"who wants to write the great Science Fiction novel set in a galaxy formed within 700 million years of the Big Bang?"

Wouldn't you have a bit of a metallicity deficit back then?

I think Larry will cover the z drop in 1689, Rychard will cover the field surveys.

Larry's object might be bright enough to get a spectrum of. Can one get two press releases out of one object?

Dude, check this out, extra-solar jupiters and saturns

I glanced at the schedule for this summer, I think I know where some will be spending part of his summer.

By Brad Holden (not verified) on 14 Feb 2008 #permalink

Ah, ok I forgot Larry was speaking today, I remember Garth mentioning the 7.4 was no longer the probably record holder.

I saw the OGLE press release, couldn't find time to do it justice.
And, yeah, the summer could be interesting. and expensive.

My spies inform me that Rychard will mention the 1689 object, but in a somewhat different context (why lensing is a lousy way to find a lot of high z galaxies).

By Brad Holden (not verified) on 15 Feb 2008 #permalink