The Very Large Telescope's (VLT) Multi-unit spectroscopic explorer (MUSE) has been used to study the galaxies in the Hubble Ultra-Deep Field. It has also revealed previously unseen galaxies:
Sometimes, astronomy is about surveying widely to get the big picture. And sometimes it's about looking more and more deeply. First released in 2004, the Hubble Ultra Deep Field is clearly about going deep. It's a composite image of a tiny region of space, located in the direction of the southern constellation Fornax, made from Hubble Space Telescope data gathered over several months. There are an estimated 10,000 galaxies in the Hubble Ultra Deep Field, which exist as far back in time as 13 billion years ago (between 400 and 800 million years after the Big Bang). Being able to see galaxies so near the beginning of our universe has been a fantastic tool for understanding how the universe has evolved. And now – thanks to an instrument called MUSE (Multi Unit Spectroscopic Explorer), astronomers have been able to eke out yet more information – a veritable bonanza of information – from the Hubble Ultra Deep Field. Their work is being published today (November 29, 2017) in a series of 10 papers in a special issue of the peer-reviewed journal Astronomy & Astrophysics.
Also at ESO.
The MUSE Hubble Ultra Deep Field Survey - I. Survey description, data reduction, and source detection (open, DOI: 10.1051/0004-6361/201730833) (DX)
The rest of the papers are paywalled:
The MUSE Hubble Ultra Deep Field Survey - II. Spectroscopic redshifts and comparisons to color selections of high-redshift galaxies (DOI: 10.1051/0004-6361/201731195) (DX)The MUSE Hubble Ultra Deep Field Survey - III. Testing photometric redshifts to 30th magnitude (DOI: 10.1051/0004-6361/201731351) (DX)
The MUSE Hubble Ultra Deep Field Survey - IV. Global properties of C III] emitters (DOI: 10.1051/0004-6361/201730985) (DX)
The MUSE Hubble Ultra Deep Field Survey - V. Spatially resolved stellar kinematics of galaxies at redshift 0.2 ≲ z ≲ 0.8 (DOI: 10.1051/0004-6361/201730905) (DX)
The MUSE Hubble Ultra Deep Field Survey - VI. The faint-end of the Lyα luminosity function at 2.91 (DOI: 10.1051/0004-6361/201731431) (DX)
The MUSE Hubble Ultra Deep Field Survey - VII. Fe ii* emission in star-forming galaxies (DOI: 10.1051/0004-6361/201731499) (DX)
The MUSE Hubble Ultra Deep Field Survey - VIII. Extended Lyman-α haloes around high-z star-forming galaxies (DOI: 10.1051/0004-6361/201731480) (DX)
The MUSE Hubble Ultra Deep Field Survey - IX. Evolution of galaxy merger fraction since z ≈ 6 (DOI: 10.1051/0004-6361/201731586) (DX)
The MUSE Hubble Ultra Deep Field Survey - X. Lyα equivalent widths at 2.9 (DOI: 10.1051/0004-6361/201731579) (DX)
(Score: 0) by Anonymous Coward on Sunday December 03 2017, @07:27AM (2 children)
I don't really think it translates like that. Not all of space is equal. The universe seems to have an ecliptic plane, just as galaxies and solar systems have ecliptics. That is, not all angles at which you can point that thing are going to be equally revealing. If there's nothing there, better eyes aren't going to see any more of nothing. We might suspect that the first place they aimed it was some place that they EXPECTED to find some new stuff.
At the end of the story, we aren't going to know how populous any portion of the sky might be until we look.
(Score: 3, Insightful) by takyon on Sunday December 03 2017, @05:21PM (1 child)
https://en.wikipedia.org/wiki/Cosmological_principle [wikipedia.org]
That's true, but if there are hidden Lyman-alpha emitter galaxies in a deep field, there are probably more elsewhere.
Eventually we will have all-sky surveys capable of mapping every galaxy (hundreds of billions). Call it the All-Sky Deep Field (ASDF). WFIRST [wikipedia.org] might help there since it will have 100 times the field of view of Hubble.
Sooner than that, we will have the LSST [wikipedia.org].
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by aristarchus on Monday December 04 2017, @09:46AM
Takyon is correct. We do not know that all of space is equal. But on the other hand, we equally do not know it is not. So the 12 million times figure could be woefully low. Or not. What is at stake here? "Your God is too small," in the words of Bruno Giordano. I hate it, when people's god is too small. It is even worse when your god is too small for the Hubble Ultra Deep Field. Tiny god. Small mind. Tiny hands. Big Real Estate! Still very, very tiny.