Universe's Very First Objects

[astrotrain]

So I recently came across this article on Yahoo and it left me with some basic queries for the minds here:


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http://news.yahoo.com/universes-1st-...163220691.html

"New observations from a NASA space telescope have spotted what may be the very first objects created in the universe in unprecedented detail, scientists say.

The faint objects, imaged in infrared light by NASA's Spitzer space telescope, might be hugely massive stars or black holes, but are too distant to see individually...

...The scientists can't confirm for sure that the objects they see date from the early universe, but say that's the most likely explanation."

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So here's what I'm left wondering:

- why all the ambiguity?
- if these aren't, in fact, the universe's earliest objects, what might they be?
- isn't the distinction between hugely massive stars and black holes, however ancient, fairly straightfwd?
- why the observed wavelength shift? (UV/visible --> infrared)

[Cougar]

- why all the ambiguity?
- if these aren't, in fact, the universe's earliest objects, what might they be?

They're hints at the Universe's earliest objects. After subtracting out foreground objects, they're imaging the cosmic infrared background, which isn't exactly like looking at an "object." But it gives an idea about what those early objects are doing.

[parejkoj]

As Cougar said, this is a study involves subtracting the known foreground objects to reveal the light from all the unresolved objects that are left. One possibility for those unresolved objects would be the first quasars and stars at a redshift of ~10, which would explain the extreme wavelength shift of the light. At these wavelengths, very massive stars (100-1000 times the mass of the Sun) and early quasars would look fairly similar: a nearly power-law spectrum that increases toward the UV.

Some other possibilities include calibration uncertainty: if the data isn't "flat fielded" correctly, patterns like that would appear; light from foreground sources like dust in our galaxy or the solar system; or excess light remaining from after the "foreground subtraction" process. The Spitzer telescope wasn't really designed for this type of observation, so they're really pushing its limits in this case.

[Jens]

- why the observed wavelength shift? (UV/visible --> infrared)

It's not that the light is shifted. It's just that the Spitzer telescope is an infrared telescope, so that's the frequencies that it sees.

[NEOWatcher]

It's not that the light is shifted. It's just that the Spitzer telescope is an infrared telescope, so that's the frequencies that it sees.

In this context, it's both. In fact, the article says that.

[antoniseb]

- why all the ambiguity?
- if these aren't, in fact, the universe's earliest objects, what might they be?
- isn't the distinction between hugely massive stars and black holes, however ancient, fairly straightfwd?
- why the observed wavelength shift? (UV/visible --> infrared)

Just to add to the answers you've been getting, the word "object" is ambiguous. You could argue that the earliest objects were whatever first particles appeared from the high energy in a small expanding space. If you want to discount mere particles, and go for the macroscopic, the first objects might be the zones of slightly higher density we observe in the CMB.

It doesn't sound as glorious to say we are observing the earliest light from collapsing, or energy generating objects in the universe... or we are observing what might be the seeds of dwarf galaxies. We're constantly fighting this problem that science journalism somehow needs a splashy headline, which obscures the actual really cool science that is happening.

[PetTastic]

It does look like the Jame Webb space telescope will have something interesting to look at.

How big are these "objects"?
I understand that converting angular size to actual size at high z in not straightforward, but are we talking thousands of light-years across? more/less?