Astronomers mapped 1.2 million galaxies in a hunt for dark energy
Hundreds of astronomers have collaborated to make the largest three-dimensional map of galaxies on our universe.
In the quest for dark energy, astronomers have created an unprecedented 3D map of 1.2 million galaxies in a volume of about 650 cubic billion light years.
more…
CrazyNeutrino said:
Astronomers mapped 1.2 million galaxies in a hunt for dark energyHundreds of astronomers have collaborated to make the largest three-dimensional map of galaxies on our universe.
In the quest for dark energy, astronomers have created an unprecedented 3D map of 1.2 million galaxies in a volume of about 650 cubic billion light years.
more…
Do you completely understand how Baryon Acoustic Oscillations work?
mollwollfumble said:
CrazyNeutrino said:
Astronomers mapped 1.2 million galaxies in a hunt for dark energyHundreds of astronomers have collaborated to make the largest three-dimensional map of galaxies on our universe.
In the quest for dark energy, astronomers have created an unprecedented 3D map of 1.2 million galaxies in a volume of about 650 cubic billion light years.
more…
“The Baryon Oscillation Spectroscopic Survey (BOSS) of the SDSS-III carried out the precise measurements found.”Do you completely understand how Baryon Acoustic Oscillations work?
no, I have read these articles but only still have a vague idea
from
https://medium.com/starts-with-a-bang/what-the-hell-are-baryon-acoustic-oscillations-cfee6d726538#.gxtxjkc4j
So what the hell are baryon acoustic oscillations? The fact that the Universe started with fluctuations, that gravity pulls on normal matter and dark matter both, but only normal matter gets pushed out by interacting electromagnetically gives rise to this “special scale” in the Universe. Today, we can see that special scale by noticing that you’re slightly more likely to have galaxies separated by a certain distance, and that distance has evolved over time as the Universe has expanded.
from
https://en.wikipedia.org/wiki/Baryon_acoustic_oscillations
In cosmology, baryon acoustic oscillations (BAO) are regular, periodic fluctuations in the density of the visible baryonic matter (normal matter) of the universe. In the same way that supernova provide a “standard candle” for astronomical observations, BAO matter clustering provides a “standard ruler” for length scale in cosmology. The length of this standard ruler (~490 million light years in today’s universe) can be measured by looking at the large scale structure of matter using astronomical surveys. BAO measurements help cosmologists understand more about the nature of dark energy (which causes the apparent slight acceleration of the expansion of the universe) by constraining cosmological parameters.
from the original link
this bit
The Baryon Oscillation Spectroscopic Survey (BOSS) of the SDSS-III carried out the precise measurements found. By studying the tugs between dark energy and dark matter, the scientists were able to determine the Baryonic Acoustic Oscillation (BAO) between the galaxies in the map to measure the expansion rate of the universe.
and this bit
Their strenuous efforts have paid off as the BOSS data show that dark energy is what is causing the expansion with an error of only 5 percent in the cosmological constant found. The cosmological constant is called Lambda, as coined by Albert Einstein as a repellant effect in the universe. These findings are still consistent with the relatively young theory of the cosmological model.
so , are they suggesting a new cosmological constant, or is it an actual one?