Posted on 01/24/2019 1:15:13 PM PST by ETL
It has taken researchers at the Instituto de Astrofísica de Canarias almost three years to produce the deepest image of the universe ever taken from space, by recovering a large quantity of "lost" light around the largest galaxies in the Hubble Ultra-Deep Field survey.
To produce the deepest image of the universe, a group of researchers from the Instituto de Astrofísica de Canarias (IAC) led by Alejandro S. Borlaff used original images from the Hubble Space Telescope (HST) taken over a region in the sky called the Hubble Ultra-Deep Field (HUDF). After improving the process of combining several images, the group was able to recover a large quantity of light from the outer zones of the largest galaxies in the HUDF. Recovering this light emitted by the stars in these outer zones was equivalent to recovering the light from a complete galaxy ("smeared out" over the whole field) and this missing light shows that some galaxies have diameters almost twice as large as previously measured.
The HUDF is the result of combining hundreds of images taken with the Wide Field Camera 3 (WFC3) of the HST during over 230 hours of observation which, in 2012, yielded the deepest image of the universe taken until then. But the method of combining the individual images was not ideally suited to detect faint extended objects. Borlaff says, "What we have done is to go back to the archive of the original images taken by the HST, and improve the process of combination, aiming at the best image quality not only for the more distant smaller galaxies, but also for the extended regions of the largest galaxies.
The WFC3 was installed by astronauts in May 2009, when the Hubble had already been in space for 19 years. This presented a major challenge for the researchers because the complete instrument (telescope and camera) could not be tested on the ground, which made calibration more difficult. To overcome the problems, they analysed several thousand images of regions across the sky with the aim of improving the calibration of the telescope on orbit.
"The deepest image of the universe has been possible thanks to a striking improvement in the techniques of image processing which has been achieved in recent years, a field in which the group working in the IAC is at the forefront," says Borlaff.
Explore further: Hubble goes deep
More information: Alejandro Borlaff et al. The missing light of the Hubble Ultra Deep Field, Astronomy & Astrophysics (2018). DOI: 10.1051/0004-6361/201834312
Journal reference: Astronomy & Astrophysics
The rate of expansion is increasing because as the ‘parts’ fly farther and farther away from each other, the drag force of gravity gets less and less........................
We analyze the state space of a Bianchi-I universe with anisotropic sources. Here we consider an extended state space which includes null geodesics in this background. The evolution equations for all the state observables are derived. Dynamical systems approach is used to study the evolution of these equations. The asymptotic stable fixed points for all the evolution equations are found. We also check our analytic results with numerical analysis of these dynamical equations. The evolution of the state observables are studied both in cosmic time and using a dimensionless time variable. Then we repeat the same analysis with a more realistic scenario, adding the isotropic (dust like dark) matter and a cosmological constant (dark energy) to our anisotropic sources, to study their co-evolution. The universe now approaches a de~Sitter space asymptotically dominated by the cosmological constant. The cosmic microwave background anisotropy maps due to shear are also generated in this scenario, assuming that the universe contains anisotropic matter along with the usual (dark) matter and vacuum (dark) energy since decoupling. We find that they contribute dominantly to the CMB quadrupole. We also constrain the current level of anisotropy and also search for any cosmic preferred axis present in the data. We use the Union~2 Supernovae data to this extent. An anisotropy axis close to the mirror symmetry axis seen in the cosmic microwave background data from Planck probe is found
What he said :-) from this
What he said is:
They used radio frequency power measurements aimed in different directions, from Earth in a spherical array, and used math to determine the ‘speed’ of the ‘fixed points’ in relation to Earth, taking into account the speed of light and time relationships with respect to us.
I think...............
I THINK what this means is they couldn't measure any curvature.
I think what this means is they found the long axis to be nearly the same as the short axis, so its close to spherical. Probably slightly ellipsoid. Which would fit my theory a little. As time goes by the perturbations would get worse and worse........................................
Except they know the direction the expansion came from so they have calculated a “center” so to speak.
I’m trying to remember if it was a National Geographic OR one of my astronomy books that has an amazing fold out that shows relatively distance wise where everything was that we had discovered so far.
Darn - now I’ll be spending part of the weekend trying to find that as I want to look at it again.
Cute... '-)
The total universe is bigger than our observable universe (since all information reaching us is limited by the speed of light).
TXnMA
It's bigger than it appears in your rear-view mirror.
If the astronomers look far enough they will see the back of their heads....
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