The Final Revision Series. Readings: LESSON 182: I Will Be Still An Instant And Go Home [para 1-4], LESSON 95: I Am One Self, United With My Creator. [para 1-4], SCIENCE ARTICLE: Understanding The Cosmos: Milky Way, LESSON 95: I Am One Self, United Wit...
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The Entangled Teleportation Series. Readings: WORKBOOK: Part II: What Is The Body? [para 1-5], SCIENCE ARTICLE: Understanding The Cosmos: Milky Way, TEXT: CHAPTER 21: Introduction [para 1], LESSON 167: There Is One Life, And That I Share With God. [par...
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The Entangled Teleportation Series. Readings: WORKBOOK: Part II: What Is Sin? [para 1-5], TEXT: CHAPTER 21: Introduction [para 1], SCIENCE ARTICLE: Understanding The Cosmos: Milky Way, Island Universe,, LESSON TITLES 41-50, TEXT: CHAPTER 19: The Fourth...
I Am Not A Body I Am Free At Last - The End Of This Sequence Of Time - Episode II #ET-06Watch at themasterteacher.tvThe Entangled Teleportation Series. Readings: WORKBOOK: Part II: What Is The Body? [para 1-5], SCIENCE ARTICLE: Understanding The C...
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Excerpt from hubblesite.org
Scientists using NASA's Hubble Space Telescope have discovered that the immense halo of gas enveloping the Andromeda galaxy, our nearest massive galactic neighbor, is about six times larger and 1,000 times more massive than previously measured. The dark, nearly invisible halo stretches about a million light-years from its host galaxy, halfway to our own Milky Way galaxy. This finding promises to tell astronomers more about the evolution and structure of majestic giant spirals, one of the most common types of galaxies in the universe.
"Halos are the gaseous atmospheres of galaxies. The properties of these gaseous halos control the rate at which stars form in galaxies according to models of galaxy formation," explained the lead investigator, Nicolas Lehner of the University of Notre Dame, Indiana. The gargantuan halo is estimated to contain half the mass of the stars in the Andromeda galaxy itself, in the form of a hot, diffuse gas. If it could be viewed with the naked eye, the halo would be 100 times the diameter of the full Moon in the sky. This is equivalent to the patch of sky covered by two basketballs held at arm's length.
The Andromeda galaxy, also known as M31, lies 2.5 million light-years away and looks like a faint spindle, about 6 times the diameter of the full Moon. It is considered a near-twin to the Milky Way galaxy.
Because the gas in Andromeda's halo is dark, the team looked at bright background objects through the gas and observed how the light changed. This is a bit like looking at a glowing light at the bottom of a pool at night. The ideal background "lights" for such a study are quasars, which are very distant bright cores of active galaxies powered by black holes. The team used 18 quasars residing far behind Andromeda to probe how material is distributed well beyond the visible disk of the galaxy. Their findings were published in the May 10, 2015, edition of The Astrophysical Journal.
Earlier research from Hubble's Cosmic Origins Spectrograph (COS)-Halos program studied 44 distant galaxies and found halos like Andromeda's, but never before has such a massive halo been seen in a neighboring galaxy. Because the previously studied galaxies were much farther away, they appeared much smaller on the sky. Only one quasar could be detected behind each faraway galaxy, providing only one light anchor point to map their halo size and structure. With its close proximity to Earth and its correspondingly large footprint on the sky, Andromeda provides a far more extensive sampling of a lot of background quasars.
"As the light from the quasars travels toward Hubble, the halo's gas will absorb some of that light and make the quasar appear a little darker in just a very small wavelength range," explains co-investigator J. Christopher Howk, also of Notre Dame. "By measuring the dip in brightness in that range, we can tell how much halo gas from M31 there is between us and that quasar."
The scientists used Hubble's unique capability to study the ultraviolet light from the quasars. Ultraviolet light is absorbed by Earth's atmosphere, which makes it difficult to observe with a ground-based telescope. The team drew from about 5 years' worth of observations stored in the Hubble data archive to conduct this research. Many previous Hubble campaigns have used quasars to study gas much farther away than — but in the general direction of — Andromeda, so a treasure trove of data already existed.
But where did the giant halo come from? Large-scale simulations of galaxies suggest that the halo formed at the same time as the rest of Andromeda. The team also determined that it is enriched in elements much heavier than hydrogen and helium, and the only way to get these heavy elements is from exploding stars called supernovae. The supernovae erupt in Andromeda's star-filled disk and violently blow these heavier elements far out into space. Over Andromeda's lifetime, nearly half of all the heavy elements made by its stars have been expelled far beyond the galaxy's 200,000-light-year-diameter stellar disk.
What does this mean for our own galaxy? Because we live inside the Milky Way, scientists cannot determine whether or not such an equally massive and extended halo exists around our galaxy. It's a case of not being able to see the forest for the trees. If the Milky Way does possess a similarly huge halo, the two galaxies' halos may be nearly touching already and quiescently merging long before the two massive galaxies collide. Hubble observations indicate that the Andromeda and Milky Way galaxies will merge to form a giant elliptical galaxy beginning about 4 billion years from now.
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| Astronomers have discovered a baby blue galaxy that is the furthest away in distance and time - 13.1 billion years - that they’ve ever seen. Photo: Pascal Oesch and Ivelina Momcheva, NASA, European Space Agency via AP |
Excerpt from smh.com.au
A team of astronomers peering deep into the heavens have discovered the earliest, most distant galaxy yet, just 670 million years after the Big Bang.
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| Close-up of the blue galaxy |
"We're actually looking back through 95 per cent of all time to see this galaxy," said study co-author Garth Illingworth, an astronomer at the University of California, Santa Cruz.
"It's really a galaxy in its infancy ... when the universe was in its infancy."
Capturing an image from a far-off light source is like looking back in time. When we look at the sun, we're seeing a snapshot of what it looked like eight minutes ago.
The same principle applies for the light coming from the galaxy known as EGS-zs8-1. We are seeing this distant galaxy as it existed roughly 13.1 billion years ago.
EGS-zs8-1 is so far away that the light coming from it is exceedingly faint. And yet, compared with other distant galaxies, it is surprisingly active and bright, forming stars at roughly 80 times the rate the Milky Way does today.
This precocious little galaxy has built up the mass equivalent to about 8 billion suns, more than 15 per cent of the mass of the Milky Way, even though it appears to have been in existence for a mere fraction of the Milky Way's more than 13 billion years.
"If it was a galaxy near the Milky Way [today], it would be this vivid blue colour, just because it's forming so many stars," Illingworth said.
One of the many challenges with looking for such faint galaxies is that it's hard to tell if they're bright and far, or dim and near. Astronomers can usually figure out which it is by measuring how much that distant starlight gets stretched, "redshifted", from higher-energy light such as ultraviolet down to optical and then infrared wavelengths. The universe is expanding faster and faster, so the further away a galaxy is, the faster it's going, and the more stretched, or "redder", those wavelengths of light will be.
The astronomers studied the faint light from this galaxy using NASA's Hubble and Spitzer space telescopes. But EGS-zs8-1 seemed to be too bright to be coming from the vast distances that the Hubble data suggested.
To narrow in, they used the MOSFIRE infrared spectrograph at the Keck I telescope in Hawaii to search for a particularly reliable fingerprint of hydrogen in the starlight known as the Lyman-alpha line. This fingerprint lies in the ultraviolet part of the light spectrum, but has been shifted to redder, longer wavelengths over the vast distance between the galaxy and Earth.
It's a dependable line on which to base redshift (and distance) estimates, Illingworth said - and with that settled, the team could put constraints on the star mass, star formation rate and formation epoch of this galaxy.
The telltale Lyman-alpha line also reveals the process through which the universe's haze of neutral hydrogen cleared up, a period called the epoch of reionisation. As stars formed and galaxies grew, their ultraviolet radiation eventually ionised the hydrogen and ended the "dark ages" of the cosmos.
Early galaxies-such as EGS-zs8-1 - are "probably the source of ultraviolet radiation that ionised the whole universe", Illingworth said.
Scientists have looked for the Lyman-alpha line in other distant galaxies and come up empty, which might mean that their light was still being blocked by a haze of neutral hydrogen that had not been ionised yet.
But it's hard to say with just isolated examples, Illingworth pointed out. If scientists can survey many galaxies from different points in the universe's very early history, they can have a better sense of how reionisation may have progressed.
"We're trying to understand how many galaxies do have this line - and that gives us some measure of when the universe itself was reionised," Illingworth said.
"One [galaxy] is interesting, but it's when you have 50 that you can really say something about what galaxies were really like then."
As astronomers push the limits of current telescopes and await the completion of NASA's James Webb Space Telescope, set for launch in 2018, scientists may soon find more of these galaxies even closer to the birth of the universe than this new record breaker.
"You don't get to be record holder very long in this business," Illingworth said, "which is good because ultimately we are trying to learn about the universe. So more is better."
Excerpt from huffingtonpost.comIntroductionWhy is it so hard to find ET? After 50 years of searching, the SETI project has so far found nothing. In the latest development, on April 14, 2015 Penn State researchers announced that after searching through...
Excerpt from nytimes.com
Leapfrogging backward in time to when the universe was apparently feeling its oats, a group of astronomers reported Tuesday that they had measured a bona fide distance to one of the farthest and thus earliest galaxies known.
The galaxy, more than a few billion light-years on the other side of the northern constellation Boötes, is one of the most massive and brightest in the early universe and goes by the name of EGS-zs8-1.
It flowered into stardom only 670 million years after the Big Bang.
The light from that galaxy has taken 13 billion years to reach telescopes on Earth. By now, however, since the universe has continued to expand during that time, the galaxy is about 30 billion light-years away, according to standard cosmological calculations.
The new measurements allow astronomers to see the galaxy in its infancy. Despite its relative youth, however, it is already about one-sixth as massive as the Milky Way, which is 10 billion years old. And it is getting bigger, making stars 80 times faster than the Milky Way is making them today. The discovery was reported in The Astrophysical Journal by Pascal Oesch of Yale University and his colleagues.
By the rules of the expanding universe, the farther away a galaxy is, the faster it is retreating from us, measured by the “redshift” of its light being broadened to longer wavelengths, the way an ambulance siren seems to lower its pitch as it goes by.
In the past few years, as astronomers have raced one another into the past with instruments like the Hubble Space Telescope, galaxies have been found that appear even more distant. Those measurements, however, were estimates based on the colors of the objects — so-called photometric redshifts.
The new galaxy stuck out in a survey of distant galaxies by the Hubble and Spitzer space telescopes known as Candels, for Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey. Its redshift was precisely measured with a powerful spectrograph known as Mosfire — Multi-Object Spectrometer for Infrared Exploration — on Keck 1, one of a pair of 10-meter-diameter telescopes on Mauna Kea in Hawaii. That makes it the highest redshift confirmed in this way, said Garth Illingworth, of the University of California, Santa Cruz, one of the astronomers in the study.
How galaxies were able to form and grow so rapidly after the lights came on in the universe is a mystery that will be addressed by a coming generation of instruments like the James Webb Space Telescope and the Thirty Meter Telescope, a goliath planned for Mauna Kea, already home to a dozen telescopes.
Recently, however, construction of the Thirty Meter Telescope, a $1.4 billion project, has been halted by protests by Hawaii residents who feel their mountain has been abused. An echo of that controversy appears in the new paper, in which Dr. Oesch and his colleagues write: “The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.”
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