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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.
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...
In this image, the magenta color indicates the mysterious glow detected by NASA's NuSTAR space telescope.Excerpt from huffingtonpost.com A mysterious glow has been observed at the center of the Milky Way, and scientists are struggling to figure o...
Excerpt from huffingtonpost.comIntroduction 65 years ago, in 1950, while having lunch with colleagues Edward Teller and Herbert York, Nobel physicist Enrico Fermi suddenly blurted out, "Where is everybody?" His question is now known as Fermi's p...
Excerpt from thespacereporter.com
The formation of water vapor after the Big Bang was constrained by the lack of oxygen; it and other elements heavier than hydrogen and helium were created only later on, in the death throes of the first generation of massive stars. Oxygen created by the demises of early stars was swept out in to space by the explosions of supernovae and stellar winds, eventually joining with hydrogen to form water.
This process created islands of gas replete with heavy elements, such as oxygen; these regions were more bereft of oxygen than gaseous regions in the modern Milky Way galaxy. However, a new study by Tel Aviv University and the Harvard-Smithsonian Center for Astrophysics (CfA) has determined that, in certain islands, water vapor might have been as plentiful as it is today, only a billion years after the Big Bang.
According to a CfA statement, the researchers looked at whether water could form in the primordial molecular clouds, which were deficient in oxygen. Their analysis indicated that large quantities of water could form at around 80 degrees Fahrenheit. Water molecules would have been shattered by ultraviolet light emitted by stars; however, after hundreds of millions of years, an equilibrium between water creation and destruction would be reached.
“We looked at the chemistry within young molecular clouds containing a thousand times less oxygen than our Sun. To our surprise, we found we can get as much water vapor as we see in our own galaxy,” said astrophysicist Avi Loeb of CfA.
The new study has been accepted for publication in the Astrophysical Journal and is accessible online.
Excerpt from stgist.com
The sun, or the nearest star from Earth, was formed around 5 billion years after the Milky Way galaxy’s peak production of stars, a new research published in the Astrophysical Journal.
It’s like traveling back in time. Researchers from Texas A&M University in College Station, headed by astronomer Casey Papovich, were able to see the undepicted past of our own galaxy by observing similar regions located billions of light years away from us.
The “baby boom” happened around 10 billion years ago, the new study published in Astrophysical Journal revealed. At that time, the Milky Way galaxy was producing 30 times more stars than today. If so, then our solar system’s 4.6 billion years old Sun was formed more than 5 billion years after the production peak.
Sun’s late formation allowed the solar system we know today to produce planets with heavier elements. Scientists say elements heavier than hydrogen and helium became more abundant in “late to the game systems”, and the death of massive stars that were formed before the Sun had provided materials needed to form planets, including Earth and its complex life forms.
Scientists scanned through a collection of more than 24,000 galaxies, and took at least 2,000 snapshots of galaxies that closely resemble our own. The census has provided the most complete picture yet of how spiral galaxies similar to Milky Way form in the universe.
According to Mr. Papovich, the lead author of the study who also serves as an associate professor in the Department of Physics and Astronomy at A&M University in Texas, they know where to find traces by analyzing how galaxies like our own were formed.
Papovich said his team has provided a data that clearly show the rapid phase of growth around 9 to 10 billion years ago, or at least more than 5 billion years after our Sun formed. They also found the connection between the size of the galaxy, and the formation of stars.
Surprisingly, the robust collection of distant galaxies confirmed that stars formed inside the Milky Way, instead of forming in other smaller baby galaxies that later merged to join the system.
In separate studies, scientists were able to confirm that our own solar system is wetter than thought. Beyond Earth, celestial objects like Jupiter’s Galilean moons Europa and Ganymede, Saturn’s Enceladus, and even the dwarf planet Ceres in the asteroid belt, are hosting fluid slightly similar to Earth’s — and it is highly possible that the Sun’s late formation allowed this setup to exist.
Papovich who worked alongside Texas A&M postdoctoral researchers Vithal Tilvi and Ryan Quadri, were joined by at least two dozen astronomers from other countries. The research is published April 9th entitled “ZFOURGE/CANDELS: ON THE EVOLUTION OF M* GALAXY PROGENITORS FROM z = 3 TO 0.5*.” The research was funded by NASA
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| The full visible sky as seen by the Planck space observatory. The band running through the middle corresponds to dust in our Milky Way galaxy. The black dots indicate the location of the proto-cluster candidates identified by Planck and subsequently observed by the Herschel space telescope. (Photo : ESA and the Planck Collaboration) |
Excerpt from natureworldnews.com
Treasure seekers have found the haul of a lifetime, but it wasn't in some ancient temple or mysterious island. Instead, it was in the sky. Researcher using two of the European Space Agency's (ESA) impressive space telescopes have successfully identified what they are calling a "treasure chest" of ancient galaxy clusters, which could help explain how the Universe came to be the way it is today.
That's at least according to a study recently published (PDF) in the journal Astronomy and Astrophysics, which details how cosmologists used the ESA's Planck space observatory to identify the distant precursor galaxy clusters, and then poured over data from the Herschel telescope for a closer look.
"Finding so many intensely star-forming, dust galaxies in such concentrated groups was a huge surprise," Hervé Dole, lead author of the report from the Institut d'Astrophysique Spatiale in France, said in a statement. "We think this is a missing piece of cosmological structure formation."
So what does he mean by that? Let's turn back to the treasure chest metaphor for this one. While Planck was the space observatory to dig up the chest, it was the Herschel data that allowed experts to look closely at each and every gold coin (galaxy cluster) inside. Now they are able to learn more about each coin's make, mint, and ultimately, its origins.
And that's a big step in better understanding the early Universe. Expects believe that it took a great deal of time after star and galaxies first sprung to life for them to assemble into large clusters.
(Photo : ESA – C. Carreau) A summary of the 14 billion years out Universe has been in existence, as seen by the Plank space telescope. Light coming from some of the oldest parts of the Universe are just reaching the observatory now, allowing for experts to see the incredible uniformity of the early matter, compared to the chaotic beautify of star, galaxy, and cluster formation that crowds space today.
That's why looking at some of the oldest 'coins' ever made - estimated to date back to up-to 11 billion light-years ago - could be exceptionally helpful.
"We still have a lot to learn about this new population," Dole said in an ESA release. "Hints of these kinds of objects had been found earlier in data from Herschel and other telescopes, but the all-sky capability of Planck revealed many more candidates for us to study."
"Even when we combined the powerful capabilities of Planck and Herschel, we were only scratching the surface of the phenomena taking place at this critical era in the history of our universe, when stars, galaxies and clusters seem to be forming simultaneously,"
added George Helou, director of the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. "That's one of the reasons this finding is exciting. It shows us that there is so much more to be learned.
Excerpt from huffingtonpost.comWhen astronomers began studying other solar systems in the Milky Way galaxy back in the 1990s, they noticed something peculiar: most of these systems have big planets that circle their host stars in tight orbits, a fin...
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| The Cassiopeia A nebula is the gaseous remnant of a supernova explosion whose light reached the Earth around the year 1680. |
Excerpt from sciencerecorder.com
A recent discovery has revealed that a supernovae is capable enough producing such quantities of cosmic dust that it can yield thousands of Earths.
An international team of researchers analyzed data obtained by SOFIA – a NASA and German Aerospace Center’s Stratospheric Observatory for Infrared Astronomy project – which took images of a cosmic dust cloud.
“This discovery is a special feather in the cap for SOFIA, demonstrating how observations made within our own Milky Way galaxy can bear directly on our understanding of the evolution of galaxies billions of light years away,” said Pamela Marcum, one of the researchers.
SOFIA, an enhanced Boeing 747 with high end telescope, flies in altitudes between 39,000 to 45,000 feet to capture its images.
Astronomers already knew that the shock waves of supernovas produce high concentrations of dust when they move outward.
The question was whether the cosmic particles could withstand the intense shock waves.
“The dust survived the later onslaught of shock waves from the supernova explosion, and is now flowing into the interstellar medium where it can become part of the ‘seed material’ for new stars and planets,” said Ryan Lau, of Cornell University, who led the research team.
This new discovery encouraged the idea that the vast quantities of dust seen in remote yet fairly young galaxies may have been produced by the explosions of large stars that were actually much older.
The research was published in Science magazine on Thursday.
Excerpt from esbtrib.com
Imagine the distinct possibility that among the billions of stars located in our vast Milky Way Galaxy, there might be a habitable zone where water probably exists and life as we know it as well.
Scientists have studied more than 150 exoplanetary systems with more than one planet circling the host star, thru the Kepler space telescope of NASA.
The new research, published in Monthly Notices of the Royal Astronomical Society, revealed the thousands of planets orbiting stars in our Milky Way galaxy. Researchers were able to compute that the stars in the Milky Way have one to three planets orbiting the habitable zone.
PhD student in the research group Astrophysics and Planetary Science at the Niels Bohr Institute at the University of Copenhagen, Steffen Kjær Jacobsen said, “In these 31 planetary systems located near the habitable zone, our calculations showed that there was an average of two planets in the habitable zone. According to statistics and the indications we have, a good share of the planets in the habitable zone will be solid planets where there might be liquid water and where life could exist.”
He added, “In 124 of the planetary systems, the Titius-Bode law fit with the position of the planets as good as or better than our own solar system. Using Titus-Bode’s law we tried to predict where there could be more planets further out in the planetary systems. But we only made calculations for planets where there is a good chance you can see them with the Kepler satellite,”
Researchers urged other scientist to look further into the records from the Kepler satellite again for more signs of the planetary systems they have predicted, as a number of them should be quite apparent.
Will this change our perception of religion? That we are not God’s only living creation?
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| CGI of how the Milky Way galaxy may appear from deep space |
Excerpt from thespacereporter.com
Analysis of data collected by NASA’s Kepler space telescope has led researchers at the Australian National University and the Niels Bohr Institute to conclude that Earth is only one of billions of potentially life-sustaining planets in our galaxy.
In order for a planet to sustain life, it must orbit its star at just the right distance to provide sufficient light and warmth to maintain liquid water without too much radiation. This perfect orbital distance is considered to be the habitable zone.
According to a Weather Channel report, there are an average of two planets per star in the Milky Way Galaxy orbiting within their habitable zones. That brings the total number of planets with the potential for holding liquid water to 100 billion.
Scientists assume that water would be an essential ingredient for life to evolve on other planets, but it is not a certainty.
“If you have liquid water, then you should have better conditions for life, we think,” said Steffen Jacobsen of Niels Bohr. “Of course, we don’t know this yet. We can’t say for certain.”
To reach their conclusion, the researchers studied 151 planetary systems and focused on those with four or more planets. They used a concept called the Titus-Bode law to calculate where unseen planets might be located in a system based on the placements of other planets around the star. The Titus-Bode law suggested the existence of Uranus before it was actually seen.
The data will require further analysis and the sky will require further searching to yield a more accurate number of potentially life-harboring planets.
“Some of these planets are so small the Kepler team will probably have missed them in the first attempt because the signals we get are so weak. They may be hidden in the noise,” Jacobsen said.
The initial analysis, however, is extremely promising in the possibility of finding habitable planets. “Our research indicates that there are a lot of planets in the habitable zone and we know there are a lot of stars like the one we’re looking at. We know that means we’re going to have many billions of planets in the habitable zone,” said Jacobsen, who considers that “very good news for the search for life.”
This map shows the full extent of the Milky Way galaxy - a spiral galaxy of at least two hundred billion stars. Our Sun is buried deep within the Orion Arm about 26 000 light years from the centre. Towards the centre of the Galaxy the stars are ...
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