An international team of scientists using a combination of radio and optical telescopes identified the distant location of a fast radio burst (FRB) for the first time. This discovery has allowed them to confirm the current cosmological model of the distribution of matter in the universe. "The good news is our observations and the model match. We have found the missing matter" explained Dr. Keane. "It's the first time a fast radio burst has been used to conduct a cosmological measurement."
The cold and dry conditions on Mars open the possibility that evidence for life may be found below the surface where negative effects of radiation are mitigated, in the form of organic molecules known as biomarkers. But until humans set foot on the Red Planet, obtaining samples from below the surface of Mars will require the ability to identify a location of high probability for current or ancient life, place a drill, and control the operation robotically.
The center of our Milky Way galaxy lies about 27,000 light-years away in the direction of the constellation of Sagittarius. At its core is a black hole about four million solar masses in size. Around the black hole is a donut-shaped structure about eight light-years across that rings the inner volume of neutral gas and thousands of individual stars. Around that, stretching out to about 700 light-years, is a dense zone of activity called the Central Molecular Zone (CMZ).
The CMZ contains almost eighty percent of all the dense gas in the galaxy - a reservoir of tens of millions of solar masses of material - and hosts giant molecular clouds and massive star forming clusters of luminous stars, among other regions many of which are poorly understood. For example, the CMZ contains many dense molecular clouds that would normally be expected to produce new stars, but which are instead eerily desolate. It also contains gas moving at highly supersonic velocities - hundreds of kilometers per second (hundreds of thousands of miles per hours).
An infrared and multi-wavelength image of the Central Molecular Zone in the Milky Way shown above. Dense gas is shown in red, and warm and cold dust in green and blue respectively. Several key objects in the region are labeled, along with a set of embedded young stellar clusters seen at 24 microns. - See more at: https://www.cfa.harvard.edu/news/su201609#sthash.7uJpe0rc.dpuf
Where did the CMZ come from? No place else in the Milky Way is remotely like it (although there may be analogues in other galaxies). How does it retain its structure as its molecular gas moves, and how do those rapid motions determine its evolution? One difficulty facing astronomers is that there is so much obscuring dust between us and the CMZ that visible light is extinguished by factors of over a trillion. Infrared, radio, and some X-ray radiation can penetrate the veil, however, and they have allowed astronomers to develop the picture just outlined.
CfA astronomers Cara Battersby, Dan Walker, and Qizhou Zhang, with their team of colleagues, used the Australian Mopra radio telescope to study the three molecules HNCO, N2H+, and HNC in the CMZ. These particular molecules were selected because they do a good job of tracing the wide range of conditions thought to be present in the CMZ, from shocked gas to quiescent material, and also because they suffer only minimally from cluttering and extinction effects that complicate more abundant species like carbon monoxide. The scientists developed a new computer code to analyze efficiently the large amounts of data they had.
The astronomers find, consistent with previous results, that the CMZ is not centered on the black hole, but (for reasons that are not understood) is offset; they also confirm that the gas motions throughout are supersonic. They identify two large-scale flows across the region, and suggest they represent one coherent (or at most two independent) streams of material, perhaps even spiral-like arms.
The team also analyzed the gas in several previously identified zones of the CMZ, finding that one shell-like region thought to be the result of supernova explosions may instead be several regions that are physically unrelated, and that a giant cloud thought to be independent is actually an extension of the large-scale flows. The scientists note that this work is a first step in unraveling an intrinsically complex galactic environment, and that pending research will trace the gas motions to larger distances and try to model the CMZ gas motions with computer simulations.
"I couldn't believe my eyes," said Esra Bulbul of the Harvard Center for Astrophysics in July of 2014. "What we found, at first glance, could not be explained by known physics." Together with a team of more than a half-dozen colleagues, Bulbul used Chandra to explore the Perseus Cluster, a swarm of galaxies approximately 250 million light years from Earth. Imagine a cloud of gas in which each atom is a whole galaxy—that's a bit what the Perseus cluster is like. It is one of the most massive known objects in the Universe. The cluster itself is immersed in an enormous 'atmosphere' of superheated plasma—and it is there that the mystery resides.
The oldest known stars, dating from before the Milky Way Galaxy formed, when the Universe was just 300 million years old were found near the center of the Milky Way, surprisingly pure but containing material from an even earlier star, which died in an enormous explosion called hypernova. "These pristine stars are among the oldest surviving stars in the Universe, and certainly the oldest stars we have ever seen," said Louise Howes from The Australian National University (ANU), lead author of the study published in the latest issue of Nature. "These stars formed before the Milky Way, and the galaxy formed around them."
By studying data from Nasa’s Cassini spacecraft orbiting Saturn, the seventh planet from the Sun, French scientists confirmed that a ninth planet might exist in the far reaches of our solar system, co-author Jacques Laskar of the Paris Observatory told AFP, “but not just anywhere”. US astronomers announced in January that they may have found a ninth planet beyond Neptune but said it could take 10,000 to 20,000 years to orbit the Sun and they had no idea where it might be.
"The Center of our Milky Way Galaxy is a place of extremes," says Mark Morris, an expert on The Galactic Center at UCLA. "For every star in our nighttime sky, for example, there would be a million for someone looking up from a planet near the Galactic center. So stars are packed quite close together. Then, there’s that supermassive black hole that is sitting in there, relatively quiet for now, but occasionally producing a dramatic outpouring of energy. The UCLA Galactic center group been use the Keck Telescopes in Hawaii to follow its activity for the last 17 years, watching not only the fluctuating emission from the black hole, but also watching the stars around it as they rapidly orbit the black hole."
"The sun’s location within the dust-obscured galactic disk is a complicating factor to observe the galactic structure," said Denilso Camargo, lead author of the paper from the Federal University of Rio Grande do Sul in Brazil.
For the first time a team of scientists has tracked down the location of a fast radio burst (FRB) in an elliptical galaxy -- a huge football-shaped mass of stars., confirming that these short but spectacular flashes of radio waves originated in the distant universe. FRBs emit as much energy in one millisecond as the sun emits in 10,000 years, but the physical phenomenon that causes them is unknown. The breakthrough, published today in the journal Nature, was made using CSIRO radio telescopes in eastern Australia and the National Astronomical Observatory of Japan's Subaru telescope in Hawaii.
In July 2003, Hubble helped make the astounding discovery of a planet called PSR B1620-26 b, 2.5 times the mass of Jupiter, which is located in globular cluster M4 (center of the cluster shown in the NASA/ESA Hubble Space Telescope image above). It contains several tens of thousands stars and is noteworthy in being home to many white dwarfs—the cores of ancient, dying stars whose outer layers have drifted away into space.