• úvod
  • témata
  • události
  • tržiště
  • diskuze
  • nástěnka
  • přihlásit
    registrace
    ztracené heslo?
    VIRGOCosmos In Brief - Aktualní novinky vesmírného výzkumu v kostce
    VIRGO
    VIRGO --- ---
    Why Cosmic Inflation Is Here To Stay
    http://nautil.us/issue/48/chaos/the-inflated-debate-over-cosmic-inflation

    Why the majority of physicists are on one side of a recent exchange of letters.

    VIRGO
    VIRGO --- ---
    The Story of a Boring Encounter with a Black Hole
    http://aasnova.org/2017/07/24/the-story-of-a-boring-encounter-with-a-black-hole/

    Remember the excitement three years ago before the gas cloud G2’s encounter with the supermassive black hole at the center of our galaxy, Sgr A*?
    Did you notice that not much was said about it after the fact? That’s because not much happened — and a new study suggests that this isn’t surprising.

    G2, an object initially thought to be a gas cloud, was expected to make its closest approach to the 4.6-million-solar-mass Sgr A* in 2014. At the pericenter
    of its orbit, G2 was predicted to pass as close as 36 light-hours from the black hole. This close brush with such a massive black hole was predicted to tear
    G2 apart, causing much of its material to accrete onto Sgr A*. It was thought that this process would temporarily increase the accretion rate onto the black
    hole relative to its normal background accretion rate, causing Sgr A*’s luminosity to increase for a time.

    Instead, Sgr A* showed a distinct lack of fireworks, with very minimal change to its brightness after G2’s closest approach. This “cosmic fizzle” has raised
    questions about the nature of G2: was it really a gas cloud? What else might it have been instead? Now, a team of scientists led by Brian Morsony (University
    of Maryland and University of Wisconsin-Madison) have run a series of simulations of the encounter to try to address these questions.

    VIRGO
    VIRGO --- ---
    VIRGO: These telescopes observed Barnard's Star and Ross 128 last week.

    VIRGO
    VIRGO --- ---
    PHL: The Weird! Signal by Abel Mendez
    The Weird! Signal - Planetary Habitability Laboratory @ UPR Arecibo
    http://phl.upr.edu/press-releases/theweirdsignal

    VIRGO
    VIRGO --- ---
    Dark matter is likely ‘cold,’ not ‘fuzzy,’ scientists report after new simulations | UW News
    http://www.washington.edu/...atter-is-likely-cold-not-fuzzy-scientists-report-after-new-simulations/

    Dark matter is the aptly named unseen material that makes up the bulk of matter in our universe. But what dark matter is made of is a matter of debate.

    Scientists have never directly detected dark matter. But over decades, they have proposed a variety of theories about what type of material — from new
    particles to primordial black holes — could comprise dark matter and explain its many effects on normal matter. In a paper published July 20 in the journal
    Physical Review Letters, an international team of cosmologists uses data from the intergalactic medium — the vast, largely empty space between galaxies —
    to narrow down what dark matter could be.

    The team’s findings cast doubt on a relatively new theory called “fuzzy dark matter,” and instead lend credence to a different model called “cold dark matter.”
    Their results could inform ongoing efforts to detect dark matter directly, especially if researchers have a clear idea of what sorts of properties they should
    be seeking.

    VIRGO
    VIRGO --- ---
    Mapping Dark Mattersu201727 | www.cfa.harvard.edu/
    https://www.cfa.harvard.edu/news/su201727

    Galaxies generally reside at the centers of vast clumps of dark matter called haloes because they surround the clusters of galaxies. Gravitational lensing
    of more distant galaxies by dark matter haloes offers a particularly unique and powerful probe of the detailed distribution of dark matter. So-called strong
    gravitational lensing creates highly distorted, magnified and occasionally multiple images of a single source; so-called weak lensing results in modestly yet
    systematically deformed shapes of background galaxies that can also provide robust constraints on the distribution of dark matter within the clusters.

    CfA astronomers Annalisa Pillepich and Lars Hernquist and their colleagues compared gravitationally distorted Hubble images of the galaxy cluster Abell 2744
    and two other clusters with the results of computer simulations of dark matter haloes. They found, in agreement with key predictions in the conventional dark
    matter picture, that the detailed galaxy substructures depend on the dark matter halo distribution, and that the total mass and the light trace each other.
    They also found a few discrepancies: the radial distribution of the dark matter is different from that predicted by the simulations, and the effects of tidal
    stripping and friction in galaxies are smaller than expected, but they suggest these issues might be resolved with more precise simulations. Overall, however,
    the standard model of dark matter does an excellent and reassuring job of describing galaxy clustering.

    VIRGO
    VIRGO --- ---
    Seeing double | ESO Australia
    http://www.eso.org/public/australia/images/potw1730a/

    Approximately 95 million light-years away, in the southern constellation of Octans (The Octant), lies NGC 7098 — an intriguing spiral galaxy with numerous
    sets of double features. The first of NGC 7098’s double features is a duo of distinct ring-like structures that loop around the galaxy’s hazy heart. These
    are NGC 7098’s spiral arms, which have wound themselves around the galaxy’s luminous core. This central region hosts a second double feature: a double bar.

    VIRGO
    VIRGO --- ---
    Hubble’s Hunting Dog Galaxy
    https://www.nasa.gov/image-feature/goddard/2017/hubbles-hunting-dog-galaxy

    Tucked away in the small northern constellation of Canes Venatici (The Hunting Dogs) is the galaxy NGC 4242, shown here as seen by the NASA/ESA
    Hubble Space Telescope. The galaxy lies some 30 million light-years from us. At this distance from Earth, actually not all that far on a cosmic scale,
    NGC 4242 is visible to anyone armed with even a basic telescope, as British astronomer William Herschel found when he discovered the galaxy in 1788.

    VIRGO
    VIRGO --- ---
    Study teams comb through NASA’s wish list for new telescope – Spaceflight Now
    https://spaceflightnow.com/2017/07/21/study-teams-comb-through-nasas-wish-list-for-a-new-telescope/

    Scientists outlining four concepts for a powerful new space telescope that could launch in the 2030s this week said improvements in optics, detectors and access to huge new
    rockets like NASA’s Space Launch System could revolutionize the way astronomers observe potentially habitable planets, black holes, and the earliest galaxies in the universe.

    It is likely NASA will only be able to afford one of the four proposed flagship observatories, and the space agency will take the advice of an independent review by the National
    Research Council in 2020 on which type of telescope should receive highest priority.

    VIRGO
    VIRGO --- ---
    New Type Ia supernova discovered using gravitational lensing
    https://phys.org/news/2017-07-ia-supernova-gravitational-lensing.html

    Using gravitational lensing, an international team of astronomers has detected a new Type Ia supernova. The newly discovered lensed supernova was
    found behind the galaxy cluster known as MOO J1014+0038. The findings were detailed in a paper published July 14 on the arXiv pre-print repository.

    Recently, a team of researchers led by David Rubin of the Space Telescope Science Institute in Baltimore, Maryland, have used one such massive galaxy
    cluster to reveal the presence of a new type Ia supernova. This type of supernovae can be found in binary systems in which one of the stars is a white
    dwarf. Type Ia supernovae are important for the scientific community as they offer essential clues into evolution of stars and galaxies.

    Rubin's team monitored 12 massive galaxy clusters with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) as part of the Supernova Cosmology
    Project "See Change" program. These observations were complemented by an analysis of images available in the Massive and Distant Clusters of WISE Survey.

    VIRGO
    VIRGO --- ---
    Hunting Molecules with the MWA - ICRAR
    https://www.icrar.org/hunting-molecules/

    Astronomers have used an Australian radio telescope to observe molecular signatures from stars, gas and
    dust in our galaxy, which could lead to the detection of complex molecules that are precursors to life.

    Using the Murchison Widefield Array (MWA), a radio telescope located in the Murchison region of Western
    Australia, the team successfully detected two molecules called the mercapto radical (SH) and nitric oxide (NO).

    VIRGO
    VIRGO --- ---
    Booze in space: how the universe is absolutely drowning in the hard stuff
    https://theconversation.com/...space-how-the-universe-is-absolutely-drowning-in-the-hard-stuff-81122

    A cold beer on a hot day or a whisky nightcap beside a coal fire. A well earned glass can loosen your thinking until you feel able to
    pierce the mysteries of life, death, love and identity. In moments like these, alcohol and the cosmic can seem intimately entwined.

    So perhaps it should come as no surprise that the universe is awash with alcohol. In the gas that occupies the space between the stars,
    the hard stuff is almost all-pervasive. What is it doing there? Is it time to send out some big rockets to start collecting it?

    The chemical elements around us reflect the history of the universe and the stars within it. Shortly after the Big Bang, protons were
    formed throughout the expanding, cooling universe. Protons are the nuclei of hydrogen atoms and building blocks for the nuclei of all
    the other elements. These have mostly been manufactured since the Big Bang through nuclear reactions in the hot dense cores of stars.
    Heavier elements such as lead or gold are only fabricated in rare massive stars or incredibly explosive events.

    VIRGO
    VIRGO --- ---
    Saturn Surprises As Cassini Continues its Grand Finale
    https://www.nasa.gov/feature/jpl/saturn-surprises-as-cassini-continues-its-grand-finale

    As NASA's Cassini spacecraft makes its unprecedented series of weekly dives between Saturn and its rings, scientists are finding - so far -
    that the planet's magnetic field has no discernable tilt. This surprising observation, which means the true length of Saturn's day is still
    unknown, is just one of several early insights from the final phase of Cassini's mission, known as the Grand Finale.

    Other recent science highlights include promising hints about the structure and composition of the icy rings, along with high-resolution
    images of the rings and Saturn's atmosphere.

    Cassini is now in the 15th of 22 weekly orbits that pass through the narrow gap between Saturn and its rings. The spacecraft began
    its finale on April 26 and will continue its dives until Sept. 15, when it will make a mission-ending plunge into Saturn's atmosphere.

    VIRGO
    VIRGO --- ---
    Scientists find some of Mars' youngest volcanoes – and discover they could have supported life
    https://theconversation.com/...-youngest-volcanoes-and-discover-they-could-have-supported-life-81345

    It may seem that Mars was once a much more exciting planet. True, there are dust storms and possible water-seeps occurring today,
    but billions of years ago it was a dramatic place with huge volcanoes, a giant canyon system and branching river valleys being formed.

    But now planetary scientists have identified what looks like more recently formed volcanoes, in geological terms. Excitingly, they may
    have once provided the perfect environment for microbial lifeforms to thrive.

    Mars’ Olympus Mons is the solar system’s largest volcano – 22km high and more than 500km across its base. It began to grow over 3 billion
    years ago, but some lava flows high on its flanks appear to be as young as 2m years, judging from the relative lack of overlapping impact
    craters. Craters caused by asteroid impacts show how old a surface in the solar system is – the more craters the longer it has been around.
    However, fresh lava from a volcano can bury former craters, resetting this clock.

    VIRGO
    VIRGO --- ---
    Scientists spy new evidence of water in the Moon’s interior | News from Brown
    http://news.brown.edu/articles/2017/07/moonwater

    Using satellite data, Brown researchers have for the first time detected widespread water within ancient explosive
    volcanic deposits on the Moon, suggesting that its interior contains substantial amounts of indigenous water.

    VIRGO
    VIRGO --- ---
    Keeping an Eye on Ross 128
    https://www.centauri-dreams.org/?p=38137

    Any nearby stars are of interest from the standpoint of exoplanet investigations, though thus far we’ve yet to discover
    any companions around Ross 128. An M4V dwarf, Ross 128 has about 15 percent of the Sun’s mass. More significantly, it is
    an active flare star, capable of unpredictable changes in luminosity over short periods. Which leads me back to that unusual
    reception. The SETI Institute’s Seth Shostak described it this way in a post:

    What the Puerto Rican astronomers found when the data were analyzed was a wide-band radio signal. This signal not only
    repeated with time, but also slid down the radio dial, somewhat like a trombone going from a higher note to a lower one.

    And as Shostak goes on to say, “That was odd, indeed.”

    ---

    Last night photo of Ross 128 (center) by Alberto Q Vodniza from the University of Nariño Observatory - Colombia

    VIRGO
    VIRGO --- ---
    Scientists 'Teleport' a Particle Hundreds of Miles—But What Does That Mean?
    http://gizmodo.com/scientists-teleport-a-particle-hundreds-of-miles-but-w-1796818859/amp

    Humanity is advancing rapidly towards a place where the news sounds an awful lot like science fiction. In fact, yesterday, Chinese scientists
    reported that they “teleported” a photon over hundreds of miles using a “quantum satellite.” But this isn’t Star Trek. It’s the real world.

    This “quantum teleportation” doesn’t actually involve teleporting a real object—it’s not really teleportation at all. The scientists are actually
    sending information about a particle of light in a way that can only be accessed by two observers. This could have major implications for the future
    of computing—it would make for incredible data encryption. But encryption with this technology is still pretty far off.

    Still, the researchers write in their new paper, “This work establishes the first ground-to-satellite up-link for faithful and ultra-long-distance
    quantum teleportation, an essential step toward global-scale quantum internet.” Let’s walk through what that means.

    VIRGO
    VIRGO --- ---
    Planets Like Earth May Have Had Muddy Origins | Planetary Science Institute
    http://www.psi.edu/news/asteroidmud

    Scientists have long held the belief that planets – including Earth – were built from rocky asteroids, but new research challenges that view.

    Published in Science Advances, a journal of the American Association for the Advancement of Science, the research suggests that many of the
    original planetary building blocks in our solar system may actually have started life, not as rocky asteroids, but as gigantic balls of warm mud.

    Phil Bland, Curtin University planetary scientist, undertook the research to try and get a better insight into how smaller planets, the precursors
    to the larger terrestrial planets we know today, may have come about.

    VIRGO
    VIRGO --- ---
    Scientists Are Using the Universe as a "Cosmological Collider"2017-22 | www.cfa.harvard.edu/
    https://www.cfa.harvard.edu/news/2017-22

    Physicists are capitalizing on a direct connection between the largest cosmic structures and
    the smallest known objects to use the universe as a "cosmological collider" and investigate new physics.

    The three-dimensional map of galaxies throughout the cosmos and the leftover radiation from the Big Bang –
    called the cosmic microwave background (CMB) – are the largest structures in the universe that astrophysicists
    observe using telescopes. Subatomic elementary particles, on the other hand, are the smallest known objects in
    the universe that particle physicists study using particle colliders.

    A team including Xingang Chen of the Harvard-Smithsonian Center for Astrophysics (CfA), Yi Wang from the Hong
    Kong University of Science and Technology (HKUST) and Zhong-Zhi Xianyu from the Center for Mathematical Sciences
    and Applications at Harvard University has used these extremes of size to probe fundamental physics in an
    innovative way. They have shown how the properties of the elementary particles in the Standard Model of particle
    physics may be inferred by studying the largest cosmic structures. This connection is made through a process
    called cosmic inflation.

    VIRGO
    VIRGO --- ---
    Backreaction: Penrose claims LIGO noise is evidence for Cyclic Cosmology
    http://backreaction.blogspot.cz/2017/07/penrose-claims-ligo-noise-is-evidence.html

    Noise is the physicists’ biggest enemy. Unless you are a theorist whose pet idea
    masquerades as noise. Then you are best friends with noise. Like Roger Penrose.

    Penrose doesn’t like most of what’s currently in fashion, but believes that human consciousness can’t be explained
    by known physics and that the universe is cyclically reborn. This cyclic cosmology, so his recent claim, gives rise
    to correlations in the LIGO noise – just like what’s been observed.

    Kliknutím sem můžete změnit nastavení reklam