Skip to main content

Home/ Astronomy/ Group items tagged structures

Rss Feed Group items tagged

Filter: All | Bookmarks | Topics Simple Middle
Sandra Flores

Revealing pattern without planets - 0 views

Revealing pattern without planets Planets around young suns are formed in a disk of gas and dust orbiting the star just created. Many such disks have now been detected around young stars. In some y...

started by Sandra Flores on 05 Jan 15 no follow-up yet
Todd Suomela

[astro-ph/0511440] Varying Constants - 0 views

arxiv.org/0511440

cosmology astronomy astrophysics physics paper

shared by Todd Suomela on 29 Jan 09 - Cached
  • Todd Suomela on 29 Jan 09
     
    We review properties of theories for the variation of the gravitation and fine structure 'constants'. We highlight some general features of the cosmological models that exist in these theories with reference to recent quasar data that are consistent with time-variation in the fine structure 'constant' since a redshift of 3.5. The behaviour of a simple class of varying-alpha cosmologies is outlined in the light of all the observational constraints.
Astro Biology

Know When Milky Way Collision Occur - 0 views

www.astrobio.net/...ollision-100-million-years-ago

milky way satellite galaxy news from nasa solar system planet

shared by Astro Biology on 20 Nov 14 - No Cached
  • Astro Biology on 20 Nov 14
     
    NASA scientist have found proof that our Milky Way had an encounter with a small galaxy or massive dark matter structure perhaps as recently as 100 million years ago. Are you also interested to know how galaxies form, evolve and interact?
  • Astro Biology on 20 Nov 14
     
    NASA scientist have found proof that our Milky Way had an encounter with a small galaxy or massive dark matter structure perhaps as recently as 100 million years ago. Are you also interested to know how galaxies form, evolve and interact?
Kalyan Roy

SPACE.com -- New Physics? Fundamental Cosmic Constant Now Seems Shifty - 1 views

www.space.com/...stant-varies-space-100915.html

Astronomy

shared by Kalyan Roy on 15 Sep 10 - No Cached
  • Recent observations of distant galaxies suggest that the strength of the electromagnetic force – the so-called fine-structure constant – actually varies throughout the universe. In one direction, the constant seemed to grow larger the farther astronomers looked; in another direction the constant took on smaller values with greater distance.
  • If confirmed, this revelation could reshape physicists' understanding of cosmology from the ground up. It may even help solve a major conundrum: Why are all the constants of nature perfectly tuned for life to exist?
Todd Suomela

[0806.0377] A Hemispherical Power Asymmetry from Inflation - 0 views

arxiv.org/0806.0377

astronomy astrophysics observatory physics

shared by Todd Suomela on 13 Jun 08 - Cached
  • Todd Suomela on 13 Jun 08
     
    Measurements of temperature fluctuations by the Wilkinson Microwave Anisotropy Probe (WMAP) indicate that the fluctuation amplitude in one half of the sky differs from the amplitude in the other half. We show that such an asymmetry cannot be generated during single-field slow-roll inflation without violating constraints to the homogeneity of the Universe. In contrast, a multi-field inflationary theory, the curvaton model, can produce this power asymmetry without violating the homogeneity constraint. The mechanism requires the introduction of a large-amplitude superhorizon perturbation to the curvaton field, possibly a pre-inflationary remnant or a superhorizon curvaton-web structure. The model makes several predictions, including non-Gaussianity and modifications to the inflationary consistency relation, that will be tested with forthcoming CMB experiments.
Todd Suomela

Press Release: Two of the Milky Way's Spiral Arms Go Missing - 0 views

www.spitzer.caltech.edu/...release.shtml

astronomy astrophysics galactic observatory satellite spitzer-space-telescope

shared by Todd Suomela on 05 Jun 08 - Cached
  • Todd Suomela on 05 Jun 08
     
    Now, new images from NASA's Spitzer Space Telescope are shedding light on the true structure of the Milky Way, revealing that it has just two major arms of stars instead of the four it was previously thought to possess.
Janos Haits

Bolshoi Simulation | Home - 0 views

hipacc.ucsc.edu/...index.html

simulation Astronomy science space Astrophysics cosmology planetary universe galactic physics

shared by Janos Haits on 03 Oct 11 - No Cached
  • Janos Haits on 03 Oct 11
     
    The Bolshoi simulation is the most accurate cosmological simulation of the evolution of the large-scale structure of the universe yet made ("bolshoi" is the Russian word for "great" or "grand").  The first two of a series of research papers describing Bolshoi and its implications have been accepted for publication in the Astrophysical Journal. The first data release of Bolshoi outputs, including output from Bolshoi and also the BigBolshoi or MultiDark simulation of a volume 64 times bigger than Bolshoi, has just been made publicly available to the world's astronomers and astrophysicists.
Todd Suomela

ESO - ESO 24/09 - Astronomer's new guide to the galaxy: largest map of cold dust revealed - 0 views

www.eso.org/...pr-24-09.html

astronomy astrophysics galactic survey

shared by Todd Suomela on 03 Jul 09 - Cached
  • Todd Suomela on 03 Jul 09
     
    This new guide for astronomers, known as the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL) shows the Milky Way in submillimetre-wavelength light (between infrared light and radio waves [1]). Images of the cosmos at these wavelengths are vital for studying the birthplaces of new stars and the structure of the crowded galactic core.
Sandra Flores

Periodic Table of Elements completed ? - 0 views

Is the Periodic Table of Elements wholly or could it still be unknown elements in the universe?In the periodic table of the elements, the chemical elements are listed according to their atomic numb...

started by Sandra Flores on 05 Jan 15 no follow-up yet
Sandra Flores

Periodic Table of Elements completed ? - 0 views

Is the Periodic Table of Elements wholly or could it still be unknown elements in the universe?In the periodic table of the elements, the chemical elements are listed according to their atomic numb...

started by Sandra Flores on 09 Jan 15 no follow-up yet
Janos Haits

LAMOST - 0 views

www.lamost.org/public

tool generator Astronomy science Space universe planetary galactic Solar cosmology

shared by Janos Haits on 05 Jul 18 - No Cached
  • Janos Haits on 05 Jul 18
     
    "LAMOST survey contains two main parts: the LAMOST ExtraGAlactic Survey (LEGAS), and the LAMOST Experiment for Galactic Understanding and Exploration (LEGUE) survey of Milky Way stellar structure. The unique design of LAMOST enables it to take 4000 spectra in a single exposure to a limiting magnitude as faint as r=19 at the resolution R=1800, which is equivalent to the design aim of r=20 for the resolution R=500. This telescope therefore has great potential to efficiently survey a large volume of space for stars and galaxies."
Sergio Perez

SFT_preprint-EN_2_col.pdf - 0 views

Unified field theory Quantum gravity vacuum Strong nuclear force Dark matter energy

shared by Sergio Perez on 29 Jan 24 - No Cached
  • Sergio Perez on 29 Jan 24
     
    Unification theory with no extra dimensions. The first part unifies the strong nuclear force with the gravitational force in a mathematical way; the quantum vacuum is treated as a deformable system by the strong nuclear force. The second part unifies the nuclear force with the quantum vacuum in a hypothetical structure; the quantum vacuum is treated as a supersymmetric and metastable system with properties related to the different types of particles' motion.
Sandy Herrick

90 Days Installment Loans- Helpful Cash To Deal With Unplanned Fiscal Emergencies In Sh... - 0 views

90 days installment loans are most feasible cash assistance for those applicants who are unable to refund the whole amount and need the urgent money to deal with unforeseen fiscal emergencies witho...

90 days loans cash loans installment loans loans for 90 days 90 day installment loans

started by Sandy Herrick on 05 Oct 16 no follow-up yet
Todd Suomela

Guest Post: Tom Levenson on Isaac Newton as the First Cosmologist | Cosmic Variance - 0 views

cosmicvariance.com/...ewton-as-the-first-cosmologist

astronomy astrophysics history physics science sts

shared by Todd Suomela on 05 Jun 08 - Cached
  • To make his ambitions absolutely clear Newton used the same phrase for the title of book three. There his readers would discover “The System of the World.” This is where the literary structure of the work really comes into play, in my view. Through book three, Newton takes his audience through a carefully constructed tour of all the places within the grasp of his new physics. It begins with an analysis of the moons of Jupiter, demonstrating that inverse square relationships govern those motions. He went on, to show how the interaction between Jupiter and Saturn would pull each out of a perfect elliptical orbit; the real world, he says here, is messier than a geometer’s dream.
  • Newton knew what he had done. He was no accidental writer. A parabola, of course, is a curve that keeps on going – and that meant that at the end of a very long and very dense book, he lifted off again from the hard ground of daily reality and said, in effect, look: All this math and all these physical ideas govern everything we can see, out to and past the point where we can’t see anymore. Most important, he did so with implacable rigor, a demonstration that, he argued, should leave no room for dissent. He wrote “The theory that corresponds exactly to so nonuniform a motion through the greatest part of the heavens, and that observes the same laws as the theory of the planets and that agrees exactly with exact astronomical observations cannot fail to be true.” (Italics added).
Todd Suomela

Guest Post: Evalyn Gates on Cosmic Magnification (or - Invasion of the Giant Blue Space... - 0 views

blogs.discovermagazine.com/...f-the-giant-blue-space-amoebas

astronomy astrophysics gravity-lens physics science gravity methods

shared by Todd Suomela on 19 Jul 09 - Cached
  • This is not just a pretty picture, however – the image packs a lot of scientific information. The authors extract the mass distribution in the cluster (which has implications for cosmological models), measure the mass-to-light ratio of the bright galaxy in the center of the cluster, and use the magnifying power of the lens to search for even more distant galaxies. The basic idea is to construct a model of the lens, starting with the cluster galaxies and a dark matter halo; then refine the model to reproduce the multiple images that are seen. Using this refined model it’s possible to predict the location of additional images of a given source, and to identify regions of high magnification that can then be examined for multiple images of other sources. Any additional images that are found can be used to further refine the model and so on.
  • This galaxy has been lensed by the warp in spacetime created by the cluster. Light from the galaxy, which lies almost directly behind the center of the cluster but much farther away from us, travels along several curved paths through the cluster lens, producing multiple magnified images of the galaxy. The inset box shows a computer generated model of the unlensed source galaxy, enlarged by a factor of four so that the details, including the spiral arm structure, are visible. Without the lensing power of the cluster, we would see this galaxy as a single small blue smudge. In general, lensing will both magnify and distort (shear) images of a background source. This lens is fairly unique in that we see large but relatively intact images of the spiral galaxy, which implies that the mass distribution in the central region of the cluster must be nearly uniform.
Sandra Flores

Surface and core of the Earth in its sights - 0 views

Surface and core of the Earth in its sightsOn September 10, the Russian Plesetsk cosmodrome to be brought from the ESA GOCE satellite into orbit to determine the gravitational field and the referen...

started by Sandra Flores on 05 Jan 15 no follow-up yet
Sandra Flores

First images of the comet - 0 views

Send Mars probes first images of the cometOn Sunday evening, the comet C / 2013 A1 (Siding Spring) is over flown at a distance of almost 140,000 kilometers on Mars. All active Mars probes have surv...

started by Sandra Flores on 05 Jan 15 no follow-up yet
1 - 20 of 24 Next ›
Showing 20▼ items per page