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Posts Tagged ‘cold dark matter’

In a paper published in last week’s Nature, astronomers announced that a new computer model was capable of simulating the formation of so-called bulgeless dwarf galaxies. Until this development, computer models simulating the formation of dwarf galaxies, could not develop bulgeless dwarf galaxies with the presence of cold dark matter (CDM). The incorporation of “strong outflows from supernovae” was apparently the key for developing this computer model. This model supports the existence of cold dark matter and a cosmological constant. You can read the full article online here (with a subscription).

Today in the journal Nature, astronomers led by Dr. Fabio Governato, announced the development of a computer simulation of the formation of dwarf galaxies. Their model incorporates the presence of cold dark matter. If you at a location with a subscription to Nature you can read the entire story online now here. You can check out the movie online now here for free.

The Cryogenic Dark Matter Search (CDMS) is a collaborative effort among 15 universities. The experiment is being conducted “a half-mile underground at the Soudan mine in northern Minnesota,” and it “uses 30 detectors made of germanium and silicon in an attempt to detect” what is known as WIMPs. WIMPs are Weakly Interacting Massive Particles which are suspected as being a major contributor to the dark matter in the universe. The announcement summarizing the latest results from CDMS can be found here. For a more technical description of the results, check out the pre-publication paper available online now here. Very briefly, while CDMS has detected two possible dark matter WIMP events, the probability that these detections are from background noise is such that the CDMS team is not going to say that it has been a successful detection. Nonetheless, as the experiment continues, these data provide some hope to astronomers in their attempt to characterize the nature of the cold dark matter that apparently engulfs all galaxies.

In a pre-print of a paper that will be published in The Astrophysical Journal, an international team of astronomers conclude that the dark matter halo surrounding our Milky Way galaxy is actually lopsided or asymmetric. This is slightly different from the standard depictions showing a dark matter halo evenly distributed around our galaxy, however, these astronomers conclude that these asymmetries actually support the model of the universe with a cosmological constant and cold dark matter. Read more about the evidence for the asymmetric dark matter halo here.

In a white paper released today addressing the future study of dark matter (specifically cold dark matter of CDM) astronomers express what they feel the next 10 years will bring to the understanding of cold dark matter, its nature and distribution. If you are interested in the following questions, you should take the time to read this white paper. The questions addressed include: “What is the distribution of mass on sub-galactic scales? How do galaxy disks form and bulges grow in dark matter halos? How accurate are CDM predictions of halo structure? Can we distinguish between a need for a new substance (dark matter) and a need for new physics (departures from General Relativity)? What is the dark matter made of anyway?” And if you wondered how these questions should be addressed in the next ten years, these astronomers feel the best means is optical imaging and spectroscopy (including infrared). Read more about the future study of cold dark matter online now at http://xxx.lanl.gov/PS_cache/arxiv/pdf/0902/0902.2963v1.pdf