MSGID: 1:317/3 649e5a69   
   PID: hpt/lnx 1.9.0-cur 2019-01-08   
   TID: hpt/lnx 1.9.0-cur 2019-01-08   
    First 'ghost particle' image of Milky Way    
    Elusive neutrinos reveal a portrait of our galaxy unlike any before    
      
     Date:   
         June 29, 2023   
     Source:   
         National Science Foundation   
     Summary:   
         Scientists have revealed a uniquely different image of our galaxy   
         by determining the galactic origin of thousands of neutrinos --   
         invisible 'ghost particles' which exist in great quantities but   
         normally pass straight through Earth undetected. The neutrino-based   
         image of the Milky Way is the first of its kind: a galactic portrait   
         made with particles of matter rather than electromagnetic energy.   
      
      
         Facebook Twitter Pinterest LinkedIN Email   
      
   ==========================================================================   
   FULL STORY   
   ==========================================================================   
   From visible starlight to radio waves, the Milky Way galaxy has long been   
   observed through the various frequencies of electromagnetic radiation   
   it emits.   
      
   Scientists have now revealed a uniquely different image of our galaxy by   
   determining the galactic origin of thousands of neutrinos -- invisible   
   "ghost particles" which exist in great quantities but normally pass   
   straight through Earth undetected. The neutrino-based image of the Milky   
   Way is the first of its kind: a galactic portrait made with particles   
   of matter rather than electromagnetic energy.   
      
   The breakthrough was achieved by a collaboration of researchers using   
   the U.S.   
      
   National Science Foundation-supported IceCube Neutrino Observatory at   
   NSF's Amundsen-Scott South Pole Station in Antarctica. The immense   
   observatory detects the subtle signs of high-energy neutrinos from   
   space by using thousands of networked sensors buried deep within a   
   cubic kilometer of clear, pristine ice. The results were revealed at an   
   event today at Drexel University and will be published tomorrow in the   
   journal Science.   
      
   "I remember saying, 'At this point in human history, we're the first   
   ones to see our galaxy in anything other than light,'" says Drexel   
   University physicist Naoko Kurahashi Neilson of the moment she and two   
   doctoral students, Steve Sclafani with Drexel and Mirco Hu"nnefeld with   
   TU Dortmund University in Germany, first examined the image. Kurahashi   
   Neilson proposed the innovative computational analysis used to generate   
   the image and received funding to pursue her idea through a grant from   
   NSF's Faculty Early Career Development program.   
      
   "As is so often the case, significant breakthroughs in science are   
   enabled by advances in technology," says Denise Caldwell, director   
   of NSF's Physics Division. "The capabilities provided by the highly   
   sensitive IceCube detector, coupled with new data analysis tools,   
   have given us an entirely new view of our galaxy -- one that had only   
   been hinted at before. As these capabilities continue to be refined, we   
   can look forward to watching this picture emerge with ever-increasing   
   resolution, potentially revealing hidden features of our galaxy never   
   before seen by humanity."  "What's intriguing is that, unlike the case   
   for light of any wavelength, in neutrinos, the universe outshines the   
   nearby sources in our own galaxy," says Francis Halzen, a physicist at   
   the University of Wisconsin-Madison and principal investigator at IceCube.   
      
   Beyond the daunting challenge of just detecting notoriously elusive   
   neutrinos (and distinguishing them from other sorts of interstellar   
   particles) is the even more ambitious goal of determining where they came   
   from. When neutrinos happen to interact with the ice beneath IceCube,   
   those rare encounters produce faint patterns of light, which IceCube can   
   detect. Some patterns of light are highly directional and point clearly   
   to a particular area of the sky, allowing researchers to determine the   
   source of the neutrinos. Such interactions were the basis for the IceCube   
   Collaboration's 2022 discovery of neutrinos that came from another galaxy   
   47 million light-years away.   
      
   Other interactions are far less directional and produce cascading "fuzz   
   balls of light" in the clear ice, says Kurahashi Neilson. Her fellow   
   IceCube Collaboration members, Sclafani and Hu"nnefeld, developed a   
   machine-learning algorithm that compared the relative position, size   
   and energy of more than 60,000 such neutrino-generated cascades of light   
   recorded by IceCube over 10 years.   
      
   The three researchers spent over two years meticulously testing and   
   verifying their algorithm using artificial data simulating neutrino   
   detections. When they eventually fed the real IceCube-provided data to the   
   algorithm, what emerged was a picture showing bright spots corresponding   
   to locations in the Milky Way that were suspected to emit neutrinos. Those   
   locations were in places where observed gamma rays were thought to be   
   the byproducts of collisions between cosmic rays and interstellar gas,   
   which theoretically should also produce neutrinos.   
      
   "A neutrino counterpart has now been measured, thus confirming what we   
   know about our galaxy and cosmic ray sources," says Sclafani.   
      
   Over many decades, scientists have revealed countless astronomical   
   discoveries by expanding the methods used to observe the   
   universe. Once-revolutionary advances such as radio astronomy and infrared   
   astronomy have been joined by a new class of observational techniques   
   using phenomena such as gravitational waves and now, neutrinos. Kurahashi   
   Neilson says that the neutrino-based image of the Milky Way is yet another   
   step in that lineage of discovery. She predicts neutrino astronomy will   
   be honed like the methods that preceded it, until it too can reveal   
   previously unknown aspects of the universe.   
      
   "This is why we do what we do," she says. "To see something nobody has   
   ever seen, and to understand things we haven't understood."   
       * RELATED_TOPICS   
             o Space_&_Time   
                   # Galaxies # Astronomy # Astrophysics # Cosmic_Rays #   
                   Space_Telescopes # Cosmology # Space_Exploration #   
                   Black_Holes   
       * RELATED_TERMS   
             o Milky_Way o Neutrino o Subatomic_particle o Globular_cluster   
             o Dark_matter o Interstellar_medium o Magellanic_Clouds o   
             Hubble_Deep_Field   
      
   ==========================================================================   
   Story Source: Materials provided by National_Science_Foundation. Original   
   written by Jason Stoughton. Note: Content may be edited for style   
   and length.   
      
      
   ==========================================================================   
   Related Multimedia:   
       * A_composite_image_of_an_optical_view_of_the_Milky_Way_along_with_the   
         first-ever_neutrino-based_image_of_the_Milky_Way   
   ==========================================================================   
   Journal Reference:   
      1. R. Abbasi et al. Observation of high-energy neutrinos from the   
      Galactic   
         plane. Science, 2023; 380 (6652): 1338 DOI: 10.1126/science.adc9818   
   ==========================================================================   
      
   Link to news story:   
   https://www.sciencedaily.com/releases/2023/06/230629193240.htm   
      
   --- up 1 year, 17 weeks, 3 days, 10 hours, 50 minutes   
    * Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)   
   SEEN-BY: 15/0 106/201 114/705 123/120 153/7715 218/700 226/30 227/114   
   SEEN-BY: 229/110 112 113 307 317 400 426 428 470 664 700 291/111 292/854   
   SEEN-BY: 298/25 305/3 317/3 320/219 396/45 5075/35   
   PATH: 317/3 229/426