Our Galaxy hosts the annihilation

Discussion in 'Astronomy, Exobiology, & Cosmology' started by wangchaoqing, Jun 8, 2018.

Thread Status:
Not open for further replies.
  1. wangchaoqing Registered Member

    Messages:
    10
    Our Galaxy hosts the annihilation of a few 10^43 low-energy positrons every second. Radioactive isotopes capable of supplying such positrons are synthesized in stars, stellar remnants and supernovae. For decades, however, there has been no positive identification of a main stellar positron source, leading to suggestions that many positrons originate from exotic sources like the Galaxy’s central supermassive black hole or dark matter annihilation. Here we show that a single type of transient source, deriving from stellar populations of age 3–6 Gyr and yielding ∼0.03M ⊙ of the positron emitter 44-Ti, can simultaneously explain the strength and morphology of the Galactic positron annihilation signal and the Solar System abundance of the 44-Ti decay product 44-Ca. This transient is likely the merger of two low-mass white dwarfs, observed in external galaxies as the sub-luminous, thermonuclear supernova known as SN 1991bg-like.

    https://www.nature.com/articles/s41550-017-0135.epdf?referrer_access_token=pVDIL6sZQwyKJNLdmR26ydRgN0jAjWel9jnR3ZoTv0NsQ6DPIuGo0Hl8A1hHbwL-9_LAk-6u-C4bfocizScITnLuUS-T3wW9PBtBZIq6o_iZSwTIl5Xgaqs9bfpbbsUeWbmrvCQX11Nza1QWgaQWmNReelhkDo-tqYi1QIkqbuxQ8Xdk4RHy1ZMG80BZWGR2M0QxtOsZVAbpqdd86kQxPgJpE0_SjQxW8IC00eWG2cvUwl9GoCsQn3flcaswNpd1UzXxkrnZCw1JzgFvjSKWhDzuiiTxhkCz8JWOcw7yQJU=&tracking_referrer=www.space.com
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. NotEinstein Valued Senior Member

    Messages:
    1,533
    Is there anything you want to discuss? You've just copy-pasted the abstract of the article (without attribution, which is frowned upon on this forum), and posted a link.
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. James R Just this guy, you know? Staff Member

    Messages:
    31,550
    It's been a month, so I guess not. Thread closed.
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
Thread Status:
Not open for further replies.

Share This Page