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wiki:nucastastron [2012/10/09 16:06]
nucastro [neutrino telescopes observations]
wiki:nucastastron [2013/01/10 17:47] (current)
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  ​===== ​ gamma-ray observations =====  ​===== ​ gamma-ray observations =====
 +
 +== Nuclear Astrophysics ==
  
  Line features arise from radioactive isotopes, which are produced alongside nucleosynthesis. The isotopes need to be ejected into interstellar space, so that gamma-radiation is not occulted/​absorbed. ​  Line features arise from radioactive isotopes, which are produced alongside nucleosynthesis. The isotopes need to be ejected into interstellar space, so that gamma-radiation is not occulted/​absorbed. ​
  
 Isotopes which are sufficiently abundant for brightest such lines are (sorted by decay time from short to long, 77d to 2.6 My): 7Be, 56Ni, 22Na, 44Ti, 26Al, 60Fe. Annihilations from positrons emitted by β+ decays also lead to gamma-ray line emission at 511 keV. Isotopes which are sufficiently abundant for brightest such lines are (sorted by decay time from short to long, 77d to 2.6 My): 7Be, 56Ni, 22Na, 44Ti, 26Al, 60Fe. Annihilations from positrons emitted by β+ decays also lead to gamma-ray line emission at 511 keV.
 +
 +== Status, Achievements ==
  
 So far, detections and measurements are available for 511 keV annihilation gamma-rays, 56Ni decay chain gamma-rays, and gamma-rays from 26Al and 60Fe.  So far, detections and measurements are available for 511 keV annihilation gamma-rays, 56Ni decay chain gamma-rays, and gamma-rays from 26Al and 60Fe. 
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 Current capabilities in this field rate as few 10^{-6} photons per cm^2 and sec for a 10^6 sec measurement. Current capabilities in this field rate as few 10^{-6} photons per cm^2 and sec for a 10^6 sec measurement.
  
-Questions to be addressed:+== Questions to be addressed: ​==
  
    - which energy resolution is required? (this determines S/N, in this background-dominated field)    - which energy resolution is required? (this determines S/N, in this background-dominated field)
    - which field-of-view size is required? (surveys, versus pointed source observations)  ​    - which field-of-view size is required? (surveys, versus pointed source observations)  ​
  
 +== Future Instruments,​ Perspectives ==
 +
 +No space missions in coming years/​decade. Several proposals in ESA's '​Cosmic Vision'​. Clearly, Compton Telescopes are the only promising technique, possibly supplemented by a gamma-ray lesn or coded mask for preciser locations. CT limits: about 0.5 degrees.
 +Balloon programs promising/​feasible,​ e.g. NCT from UCB. 
 ... ...
  
wiki/nucastastron.txt · Last modified: 2013/01/10 17:47 (external edit)