Science Goals

Explore the behavior of matter and energy in its most extreme environments

Cosmic rays, high-energy charged particles traveling at velocities that can approach the speed of light, are a rich potential probe of chemical and nuclear in the Universe. The majority of cosmic rays are atomic nuclei from hydrogen to the heaviest elements with energies spanning more than twelve orders of magnitude. In the low energy end, these cosmic rays are most likely accelerated in supernova remnants. Their elemental and isotopic composition probes nucleosynthesis, nuclear interactions with the interstellar medium, the distribution of freshly synthesized elements, and the mechanism of supernova explosions. At energies above roughly 1017 eV a different source dominates. The acceleration engines responsible for such extreme energies are not well understood, but at the highest energies, above about 6 × 1019 eV, the rapid energy loss resulting from interactions with the cosmic microwave background limits sources to within about 100 Mpc. Other cosmic ray components include electrons, positrons and antiprotons. While these are largely the result of interactions of nuclear cosmic rays with the ISM, they may have other origins. Positrons and electrons can be produced directly in astrophysical objects such as pulsars and deviations in their spectra can provide important insights into nearby sources. Cosmic ray particles may also be produced directly by the annihilation of dark matter candidates such as nutralinos and Kaluza-Klein particles. Details of the spectra of the resulting particles would therefore provide important constraints on the nature of the dark matter.

Program News

29 Mar 2016
X-ray Surveyor Mission Concept Study Kickoff Telecon Agenda »  Details
11 Mar 2016
X-ray Surveyor STDT Membership Announced (3/11/2016) »  Details
2 Mar 2016
PCOS Call for White Papers on Probe Missions receives 14 submissions »  Details
29 Jan 2016
Announcing L3 (gravitational wave mission) study team membership »  Details

Project News

Chandra News
28 Apr 2016
"Russian Doll" Galaxy Clusters Reveal Information About Dark Energy » Details
Fermi News
28 Apr 2016
NASA's Fermi Telescope Helps Link Cosmic Neutrino to Blazar Blast » Details
Planck News
31 Mar 2015
Herschel and Planck find missing clue to galaxy cluster formation
» Details
XMM-Newton News
28 Apr 2016
Powerful Winds Spotted from Mysterious X-ray Binaries » Details

Related News

NuSTAR News
5 Jan 2016
Andromeda Galaxy Scanned with High-Energy X-ray Vision » Details
Suzaku News
26 Aug 2015
X-ray Astronomy Satellite "Suzaku" Completes Scientific Mission » Details
Swift News
6 Nov 2015
NASA's Swift Spots its Thousandth Gamma-ray Burst » Details