• social media
    • facebook
    • twitter
    • youtube
    • flickr
    • instagram
    • googleplus
Astrophsyics

PCOS 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 the only direct probe of chemical composition and nuclearsynthesis 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. Cosmic rays with energies below and just above the so-called "knee" in the middle of this energy range are most likely accelerated in supernova remnants. Their elemental and isotopic composition probes nucleosynthesis, nuclear interactions in the interstellar medium, the distribution of freshly synthesized elements, global Galactic properties, the mechanisms of supernova explosions, and particle acceleration in supernova shocks. 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 6 x 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. Electrons are quite abundant and can be accelerated in many different types of sources, while positrons and antiprotons are largely the result of interactions of nuclear cosmic rays with the ISM but may also have other origins. Positrons as well as 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 in the annihilation of dark matter candidate particles such as, e.g., WIMPs, neutralinos, and Kaluza-Klein particles. Details of the spectra and composition of the resulting particles therefore provide important insights into the physics of particle accelerators and properties of the interstellar and/or intergalactic medium, and provide important constraints on the nature of the dark matter.



PCOS News

Program News and Announcements

7 November 2019
NASA HQ has announced that all GO & GI programs will be converting to dual-anonymous peer review over the next year. »  Details
30 October 2019
The deadline to submit abstracts to give a lightning talk at the Jan AAS PCOS & PhysPAG session on a revolutionary multimessenger / multimission astrophysics discovery that involves at least one NASA mission is extended to Wed 27 Nov 2019.
7 October 2019
The deadline for Call for Nominations to Augment the NASA LISA Study Team has been extended to 11 Oct 2019. »  Details
30 September 2019
The application deadline for "The PI Launchpad: From Science Idea to NASA Mission" is extended to 15 Oct 2019. NASA Headquarters Science Mission Directorate (the level up from NASA Astrophysics Division) is co-organizing the Nov 18–20 workshop in Tuscon, AZ, in the interests of broadening the pool of potential NASA PIs. »  Details
19 September 2019
The PhysPAG EC nomination deadline, including self-nominations, is extended to Monday 30 Sept 2019. We welcome self nominations and particularly encourage people of diverse backgrounds and viewpoints. Useful skills include good communication, a desire and ability to facilitate community organization and collaborative conclusions, and a broad perspective. See the announcement letter with instructions for nominating
13 September 2019
Submit your abstract today to give a 5min lightning talk on a revolutionary multimessenger / multimission astrophysics discovery that involves at least one NASA mission at the Jan AAS PCOS & PhysPAG session! Abstracts due by 31 Oct 2019.

Project News

Related News


Links

NASA logo
  • NASA Official: Phil Newman
  • Web Curator: Pat Tyler
Goddard Space Flight Center
privacy