GENERAL
ABOUT INFN
ORGANISATION CHART
INFN HEADQUARTERS
PRESS OFFICE
ADMINISTRATION
PHONE BOOK
JOB OPPORTUNITIES
 ACTIVITIES
PARTICLE PHYSICS
ASTROPARTICLE PHYSICS
NUCLEAR PHYSICS
THEORETICAL PHYSICS
TECHNOLOGY
EXPERIMENTS
INFN PUBLICATIONS
THESIS
 SERVICES
PORTALE INFN
AGENDA INFN
EDUCATIONAL
WEBCAST
MULTIMEDIA
EU FP7
 

Trasparenza valutazione e merito  

DataWeb Support ticket  -  e-mail  

 

  04-03-2011: IN THE UNIVERSE THERE IS AN UNEXPECTED ACCELERATOR 
 COMPLETE LIST 

Copyright INFN The use of photos is free of charge. Please request authorisation from the INFN Communication Office




The PAMELA experiment – an international scientific enterprise coordinated by the National Nuclear Physiscs Insitute (INFN) – has shown that protons and helium nuclei in cosmic rays in the Galaxy are not accelerated in the same way at high energy levels (in the range of hundreds of GeV). This could mean that there are several types of cosmic particle accelerators working with different mechanisms. So far the idea was that this “job” might be carried out by the extremely turbulent remains of large exploded stars (supernovae) in exactly the same way for all charged particles. On the contrary, the PAMELA studies show that protons and helium may be accelerated by different sources.

The study which explains this phenomenon will be published in the forthcoming edition of Science Express, the service by the American magazine Science presenting articles before final publication.

The data were collected by PAMELA between 2006 and 2008; they concern the flow of protons and helium nuclei, that is to say almost all the cosmic radiation which we intercept. It has been discovered that the spectrum of protons and helium nuclei follows different paths. This difference could therefore prove that something causes them to accelerate in a different way. One possibility could be an unknown acceleration mechanism which acts in different ways for the various particle species. A more traditional explanation could be that galactic cosmic radiation is accelerated both by novae, enormous nuclear explosions caused by hydrogen accumulation on the surface of a white dwarf, and by a different kind of supernovae. Protons are supposedly accelerated in the explosion of smaller supernovae – where the star atmosphere is mainly rich in protons – and the helium nuclei in larger stars, where the atmosphere is richer in helium. Such different conditions could be the cause of their energy flows being affected differently as observed by PAMELA.

“These results” says Piergiorgio Picozza, the PAMELA project manager, “seriously question the paradigm whereby cosmic rays are accelerated only by the shock wave from supernova remains, then propagate through the Galaxy. They require more complex acceleration processes which will soon be theoretically studied in depth. It is a breakthrough towards understanding cosmic ray acceleration mechanisms in our galaxy, in addition to the recent AGILE and FERMI experiments”.

“This is a very important result for the understanding of cosmic ray origin, which is one of the great enigmas of modern science” says Barbara Negri, manager of the Universe Exploration and Observation Unit of ASI. “The PAMELA experiment was also conducted with the contribution of ASI and it is currently the most advanced observatory for the study of cosmic rays. Since its launch in 2006, ASI has been committed to supporting the management of the PAMELA experiment in orbit and the scientific community which has to interpret the data obtained. The many important results which experiments like PAMELA, as well as those on the satellites AGILE and FERMI, are obtaining by studying the cosmos at very high energy levels, are a point of pride for ASI because they clearly demonstrate the effective support given by the agency to national science”.

PAMELA is an experiment in orbit at a height between 350 and 610 km on a Russian satellite and it is the result of the cooperation between the National Nuclear Physics Institute (INFN), the Russian Space Agency and Russian research institutes, with the involvement of the Italian Space Agency (ASI) and the contribution of German and Swedish space agencies and universities.

For information
Piergiorgio Picozza – PAMELA project manager
work +39 06 2022926
mob. +39 348 8732945

Antonella Varaschin – Presso Office INFN
work +39 06 6868162
mob. +39 349 5384481

Giuseppina Piccirilli – Press Office ASI
work +39 06.8567431
mob. +39 335 8157224


 RELATED SITES 

 RECENT NEWS  
26-03-2013: OPERA observed a third neutrino tau
08-06-2012: Neutrinos sent from CERN to Gran Sasso respect the cosmic speed limit
06-06-2012: OPERA OBSERVES THE SECOND TAU NEUTRINO
18-05-2012: FEL, A SUPER LASER FOR SUPERB
15-05-2012: Research on neutrinos allows the discovery of vortices in the abysses of the eastern Mediterranean
16-03-2012: The Icarus experiment measures the neutrino speed: even neutrinos are not faster than light
23-02-2012: NEUTRINOS: STATEMENT ISSUED BY THE OPERA COLLABORATION
13-12-2011: ato attuale della ricerca dell’Higgs
18-11-2011: NEW TESTS CONFIRM THE RESULTS OF OPERA ON THE NEUTRINO VELOCITY. BUT IT IS NOT YET THE FINAL CONFIRMATION
26-10-2011: Fernando Ferroni appointed as the president of the Italian National Institute for Nuclear Physics

[Back]

 

Ufficio Comunicazione Infn - Piazza dei Caprettari, 70 - 00186 Roma
Tel: 06 68 68 162 - Fax: 06 68 307 944 - email: comunicazione@presid.infn.it

F.M . F.E.

 

 

 

 

 

 CONFERENCES
11-12-2017
TRANSVERSITY 2017
13-12-2017
SM&FT 2017 : THE XVII WORKSHOP ON STATISTICAL MECHANICS AND NONPERTURBATIVE FIELD THEORY
 REVIEWS AREA
PRESS REVIEWS
VIDEO REVIEWS
 PRESS RELEASE
26-03-2013
OPERA OBSERVED A THIRD NEUTRINO TAU
08-06-2012
NEUTRINOS SENT FROM CERN TO GRAN SASSO RESPECT THE COSMIC SPEED LIMIT
06-06-2012
OPERA OBSERVES THE SECOND TAU NEUTRINO
Ricerca Italiana