O. Adriani, G. C. Barbarino, G. A. Bazilevskaya, R. Bellotti, M. Boezio, E. A. Bogomolov, L. Bonechi, M. Bongi, V. Bonvicini, S. Bottai, A. Bruno, F. Cafagna, D. Campana, P. Carlson, M. Casolino, G. Castellini, M. P. De Pascale, G. De Rosa, D. Fedele, A. M. Galper, L. Grishantseva, P. Hofverberg, S. V. Koldashov, S. Y. Krutkov, A. N. Kvashnin, A. Leonov, V. Malvezzi, L. Marcelli, W. Menn, V. V. Mikhailov, M. Minori, E. Mocchiutti, M. Nagni, S. Orsi, G. Osteria, P. Papini, M. Pearce, P. Picozza, M. Ricci, S. B. Ricciarini, M. Simon, R. Sparvoli, P. Spillantini, Y. I. Stozhkov, E. Taddei, A. Vacchi, E. Vannuccini, G. Vasilyev, S. A. Voronov, Y. T. Yurkin, G. Zampa, N. Zampa, V. G. Zverev
Oct 28, 2008·astro-ph·PDF A new measurement of the cosmic ray antiproton-to-proton flux ratio between 1 and 100 GeV is presented. The results were obtained with the PAMELA experiment, which was launched into low-earth orbit on-board the Resurs-DK1 satellite on June 15th 2006. During 500 days of data collection a total of about 1000 antiprotons have been identified, including 100 above an energy of 20 GeV. The high-energy results are a ten-fold improvement in statistics with respect to all previously published data. The data follow the trend expected from secondary production calculations and significantly constrain contributions from exotic sources, e.g. dark matter particle annihilations.
O. Adriani, G. C. Barbarino, G. A. Bazilevskaya, R. Bellotti, M. Boezio, E. A. Bogomolov, M. Bongi, V. Bonvicini, S. Borisov, S. Bottai, A. Bruno, F. Cafagna, D. Campana, R. Carbone, P. Carlson, M. Casolino, G. Castellini, L. Consiglio, M. P. De Pascale, C. De Santis, N. De Simone, V. Di Felice, A. M. Galper, W. Gillard, L. Grishantseva, G. Jerse, A. V. Karelin, M. D. Kheymits, S. V. Koldashov, S. Y. Krutkov, A. N. Kvashnin, A. Leonov, V. Malakhov, L. Marcelli, A. G. Mayorov, W. Menn, V. V. Mikhailov, E. Mocchiutti, A. Monaco, N. Mori, N. Nikonov, G. Osteria, F. Palma, P. Papini, M. Pearce, P. Picozza, C. Pizzolotto, M. Ricci, S. B. Ricciarini, L. Rossetto, R. Sarkar, M. Simon, R. Sparvoli, P. Spillantini, Y. I. Stozhkov, A. Vacchi, E. Vannuccini, G. Vasilyev, S. A. Voronov, Y. T. Yurkin, J. Wu, G. Zampa, N. Zampa, V. G. Zverev
Jul 25, 2011·astro-ph.HE·PDF The existence of a significant flux of antiprotons confined to Earth's magnetosphere has been considered in several theoretical works. These antiparticles are produced in nuclear interactions of energetic cosmic rays with the terrestrial atmosphere and accumulate in the geomagnetic field at altitudes of several hundred kilometers. A contribution from the decay of albedo antineutrons has been hypothesized in analogy to proton production by neutron decay, which constitutes the main source of trapped protons at energies above some tens of MeV. This Letter reports the discovery of an antiproton radiation belt around the Earth. The trapped antiproton energy spectrum in the South Atlantic Anomaly (SAA) region has been measured by the PAMELA experiment for the kinetic energy range 60--750 MeV. A measurement of the atmospheric sub-cutoff antiproton spectrum outside the radiation belts is also reported. PAMELA data show that the magnetospheric antiproton flux in the SAA exceeds the cosmic-ray antiproton flux by three orders of magnitude at the present solar minimum, and exceeds the sub-cutoff antiproton flux outside radiation belts by four orders of magnitude, constituting the most abundant source of antiprotons near the Earth.
N. P. Topchiev, A. M. Galper, I. V. Arkhangelskaja, A. I. Arkhangelskiy, A. V. Bakaldin, R. A. Cherniy, I. V. Chernysheva, E. N. Gudkova, Yu. V. Gusakov, O. D. Dalkarov, A. E. Egorov, M. D. Kheymits, M. G. Korotkov, A. A. Leonov, A. G. Malinin, V. V. Mikhailov, A. V. Mikhailova, P. Yu. Minaev, N. Yu. Pappe, M. V. Razumeyko, M. F. Runtso, Yu. I. Stozhkov, S. I. Suchkov, Yu. T. Yurkin
Aug 28, 2021·astro-ph.IM·PDF The future space-based GAMMA-400 gamma-ray telescope will operate onboard the Russian astrophysical observatory in a highly elliptic orbit during 7 years to observe Galactic plane, Galactic Center, Fermi Bubbles, Crab, Vela, Cygnus X, Geminga, Sun, and other regions and measure gamma- and cosmic-ray fluxes. Observations will be performed in the point-source mode continuously for a long time (~100 days). GAMMA-400 will measure gamma rays in the energy range from ~20 MeV to several TeV and cosmic-ray electrons + positrons up to several tens TeV. GAMMA-400 instrument will have very good angle and energy resolutions, high separation efficiency of gamma rays from cosmic-ray background, as well as electrons + positrons from protons. The main feature of GAMMA-400 is the unprecedented angular resolution for energies >30 GeV better than the space-based and ground-based gamma-ray telescopes by a factor of 5-10. GAMMA-400 observations will permit to resolve gamma rays from annihilation or decay of dark matter particles, identify many discrete sources, clarify the structure of extended sources, specify the data on cosmic-ray electron + positron spectra.
A. M. Galper, O. Adriani, R. L. Aptekar, I. V. Arkhangelskaja, A. I. Arkhangelskiy, G. A. Avanesov, L. Bergstrom, E. A. Bogomolov, M. Boezio, V. Bonvicini, K. A. Boyarchuk, V. A. Dogiel, Yu. V. Gusakov, M. I. Fradkin, Ch. Fuglesang, B. I. Hnatyk, V. A. Kachanov, V. V. Kadilin, V. A. Kaplin, M. D. Kheymits, V. Korepanov, J. Larsson, A. A. Leonov, F. Longo, P. Maestro, P. Marrocchesi, V. V. Mikhailov, E. Mocchiutti, A. A. Moiseev, N. Mori, I. Moskalenko, P. Yu. Naumov, P. Papini, M. Pearce, P. Picozza, M. F. Runtso, F. Ryde, R. Sparvoli, P. Spillantini, S. I. Suchkov, M. Tavani, N. P. Topchiev, A. Vacchi, E. Vannuccini, G. I. Vasiliev, Yu. T. Yurkin, N. Zampa, V. N. Zarikashvili, V. G. Zverev
Jun 26, 2013·astro-ph.IM·PDF The design of the new space-based gamma-ray telescope GAMMA-400 is presented. GAMMA-400 is optimized for the energy 100 GeV with the best parameters: the angular resolution ~0.01 deg, the energy resolution ~1%, and the proton rejection factor ~10E6, but is able to measure gamma-ray and electron + positron fluxes in the energy range from 100 MeV to 10 TeV. GAMMA-400 is aimed to a broad range of science topics, such as search for signatures of dark matter, studies of Galactic and extragalactic gamma-ray sources, Galactic and extragalactic diffuse emission, gamma-ray bursts, as well as high-precision measurements of spectra of cosmic-ray electrons + positrons, and nuclei.
O. Adriani, G. C. Barbarino, G. A. Bazilevskaya, R. Bellotti, M. Boezio, E. A. Bogomolov, M. Bongi, V. Bonvicini, S. Bottai, A. Bruno, F. Cafagna, D. Campana, P. Carlson, M. Casolino, G. Castellini, C. De Donato, C. De Santis, N. De Simone, V. Di Felice, V. Formato, A. M. Galper, A. V. Karelin, S. V. Koldashov, S. Koldobskiy, S. Y. Krutkov, A. N. Kvashnin, A. Leonov, V. Malakhov, L. Marcelli, M. Martucci, A. G. Mayorov, W. Menn, M Mergè, V. V. Mikhailov, E. Mocchiutti, A. Monaco, N. Mori, R. Munini, G. Osteria, F. Palma, B. Panico, P. Papini, M. Pearce, P. Picozza, M. Ricci, S. B. Ricciarini, R. Sarkar, V. Scotti, M. Simon, R. Sparvoli, P. Spillantini, Y. I. Stozhkov, A. Vacchi, E. Vannuccini, G. Vasilyev, S. A. Voronov, Y. T. Yurkin, G. Zampa, N. Zampa
Dec 21, 2015·astro-ph.HE·PDF The cosmic-ray hydrogen and helium ($^1$H, $^2$H, $^3$He, $^4$He) isotopic composition has been measured with the satellite-borne experiment PAMELA, which was launched into low-Earth orbit on-board the Resurs-DK1 satellite on June 15th 2006. The rare isotopes $^2$H and $^3$He in cosmic rays are believed to originate mainly from the interaction of high energy protons and helium with the galactic interstellar medium. The isotopic composition was measured between 100 and 1100 MeV/n for hydrogen and between 100 and 1400 MeV/n for helium isotopes using two different detector systems over the 23rd solar minimum from July 2006 to December 2007.
A. M. Galper, B. I. Luchkov, Yu. T. Yurkin
Long observation (1972 - 2009) of the powerful discrete source in Galaxy Cygnus X-3 discovered its main properties and let to develop a real model of this unique object. It is short binary system with 4.8 hour orbital period including relativistic object (neutron star or black hole) and massive star. Source most activity is seen in gamma-rays from tens MeV to thousands TeV.
O. Adriani, G. C. Barbarino, G. A. Bazilevskaya, R. Bellotti, M. Boezio, E. A. Bogomolov, L. Bonechi, M. Bongi, V. Bonvicini, S. Bottai, A. Bruno, F. Cafagna, D. Campana, P. Carlson, M. Casolino, G. Castellini, M. P. De Pascale, G. De Rosa, N. De Simone, V. Di Felice, A. M. Galper, L. Grishantseva, P. Hofverberg, S. V. Koldashov, S. Y. Krutkov, A. N. Kvashnin, A. Leonov, V. Malvezzi, L. Marcelli, W. Menn, V. V. Mikhailov, E. Mocchiutti, S. Orsi, G. Osteria, P. Papini, M. Pearce, P. Picozza, M. Ricci, S. B. Ricciarini, M. Simon, R. Sparvoli, P. Spillantini, Y. I. Stozhkov, A. Vacchi, E. Vannuccini, G. Vasilyev, S. A. Voronov, Y. T. Yurkin, G. Zampa, N. Zampa, V. G. Zverev
Oct 28, 2008·astro-ph·PDF Positrons are known to be produced in interactions between cosmic-ray nuclei and interstellar matter ("secondary production"). Positrons may, however, also be created by dark matter particle annihilations in the galactic halo or in the magnetospheres of near-by pulsars. The nature of dark matter is one of the most prominent open questions in science today. An observation of positrons from pulsars would open a new observation window on these sources. Here we present results from the PAMELA satellite experiment on the positron abundance in the cosmic radiation for the energy range 1.5 - 100 GeV. Our high energy data deviate significantly from predictions of secondary production models, and may constitute the first indirect evidence of dark matter particle annihilations, or the first observation of positron production from near-by pulsars. We also present evidence that solar activity significantly affects the abundance of positrons at low energies.
O. Adriani, G. C. Barbarino, G. A. Bazilevskaya, R. Bellotti, M. Boezio, E. A. Bogomolov, L. Bonechi, M. Bongi, V. Bonvicini, S. Borisov, S. Bottai, A. Bruno, F. Cafagna, D. Campana, R. Carbone, P. Carlson, M. Casolino, G. Castellini, L. Consiglio, M. P. De Pascale, C. De Santis, N. De Simone, V. Di Felice, A. M. Galper, W. Gillard, L. Grishantseva, P. Hofverberg, G. Jerse, S. V. Koldashov, S. Y. Krutkov, A. N. Kvashnin, A. Leonov, V. Malvezzi, L. Marcelli, W. Menn, V. V. Mikhailov, E. Mocchiutti, A. Monaco, N. Mori, N. Nikonov, G. Osteria, P. Papini, M. Pearce, P. Picozza, M. Ricci, S. B. Ricciarini, L. Rossetto, M. Simon, R. Sparvoli, P. Spillantini, Y. I. Stozhkov, A. Vacchi, E. Vannuccini, G. Vasilyev, S. A. Voronov, J. Wu, Y. T. Yurkin, G. Zampa, N. Zampa, V. G. Zverev, D. Marinucci
Jan 20, 2010·astro-ph.HE·PDF The PAMELA satellite experiment has measured the cosmic-ray positron fraction between 1.5 GeV and 100 GeV. The need to reliably discriminate between the positron signal and proton background has required the development of an ad hoc analysis procedure. In this paper, a method for positron identification is described and its stability and capability to yield a correct background estimate is shown. The analysis includes new experimental data, the application of three different fitting techniques for the background sample and an estimate of systematic uncertainties due to possible inaccuracies in the background selection. The new experimental results confirm both solar modulation effects on cosmic-rays with low rigidities and an anomalous positron abundance above 10 GeV.
O. Adriani, G. C. Barbarino, G. A. Bazilevskaya, R. Bellotti, M. Boezio, E. A. Bogomolov, M. Bongi, V. Bonvicini, S. Borisov, S. Bottai, A. Bruno, F. Cafagna, D. Campana, R. Carbone, P. Carlson, M. Casolino, G. Castellini, I. A. Danilchenko, M. P. De Pascale, C. De Santis, N. De Simone, V. Di Felice, V. Formato, A. M. Galper, A. V. Karelin, S. V. Koldashov, S. Koldobskiy, S. Y. Krutkov, A. N. Kvashnin, A. Leonov, V. Malakhov, L. Marcelli, A. G. Mayorov, W. Menn, V. V. Mikhailov, E. Mocchiutti, A. Monaco, N. Mori, N. Nikonov, G. Osteria, F. Palma, P. Papini, M. Pearce, P. Picozza, C. Pizzolotto, M. Ricci, S. B. Ricciarini, L. Rossetto, R. Sarkar, M. Simon, R. Sparvoli, P. Spillantini, Y. I. Stozhkov, A. Vacchi, E. Vannuccini, G. Vasilyev, S. A. Voronov, Y. T. Yurkin, J. Wu, G. Zampa, N. Zampa, V. G. Zverev
Apr 19, 2013·astro-ph.HE·PDF The satellite-borne experiment PAMELA has been used to make new measurements of cosmic ray H and He isotopes. The isotopic composition was measured between 100 and 600 MeV/n for hydrogen and between 100 and 900 MeV/n for helium isotopes over the 23rd solar minimum from July 2006 to December 2007. The energy spectrum of these components carries fundamental information regarding the propagation of cosmic rays in the galaxy which are competitive with those obtained from other secondary to primary measurements such as B/C.
M. Martucci, R. Munini, M. Boezio, V. Di Felice, O. Adriani, G. C. Barbarino, G. A. Bazilevskaya, R. Bellotti, M. Bongi, V. Bonvicini, S. Bottai, A. Bruno, F. Cafagna, D. Campana, P. Carlson, M. Casolino, G. Castellini, C. De Santis, A. M. Galper, A. V. Karelin, S. V. Koldashov, S. Koldobskiy, S. Y. Krutkov, A. N. Kvashnin, A. Leonov, V. Malakhov, L. Marcelli, N. Marcelli, A. G. Mayorov, W. Menn, M. Mergè, V. V. Mikhailov, E. Mocchiutti A. Monaco, N. Mori, G. Osteria, B. Panico, P. Papini, M. Pearce, P. Picozza, M. Ricci, S. B. Ricciarini, M. Simon, R. Sparvoli, P. Spillantini, Y. I. Stozhkov, A. Vacchi, E. Vannuccini, G. Vasilyev, S. A. Voronov, Y. T. Yurkin, G. Zampa, N. Zampa, M. S. Potgieter, J. L. Raath
Precise measurements of the time-dependent intensity of the low energy ($<50$ GeV) galactic cosmic rays are fundamental to test and improve the models which describe their propagation inside the heliosphere. Especially, data spanning different solar activity periods, i.e. from minimum to maximum, are needed to achieve comprehensive understanding of such physical phenomenon. The minimum phase between the 23$^{rd}$ and the 24$^{th}$ solar cycles was peculiarly long, extending up to the beginning of 2010 and followed by the maximum phase, reached during early 2014. In this paper, we present proton differential spectra measured from January 2010 to February 2014 by the PAMELA experiment. For the first time the galactic cosmic ray proton intensity was studied over a wide energy range (0.08-50 GeV) by a single apparatus from a minimum to a maximum period of solar activity. The large statistics allowed the time variation to be investigated on a nearly monthly basis. Data were compared and interpreted in the context of a state-of-the-art three-dimensional model describing the galactic cosmic rays propagation through the heliosphere.
A. Bruno, O. Adriani, G. C. Barbarino, G. A. Bazilevskaya, R. Bellotti, M. Boezio, E. A. Bogomolov, M. Bongi, V. Bonvicini, S. Bottai, U. Bravar, F. Cafagna, D. Campana, R. Carbone, P. Carlson, M. Casolino, G. Castellini, E. C. Christian, C. De Donato, G. A. de Nolfo, C. De Santis, N. De Simone, V. Di Felice, V. Formato, A. M. Galper, A. V. Karelin, S. V. Koldashov, S. Koldobskiy, S. Y. Krutkov, A. N. Kvashnin, M. Lee, A. Leonov, V. Malakhov, L. Marcelli, M. Martucci, A. G. Mayorov, W. Menn, M. Mergè, V. V. Mikhailov, E. Mocchiutti, A. Monaco, N. Mori, R. Munini, G. Osteria, F. Palma, B. Panico, P. Papini, M. Pearce, P. Picozza, M. Ricci, S. B. Ricciarini, J. M. Ryan, R. Sarkar, V. Scotti, M. Simon, R. Sparvoli, P. Spillantini, S. Stochaj, Y. I. Stozhkov, A. Vacchi, E. Vannuccini, G. I. Vasilyev, S. A. Voronov, Y. T. Yurkin, G. Zampa, N. Zampa, V. G. Zverev
The PAMELA satellite experiment is providing first direct measurements of Solar Energetic Particles (SEPs) with energies from about 80 MeV to several GeV in near-Earth space, bridging the low energy data by other space-based instruments and the Ground Level Enhancement (GLE) data by the worldwide network of neutron monitors. Its unique observational capabilities include the possibility of measuring the flux angular distribution and thus investigating possible anisotropies. This work reports the analysis methods developed to estimate the SEP energy spectra as a function of the particle pitch-angle with respect to the Interplanetary Magnetic Field (IMF) direction. The crucial ingredient is provided by an accurate simulation of the asymptotic exposition of the PAMELA apparatus, based on a realistic reconstruction of particle trajectories in the Earth's magnetosphere. As case study, the results for the May 17, 2012 event are presented.
O. Adriani, G. C. Barbarino, G. A. Bazilevskaya, R. Bellotti, A. Bianco, M. Boezio, E. A. Bogomolov, M. Bongi, V. Bonvicini, S. Bottai, A. Bruno, F. Cafagna, D. Campana, R. Carbone, P. Carlson, M. Casolino, G. Castellini, C. De Santis, M. P. De Pascale, C. De Donato, N. De Simone, V. Di Felice, V. Formato, A. M. Galper, A. V. Karelin, S. V. Koldashov, S. Koldobskiy, S. Yu. Krut'kov, A. N. Kvashnin, A. Leonov, V. Malakhov, L. Marcelli, M. Martucci, A. G. Mayorov, W. Menn, M. Merge`, V. V. Mikhailov, E. Mocchiutti, A. Monaco, N. Mori, R. Munini, G. Osteria, F. Palma, P. Papini, M. Pearce, P. Picozza, C. Pizzolotto, M. Ricci, S. B. Ricciarini, L. Rossetto, R. Sarkar, M. Simon, V. Scotti, R. Sparvoli, P. Spillantini, S. J. Stochaj, J. C. Stockton, Y. I. Stozhkov, A. Vacchi, E. Vannuccini, G. Vasilyev, S. A. Voronov, Y. T. Yurkin, G. Zampa, N. Zampa, V. G. Zverev
Jun 10, 2013·astro-ph.HE·PDF The PAMELA satellite borne experiment is designed to study cosmic rays with great accuracy in a wide energy range. One of PAMELA's main goal is the study of the antimatter component of cosmic rays. The experiment, housed on board the Russian satellite Resurs-DK1, was launched on June 15th 2006 and it is still taking data. In this work we present the measurement of galactic positron energy spectrum in the energy range between 500 MeV and few hundred GeV.
N. P. Topchiev, A. M. Galper, V. Bonvicini, O. Adriani, R. L. Aptekar, I. V. Arkhangelskaja, A. I. Arkhangelskiy, A. V. Bakaldin, L. Bergstrom, E. Berti, G. Bigongiari, S. G. Bobkov, M. Boezio, E. A. Bogomolov, L. Bonechi, M. Bongi, S. Bottai, G. Castellini, P. W. Cattaneo, P. Cumani, O. D. Dalkarov, G. L. Dedenko, C. De Donato, V. A. Dogiel, N. Finetti, D. Gascon, M. S. Gorbunov, Yu. V. Gusakov, B. I. Hnatyk, V. V. Kadilin, V. A. Kaplin, A. A. Kaplun, M. D. Kheymits, V. E. Korepanov, J. Larsson, A. A. Leonov, V. A. Loginov, F. Longo, P. Maestro, P. S. Marrocchesi, M. Martinez, A. L. Menshenin, V. V. Mikhailov, E. Mocchiutti, A. A. Moiseev, N. Mori, I. V. Moskalenko, P. Yu. Naumov, P. Papini, J. M. Paredes, M. Pearce, P. Picozza, A. Rappoldi, S. Ricciarini, M. F. Runtso, F. Ryde, O. V. Serdin, R. Sparvoli, P. Spillantini, Yu. I. Stozhkov, S. I. Suchkov, A. A. Taraskin, M. Tavani, A. Tiberio, E. M. Tyurin, M. V. Ulanov, A. Vacchi, E. Vannuccini, G. I. Vasilyev, J. E. Ward, Yu. T. Yurkin, N. Zampa, V. N. Zirakashvili, V. G. Zverev
Jul 22, 2015·astro-ph.IM·PDF The GAMMA-400 gamma-ray telescope with excellent angular and energy resolutions is designed to search for signatures of dark matter in the fluxes of gamma-ray emission and electrons + positrons. Precision investigations of gamma-ray emission from Galactic Center, Crab, Vela, Cygnus, Geminga, and other regions will be performed, as well as diffuse gamma-ray emission, along with measurements of high-energy electron + positron and nuclei fluxes. Furthermore, it will study gamma-ray bursts and gamma-ray emission from the Sun during periods of solar activity. The energy range of GAMMA-400 is expected to be from ~20 MeV up to TeV energies for gamma rays, up to 20 TeV for electrons + positrons, and up to 10E15 eV for cosmic-ray nuclei. For high-energy gamma rays with energy from 10 to 100 GeV, the GAMMA-400 angular resolution improves from 0.1° to ~0.01° and energy resolution from 3% to ~1%; the proton rejection factor is ~5x10E5. GAMMA-400 will be installed onboard the Russian space observatory.
A. Bruno, O. Adriani, G. C. Barbarino, G. A. Bazilevskaya, R. Bellotti, M. Boezio, E. A. Bogomolov, M. Bongi, V. Bonvicini, S. Bottai, F. Cafagna, D. Campana, P. Carlson, M. Casolino, G. Castellini, E. C. Christian, C. De Donato, G. A. de Nolfo, C. De Santis, N. De Simone, V. Di Felice, A. M. Galper, A. V. Karelin, S. V. Koldashov, S. Koldobskiy, S. Y. Krutkov, A. N. Kvashnin, A. Leonov, V. Malakhov, L. Marcelli, M. Martucci, A. G. Mayorov, W. Menn, M. Mergé, V. V. Mikhailov, E. Mocchiutti, A. Monaco, N. Mori, R. Munini, G. Osteria, F. Palma, B. Panico, P. Papini, M. Pearce, P. Picozza, M. Ricci, S. B. Ricciarini, J. M. Ryan, R. Sarkar, V. Scotti, M. Simon, R. Sparvoli, P. Spillantini, S. Stochaj, Y. I. Stozhkov, A. Vacchi, E. Vannuccini, G. I. Vasilyev, S. A. Voronov, Y. T. Yurkin, G. Zampa, N. Zampa
The PAMELA satellite experiment is providing comprehensive observations of the interplanetary and magnetospheric radiation in the near-Earth environment. Thanks to its identification capabilities and the semi-polar orbit, PAMELA is able to precisely measure the energetic spectra and the angular distributions of the different cosmic-ray populations over a wide latitude region, including geomagnetically trapped and albedo particles. Its observations comprise the solar energetic particle events between solar cycles 23 and 24, and the geomagnetic cutoff variations during magnetospheric storms. PAMELA's measurements are supported by an accurate analysis of particle trajectories in the Earth's magnetosphere based on a realistic geomagnetic field modeling, which allows the classification of particle populations of different origin and the investigation of the asymptotic directions of arrival.
T. Zharaspayev, S. Aleksandrin, A. M. Galper, S. Koldashov
Jan 16, 2017·astro-ph.HE·PDF Orbital experiment ARINA on the board of Russian satellite Resurs-DK1 launched in 2006 developed to study charged particle flux (electrons E ~ 3 - 30MeV , protons E ~ 30 - 100MeV ) in near-Earth space, especially high-energy electron precipitation from the inner radiation belt caused by various geophysical and solar-magnetospheric phenomena. Precipitated electrons under certain conditions (energy, LB-coordinate) drifts around the Earth and can be detected as fast increase in count rate of satellite spectrometer (so called bursts). High-energy electron bursts can be caused by local geophysical phenomena (like earthquakes or thunderstorms). Such bursts have distinct features in their measured energy-time distribution. These features contains information about initial location of electron precipitation. Several methods (linear, robust regression) were used previously to find longitudinal distance between region of precipitation and burst registration location on the board of satellite. In this report, the new ensemble method was developed, it uses the combining results from several methods in dependence of burst registration conditions. Numerical simulation of local particles precipitations based on well-known equations of relativistic particle movement in Earth magnetosphere. In experimental data analysis, the results from ARINA experiment for 10 years was used. Several results based on burst experimental data are shown. Ensemble method shows better results than any single method alone.
A. Bruno, O. Adriani, G. C. Barbarino, G. A. Bazilevskaya, R. Bellotti, M. Boezio, E. A. Bogomolov, M. Bongi, V. Bonvicini, S. Bottai, U. Bravar, F. Cafagna, D. Campana, R. Carbone, P. Carlson, M. Casolino, G. Castellini, E. C. Christian, C. De Donato, G. A. de Nolfo, C. De Santis, N. De Simone, V. Di Felice, V. Formato, A. M. Galper, A. V. Karelin, S. V. Koldashov, S. Koldobskiy, S. Y. Krutkov, A. N. Kvashnin, M. Lee, A. Leonov, V. Malakhov, L. Marcelli, M. Martucci, A. G. Mayorov, W. Menn, M. Mergé, V. V. Mikhailov, E. Mocchiutti, A. Monaco, N. Mori, R. Munini, G. Osteria, F. Palma, B. Panico, P. Papini, M. Pearce, P. Picozza, M. Ricci, S. B. Ricciarini, J. M. Ryan, R. Sarkar, V. Scotti, M. Simon, R. Sparvoli, P. Spillantini, S. Stochaj, Y. I. Stozhkov, A. Vacchi, E. Vannuccini, G. I. Vasilyev, S. A. Voronov, Y. T. Yurkin, G. Zampa, N. Zampa, V. G. Zverev
The PAMELA satellite-borne experiment is providing first direct measurements of Solar Energetic Particles (SEPs) with energies from $\sim$80 MeV to several GeV in near-Earth space. Its unique observational capabilities include the possibility of measuring the flux angular distribution and thus investigating possible anisotropies related to SEP events. This paper focuses on the analysis methods developed to estimate SEP energy spectra as a function of the particle pitch angle with respect to the Interplanetary Magnetic Field (IMF). The crucial ingredient is provided by an accurate simulation of the asymptotic exposition of the PAMELA apparatus, based on a realistic reconstruction of particle trajectories in the Earth's magnetosphere. As case study, the results of the calculation for the May 17, 2012 event are reported.
O. Adriani, G. C. Barbarino, G. A. Bazilevskaya, R. Bellotti, M. Boezio, E. A. Bogomolov, M. Bongi, V. Bonvicini, S. Bottai, A. Bruno, F. Cafagna, D. Campana, P. Carlson, M. Casolino, G. Castellini, C. De Donato, C. De Santis, N. De Simone, V. Di Felice, V. Formato, A. M. Galper, A. V. Karelin, S. V. Koldashov, S. Koldobskiy, S. Y. Krutkov, A. N. Kvashnin, A. Leonov, V. Malakhov, L. Marcelli, M. Martucci, A. G. Mayorov, W. Menn, M. Mergé, V. V. Mikhailov, E. Mocchiutti, A. Monaco, N. Mori, R. Munini, G. Osteria, F. Palma, B. Panico, P. Papini, M. Pearce, P. Picozza, M. Ricci, S. B. Ricciarini, R. Sarkar, V. Scotti, M. Simon, R. Sparvoli, P. Spillantini, Y. I. Stozhkov, A. Vacchi, E. Vannuccini, G. I. Vasilyev, S. A. Voronov, Y. T. Yurkin, G. Zampa, N. Zampa
Apr 23, 2015·astro-ph.HE·PDF We present a precise measurement of downward-going albedo proton fluxes for kinetic energy above $\sim$ 70 MeV performed by the PAMELA experiment at an altitude between 350 and 610 km. On the basis of a trajectory tracing simulation, the analyzed protons were classified into quasi-trapped, concentrating in the magnetic equatorial region, and un-trapped spreading over all latitudes, including both short-lived (precipitating) and long-lived (pseudo-trapped) components. In addition, features of the penumbra region around the geomagnetic cutoff were investigated in detail. PAMELA results significantly improve the characterization of the high energy albedo proton populations at low Earth orbits.
PAMELA Collaboration, O. Adriani, G. C. Barbarino, G. A. Bazilevskaya, R. Bellotti, M. Boezio, E. A. Bogomolov, M. Bongi, V. Bonvicini, S. Borisov, S. Bottai, A. Bruno, F. Cafagna, D. Campana, R. Carbone, P. Carlson, M. Casolino, G. Castellini, L. Consiglio, M. P. De Pascale, C. De Santis, N. De Simone, V. Di Felice, A. M. Galper, W. Gillard, L. Grishantseva, G. Jerse, A. V. Karelin, S. V. Koldashov, S. Y. Krutkov, A. N. Kvashnin, A. Leonov, V. Malakhov, V. Malvezzi, L. Marcelli, A. G. Mayorov, W. Menn, V. V. Mikhailov, E. Mocchiutti, A. Monaco, N. Mori, N. Nikonov, G. Osteria, F. Palma, P. Papini, M. Pearce, P. Picozza, C. Pizzolotto, M. Ricci, S. B. Ricciarini, L. Rossetto, R. Sarkar, M. Simon, R. Sparvoli, P. Spillantini, S. J. Stochaj, J. C. Stockton, Y. I. Stozhkov, A. Vacchi, E. Vannuccini, G. Vasilyev, S. A. Voronov, J. Wu, Y. T. Yurkin, G. Zampa, N. Zampa, V. G. Zverev
Mar 15, 2011·astro-ph.HE·PDF Precision measurements of the electron component in the cosmic radiation provide important information about the origin and propagation of cosmic rays in the Galaxy. Here we present new results regarding negatively charged electrons between 1 and 625 GeV performed by the satellite-borne experiment PAMELA. This is the first time that cosmic-ray electrons have been identified above 50 GeV. The electron spectrum can be described with a single power law energy dependence with spectral index -3.18 +- 0.05 above the energy region influenced by the solar wind (> 30 GeV). No significant spectral features are observed and the data can be interpreted in terms of conventional diffusive propagation models. However, the data are also consistent with models including new cosmic-ray sources that could explain the rise in the positron fraction.
A. Bruno, G. A. Bazilevskaya, M. Boezio, E. R. Christian, G. A. de Nolfo, M. Martucci, M. Merge', V. V. Mikhailov, R. Munini, I. G. Richardson, J. M. Ryan, S. Stochaj, O. Adriani, G. C. Barbarino, R. Bellotti, E. A. Bogomolov, M. Bongi, V. Bonvicini, S. Bottai, F. Cafagna, D. Campana, P. Carlson, M. Casolino, G. Castellini, C. De Santis, V. Di Felice, A. M. Galper, A. V. Karelin, S. V. Koldashov, S. Koldobskiy, S. Y. Krutkov, A. N. Kvashnin, A. Leonov, V. Malakhov, L. Marcelli, A. G. Mayorov, W. Menn, E. Mocchiutti, A. Monaco, N. Mori, G. Osteria, B. Panico, P. Papini, M. Pearce, P. Picozza, M. Ricci, S. B. Ricciarini, M. Simon, R. Sparvoli, P. Spillantini, Y. I. Stozhkov, A. Vacchi, E. Vannuccini, G. I. Vasilyev, S. A. Voronov, Y. T. Yurkin, G. Zampa, N. Zampa
Jul 26, 2018·astro-ph.SR·PDF Despite the significant progress achieved in recent years, the physical mechanisms underlying the origin of solar energetic particles (SEPs) are still a matter of debate. The complex nature of both particle acceleration and transport poses challenges to developing a universal picture of SEP events that encompasses both the low-energy (from tens of keV to a few hundreds of MeV) observations made by space-based instruments and the GeV particles detected by the worldwide network of neutron monitors in ground-level enhancements (GLEs). The high-precision data collected by the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) satellite experiment offer a unique opportunity to study the SEP fluxes between $\sim$80 MeV and a few GeV, significantly improving the characterization of the most energetic events. In particular, PAMELA can measure for the first time with good accuracy the spectral features at moderate and high energies, providing important constraints for current SEP models. In addition, the PAMELA observations allow the relationship between low and high-energy particles to be investigated, enabling a clearer view of the SEP origin. No qualitative distinction between the spectral shapes of GLE, sub-GLE and non-GLE events is observed, suggesting that GLEs are not a separate class, but are the subset of a continuous distribution of SEP events that are more intense at high energies. While the spectral forms found are to be consistent with diffusive shock acceleration theory, which predicts spectral rollovers at high energies that are attributed to particles escaping the shock region during acceleration, further work is required to explore the relative influences of acceleration and transport processes on SEP spectra.
O. Adriani, G. C. Barbarino, G. A. Bazilevskaya, R. Bellotti, M. Boezio, E. A. Bogomolov, M. Bongi, V. Bonvicini, S. Bottai, A. Bruno, F. Cafagna, D. Campana, P. Carlson, M. Casolino, G. Castellini, C. De Donato, C. De Santis, N. De Simone, V. Di Felice, V. Formato, A. M. Galper, U. Giaccari, A. V. Karelin, S. V. Koldashov, S. Koldobskiy, S. Y. Krutkov, A. N. Kvashnin, A. Leonov, V. Malakhov, L. Marcelli, M. Martucci, A. G. Mayorov, W. Menn, M. Mergè, V. V. Mikhailov, E. Mocchiutti, A. Monaco, N. Mori, R. Munini, G. Osteria, F. Palma, B. Panico, P. Papini, M. Pearce, P. Picozza, M. Ricci, S. B. Ricciarini, R. Sarkar, V. Scotti, M. Simon, R. Sparvoli, P. Spillantini, Y. I. Stozhkov, A. Vacchi, E. Vannuccini, G. I. Vasilyev, S. A. Voronov, Y. T. Yurkin, G. Zampa, N. Zampa
Sep 21, 2015·astro-ph.HE·PDF The PAMELA detector was launched on board of the Russian Resurs-DK1 satellite on June 15, 2006. Data collected during the first four years have been used to search for large-scale anisotropies in the arrival directions of cosmic-ray positrons. The PAMELA experiment allows for a full sky investigation, with sensitivity to global anisotropies in any angular window of the celestial sphere. Data samples of positrons in the rigidity range 10 GV $\leq$ R $\leq$ 200 GV were analyzed. This article discusses the method and the results of the search for possible local sources through analysis of anisotropy in positron data compared to the proton background. The resulting distributions of arrival directions are found to be isotropic. Starting from the angular power spectrum, a dipole anisotropy upper limit δ= 0.166 at 95% C.L. is determined. Additional search is carried out around the Sun. No evidence of an excess correlated with that direction was found.