E-viri
Recenzirano
Odprti dostop
-
Giuliani, A; Cardillo, M; Tavani, M; Fukui, Y; Yoshiike, S; Torii, K; Dubner, G; Castelletti, G; Barbiellini, G; Bulgarelli, A; Caraveo, P; Costa, E; Cattaneo, P. W; Chen, A; Contessi, T; Monte, E. Del; Donnarumma, I; Evangelista, Y; Feroci, M; Gianotti, F; Lazzarotto, F; Lucarelli, F; Longo, F; Marisaldi, M; Mereghetti, S; Pacciani, L; Pellizzoni, A; Piano, G; Picozza, P; Pittori, C; Pucella, G; Rapisarda, M; Rappoldi, A; Sabatini, S; Soffitta, P; Striani, E; Trifoglio, M; Trois, A; Vercellone, S; Verrecchia, F; Vittorini, V; Colafrancesco, S; Giommi, P; Bignami, G
Astrophysical journal. Letters, 12/2011, Letnik: 742, Številka: 2Journal Article
We present the AGILE gamma-ray observations in the energy range 50 MeV-10 GeV of the supernova remnant (SNR) W44, one of the most interesting systems for studying cosmic-ray production. W44 is an intermediate-age SNR (~2,000 years) and its ejecta expand in a dense medium as shown by a prominent radio shell, nearby molecular clouds, and bright S II emitting regions. We extend our gamma-ray analysis to energies substantially lower than previous measurements which could not conclusively establish the nature of the radiation. We find that gamma-ray emission matches remarkably well both the position and shape of the inner SNR shocked plasma. Furthermore, the gamma-ray spectrum shows a prominent peak near 1 GeV with a clear decrement at energies below a few hundreds of MeV as expected from neutral pion decay. Here we demonstrate that (1) hadron-dominated models are consistent with all W44 multiwavelength constraints derived from radio, optical, X-ray, and gamma-ray observations; (2) ad hoc lepton-dominated models fail to explain simultaneously the well-constrained gamma-ray and radio spectra, and require a circumstellar density much larger than the value derived from observations; and (3) the hadron energy spectrum is well described by a power law (with index s = 3.0 ? 0.1) and a low-energy cut-off at Ec = 6 ? 1 GeV. Direct evidence for pion emission is then established in an SNR for the first time.
Avtor
Vnos na polico
Trajna povezava
- URL:
Faktor vpliva
Dostop do baze podatkov JCR je dovoljen samo uporabnikom iz Slovenije. Vaš trenutni IP-naslov ni na seznamu dovoljenih za dostop, zato je potrebna avtentikacija z ustreznim računom AAI.
Leto | Faktor vpliva | Izdaja | Kategorija | Razvrstitev | ||||
---|---|---|---|---|---|---|---|---|
JCR | SNIP | JCR | SNIP | JCR | SNIP | JCR | SNIP |
Baze podatkov, v katerih je revija indeksirana
Ime baze podatkov | Področje | Leto |
---|
Povezave do osebnih bibliografij avtorjev | Povezave do podatkov o raziskovalcih v sistemu SICRIS |
---|
Vir: Osebne bibliografije
in: SICRIS
To gradivo vam je dostopno v celotnem besedilu. Če kljub temu želite naročiti gradivo, kliknite gumb Nadaljuj.