title: A cocoon of freshly accelerated cosmic rays detected by Fermi in the Cygnus superbubble.
abstract: The origin of Galactic cosmic rays is a century-long puzzle. Indirect evidence points to their acceleration by supernova shockwaves, but we know little of their escape from the shock and their evolution through the turbulent medium surrounding massive stars. Gamma rays can probe their spreading through the ambient gas and radiation fields. The Fermi Large Area Telescope (LAT) has observed the star-forming region of Cygnus X. The 1- to 100-gigaelectronvolt images reveal a 50-parsec-wide cocoon of freshly accelerated cosmic rays that flood the cavities carved by the stellar winds and ionization fronts from young stellar clusters. It provides an example to study the youth of cosmic rays in a superbubble environment before they merge into the older Galactic population.
authors: W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305, USA.
authors: M
authors: M
authors: Ackermann
authors: M
authors: M
authors: Ajello
authors: A
authors: A
authors: Allafort
authors: L
authors: L
authors: Baldini
authors: J
authors: J
authors: Ballet
authors: G
authors: G
authors: Barbiellini
authors: D
authors: D
authors: Bastieri
authors: A
authors: A
authors: Belfiore
authors: R
authors: R
authors: Bellazzini
authors: B
authors: B
authors: Berenji
authors: R D
authors: RD
authors: Blandford
authors: E D
authors: ED
authors: Bloom
authors: E
authors: E
authors: Bonamente
authors: A W
authors: AW
authors: Borgland
authors: E
authors: E
authors: Bottacini
authors: M
authors: M
authors: Brigida
authors: P
authors: P
authors: Bruel
authors: R
authors: R
authors: Buehler
authors: S
authors: S
authors: Buson
authors: G A
authors: GA
authors: Caliandro
authors: R A
authors: RA
authors: Cameron
authors: P A
authors: PA
authors: Caraveo
authors: J M
authors: JM
authors: Casandjian
authors: C
authors: C
authors: Cecchi
authors: A
authors: A
authors: Chekhtman
authors: C C
authors: CC
authors: Cheung
authors: J
authors: J
authors: Chiang
authors: S
authors: S
authors: Ciprini
authors: R
authors: R
authors: Claus
authors: J
authors: J
authors: Cohen-Tanugi
authors: A
authors: A
authors: de Angelis
authors: F
authors: F
authors: de Palma
authors: C D
authors: CD
authors: Dermer
authors: E
authors: E
authors: do Couto E Silva
authors: P S
authors: PS
authors: Drell
authors: D
authors: D
authors: Dumora
authors: C
authors: C
authors: Favuzzi
authors: S J
authors: SJ
authors: Fegan
authors: W B
authors: WB
authors: Focke
authors: P
authors: P
authors: Fortin
authors: Y
authors: Y
authors: Fukazawa
authors: P
authors: P
authors: Fusco
authors: F
authors: F
authors: Gargano
authors: S
authors: S
authors: Germani
authors: N
authors: N
authors: Giglietto
authors: F
authors: F
authors: Giordano
authors: M
authors: M
authors: Giroletti
authors: T
authors: T
authors: Glanzman
authors: G
authors: G
authors: Godfrey
authors: I A
authors: IA
authors: Grenier
authors: L
authors: L
authors: Guillemot
authors: S
authors: S
authors: Guiriec
authors: D
authors: D
authors: Hadasch
authors: Y
authors: Y
authors: Hanabata
authors: A K
authors: AK
authors: Harding
authors: M
authors: M
authors: Hayashida
authors: K
authors: K
authors: Hayashi
authors: E
authors: E
authors: Hays
authors: G
authors: G
authors: Jóhannesson
authors: A S
authors: AS
authors: Johnson
authors: T
authors: T
authors: Kamae
authors: H
authors: H
authors: Katagiri
authors: J
authors: J
authors: Kataoka
authors: M
authors: M
authors: Kerr
authors: J
authors: J
authors: Knödlseder
authors: M
authors: M
authors: Kuss
authors: J
authors: J
authors: Lande
authors: L
authors: L
authors: Latronico
authors: S-H
authors: SH
authors: Lee
authors: F
authors: F
authors: Longo
authors: F
authors: F
authors: Loparco
authors: B
authors: B
authors: Lott
authors: M N
authors: MN
authors: Lovellette
authors: P
authors: P
authors: Lubrano
authors: P
authors: P
authors: Martin
authors: M N
authors: MN
authors: Mazziotta
authors: J E
authors: JE
authors: McEnery
authors: J
authors: J
authors: Mehault
authors: P F
authors: PF
authors: Michelson
authors: W
authors: W
authors: Mitthumsiri
authors: T
authors: T
authors: Mizuno
authors: C
authors: C
authors: Monte
authors: M E
authors: ME
authors: Monzani
authors: A
authors: A
authors: Morselli
authors: I V
authors: IV
authors: Moskalenko
authors: S
authors: S
authors: Murgia
authors: M
authors: M
authors: Naumann-Godo
authors: P L
authors: PL
authors: Nolan
authors: J P
authors: JP
authors: Norris
authors: E
authors: E
authors: Nuss
authors: T
authors: T
authors: Ohsugi
authors: A
authors: A
authors: Okumura
authors: E
authors: E
authors: Orlando
authors: J F
authors: JF
authors: Ormes
authors: M
authors: M
authors: Ozaki
authors: D
authors: D
authors: Paneque
authors: D
authors: D
authors: Parent
authors: M
authors: M
authors: Pesce-Rollins
authors: M
authors: M
authors: Pierbattista
authors: F
authors: F
authors: Piron
authors: M
authors: M
authors: Pohl
authors: D
authors: D
authors: Prokhorov
authors: S
authors: S
authors: Rainò
authors: R
authors: R
authors: Rando
authors: M
authors: M
authors: Razzano
authors: T
authors: T
authors: Reposeur
authors: S
authors: S
authors: Ritz
authors: P M Saz
authors: PM
authors: Parkinson
authors: C
authors: C
authors: Sgrò
authors: E J
authors: EJ
authors: Siskind
authors: P D
authors: PD
authors: Smith
authors: P
authors: P
authors: Spinelli
authors: A W
authors: AW
authors: Strong
authors: H
authors: H
authors: Takahashi
authors: T
authors: T
authors: Tanaka
authors: J G
authors: JG
authors: Thayer
authors: J B
authors: JB
authors: Thayer
authors: D J
authors: DJ
authors: Thompson
authors: L
authors: L
authors: Tibaldo
authors: D F
authors: DF
authors: Torres
authors: G
authors: G
authors: Tosti
authors: A
authors: A
authors: Tramacere
authors: E
authors: E
authors: Troja
authors: Y
authors: Y
authors: Uchiyama
authors: J
authors: J
authors: Vandenbroucke
authors: V
authors: V
authors: Vasileiou
authors: G
authors: G
authors: Vianello
authors: V
authors: V
authors: Vitale
authors: A P
authors: AP
authors: Waite
authors: P
authors: P
authors: Wang
authors: B L
authors: BL
authors: Winer
authors: K S
authors: KS
authors: Wood
authors: Z
authors: Z
authors: Yang
authors: S
authors: S
authors: Zimmer
authors: S
authors: S
authors: Bontemps