title: The imprint of the extragalactic background light in the gamma-ray spectra of blazars.
abstract: The light emitted by stars and accreting compact objects through the history of the universe is encoded in the intensity of the extragalactic background light (EBL). Knowledge of the EBL is important to understand the nature of star formation and galaxy evolution, but direct measurements of the EBL are limited by galactic and other foreground emissions. Here, we report an absorption feature seen in the combined spectra of a sample of gamma-ray blazars out to a redshift of z ∼ 1.6. This feature is caused by attenuation of gamma rays by the EBL at optical to ultraviolet frequencies and allowed us to measure the EBL flux density in this frequency band.
authors.affiliation: Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Ackermann
authors.forename: M
authors.initials: M
authors.lastname: Ajello
authors.forename: A
authors.initials: A
authors.lastname: Allafort
authors.forename: P
authors.initials: P
authors.lastname: Schady
authors.forename: L
authors.initials: L
authors.lastname: Baldini
authors.forename: J
authors.initials: J
authors.lastname: Ballet
authors.forename: G
authors.initials: G
authors.lastname: Barbiellini
authors.forename: D
authors.initials: D
authors.lastname: Bastieri
authors.forename: R
authors.initials: R
authors.lastname: Bellazzini
authors.forename: R D
authors.initials: RD
authors.lastname: Blandford
authors.forename: E D
authors.initials: ED
authors.lastname: Bloom
authors.forename: A W
authors.initials: AW
authors.lastname: Borgland
authors.forename: E
authors.initials: E
authors.lastname: Bottacini
authors.forename: A
authors.initials: A
authors.lastname: Bouvier
authors.forename: J
authors.initials: J
authors.lastname: Bregeon
authors.forename: M
authors.initials: M
authors.lastname: Brigida
authors.forename: P
authors.initials: P
authors.lastname: Bruel
authors.forename: R
authors.initials: R
authors.lastname: Buehler
authors.forename: S
authors.initials: S
authors.lastname: Buson
authors.forename: G A
authors.initials: GA
authors.lastname: Caliandro
authors.forename: R A
authors.initials: RA
authors.lastname: Cameron
authors.forename: P A
authors.initials: PA
authors.lastname: Caraveo
authors.forename: E
authors.initials: E
authors.lastname: Cavazzuti
authors.forename: C
authors.initials: C
authors.lastname: Cecchi
authors.forename: E
authors.initials: E
authors.lastname: Charles
authors.forename: R C G
authors.initials: RC
authors.lastname: Chaves
authors.forename: A
authors.initials: A
authors.lastname: Chekhtman
authors.forename: C C
authors.initials: CC
authors.lastname: Cheung
authors.forename: J
authors.initials: J
authors.lastname: Chiang
authors.forename: G
authors.initials: G
authors.lastname: Chiaro
authors.forename: S
authors.initials: S
authors.lastname: Ciprini
authors.forename: R
authors.initials: R
authors.lastname: Claus
authors.forename: J
authors.initials: J
authors.lastname: Cohen-Tanugi
authors.forename: J
authors.initials: J
authors.lastname: Conrad
authors.forename: S
authors.initials: S
authors.lastname: Cutini
authors.forename: F
authors.initials: F
authors.lastname: D'Ammando
authors.forename: F
authors.initials: F
authors.lastname: de Palma
authors.forename: C D
authors.initials: CD
authors.lastname: Dermer
authors.forename: S W
authors.initials: SW
authors.lastname: Digel
authors.forename: E
authors.initials: E
authors.lastname: do Couto e Silva
authors.forename: A
authors.initials: A
authors.lastname: Domínguez
authors.forename: P S
authors.initials: PS
authors.lastname: Drell
authors.forename: A
authors.initials: A
authors.lastname: Drlica-Wagner
authors.forename: C
authors.initials: C
authors.lastname: Favuzzi
authors.forename: S J
authors.initials: SJ
authors.lastname: Fegan
authors.forename: W B
authors.initials: WB
authors.lastname: Focke
authors.forename: A
authors.initials: A
authors.lastname: Franckowiak
authors.forename: Y
authors.initials: Y
authors.lastname: Fukazawa
authors.forename: S
authors.initials: S
authors.lastname: Funk
authors.forename: P
authors.initials: P
authors.lastname: Fusco
authors.forename: F
authors.initials: F
authors.lastname: Gargano
authors.forename: D
authors.initials: D
authors.lastname: Gasparrini
authors.forename: N
authors.initials: N
authors.lastname: Gehrels
authors.forename: S
authors.initials: S
authors.lastname: Germani
authors.forename: N
authors.initials: N
authors.lastname: Giglietto
authors.forename: F
authors.initials: F
authors.lastname: Giordano
authors.forename: M
authors.initials: M
authors.lastname: Giroletti
authors.forename: T
authors.initials: T
authors.lastname: Glanzman
authors.forename: G
authors.initials: G
authors.lastname: Godfrey
authors.forename: I A
authors.initials: IA
authors.lastname: Grenier
authors.forename: J E
authors.initials: JE
authors.lastname: Grove
authors.forename: S
authors.initials: S
authors.lastname: Guiriec
authors.forename: M
authors.initials: M
authors.lastname: Gustafsson
authors.forename: D
authors.initials: D
authors.lastname: Hadasch
authors.forename: M
authors.initials: M
authors.lastname: Hayashida
authors.forename: E
authors.initials: E
authors.lastname: Hays
authors.forename: M S
authors.initials: MS
authors.lastname: Jackson
authors.forename: T
authors.initials: T
authors.lastname: Jogler
authors.forename: J
authors.initials: J
authors.lastname: Kataoka
authors.forename: J
authors.initials: J
authors.lastname: Knödlseder
authors.forename: M
authors.initials: M
authors.lastname: Kuss
authors.forename: J
authors.initials: J
authors.lastname: Lande
authors.forename: S
authors.initials: S
authors.lastname: Larsson
authors.forename: L
authors.initials: L
authors.lastname: Latronico
authors.forename: F
authors.initials: F
authors.lastname: Longo
authors.forename: F
authors.initials: F
authors.lastname: Loparco
authors.forename: M N
authors.initials: MN
authors.lastname: Lovellette
authors.forename: P
authors.initials: P
authors.lastname: Lubrano
authors.forename: M N
authors.initials: MN
authors.lastname: Mazziotta
authors.forename: J E
authors.initials: JE
authors.lastname: McEnery
authors.forename: J
authors.initials: J
authors.lastname: Mehault
authors.forename: P F
authors.initials: PF
authors.lastname: Michelson
authors.forename: T
authors.initials: T
authors.lastname: Mizuno
authors.forename: C
authors.initials: C
authors.lastname: Monte
authors.forename: M E
authors.initials: ME
authors.lastname: Monzani
authors.forename: A
authors.initials: A
authors.lastname: Morselli
authors.forename: I V
authors.initials: IV
authors.lastname: Moskalenko
authors.forename: S
authors.initials: S
authors.lastname: Murgia
authors.forename: A
authors.initials: A
authors.lastname: Tramacere
authors.forename: E
authors.initials: E
authors.lastname: Nuss
authors.forename: J
authors.initials: J
authors.lastname: Greiner
authors.forename: M
authors.initials: M
authors.lastname: Ohno
authors.forename: T
authors.initials: T
authors.lastname: Ohsugi
authors.forename: N
authors.initials: N
authors.lastname: Omodei
authors.forename: M
authors.initials: M
authors.lastname: Orienti
authors.forename: E
authors.initials: E
authors.lastname: Orlando
authors.forename: J F
authors.initials: JF
authors.lastname: Ormes
authors.forename: D
authors.initials: D
authors.lastname: Paneque
authors.forename: J S
authors.initials: JS
authors.lastname: Perkins
authors.forename: M
authors.initials: M
authors.lastname: Pesce-Rollins
authors.forename: F
authors.initials: F
authors.lastname: Piron
authors.forename: G
authors.initials: G
authors.lastname: Pivato
authors.forename: T A
authors.initials: TA
authors.lastname: Porter
authors.forename: S
authors.initials: S
authors.lastname: Rainò
authors.forename: R
authors.initials: R
authors.lastname: Rando
authors.forename: M
authors.initials: M
authors.lastname: Razzano
authors.forename: S
authors.initials: S
authors.lastname: Razzaque
authors.forename: A
authors.initials: A
authors.lastname: Reimer
authors.forename: O
authors.initials: O
authors.lastname: Reimer
authors.forename: L C
authors.initials: LC
authors.lastname: Reyes
authors.forename: S
authors.initials: S
authors.lastname: Ritz
authors.forename: A
authors.initials: A
authors.lastname: Rau
authors.forename: C
authors.initials: C
authors.lastname: Romoli
authors.forename: M
authors.initials: M
authors.lastname: Roth
authors.forename: M
authors.initials: M
authors.lastname: Sánchez-Conde
authors.forename: D A
authors.initials: DA
authors.lastname: Sanchez
authors.forename: J D
authors.initials: JD
authors.lastname: Scargle
authors.forename: C
authors.initials: C
authors.lastname: Sgrò
authors.forename: E J
authors.initials: EJ
authors.lastname: Siskind
authors.forename: G
authors.initials: G
authors.lastname: Spandre
authors.forename: P
authors.initials: P
authors.lastname: Spinelli
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Stawarz
authors.forename: D J
authors.initials: DJ
authors.lastname: Suson
authors.forename: H
authors.initials: H
authors.lastname: Takahashi
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
authors.forename: J G
authors.initials: JG
authors.lastname: Thayer
authors.forename: D J
authors.initials: DJ
authors.lastname: Thompson
authors.forename: L
authors.initials: L
authors.lastname: Tibaldo
authors.forename: M
authors.initials: M
authors.lastname: Tinivella
authors.forename: D F
authors.initials: DF
authors.lastname: Torres
authors.forename: G
authors.initials: G
authors.lastname: Tosti
authors.forename: E
authors.initials: E
authors.lastname: Troja
authors.forename: T L
authors.initials: TL
authors.lastname: Usher
authors.forename: J
authors.initials: J
authors.lastname: Vandenbroucke
authors.forename: V
authors.initials: V
authors.lastname: Vasileiou
authors.forename: G
authors.initials: G
authors.lastname: Vianello
authors.forename: V
authors.initials: V
authors.lastname: Vitale
authors.forename: A P
authors.initials: AP
authors.lastname: Waite
authors.forename: B L
authors.initials: BL
authors.lastname: Winer
authors.forename: K S
authors.initials: KS
authors.lastname: Wood
authors.forename: M
authors.initials: M
authors.lastname: Wood