A low level of extragalactic background light as revealed by big gamma-rays from blazars

Aharonian, F.; Akhperjanian, A.G.; Bazer-Bachi, A.R.; Beilicke, M.; Benbow, W.; Berge, D.; Bernlöhr, K.; Boisson, C.; Bolz, O.; Borrel, V.; Braun, I.; Breitling, F.; Brown, A.M.; Chadwick, P.M.; Chounet, L.M.; Cornils, R.; Costamante, L.; Degrange, B.; Dickinson, H.J.; Djannati-Ataï, A.; Drury, L.O.; Dubus, G.; Emmanoulopoulos, D.; Espigat, P.; Feinstein, F.; Fontaine, G.; Fuchs, Y.; Funk, S.; Gallant, Y.A.; Giebels, B.; Gillessen, S.; Glicenstein, J.F.; Goret, P.; Hadjichristidis, C.; Hauser, D.; Hauser, M.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J.A.; Hofmann, W.; Holleran, M.; Horns, D.; Jacholkowska, A.; Jager de, O.C.; Khélifi, B.; Klages, S.; Komin, N.; Konopelko, A.; Latham, I.J.; Le Gallou, R.; Lemière, A.; Lemoine-Goumard, M.; Leroy, N.; Lohse, T.; Martin, J.M.; Martineau-Huynh, O.; Marcowith, A.; Masterson, C.; McComb, T.J.L.; Naurois de, M.; Nolan, S.J.; Noutsos, A.; Orford, K.J.; Osborne, J.L.; Ouchrif, M.; Panter, M.; Pelletier, G.; Pita, S.; Pühlhofer, G.; Punch, M.; Raubenheimer, B.C.; Raue, M.; Raux, J.; Rayner, S.M.; Reimer, A.; Reimer, O.; Ripken, J.; Rob, L.; Rolland, L.; Rowell, G.; Sahakian, V.; Saugé, L.; Schlenker, S.; Schlickeiser, R.; Schuster, C.; Schwanke, U.; Siewert, M.; Sol, H.; Spangler, D.; Steenkamp, R.; Stegmann, C.; Tavernet, J.P.; Terrier, R.; Théoret, C.G.; Tluczykont, M.; Eldik van, C.; Vasileiadis, G.; Venter, C.; Vincent, P.; Völk, HJ.; Wagner, S.J.

doi:10.1038/nature04680

A low level of extragalactic background light as revealed by big gamma-rays from blazars

Aharonian, F.; Akhperjanian, A.G.; Bazer-Bachi, A.R.; Beilicke, M.; Benbow, W.; Berge, D.; Bernlöhr, K.; Boisson, C.; Bolz, O.; Borrel, V.; Braun, I.; Breitling, F.; Brown, A.M.; Chadwick, P.M.; Chounet, L.M.; Cornils, R.; Costamante, L.; Degrange, B.; Dickinson, H.J.; Djannati-Ataï, A.; Drury, L.O.; Dubus, G.; Emmanoulopoulos, D.; Espigat, P.; Feinstein, F.; Fontaine, G.; Fuchs, Y.; Funk, S.; Gallant, Y.A.; Giebels, B.; Gillessen, S.; Glicenstein, J.F.; Goret, P.; Hadjichristidis, C.; Hauser, D.; Hauser, M.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J.A.; Hofmann, W.; Holleran, M.; Horns, D.; Jacholkowska, A.; Jager de, O.C.; Khélifi, B.; Klages, S.; Komin, N.; Konopelko, A.; Latham, I.J.; Le Gallou, R.; Lemière, A.; Lemoine-Goumard, M.; Leroy, N.; Lohse, T.; Martin, J.M.; Martineau-Huynh, O.; Marcowith, A.; Masterson, C.; McComb, T.J.L.; Naurois de, M.; Nolan, S.J.; Noutsos, A.; Orford, K.J.; Osborne, J.L.; Ouchrif, M.; Panter, M.; Pelletier, G.; Pita, S.; Pühlhofer, G.; Punch...

Authors

F. Aharonian

A.G. Akhperjanian

A.R. Bazer-Bachi

M. Beilicke

W. Benbow

D. Berge

K. Bernlöhr

C. Boisson

O. Bolz

V. Borrel

I. Braun

F. Breitling

A.M. Brown

Professor Paula Chadwick p.m.chadwick@durham.ac.uk
Head Of Department

L.M. Chounet

R. Cornils

L. Costamante

B. Degrange

H.J. Dickinson

A. Djannati-Ataï

L.O. Drury

G. Dubus

D. Emmanoulopoulos

P. Espigat

F. Feinstein

G. Fontaine

Y. Fuchs

S. Funk

Y.A. Gallant

B. Giebels

S. Gillessen

J.F. Glicenstein

P. Goret

C. Hadjichristidis

D. Hauser

M. Hauser

G. Heinzelmann

G. Henri

G. Hermann

J.A. Hinton

W. Hofmann

M. Holleran

D. Horns

A. Jacholkowska

O.C. Jager de

B. Khélifi

S. Klages

N. Komin

A. Konopelko

I.J. Latham

R. Le Gallou

A. Lemière

M. Lemoine-Goumard

N. Leroy

T. Lohse

J.M. Martin

O. Martineau-Huynh

A. Marcowith

C. Masterson

T.J.L. McComb

M. Naurois de

Professor Sam Nolan s.j.nolan@durham.ac.uk
Director Of Dcad

A. Noutsos

K.J. Orford

Dr John Osborne j.l.osborne@durham.ac.uk
Academic Visitor

M. Ouchrif

M. Panter

G. Pelletier

S. Pita

G. Pühlhofer

M. Punch

B.C. Raubenheimer

M. Raue

J. Raux

S.M. Rayner

A. Reimer

O. Reimer

J. Ripken

L. Rob

L. Rolland

G. Rowell

V. Sahakian

L. Saugé

S. Schlenker

R. Schlickeiser

C. Schuster

U. Schwanke

M. Siewert

H. Sol

D. Spangler

R. Steenkamp

C. Stegmann

J.P. Tavernet

R. Terrier

C.G. Théoret

M. Tluczykont

C. Eldik van

G. Vasileiadis

C. Venter

P. Vincent

HJ. Völk

S.J. Wagner

Abstract

The diffuse extragalactic background light consists of the sum of the starlight emitted by galaxies through the history of the Universe, and it could also have an important contribution from the 'first stars', which may have formed before galaxy formation began. Direct measurements are difficult and not yet conclusive, owing to the large uncertainties caused by the bright foreground emission associated with zodiacal light1. An alternative approach2, 3, 4, 5 is to study the absorption features imprinted on the -ray spectra of distant extragalactic objects by interactions of those photons with the background light photons6. Here we report the discovery of -ray emission from the blazars7 H 2356 - 309 and 1ES 1101 - 232, at redshifts z = 0.165 and z = 0.186, respectively. Their unexpectedly hard spectra provide an upper limit on the background light at optical/near-infrared wavelengths that appears to be very close to the lower limit given by the integrated light of resolved galaxies8. The background flux at these wavelengths accordingly seems to be strongly dominated by the direct starlight from galaxies, thus excluding a large contribution from other sources—in particular from the first stars formed9. This result also indicates that intergalactic space is more transparent to -rays than previously thought.

Citation

Aharonian, F., Akhperjanian, A., Bazer-Bachi, A., Beilicke, M., Benbow, W., Berge, D., …Wagner, S. (2006). A low level of extragalactic background light as revealed by big gamma-rays from blazars. Nature, 440(7087), 1018-1021. https://doi.org/10.1038/nature04680

Journal Article Type	Article
Acceptance Date	Feb 22, 2006
Publication Date	Apr 20, 2006
Deposit Date	May 8, 2008
Publicly Available Date	May 8, 2008
Journal	Nature
Print ISSN	0028-0836
Electronic ISSN	1476-4687
Publisher	Nature Research
Peer Reviewed	Peer Reviewed
Volume	440
Issue	7087
Pages	1018-1021
DOI	https://doi.org/10.1038/nature04680
Keywords	High-energy photons, MKN 501, Telescope, Space, Absorption, H1426+428, Spectrum, Universe, Stars, 2Mass.