Flux upper limits for 47 AGN observed with H.E.S.S. in 2004-2011

Collaboration, H.E.S.S.; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A.G.; Angüner, E.; Anton, G.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Bernlöhr, K.; Birsin, E.; Bissaldi, E.; Biteau, J.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P.M.; Chalme-Calvet, R.; Chaves, R.C.G.; Cheesebrough, A.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Cui, Y.; Dalton, M.; Daniel, M.K.; Davids, I.D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H.J.; Djannati-Ataï, A.; Domainko, W.; Drury, L.O’C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M.V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gajdus, M.; Gallant, Y.A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J.F.; Grondin, M.-H.; Grudzińska, M.; Häffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J.A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung, I.; Kastendieck, M.A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Kolitzus, D.; Komin, Nu; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P.P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T.J.L.; Méhault, J.; Meintjes, P.J.; Menzler, U.; Meyer, M.; Moderski, R.; Mohamed, M.; Moulin, E.; Murach, T.; Naumann, C.L.; de Naurois, M.; Niemiec, J.; Nolan, S.J.; Oakes, L.; Ohm, S.; de Oña Wilhelmi, E.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R.D.; Paz Arribas, M.; Pekeur, N.W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Rob, L.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C.B.; Sahakian, V.; Sanchez, D.A.; Santangelo, A.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spengler, G.; Spies, F.; Stawarz, Ł; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Tavernier, T.; Taylor, A.M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Völk, H.J.; Volpe, F.; Vorster, M.; Vuillaume, T.; Wagner, S.J.; Wagner, P.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Zabalza, V.; Zacharias, M.; Zajczyk, A.; Zdziarski, A.A.; Zech, A.; Zechlin, H.-S.

doi:10.1051/0004-6361/201322897

Flux upper limits for 47 AGN observed with H.E.S.S. in 2004-2011

Collaboration, H.E.S.S.; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A.G.; Angüner, E.; Anton, G.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Bernlöhr, K.; Birsin, E.; Bissaldi, E.; Biteau, J.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P.M.; Chalme-Calvet, R.; Chaves, R.C.G.; Cheesebrough, A.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Cui, Y.; Dalton, M.; Daniel, M.K.; Davids, I.D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H.J.; Djannati-Ataï, A.; Domainko, W.; Drury, L.O’C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M.V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gajdus, M.; Gallant, Y.A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J.F.; Grondin, M.-H.; Grudzi...

Authors

H.E.S.S. Collaboration

A. Abramowski

F. Aharonian

F. Ait Benkhali

A.G. Akhperjanian

E. Angüner

G. Anton

S. Balenderan

A. Balzer

A. Barnacka

Y. Becherini

J. Becker Tjus

K. Bernlöhr

E. Birsin

E. Bissaldi

J. Biteau

M. Böttcher

C. Boisson

J. Bolmont

P. Bordas

J. Brucker

F. Brun

P. Brun

T. Bulik

S. Carrigan

S. Casanova

M. Cerruti

P.M. Chadwick

R. Chalme-Calvet

R.C.G. Chaves

A. Cheesebrough

M. Chrétien

S. Colafrancesco

G. Cologna

J. Conrad

C. Couturier

Y. Cui

M. Dalton

M.K. Daniel

I.D. Davids

B. Degrange

C. Deil

P. deWilt

H.J. Dickinson

A. Djannati-Ataï

W. Domainko

L.O’C. Drury

G. Dubus

K. Dutson

J. Dyks

M. Dyrda

T. Edwards

K. Egberts

P. Eger

P. Espigat

C. Farnier

S. Fegan

F. Feinstein

M.V. Fernandes

D. Fernandez

A. Fiasson

G. Fontaine

A. Förster

M. Füßling

M. Gajdus

Y.A. Gallant

T. Garrigoux

G. Giavitto

B. Giebels

J.F. Glicenstein

M.-H. Grondin

M. Grudzińska

S. Häffner

J. Hahn

J. Harris

G. Heinzelmann

G. Henri

G. Hermann

O. Hervet

A. Hillert

J.A. Hinton

W. Hofmann

P. Hofverberg

M. Holler

D. Horns

A. Jacholkowska

C. Jahn

M. Jamrozy

M. Janiak

F. Jankowsky

I. Jung

M.A. Kastendieck

K. Katarzyński

U. Katz

S. Kaufmann

B. Khélifi

M. Kieffer

S. Klepser

D. Klochkov

W. Kluźniak

T. Kneiske

D. Kolitzus

Nu Komin

K. Kosack

S. Krakau

F. Krayzel

P.P. Krüger

H. Laffon

G. Lamanna

J. Lefaucheur

A. Lemière

M. Lemoine-Goumard

J.-P. Lenain

D. Lennarz

T. Lohse

A. Lopatin

C.-C. Lu

V. Marandon

A. Marcowith

R. Marx

G. Maurin

N. Maxted

M. Mayer

T.J.L. McComb

J. Méhault

P.J. Meintjes

U. Menzler

M. Meyer

R. Moderski

M. Mohamed

E. Moulin

T. Murach

C.L. Naumann

M. de Naurois

J. Niemiec

S.J. Nolan

L. Oakes

S. Ohm

E. de Oña Wilhelmi

B. Opitz

M. Ostrowski

I. Oya

M. Panter

R.D. Parsons

M. Paz Arribas

N.W. Pekeur

G. Pelletier

J. Perez

P.-O. Petrucci

B. Peyaud

S. Pita

H. Poon

G. Pühlhofer

M. Punch

A. Quirrenbach

S. Raab

M. Raue

A. Reimer

O. Reimer

M. Renaud

R. de los Reyes

F. Rieger

L. Rob

C. Romoli

S. Rosier-Lees

G. Rowell

B. Rudak

C.B. Rulten

V. Sahakian

D.A. Sanchez

A. Santangelo

R. Schlickeiser

F. Schüssler

A. Schulz

U. Schwanke

S. Schwarzburg

S. Schwemmer

H. Sol

G. Spengler

F. Spies

Ł Stawarz

R. Steenkamp

C. Stegmann

F. Stinzing

K. Stycz

I. Sushch

A. Szostek

J.-P. Tavernet

T. Tavernier

A.M. Taylor

R. Terrier

M. Tluczykont

C. Trichard

K. Valerius

C. van Eldik

B. van Soelen

G. Vasileiadis

C. Venter

A. Viana

P. Vincent

H.J. Völk

F. Volpe

M. Vorster

T. Vuillaume

S.J. Wagner

P. Wagner

Professor Martin Ward martin.ward@durham.ac.uk
External Examiner (PGR)

M. Weidinger

Q. Weitzel

R. White

A. Wierzcholska

P. Willmann

A. Wörnlein

D. Wouters

V. Zabalza

M. Zacharias

A. Zajczyk

A.A. Zdziarski

A. Zech

H.-S. Zechlin

Abstract

Context. About 40% of the observation time of the High Energy Stereoscopic System (H.E.S.S.) is dedicated to studying active galactic nuclei (AGN), with the aim of increasing the sample of known extragalactic very-high-energy (VHE, E > 100 GeV) sources and constraining the physical processes at play in potential emitters. Aims. H.E.S.S. observations of AGN, spanning a period from April 2004 to December 2011, are investigated to constrain their γ-ray fluxes. Only the 47 sources without significant excess detected at the position of the targets are presented. Methods. Upper limits on VHE fluxes of the targets were computed and a search for variability was performed on the nightly time scale. Results. For 41 objects, the flux upper limits we derived are the most constraining reported to date. These constraints at VHE are compared with the flux level expected from extrapolations of Fermi-LAT measurements in the two-year catalog of AGN. The H.E.S.S. upper limits are at least a factor of two lower than the extrapolated Fermi-LAT fluxes for 11 objects. Taking into account the attenuation by the extragalactic background light reduces the tension for all but two of them, suggesting intrinsic curvature in the high-energy spectra of these two AGN. Conclusions. Compilation efforts led by current VHE instruments are of critical importance for target-selection strategies before the advent of the Cherenkov Telescope Array (CTA).

Citation

Collaboration, H., Abramowski, A., Aharonian, F., Ait Benkhali, F., Akhperjanian, A., Angüner, E., …Zechlin, H. (2014). Flux upper limits for 47 AGN observed with H.E.S.S. in 2004-2011. Astronomy & Astrophysics, 564, Article A9. https://doi.org/10.1051/0004-6361/201322897

Journal Article Type	Article
Publication Date	Apr 1, 2014
Deposit Date	May 29, 2014
Publicly Available Date	Jul 15, 2014
Journal	Astronomy and astrophysics.
Print ISSN	0004-6361
Electronic ISSN	1432-0746
Publisher	EDP Sciences
Peer Reviewed	Peer Reviewed
Volume	564
Article Number	A9
DOI	https://doi.org/10.1051/0004-6361/201322897
Keywords	Gamma rays: galaxies, Galaxies: active.