Determination of the Point-spread Function for the Fermi Large Area Telescope from On-orbit Data and Limits on Pair Halos of Active Galactic Nuclei
Markus Ackermann
,
Marco Ajello
,
A. Allafort
,
K. Asano
,
W.B. Atwood
,
Luca Baldini
,
Jean Ballet
(1)
,
Guido Barbiellini
,
D. Bastieri
,
K. Bechtol
,
R. Bellazzini
,
E.D. Bloom
,
E. Bonamente
,
A.W. Borgland
,
E. Bottacini
,
T.J. Brandt
,
J. Bregeon
,
M. Brigida
,
Pascal Bruel
(2)
,
R. Buehler
,
T.H. Burnett
,
G. Busetto
,
S. Buson
,
G.A. Caliandro
,
R.A. Cameron
,
P. A. Caraveo
,
J.M. Casandjian
(1)
,
C. Cecchi
,
E. Charles
(3)
,
S. Chaty
,
A. Chekhtman
,
C.C. Cheung
,
J. Chiang
,
A.N. Cillis
,
S. Ciprini
,
R. Claus
,
J. Cohen-Tanugi
,
S. Colafrancesco
,
J. Conrad
,
S. Cutini
,
F. d'Ammando
,
F. de Palma
,
C.D. Dermer
,
E.D.E. Silva
,
Do Couto
,
S. Drell
,
A. Drlica-Wagner
,
R. Dubois
,
C. Favuzzi
,
S.J. Fegan
(2)
,
E.C. Ferrara
,
W.B. Focke
,
Y. Fukazawa
,
S. Funk
,
P. Fusco
(4)
,
F. Gargano
(4)
,
D. Gasparrini
,
N. Gehrels
,
S. Germani
,
N. Giglietto
,
F. Giordano
(4)
,
M. Giroletti
,
T. Glanzman
,
G. Godfrey
,
P. Grandi
,
I.A. Grenier
,
J.E. Grove
,
S. Guiriec
,
D. Hadasch
,
M. Hayashida
,
E. Hays
,
D. Horan
(2)
,
X. Hou
(5)
,
R.E. Hughes
,
M.S. Jackson
,
T. Jogler
,
G. Jóhannesson
,
R.P. Johnson
,
A.S. Johnson
,
T. Kamae
,
J. Kataoka
,
M. Kerr
,
Jürgen Knödlseder
,
M. Kuss
,
J. Lande
,
S. Larsson
,
L. Latronico
,
C. Lavalley
,
S.H. Lee
,
F. Longo
,
F. Loparco
(4)
,
B. Lott
(5)
,
M.N. Lovellette
,
P. Lubrano
,
M.N. Mazziotta
(4)
,
W. Mcconville
,
J.E. Mcenery
,
J. Mehault
(6)
,
P.F. Michelson
,
R.P. Mignani
,
W. Mitthumsiri
,
T. Mizuno
,
A.A. Moiseev
,
C. Monte
,
M.E. Monzani
,
A. Morselli
,
I.V. Moskalenko
,
S. Murgia
,
M. Naumann-Godo
,
R. Nemmen
,
S. Nishino
,
J.P. Norris
,
E. Nuss
(6)
,
T. Ohsugi
,
N. Omodei
,
M. Orienti
,
E. Orlando
,
J.F. Ormes
,
D. Paneque
,
J.H. Panetta
,
V. Pelassa
,
J.S. Perkins
,
M. Pesce-Rollins
,
M. Pierbattista
(1)
,
F. Piron
(6)
,
G. Pivato
,
H. Poon
,
T.A. Porter
,
S. Rainò
,
R. Rando
,
M. Razzano
,
S. Razzaque
,
A. Reimer
,
O. Reimer
,
L.C. Reyes
,
S. Ritz
,
L.S. Rochester
,
C. Romoli
,
M. Roth
,
D.A. Sanchez
,
P.M. Saz Parkinson
,
J.D. Scargle
,
C. Sgrò
,
E.J. Siskind
,
A. Snyder
,
G. Spandre
,
P. Spinelli
,
T.E. Stephens
,
D.J. Suson
,
H. Tajima
,
H. Takahashi
,
T. Tanaka
,
J.G. Thayer
,
D.J. Thompson
,
L. Tibaldo
,
O. Tibolla
,
M. Tinivella
,
G. Tosti
,
E. Troja
,
T.L. Usher
,
J. Vandenbroucke
,
V. Vasileiou
(6)
,
G. Vianello
,
V. Vitale
,
A. von Kienlin
,
A.M. Waite
,
E. Wallace
,
P. Weltevrede
,
B.L. Winer
,
K.S. Wood
,
M. Wood
,
S. Zimmer
1
AIM (UMR7158 / UMR_E_9005 / UM_112) -
Astrophysique Interprétation Modélisation
2 LLR - Laboratoire Leprince-Ringuet
3 CSIRO - Commonwealth Scientific and Industrial Research Organisation [Australia]
4 INFN, sezione di Bari - Istituto Nazionale di Fisica Nucleare, sezione di Bari
5 GLAST
6 LUPM - Laboratoire Univers et Particules de Montpellier
2 LLR - Laboratoire Leprince-Ringuet
3 CSIRO - Commonwealth Scientific and Industrial Research Organisation [Australia]
4 INFN, sezione di Bari - Istituto Nazionale di Fisica Nucleare, sezione di Bari
5 GLAST
6 LUPM - Laboratoire Univers et Particules de Montpellier
Markus Ackermann
- Function : Author
Marco Ajello
- Function : Author
A. Allafort
- Function : Author
K. Asano
- Function : Author
- PersonId : 757802
- ORCID : 0000-0001-9064-160X
W.B. Atwood
- Function : Author
Luca Baldini
- Function : Author
Guido Barbiellini
- Function : Author
D. Bastieri
- Function : Author
K. Bechtol
- Function : Author
R. Bellazzini
- Function : Author
E.D. Bloom
- Function : Author
E. Bonamente
- Function : Author
A.W. Borgland
- Function : Author
E. Bottacini
- Function : Author
T.J. Brandt
- Function : Author
J. Bregeon
- Function : Author
- PersonId : 741214
- IdHAL : johan-bregeon
- ORCID : 0000-0002-6790-5328
- IdRef : 095856943
M. Brigida
- Function : Author
R. Buehler
- Function : Author
T.H. Burnett
- Function : Author
G. Busetto
- Function : Author
- PersonId : 755318
- ORCID : 0000-0002-2687-6380
S. Buson
- Function : Author
G.A. Caliandro
- Function : Author
R.A. Cameron
- Function : Author
P. A. Caraveo
- Function : Author
C. Cecchi
- Function : Author
S. Chaty
- Function : Author
- PersonId : 828874
- ORCID : 0000-0002-5769-8601
- IdRef : 035347910
A. Chekhtman
- Function : Author
C.C. Cheung
- Function : Author
J. Chiang
- Function : Author
A.N. Cillis
- Function : Author
S. Ciprini
- Function : Author
R. Claus
- Function : Author
J. Cohen-Tanugi
- Function : Author
- PersonId : 3626
- IdHAL : johann-cohen-tanugi
- ORCID : 0000-0001-9022-4232
- IdRef : 172626544
S. Colafrancesco
- Function : Author
J. Conrad
- Function : Author
S. Cutini
- Function : Author
F. d'Ammando
- Function : Author
F. de Palma
- Function : Author
C.D. Dermer
- Function : Author
E.D.E. Silva
- Function : Author
Do Couto
- Function : Author
S. Drell
- Function : Author
A. Drlica-Wagner
- Function : Author
R. Dubois
- Function : Author
C. Favuzzi
- Function : Author
S.J. Fegan
- Function : Author
- PersonId : 740343
- IdHAL : stephen-fegan
- ORCID : 0000-0002-9978-2510
- IdRef : 253133149
E.C. Ferrara
- Function : Author
W.B. Focke
- Function : Author
Y. Fukazawa
- Function : Author
- PersonId : 760581
- ORCID : 0000-0002-0921-8837
S. Funk
- Function : Author
D. Gasparrini
- Function : Author
N. Gehrels
- Function : Author
S. Germani
- Function : Author
N. Giglietto
- Function : Author
- PersonId : 755413
- ORCID : 0000-0002-9021-2888
M. Giroletti
- Function : Author
T. Glanzman
- Function : Author
G. Godfrey
- Function : Author
P. Grandi
- Function : Author
I.A. Grenier
- Function : Author
J.E. Grove
- Function : Author
S. Guiriec
- Function : Author
D. Hadasch
- Function : Author
- PersonId : 761675
- ORCID : 0000-0001-8663-6461
M. Hayashida
- Function : Author
E. Hays
- Function : Author
R.E. Hughes
- Function : Author
M.S. Jackson
- Function : Author
T. Jogler
- Function : Author
G. Jóhannesson
- Function : Author
R.P. Johnson
- Function : Author
A.S. Johnson
- Function : Author
T. Kamae
- Function : Author
J. Kataoka
- Function : Author
M. Kerr
- Function : Author
Jürgen Knödlseder
- Function : Author
- PersonId : 178646
- IdHAL : jurgen-knodlseder
- ORCID : 0000-0002-0014-7809
- IdRef : 069521360
M. Kuss
- Function : Author
J. Lande
- Function : Author
S. Larsson
- Function : Author
L. Latronico
- Function : Author
C. Lavalley
- Function : Author
S.H. Lee
- Function : Author
F. Longo
- Function : Author
- PersonId : 755442
- ORCID : 0000-0003-2501-2270
B. Lott
- Function : Author
- PersonId : 739369
- IdHAL : benoit-lott
- ORCID : 0000-0003-2186-9242
- IdRef : 031300065
M.N. Lovellette
- Function : Author
P. Lubrano
- Function : Author
W. Mcconville
- Function : Author
J.E. Mcenery
- Function : Author
P.F. Michelson
- Function : Author
R.P. Mignani
- Function : Author
W. Mitthumsiri
- Function : Author
T. Mizuno
- Function : Author
A.A. Moiseev
- Function : Author
- PersonId : 743616
- IdHAL : amira-raounak-kolla
C. Monte
- Function : Author
M.E. Monzani
- Function : Author
A. Morselli
- Function : Author
I.V. Moskalenko
- Function : Author
S. Murgia
- Function : Author
M. Naumann-Godo
- Function : Author
R. Nemmen
- Function : Author
S. Nishino
- Function : Author
J.P. Norris
- Function : Author
T. Ohsugi
- Function : Author
N. Omodei
- Function : Author
M. Orienti
- Function : Author
E. Orlando
- Function : Author
J.F. Ormes
- Function : Author
D. Paneque
- Function : Author
- PersonId : 755279
- ORCID : 0000-0002-2830-0502
J.H. Panetta
- Function : Author
V. Pelassa
- Function : Author
J.S. Perkins
- Function : Author
M. Pesce-Rollins
- Function : Author
- PersonId : 760585
- ORCID : 0000-0003-1790-8018
F. Piron
- Function : Author
- PersonId : 172749
- IdHAL : frederic-piron
- ORCID : 0000-0001-6885-7156
G. Pivato
- Function : Author
H. Poon
- Function : Author
T.A. Porter
- Function : Author
S. Rainò
- Function : Author
R. Rando
- Function : Author
M. Razzano
- Function : Author
S. Razzaque
- Function : Author
A. Reimer
- Function : Author
- PersonId : 755465
- ORCID : 0000-0001-8604-7077
O. Reimer
- Function : Author
L.C. Reyes
- Function : Author
S. Ritz
- Function : Author
L.S. Rochester
- Function : Author
C. Romoli
- Function : Author
- PersonId : 766942
- ORCID : 0000-0003-2541-4499
M. Roth
- Function : Author
D.A. Sanchez
- Function : Author
P.M. Saz Parkinson
- Function : Author
J.D. Scargle
- Function : Author
C. Sgrò
- Function : Author
E.J. Siskind
- Function : Author
A. Snyder
- Function : Author
G. Spandre
- Function : Author
P. Spinelli
- Function : Author
T.E. Stephens
- Function : Author
D.J. Suson
- Function : Author
H. Tajima
- Function : Author
H. Takahashi
- Function : Author
T. Tanaka
- Function : Author
- PersonId : 756461
- ORCID : 0000-0002-4383-0368
J.G. Thayer
- Function : Author
D.J. Thompson
- Function : Author
L. Tibaldo
- Function : Author
O. Tibolla
- Function : Author
M. Tinivella
- Function : Author
G. Tosti
- Function : Author
E. Troja
- Function : Author
T.L. Usher
- Function : Author
J. Vandenbroucke
- Function : Author
G. Vianello
- Function : Author
V. Vitale
- Function : Author
- PersonId : 760184
- ORCID : 0000-0001-8040-7852
A. von Kienlin
- Function : Author
A.M. Waite
- Function : Author
E. Wallace
- Function : Author
P. Weltevrede
- Function : Author
B.L. Winer
- Function : Author
K.S. Wood
- Function : Author
M. Wood
- Function : Author
S. Zimmer
- Function : Author
Abstract
The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to detect photons with energies from ≈20 MeV to >300 GeV. The pre-launch response functions of the LAT were determined through extensive Monte Carlo simulations and beam tests. The point-spread function (PSF) characterizing the angular distribution of reconstructed photons as a function of energy and geometry in the detector is determined here from two years of on-orbit data by examining the distributions of γ rays from pulsars and active galactic nuclei (AGNs). Above 3 GeV, the PSF is found to be broader than the pre-launch PSF. We checked for dependence of the PSF on the class of γ-ray source and observation epoch and found none. We also investigated several possible spatial models for pair-halo emission around BL Lac AGNs. We found no evidence for a component with spatial extension larger than the PSF and set upper limits on the amplitude of halo emission in stacked images of low- and high-redshift BL Lac AGNs and the TeV blazars 1ES0229+200 and 1ES0347-121.