Upper limits from five years of blazar observations with the VERITAS Cherenkov telescopes

Archambault, S.; Archer, A.; Benbow, W.; Bird, R.; Biteau, J.; Buchovecky, M.; Buckley, J.H.; Bugaev, V.; Byrum, K.; Cerruti, M.; Chen, X.; Ciupik, L.; Connolly, M.P.; Cui, W.; Eisch, J.D.; Errando, M.; Falcone, A.; Feng, Q.; Finley, J.P.; Fleischhack, H.; Fortin, P.; Fortson, L.; Furniss, A.; Gillanders, G.H.; Griffin, S.; Grube, J.; Gyuk, G.; Hütten, M.; Håkansson, N.; Hanna, D.; Holder, J.; Humensky, T.B.; Johnson, C.A.; Kaaret, P.; Kar, P.; Kelley-Hoskins, N.; Kertzman, M.; Kieda, D.; Krause, M.; Krennrich, F.; Kumar, S.; Lang, M.J.; Maier, G.; McArthur, S.; McCann, A.; Meagher, K.; Moriarty, P.; Mukherjee, R.; Nguyen, T.; Nieto, D.; O’Faoláin de Bhróithe, A.; Ong, R.A.; Otte, A.N.; Park, N.; Perkins, J.S.; Pichel, A.; Pohl, M.; Popkow, A.; Pueschel, E.; Quinn, J.; Ragan, K.; Reynolds, P.T.; Richards, G.T.; Roache, E.; Rovero, A.C.; Santander, M.; Sembroski, G.H.; Shahinyan, K.; Smith, A.W.; Staszak, D.; Telezhinsky, I.; Tucci, J.V.; Tyler, J.; Vincent, S.; Wakely, S.P.; Weiner, O.M.; Weinstein, A.; Williams, D.A.; Zitzer, B.; collaboration, the VERITAS; Fumagalli, M.; Prochaska, J.X.

doi:10.3847/0004-6256/151/6/142

Upper limits from five years of blazar observations with the VERITAS Cherenkov telescopes

Archambault, S.; Archer, A.; Benbow, W.; Bird, R.; Biteau, J.; Buchovecky, M.; Buckley, J.H.; Bugaev, V.; Byrum, K.; Cerruti, M.; Chen, X.; Ciupik, L.; Connolly, M.P.; Cui, W.; Eisch, J.D.; Errando, M.; Falcone, A.; Feng, Q.; Finley, J.P.; Fleischhack, H.; Fortin, P.; Fortson, L.; Furniss, A.; Gillanders, G.H.; Griffin, S.; Grube, J.; Gyuk, G.; Hütten, M.; Håkansson, N.; Hanna, D.; Holder, J.; Humensky, T.B.; Johnson, C.A.; Kaaret, P.; Kar, P.; Kelley-Hoskins, N.; Kertzman, M.; Kieda, D.; Krause, M.; Krennrich, F.; Kumar, S.; Lang, M.J.; Maier, G.; McArthur, S.; McCann, A.; Meagher, K.; Moriarty, P.; Mukherjee, R.; Nguyen, T.; Nieto, D.; O’Faoláin de Bhróithe, A.; Ong, R.A.; Otte, A.N.; Park, N.; Perkins, J.S.; Pichel, A.; Pohl, M.; Popkow, A.; Pueschel, E.; Quinn, J.; Ragan, K.; Reynolds, P.T.; Richards, G.T.; Roache, E.; Rovero, A.C.; Santander, M.; Sembroski, G.H.; Shahinyan, K.; Smith, A.W.; Staszak, D.; Telezhinsky, I.; Tucci, J.V.; Tyler, J.; Vincent, S.; Wakely, S.P.; Weiner, O....

Authors

S. Archambault

A. Archer

W. Benbow

R. Bird

J. Biteau

M. Buchovecky

J.H. Buckley

V. Bugaev

K. Byrum

M. Cerruti

X. Chen

L. Ciupik

M.P. Connolly

W. Cui

J.D. Eisch

M. Errando

A. Falcone

Q. Feng

J.P. Finley

H. Fleischhack

P. Fortin

L. Fortson

A. Furniss

G.H. Gillanders

S. Griffin

J. Grube

G. Gyuk

M. Hütten

N. Håkansson

D. Hanna

J. Holder

T.B. Humensky

C.A. Johnson

P. Kaaret

P. Kar

N. Kelley-Hoskins

M. Kertzman

D. Kieda

M. Krause

F. Krennrich

S. Kumar

M.J. Lang

G. Maier

S. McArthur

A. McCann

K. Meagher

P. Moriarty

R. Mukherjee

T. Nguyen

D. Nieto

A. O’Faoláin de Bhróithe

R.A. Ong

A.N. Otte

N. Park

J.S. Perkins

A. Pichel

M. Pohl

A. Popkow

E. Pueschel

J. Quinn

K. Ragan

P.T. Reynolds

G.T. Richards

E. Roache

A.C. Rovero

M. Santander

G.H. Sembroski

K. Shahinyan

A.W. Smith

D. Staszak

I. Telezhinsky

J.V. Tucci

J. Tyler

S. Vincent

S.P. Wakely

O.M. Weiner

A. Weinstein

D.A. Williams

B. Zitzer

the VERITAS collaboration

Professor Michele Fumagalli michele.fumagalli@durham.ac.uk
Academic Visitor

J.X. Prochaska

Abstract

Between the beginning of its full-scale scientific operations in 2007 and 2012, the VERITAS Cherenkov telescope array observed more than 130 blazars; of these, 26 were detected as very-high-energy (VHE; E > 100 GeV) γ-ray sources. In this work, we present the analysis results of a sample of 114 undetected objects. The observations constitute a total live-time of ~570 hr. The sample includes several unidentified Fermi-Large Area Telescope (LAT) sources (located at high Galactic latitude) as well as all the sources from the second Fermi-LAT catalog that are contained within the field of view of the VERITAS observations. We have also performed optical spectroscopy measurements in order to estimate the redshift of some of these blazars that do not have spectroscopic distance estimates. We present new optical spectra from the Kast instrument on the Shane telescope at the Lick observatory for 18 blazars included in this work, which allowed for the successful measurement or constraint on the redshift of four of them. For each of the blazars included in our sample, we provide the flux upper limit in the VERITAS energy band. We also study the properties of the significance distributions and we present the result of a stacked analysis of the data set, which shows a 4σ excess.

Citation

Archambault, S., Archer, A., Benbow, W., Bird, R., Biteau, J., Buchovecky, M., …Prochaska, J. (2016). Upper limits from five years of blazar observations with the VERITAS Cherenkov telescopes. Astronomical Journal, 151(6), Article 142. https://doi.org/10.3847/0004-6256/151/6/142

Journal Article Type	Article
Acceptance Date	Mar 7, 2016
Online Publication Date	May 18, 2016
Publication Date	Jun 1, 2016
Deposit Date	Jun 2, 2016
Publicly Available Date	Jun 2, 2016
Journal	Astronomical Journal
Print ISSN	0004-6256
Electronic ISSN	1538-3881
Publisher	IOP Publishing
Peer Reviewed	Peer Reviewed
Volume	151
Issue	6
Article Number	142
DOI	https://doi.org/10.3847/0004-6256/151/6/142