Veritas observations of the BL Lac object 1ES 1218+304

V. A. Acciari; E. Aliu; T. Arlen; M. Beilicke; W. Benbow; S. M. Bradbury; J. H. Buckley; V. Bugaev; Y. Butt; K. L. Byrum; O. Celik; A. Cesarini; L. Ciupik; Y. C.K. Chow; P. Cogan; P. Colin; W. Cui; M. K. Daniel; T. Ergin; A. D. Falcone; S. J. Fegan; J. P. Finley; P. Fortin; L. F. Fortson; A. Furniss; G. H. Gillanders; J. Grube; R. Guenette; G. Gyuk; D. Hanna; E. Hays; J. Holder; D. Horan; C. M. Hui; T. B. Humensky; A. Imran; P. Kaaret; N. Karlsson; M. Kertzman; D. B. Kieda; J. Kildea; A. Konopelko; H. Krawczynski; F. Krennrich; M. J. Lang; S. LeBohec; G. Maier; A. McCann; M. McCutcheon; P. Moriarty; R. Mukherjee; T. Nagai; J. Niemiec; R. A. Ong; D. Pandel; J. S. Perkins; M. Pohl; J. Quinn; K. Ragan; L. C. Reyes; P. T. Reynolds; H. J. Rose; M. Schroedter; G. H. Sembroski; A. W. Smith; D. Steele; S. P. Swordy; J. A. Toner; L. Valcarcel; V. V. Vassiliev; R. Wagner; S. P. Wakely; J. E. Ward; T. C. Weekes; A. Weinstein; R. J. White; D. A. Williams; S. A. Wissel; M. Wood; B. Zitzer

doi:10.1088/0004-637X/695/2/1370

Veritas observations of the BL Lac object 1ES 1218+304

V. A. Acciari
, E. Aliu
, T. Arlen
, M. Beilicke
, W. Benbow
, S. M. Bradbury
, J. H. Buckley
, V. Bugaev
, Y. Butt
, K. L. Byrum
, O. Celik
, A. Cesarini
, L. Ciupik
, Y. C.K. Chow
, P. Cogan
, P. Colin
, W. Cui
, M. K. Daniel
, T. Ergin
, A. D. Falcone

S. J. Fegan, J. P. Finley, P. Fortin, L. F. Fortson, A. Furniss, G. H. Gillanders, J. Grube, R. Guenette, G. Gyuk, D. Hanna, E. Hays, J. Holder, D. Horan, C. M. Hui, T. B. Humensky, A. Imran, P. Kaaret, N. Karlsson, M. Kertzman, D. B. Kieda, J. Kildea, A. Konopelko, H. Krawczynski, F. Krennrich, M. J. Lang, S. LeBohec, G. Maier, A. McCann, M. McCutcheon, P. Moriarty, R. Mukherjee, T. Nagai, J. Niemiec, R. A. Ong, D. Pandel, J. S. Perkins, M. Pohl, J. Quinn, K. Ragan, L. C. Reyes, P. T. Reynolds, H. J. Rose, M. Schroedter, G. H. Sembroski, A. W. Smith, D. Steele, S. P. Swordy, J. A. Toner, L. Valcarcel, V. V. Vassiliev, R. Wagner, S. P. Wakely, J. E. Ward, T. C. Weekes, A. Weinstein, R. J. White, D. A. Williams, S. A. Wissel, M. Wood, B. Zitzer

Department of Life and Physical Sciences
Galway-Mayo Institute of Technology
Center for Astrophysics | Harvard & Smithsonian
Max Planck Institut für Extraterrestrische Physik
Bartol Research Institute
The Bartol Research Institute
University of California, Santa Cruz
Physics Department
Washington University in St. Louis
School of Physics and Astronomy
University of Leeds
Smithsonian Astrophysical Observatory
Argonne National Laboratory
Department of Physics and Astronomy
University of California, Los Angeles
Physics Department
IDA Business Park
Astronomy Department
Adler Planetarium
Department of Physics
McGill University
Department of Physics
University of Utah
Department of Physics
Purdue University
Department of Physics
Durham University
Department of Physics
UMass Amherst
Department of Astronomy and Astrophysics
Pennsylvania State University
Department of Physics
Grinnell College
Department of Physics and Astronomy
Barnard College
School of Physics
University College Dublin
University of Chicago
Department of Physics and Astronomy
Iowa State University
Department of Physics and Astronomy
University of Iowa
Institute for Nuclear Physics
Department of Applied Physics and Instrumentation
Cork Institute of Technology

Research output: Contribution to journal › Article › peer-review

64 Citations (Scopus)

Abstract

The VERITAS collaboration reports the detection of very-high-energy gamma-ray emission from the highfrequency-peaked BL Lac object 1ES 1218+304 located at a redshift of z = 0.182. A gamma-ray signal was detected with a statistical significance of 10.4 standard deviations (10.4σ) for the observations taken during the first three months of 2007, confirming the discovery of this object made by the MAGIC collaboration. The photon spectrum between ∼ 160 GeV and ∼ 1.8 TeV is well described by a power law with an index of Γ = 3.08 ± 0.34_stat ± 0.2_sys. The integral flux is Φ (E > 200 GeV) = (12.2 ± 2.6) × 10^-12 cm^-2 s^-1, which corresponds to ∼ 6% of that of the Crab Nebula. The light curve does not show any evidence for very high energy flux variability. Using lower limits on the density of the extragalactic background light in the near to mid-infrared, we are able to limit the range of intrinsic energy spectra for 1ES 1218+304. We show that the intrinsic photon spectrum has an index that is harder than Γ = 2.32 ± 0.37_stat. When including constraints from the spectra of 1ES 1101-232 and 1ES 0229+200, the spectrum of 1ES 1218+304 is likely to be harder than Γ = 1.86 ± 0.37_stat.

Original language	English
Pages (from-to)	1370-1375
Number of pages	6
Journal	Astrophysical Journal
Volume	695
Issue number	2
DOIs	https://doi.org/10.1088/0004-637X/695/2/1370
Publication status	Published - 20 Apr 2009
Externally published	Yes

Keywords

BL Lacertae objects: individual (1ES 1218+304)
Galaxies: active
Gamma rays: observations

Access to Document

10.1088/0004-637X/695/2/1370

Cite this

Acciari, V. A., Aliu, E., Arlen, T., Beilicke, M., Benbow, W., Bradbury, S. M., Buckley, J. H., Bugaev, V., Butt, Y., Byrum, K. L., Celik, O., Cesarini, A., Ciupik, L., Chow, Y. C. K., Cogan, P., Colin, P., Cui, W., Daniel, M. K., Ergin, T., ... Zitzer, B. (2009). Veritas observations of the BL Lac object 1ES 1218+304. Astrophysical Journal, 695(2), 1370-1375. https://doi.org/10.1088/0004-637X/695/2/1370

@article{6d3c31cd90a54cafb1a63b2f97b0fc31,

title = "Veritas observations of the BL Lac object 1ES 1218+304",

abstract = "The VERITAS collaboration reports the detection of very-high-energy gamma-ray emission from the highfrequency-peaked BL Lac object 1ES 1218+304 located at a redshift of z = 0.182. A gamma-ray signal was detected with a statistical significance of 10.4 standard deviations (10.4σ) for the observations taken during the first three months of 2007, confirming the discovery of this object made by the MAGIC collaboration. The photon spectrum between ∼ 160 GeV and ∼ 1.8 TeV is well described by a power law with an index of Γ = 3.08 ± 0.34stat ± 0.2sys. The integral flux is Φ (E > 200 GeV) = (12.2 ± 2.6) {\texttimes} 10-12 cm-2 s-1, which corresponds to ∼ 6\% of that of the Crab Nebula. The light curve does not show any evidence for very high energy flux variability. Using lower limits on the density of the extragalactic background light in the near to mid-infrared, we are able to limit the range of intrinsic energy spectra for 1ES 1218+304. We show that the intrinsic photon spectrum has an index that is harder than Γ = 2.32 ± 0.37stat. When including constraints from the spectra of 1ES 1101-232 and 1ES 0229+200, the spectrum of 1ES 1218+304 is likely to be harder than Γ = 1.86 ± 0.37stat.",

keywords = "BL Lacertae objects: individual (1ES 1218+304), Galaxies: active, Gamma rays: observations",

author = "Acciari, \{V. A.\} and E. Aliu and T. Arlen and M. Beilicke and W. Benbow and Bradbury, \{S. M.\} and Buckley, \{J. H.\} and V. Bugaev and Y. Butt and Byrum, \{K. L.\} and O. Celik and A. Cesarini and L. Ciupik and Chow, \{Y. C.K.\} and P. Cogan and P. Colin and W. Cui and Daniel, \{M. K.\} and T. Ergin and Falcone, \{A. D.\} and Fegan, \{S. J.\} and Finley, \{J. P.\} and P. Fortin and Fortson, \{L. F.\} and A. Furniss and Gillanders, \{G. H.\} and J. Grube and R. Guenette and G. Gyuk and D. Hanna and E. Hays and J. Holder and D. Horan and Hui, \{C. M.\} and Humensky, \{T. B.\} and A. Imran and P. Kaaret and N. Karlsson and M. Kertzman and Kieda, \{D. B.\} and J. Kildea and A. Konopelko and H. Krawczynski and F. Krennrich and Lang, \{M. J.\} and S. LeBohec and G. Maier and A. McCann and M. McCutcheon and P. Moriarty and R. Mukherjee and T. Nagai and J. Niemiec and Ong, \{R. A.\} and D. Pandel and Perkins, \{J. S.\} and M. Pohl and J. Quinn and K. Ragan and Reyes, \{L. C.\} and Reynolds, \{P. T.\} and Rose, \{H. J.\} and M. Schroedter and Sembroski, \{G. H.\} and Smith, \{A. W.\} and D. Steele and Swordy, \{S. P.\} and Toner, \{J. A.\} and L. Valcarcel and Vassiliev, \{V. V.\} and R. Wagner and Wakely, \{S. P.\} and Ward, \{J. E.\} and Weekes, \{T. C.\} and A. Weinstein and White, \{R. J.\} and Williams, \{D. A.\} and Wissel, \{S. A.\} and M. Wood and B. Zitzer",

year = "2009",

month = apr,

day = "20",

doi = "10.1088/0004-637X/695/2/1370",

language = "English",

volume = "695",

pages = "1370--1375",

journal = "Astrophysical Journal",

issn = "0004-637X",

publisher = "American Astronomical Society",

number = "2",

}

Acciari, VA, Aliu, E, Arlen, T, Beilicke, M, Benbow, W, Bradbury, SM, Buckley, JH, Bugaev, V, Butt, Y, Byrum, KL, Celik, O, Cesarini, A, Ciupik, L, Chow, YCK, Cogan, P, Colin, P, Cui, W, Daniel, MK, Ergin, T, Falcone, AD, Fegan, SJ, Finley, JP, Fortin, P, Fortson, LF, Furniss, A, Gillanders, GH, Grube, J, Guenette, R, Gyuk, G, Hanna, D, Hays, E, Holder, J, Horan, D, Hui, CM, Humensky, TB, Imran, A, Kaaret, P, Karlsson, N, Kertzman, M, Kieda, DB, Kildea, J, Konopelko, A, Krawczynski, H, Krennrich, F, Lang, MJ, LeBohec, S, Maier, G, McCann, A, McCutcheon, M, Moriarty, P, Mukherjee, R, Nagai, T, Niemiec, J, Ong, RA, Pandel, D, Perkins, JS, Pohl, M, Quinn, J, Ragan, K, Reyes, LC, Reynolds, PT, Rose, HJ, Schroedter, M, Sembroski, GH, Smith, AW, Steele, D, Swordy, SP, Toner, JA, Valcarcel, L, Vassiliev, VV, Wagner, R, Wakely, SP, Ward, JE, Weekes, TC, Weinstein, A, White, RJ, Williams, DA, Wissel, SA, Wood, M & Zitzer, B 2009, 'Veritas observations of the BL Lac object 1ES 1218+304', Astrophysical Journal, vol. 695, no. 2, pp. 1370-1375. https://doi.org/10.1088/0004-637X/695/2/1370

TY - JOUR

T1 - Veritas observations of the BL Lac object 1ES 1218+304

AU - Acciari, V. A.

AU - Aliu, E.

AU - Arlen, T.

AU - Beilicke, M.

AU - Benbow, W.

AU - Bradbury, S. M.

AU - Buckley, J. H.

AU - Bugaev, V.

AU - Butt, Y.

AU - Byrum, K. L.

AU - Celik, O.

AU - Cesarini, A.

AU - Ciupik, L.

AU - Chow, Y. C.K.

AU - Cogan, P.

AU - Colin, P.

AU - Cui, W.

AU - Daniel, M. K.

AU - Ergin, T.

AU - Falcone, A. D.

AU - Fegan, S. J.

AU - Finley, J. P.

AU - Fortin, P.

AU - Fortson, L. F.

AU - Furniss, A.

AU - Gillanders, G. H.

AU - Grube, J.

AU - Guenette, R.

AU - Gyuk, G.

AU - Hanna, D.

AU - Hays, E.

AU - Holder, J.

AU - Horan, D.

AU - Hui, C. M.

AU - Humensky, T. B.

AU - Imran, A.

AU - Kaaret, P.

AU - Karlsson, N.

AU - Kertzman, M.

AU - Kieda, D. B.

AU - Kildea, J.

AU - Konopelko, A.

AU - Krawczynski, H.

AU - Krennrich, F.

AU - Lang, M. J.

AU - LeBohec, S.

AU - Maier, G.

AU - McCann, A.

AU - McCutcheon, M.

AU - Moriarty, P.

AU - Mukherjee, R.

AU - Nagai, T.

AU - Niemiec, J.

AU - Ong, R. A.

AU - Pandel, D.

AU - Perkins, J. S.

AU - Pohl, M.

AU - Quinn, J.

AU - Ragan, K.

AU - Reyes, L. C.

AU - Reynolds, P. T.

AU - Rose, H. J.

AU - Schroedter, M.

AU - Sembroski, G. H.

AU - Smith, A. W.

AU - Steele, D.

AU - Swordy, S. P.

AU - Toner, J. A.

AU - Valcarcel, L.

AU - Vassiliev, V. V.

AU - Wagner, R.

AU - Wakely, S. P.

AU - Ward, J. E.

AU - Weekes, T. C.

AU - Weinstein, A.

AU - White, R. J.

AU - Williams, D. A.

AU - Wissel, S. A.

AU - Wood, M.

AU - Zitzer, B.

PY - 2009/4/20

Y1 - 2009/4/20

N2 - The VERITAS collaboration reports the detection of very-high-energy gamma-ray emission from the highfrequency-peaked BL Lac object 1ES 1218+304 located at a redshift of z = 0.182. A gamma-ray signal was detected with a statistical significance of 10.4 standard deviations (10.4σ) for the observations taken during the first three months of 2007, confirming the discovery of this object made by the MAGIC collaboration. The photon spectrum between ∼ 160 GeV and ∼ 1.8 TeV is well described by a power law with an index of Γ = 3.08 ± 0.34stat ± 0.2sys. The integral flux is Φ (E > 200 GeV) = (12.2 ± 2.6) × 10-12 cm-2 s-1, which corresponds to ∼ 6% of that of the Crab Nebula. The light curve does not show any evidence for very high energy flux variability. Using lower limits on the density of the extragalactic background light in the near to mid-infrared, we are able to limit the range of intrinsic energy spectra for 1ES 1218+304. We show that the intrinsic photon spectrum has an index that is harder than Γ = 2.32 ± 0.37stat. When including constraints from the spectra of 1ES 1101-232 and 1ES 0229+200, the spectrum of 1ES 1218+304 is likely to be harder than Γ = 1.86 ± 0.37stat.

AB - The VERITAS collaboration reports the detection of very-high-energy gamma-ray emission from the highfrequency-peaked BL Lac object 1ES 1218+304 located at a redshift of z = 0.182. A gamma-ray signal was detected with a statistical significance of 10.4 standard deviations (10.4σ) for the observations taken during the first three months of 2007, confirming the discovery of this object made by the MAGIC collaboration. The photon spectrum between ∼ 160 GeV and ∼ 1.8 TeV is well described by a power law with an index of Γ = 3.08 ± 0.34stat ± 0.2sys. The integral flux is Φ (E > 200 GeV) = (12.2 ± 2.6) × 10-12 cm-2 s-1, which corresponds to ∼ 6% of that of the Crab Nebula. The light curve does not show any evidence for very high energy flux variability. Using lower limits on the density of the extragalactic background light in the near to mid-infrared, we are able to limit the range of intrinsic energy spectra for 1ES 1218+304. We show that the intrinsic photon spectrum has an index that is harder than Γ = 2.32 ± 0.37stat. When including constraints from the spectra of 1ES 1101-232 and 1ES 0229+200, the spectrum of 1ES 1218+304 is likely to be harder than Γ = 1.86 ± 0.37stat.

KW - BL Lacertae objects: individual (1ES 1218+304)

KW - Galaxies: active

KW - Gamma rays: observations

U2 - 10.1088/0004-637X/695/2/1370

DO - 10.1088/0004-637X/695/2/1370

M3 - Article

AN - SCOPUS:84893254418

SN - 0004-637X

VL - 695

SP - 1370

EP - 1375

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 2

ER -

Veritas observations of the BL Lac object 1ES 1218+304

Abstract

Keywords

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