Observations of a correlated gamma-ray and optical flare for BL Lacertae

S. D. Bloom; D. L. Bertsch; R. C. Hartman; P. Sreekumar; D. J. Thompson; T. J. Balonek; E. Beckerman; S. M. Davis; K. Whitman; H. R. Miller; A. D. Nair; L. C. Roberts; G. Tosti; E. Massaro; R. Nesci; M. Maesano; F. Montagni; M. Jang; H. A. Bock; M. Dietrich; M. Herter; K. Otterbein; M. Pfeiffer; T. Seitz; S. Wagner

doi:10.1086/311035

Observations of a correlated gamma-ray and optical flare for BL Lacertae

S. D. Bloom^*, D. L. Bertsch, R. C. Hartman, P. Sreekumar, D. J. Thompson, T. J. Balonek, E. Beckerman, S. M. Davis, K. Whitman, H. R. Miller, A. D. Nair, L. C. Roberts, G. Tosti, E. Massaro, R. Nesci, M. Maesano, F. Montagni, M. Jang, H. A. Bock, M. DietrichM. Herter, K. Otterbein, M. Pfeiffer, T. Seitz, S. Wagner

^*Corresponding author for this work

Manipal Centre for Natural Sciences, Manipal

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

77 Citations (Scopus)

Abstract

BL Lacertae was detected by the EGRET instrument on the Compton Gamma Ray Obsenatory at the 10.2 σ level with an average flux of (171 ± 42) × 10^-8 photons cm^-2 s^-1, at energies greater than 100 MeV, during the optical outburst of 1997 July. This flux is more than 4 times the previously highest level. Within the July 15-22 observation there was a dramatic factor of 2.5 increase in the gamma-ray flux on July 18.75-19.08, apparently preceding, by several hours, a brief optical flare. The gamma-ray flux decreased to its previous level within 8 hr, and the optical flux decreased to its prior level in less than 2 hr. The gamma-ray photon spectral index of 1.68 ± 0.12 indicates that the spectrum during the 7 day observation was harder than the previous detection.

Original language	English
Pages (from-to)	L145-L148
Journal	Astrophysical Journal
Volume	490
Issue number	2 PART II
DOIs	https://doi.org/10.1086/311035
Publication status	Published - 1997

All Science Journal Classification (ASJC) codes

Astronomy and Astrophysics
Space and Planetary Science

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Bloom, S. D., Bertsch, D. L., Hartman, R. C., Sreekumar, P., Thompson, D. J., Balonek, T. J., Beckerman, E., Davis, S. M., Whitman, K., Miller, H. R., Nair, A. D., Roberts, L. C., Tosti, G., Massaro, E., Nesci, R., Maesano, M., Montagni, F., Jang, M., Bock, H. A., ... Wagner, S. (1997). Observations of a correlated gamma-ray and optical flare for BL Lacertae. Astrophysical Journal, 490(2 PART II), L145-L148. https://doi.org/10.1086/311035

@article{e900dcce667e4d3281ac5da57ba04286,

title = "Observations of a correlated gamma-ray and optical flare for BL Lacertae",

abstract = "BL Lacertae was detected by the EGRET instrument on the Compton Gamma Ray Obsenatory at the 10.2 σ level with an average flux of (171 ± 42) × 10-8 photons cm-2 s-1, at energies greater than 100 MeV, during the optical outburst of 1997 July. This flux is more than 4 times the previously highest level. Within the July 15-22 observation there was a dramatic factor of 2.5 increase in the gamma-ray flux on July 18.75-19.08, apparently preceding, by several hours, a brief optical flare. The gamma-ray flux decreased to its previous level within 8 hr, and the optical flux decreased to its prior level in less than 2 hr. The gamma-ray photon spectral index of 1.68 ± 0.12 indicates that the spectrum during the 7 day observation was harder than the previous detection.",

author = "Bloom, \{S. D.\} and Bertsch, \{D. L.\} and Hartman, \{R. C.\} and P. Sreekumar and Thompson, \{D. J.\} and Balonek, \{T. J.\} and E. Beckerman and Davis, \{S. M.\} and K. Whitman and Miller, \{H. R.\} and Nair, \{A. D.\} and Roberts, \{L. C.\} and G. Tosti and E. Massaro and R. Nesci and M. Maesano and F. Montagni and M. Jang and Bock, \{H. A.\} and M. Dietrich and M. Herter and K. Otterbein and M. Pfeiffer and T. Seitz and S. Wagner",

year = "1997",

doi = "10.1086/311035",

language = "English",

volume = "490",

pages = "L145--L148",

journal = "Astrophysical Journal",

issn = "0004-637X",

publisher = "American Astronomical Society",

number = "2 PART II",

}

Bloom, SD, Bertsch, DL, Hartman, RC, Sreekumar, P, Thompson, DJ, Balonek, TJ, Beckerman, E, Davis, SM, Whitman, K, Miller, HR, Nair, AD, Roberts, LC, Tosti, G, Massaro, E, Nesci, R, Maesano, M, Montagni, F, Jang, M, Bock, HA, Dietrich, M, Herter, M, Otterbein, K, Pfeiffer, M, Seitz, T & Wagner, S 1997, 'Observations of a correlated gamma-ray and optical flare for BL Lacertae', Astrophysical Journal, vol. 490, no. 2 PART II, pp. L145-L148. https://doi.org/10.1086/311035

TY - JOUR

T1 - Observations of a correlated gamma-ray and optical flare for BL Lacertae

AU - Bloom, S. D.

AU - Bertsch, D. L.

AU - Hartman, R. C.

AU - Sreekumar, P.

AU - Thompson, D. J.

AU - Balonek, T. J.

AU - Beckerman, E.

AU - Davis, S. M.

AU - Whitman, K.

AU - Miller, H. R.

AU - Nair, A. D.

AU - Roberts, L. C.

AU - Tosti, G.

AU - Massaro, E.

AU - Nesci, R.

AU - Maesano, M.

AU - Montagni, F.

AU - Jang, M.

AU - Bock, H. A.

AU - Dietrich, M.

AU - Herter, M.

AU - Otterbein, K.

AU - Pfeiffer, M.

AU - Seitz, T.

AU - Wagner, S.

PY - 1997

Y1 - 1997

N2 - BL Lacertae was detected by the EGRET instrument on the Compton Gamma Ray Obsenatory at the 10.2 σ level with an average flux of (171 ± 42) × 10-8 photons cm-2 s-1, at energies greater than 100 MeV, during the optical outburst of 1997 July. This flux is more than 4 times the previously highest level. Within the July 15-22 observation there was a dramatic factor of 2.5 increase in the gamma-ray flux on July 18.75-19.08, apparently preceding, by several hours, a brief optical flare. The gamma-ray flux decreased to its previous level within 8 hr, and the optical flux decreased to its prior level in less than 2 hr. The gamma-ray photon spectral index of 1.68 ± 0.12 indicates that the spectrum during the 7 day observation was harder than the previous detection.

AB - BL Lacertae was detected by the EGRET instrument on the Compton Gamma Ray Obsenatory at the 10.2 σ level with an average flux of (171 ± 42) × 10-8 photons cm-2 s-1, at energies greater than 100 MeV, during the optical outburst of 1997 July. This flux is more than 4 times the previously highest level. Within the July 15-22 observation there was a dramatic factor of 2.5 increase in the gamma-ray flux on July 18.75-19.08, apparently preceding, by several hours, a brief optical flare. The gamma-ray flux decreased to its previous level within 8 hr, and the optical flux decreased to its prior level in less than 2 hr. The gamma-ray photon spectral index of 1.68 ± 0.12 indicates that the spectrum during the 7 day observation was harder than the previous detection.

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U2 - 10.1086/311035

DO - 10.1086/311035

M3 - Article

AN - SCOPUS:21944439763

SN - 0004-637X

VL - 490

SP - L145-L148

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 2 PART II

ER -

Observations of a correlated gamma-ray and optical flare for BL Lacertae

Abstract

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