J/A+A/623/A175 2015 BL Lac VHE gamma-ray flare (MAGIC Collaboration, 2019)
A fast very high energy γ-ray flare from BL Lacertae during a period of
multiwavelength activity in June 2015.
MAGIC Collaboration, Acciari V.A., Ansoldi S., Antonelli L.A.,
Arbet Engels A., Baack D., Babic A., Banerjee B., Bangale P.,
Barres de Almeida U., Barrio J.A., Becerra Gonzalez J., Bednarek W.,
Bernardini E., Berti A., Besenrieder J., Bhattacharyya W., Bigongiari C.,
Biland A., Blanch O., Bonnoli G., Carosi R., Ceribella G., Cikota S.,
Colak S.M., Colin P., Colombo E., Contreras J.L., Cortina J., Covino S.,
D'Elia V., Da Vela P., Dazzi F., De Angelis A., De Lotto B., Delfino M.,
Delgado J., Di Pierro F., Do Souto Espinera E., Dominguez A.,
Dominis Prester D., Dorner D., Doro M., Einecke S., Elsaesser D.,
Fallah Ramazani V., Fattorini A., Fernandez-Barral A., Ferrara G.,
Fidalgo D., Foffano L., Fonseca M.V., Font L., Fruck C., Galindo D.,
Gallozzi S., Garcia Lopez R.J., Garczarczyk M., Gaug M., Giammaria P.,
Godinovic N., Guberman D., Hadasch D., Hahn A., Hassan T., Herrera J.,
Hoang J., Hrupec D., Inoue S., Ishio K., Iwamura Y., Kubo H., Kushida J.,
Kuvezdic D., Lamastra A., Lelas D., Leone F., Lindfors E., Lombardi S.,
Longo F., Lopez M., Lopez-Oramas A., Maggio C., Majumdar P., Makariev M.,
Maneva G., Manganaro M., Mannheim K., Maraschi L., Mariotti M., Martinez M.,
Masuda S., Mazin D., Minev M., Miranda J.M., Mirzoyan R., Molina E.,
Moralejo A., Moreno V., Moretti E., Munar-Adrover P., Neustroev V.,
Niedzwiecki A., Nievas Rosillo M., Nigro C., Nilsson K., Ninci D.,
Nishijima K., Noda K., Nogues L., Noethe M., Paiano S., Palacio J.,
Paneque D., Paoletti R., Paredes J.M., Pedaletti G., Penil P., Peresano M.,
Persic M., Prada Moroni P.G., Prandini E., Puljak I., Garcia J.R., Rhode W.,
Ribo M., Rico J., Righi C., Rugliancich A., Saha L., Saito T., Satalecka K.,
Schweizer T., Sitarek J., Snidaric I., Sobczynska D., Somero A.,
Stamerra A., Strzys M., Suric T., Tavecchio F., Temnikov P., Terzic T.,
Teshima M., Torres-Alba N., Tsujimoto S., van Scherpenberg J., Vanzo G.,
Vazquez Acosta M., Vovk I., Will M., Zaric D., D'Ammando F., Hada K.,
Jorstad S., Marscher A.P., Mobeen M.Z., Hovatta T., Larionov V.M.,
Borman G.A., Grishina T.S., Kopatskaya E.N., Morozova D.A., Nikiforova A.A.,
Laehteenmaeki A., Tornikoski M., Agudo I.
<Astron. Astrophys. 623, A175 (2019)>
=2019A&A...623A.175M 2019A&A...623A.175M (SIMBAD/NED BibCode)
ADC_Keywords: Gamma rays ; BL Lac objects
Keywords: BL Lacertae objects: individual: BL Lacertae - gamma rays: galaxies
Abstract:
The mechanisms producing fast variability of the γ-ray emission
in active galactic nuclei (AGNs) are under debate. The MAGIC
telescopes detected a fast, very-high-energy (VHE, E>100GeV)
γ-ray flare from BL Lacertae on 2015 June 15. The flare had a
maximum flux of (1.5±0.3)x10-10photons/cm2/s and halving time of
26±8min. The MAGIC observations were triggered by a high state in
the optical and high-energy (HE, E>100MeV) γ-ray bands. In this
paper we present the MAGIC VHE γ-ray data together with
multi-wavelength data from radio, optical, X-rays, and HE γ rays
from 2015 May 1 to July 31. Well-sampled multi-wavelength data allow
us to study the variability in detail and compare it to the other
epochs when fast, VHE γ-ray flares have been detected from this
source. Interestingly, we find that the behaviour in radio, optical,
X-rays, and HE γ-rays is very similar to two other observed VHE
γ-ray flares. In particular, also during this flare there was an
indication of rotation of the optical polarization angle and of
activity at the 43GHz core. These repeating patterns indicate a
connection between the three events. We also test modelling of the
spectral energy distribution based on constraints from the light
curves and VLBA observations, with two different geometrical setups of
two-zone inverse Compton models. In addition we model the γ-ray
data with the star-jet interaction model. We find that all of the
tested emission models are compatible with the fast VHE γ-ray
flare, but all have some tension with the multi-wavelength
observations.
Description:
The multiwavelength light curve and spectral energy distribution of
BL Lacertae in June 2015 as presented in Figures 4 and 10 of the
paper.
Objects:
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RA (2000) DE Designation(s)
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22 02 43.29 +42 16 40.0 BL Lac = QSO J2202+4216
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
f2vhe.dat 43 10 BL Lac daily VHE light curve with upperlimits,
same as the top panel in Fig.4. ,
MAGIC Telescope
f2flare.dat 31 9 BL Lac intraday light curve of MJD 57188,
MAGIC Telescope
f4fermi.dat 23 91 *BL Lac daily GeV light curve, UL marked with
errorbar 0. Fermi-LAT
f4xray.dat 31 26 BL Lac daily X-ray light curve. Swift/XRT
f4uvot.dat 26 125 BL Lac daily optical light curve in
UVOT U, B, V, M2, W1 and W2 bands
f4kva.dat 22 32 BL Lac daily optical polarization light curve
in R-band, KVA Telescope
f4pol.dat 47 107 BL Lac daily optical polarization light curve
in R-band
f4mets.dat 17 47 BL LAC daily radio light curve at 37GHz,
Metsahovi radio telescope
f4ovro.dat 25 3 BL Lcat daily radio light curve at 15GHz,
Owens Valley Telescope
f10sed.dat 47 25 BL Lac spectral energy distribution
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Note on f4fermi.dat: Fermi-LAT "butterfly" was produced with
F=(9.41998±3.00515)e-07ph.cm-2.s-1, Gamma=-2.1151±0.21,
Energy range: 0.1-70GeV.
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See also:
J/A+A/369/758 : VRI photometry of BL Lac (1997-1999) (Fan+, 2001)
J/A+A/385/55 : Long-Term Polarization of BL Lac (Hagen-Thorn+ 2002)
J/AZh/71/717 : Polarimetric Observations of BL Lac (Gagen-Torn+ 1994)
J/PAZh/30/243 : BV(RI)c-JHK photometry of BL Lac in 1999-2001
(Hagen-Thorn+, 2004)
J/MNRAS/373/209 : BATC eim photometry of BL Lac (Hu+, 2006)
J/ApJ/787/151 : Fitted jet components in BL Lacertae (Cohen+, 2014)
J/ApJ/816/53 : Multiwavelength obs. of BL Lac in 2012-2013 (Wehrle+, 2016)
Byte-by-byte Description of file: f2vhe.dat
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Bytes Format Units Label Explanations
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1- 7 F7.1 d MJD Modified Julian Date
9- 19 E11.6 cm-2.s-1 Flux Flux, E>200GeV, MAGIC Telescope
21- 31 E11.6 cm-2.s-1 e_Flux Flux Error, E>200GeV
33- 43 E11.6 cm-2.s-1 FluxUL ?=- Flux Upperlimit, E>200GeV
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Byte-by-byte Description of file: f2flare.dat
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Bytes Format Units Label Explanations
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1- 7 F7.4 min Time Elapsed time [min](since MJD=57188.1)
9- 19 E11.6 cm-2.s-1 Flux Flux, E>200 GeV, MAGIC Telescope
21- 31 E11.6 cm-2.s-1 e_Flux Flux Error, E>200 GeV
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Byte-by-byte Description of file: f4fermi.dat
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Bytes Format Units Label Explanations
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1- 5 I5 d MJD Modified Julian Date
7- 15 E9.3 cm-2.s-1 Flux Flux, 100 MeV-300 GeV, Fermi-LAT
16- 23 E8.3 cm-2.s-1 e_Flux Flux Error, 100 MeV-300 GeV
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Byte-by-byte Description of file: f4xray.dat
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Bytes Format Units Label Explanations
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1- 7 F7.1 d MJD Modified Julian Date
9- 19 E11.6 mW/m2 Flux Flux 2-10keV, Swift XRT (erg/cm2/s)
21- 31 E11.6 mW/m2 e_Flux Flux Error 2-10keV (erg/cm2/s)
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Byte-by-byte Description of file: f4uvot.dat
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Bytes Format Units Label Explanations
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1- 5 I5 d MJD Modified Julian Date
7- 15 F9.6 mJy Flux Flux, UVOTV
16- 23 F8.6 mJy e_Flux Flux Error, UVOTV
25- 26 A2 --- Band [UBV M2 W1 W2] UVOT band
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Byte-by-byte Description of file: f4kva.dat
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Bytes Format Units Label Explanations
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1- 7 F7.1 d MJD Modified Julian Date
9- 14 F6.3 mJy Flux Flux, R-band, KVA Telescope
16- 22 F7.5 mJy e_Flux Flux Error, R-band, KVA Telescope
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Byte-by-byte Description of file: f4pol.dat
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Bytes Format Units Label Explanations
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2- 10 F9.3 d MJD Modified Julian Date
12- 17 F6.3 % P Polarization degree
18- 23 F6.3 % e_P [] Polarization degree errorbar
25- 31 F7.3 deg EVPA Electric Vector Position Angle
33- 37 F5.3 deg e_EVPA Electric Vector Position Angle errorbar
39- 47 A9 - Tel Name of the Telescope
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Byte-by-byte Description of file: f4mets.dat
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Bytes Format Units Label Explanations
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1- 7 F7.1 d MJD Modified Julian Date
9- 12 F4.2 Jy Flux Flux, 37GHz, Metsahovi radio telescope
14- 17 F4.2 Jy e_Flux Flux Error
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Byte-by-byte Description of file: f4ovro.dat
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Bytes Format Units Label Explanations
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1- 7 F7.1 d MJD Modified Julian Date
9- 15 F7.5 Jy Flux Flux, 15GHz, Owens Valley Telescope
17- 25 F9.7 Jy e_Flux Flux Error
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Byte-by-byte Description of file: f10sed.dat
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Bytes Format Units Label Explanations
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1- 11 E11.5 GeV Energy Energy in GeV
13- 23 E11.6 mW/m2 nuFnu Flux, 15GHz, Owens Valley Telescope (erg/cm2/s)
25- 35 E11.6 mW/m2 e_nuFnu Flux Error, lower value (erg/cm2/s)
37- 47 E11.6 mW/m2 E_nuFnu Flux Error, upper value (erg/cm2/s)
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Acknowledgements:
Elina Lindfors, elilin(at)utu.fi
(End) Patricia Vannier [CDS] 04-Mar-2019