J/MNRAS/496/3912 1ES 2344+514 Multi-wavelength study (MAGIC Collaboration, 2020)
An intermittent extreme BL Lac: MWL study of 1ES 2344+514 in an enhanced state.
MAGIC Collaboration, Acciari V.A., Ansoldi S., Antonelli L.A.,
Arbet Engels A., Babic A., Banerjee B., Barres de Almeida U., Barrio J.A.,
Becerra Gonzalez J., Bednarek W., Bellizzi L., Bernardini E., Berti A.,
Besenrieder J., Bhattacharyya W., Bigongiari C., Blanch O., Bonnoli G.,
Bosnjak Z., Busetto G., Carosi R., Ceribella G., Cerruti M., Chai Y.,
Chilingaryan A., Cikota S., Colak S.M., Colin U., Colombo E.,
Contreras J.L., Cortina J., Covino S., D'Elia V., Da Vela P., Dazzi F.,
De Angelis A., De Lotto B., Delno M., Delgado J., Depaoli D., Di Pierro F.,
Di Venere L., Do Souto Espi∼neira E., Dominis Prester D., Donini A.,
Doro M., Elsaessery D., Fallah Ramazani V., Fattorini A., Ferrara G.,
Foano L., Fonseca M.V., Font L., Fruck C., Fukami S., Garca Lopez R.J.,
Garczarczyk M., Gasparyan S., Gaug M., Giglietto N., Giordano F.,
Godinovic N., Gliwny P., Green D., Hadasch D., Hahn A., Herrera J.,
Hoang J., Hrupec D., Huetten M., Inada T., Inoue S., Ishio K., Iwamura Y.,
Jouvin L., Kajiwara Y., Kerszberg D., Kobayashi Y., Kubo H., Kushida J.,
Lamastra A., Lelas D., Leone F., Lindfors E., Lombardi S., Longo F.,
Lopez M., Lopez-Coto R., Lopez-Oramas A., Loporchio S.,
Machado de Oliveira Fraga B., Maggio C., Majumdar P., Makariev M.,
Mallamaci M., Maneva G., Manganaro M., Maraschi L., Mariotti M., Martnez M.,
Mazin D., Mender S., Micanovic S., Miceli D., Miener T., Minev M.,
Miranda J.M., Mirzoyan R., Molina E., Moralejo A., Morcuende D., Moreno V.,
Moretti E., Munar-Adrover P., Neustroev V., Nigro C., Nilsson K., Ninci D.,
Nishijima K., Noda K., Nogues L., Nozaki S., Ohtani Y., Oka T.,
Otero-Santos J., Palatiello M., Paneque D., Paoletti R., Paredes J.M.,
Pavletic L., Pe∼nil P., Peresano M., Persic M., Prada Moroni P.G.,
Prandini E., Puljak I., Ribo M., Rico J., Righi C., Rugliancich A., Saha L.,
Sahakyan N., Saito T., Sakurai S., Satalecka K., Schleicher B., Schmidt K.,
Schweizer T., Sitarek J., Snidaric I., Sobczynska D., Spolon A.,
Stamerra A., Strom D., Strzys M., Suda Y., Suric T., Takahashi M.,
Tavecchio F., Temnikov P., Terzic T., Teshima M., Torres-Alba N., Tosti L.,
van Scherpenberg J., Vanzo G., Vazquez Acosta M., Ventura S., Verguilov V.,
Vigorito C.F., Vitale V., Vovk I., Will M., Zaric D.,
FACT Collaboration, Baackz D., Balbo M., Beck M., Biederbeck N., Bilandz A.,
Blank M., Bretz T., Bruegge K., Bulinski M., Buss J., Doerr M., Dorner D.,
Hildebrand D., Iotov R., Klinger M., Mannheimz K., Achim Mueller S.,
Neise D., Neronov A., Noethe M., Paravac A., Rhodez W., Schleicher B.,
Sedlaczek K., Shukla A., Sliusar V., Tani L., Theissen F., Walter R.,
MWL Collaborators: Acosta Pulido J., Filippenko A.V., Hovatta T.,
Kiehlmann S., Larionov V.M., Max-Moerbeck W., Raiteri C.M., Readhead A.C.S.,
Segon M., Villata M., Zheng W.
<Mon. Not. R. Astron. Soc. 496, 3912-3928 (2020)>
=2020MNRAS.496.3912M 2020MNRAS.496.3912M (SIMBAD/NED BibCode)
ADC_Keywords: BL Lac objects ; Energy distributions
Keywords: galaxies: active - BL Lacertae objects: individual: 1ES 2344+514 -
gamma-rays: galaxies
Abstract:
Extreme High-frequency BL Lacs (EHBL) feature their synchrotron peak
of the broadband spectral energy distribution (SED) at
νs≥1017Hz. The BL Lac object 1ES 2344+514 was included in the
EHBL family because of its impressive shift of the synchrotron peak in
1996. During the following years, the source appeared to be in a low
state without showing any extreme behaviours. In August 2016, 1ES
2344+514 was detected with the ground-based γ-ray telescope FACT
during a high γ-ray state, triggering multi-wavelength (MWL)
observations. We studied the MWL light curves of 1ES 2344+514 during
the 2016 flaring state, using data from radio to VHE γ rays
taken with OVRO, KAIT, KVA, NOT, some telescopes of the GASP-WEBT
collaboration at the Teide, Crimean, and St. Petersburg observatories,
Swift-UVOT, Swift-XRT, Fermi-LAT, FACT and MAGIC. With simultaneous
observations of the flare, we built the broadband SED and studied it
in the framework of a leptonic and an hadronic model. The VHE
γ-ray observations show a flux level of 55% of the Crab Nebula
flux above 300GeV, similar to the historical maximum of 1995. The
combination of MAGIC and Fermi-LAT spectra provides an unprecedented
characterization of the inverse-Compton peak for this object during a
flaring episode. The {GAMMA} index of the intrinsic spectrum in the
VHE γ-ray band is 2.04±0.12stat±0.15sys. We find the source
in an extreme state with a shift of the position of the synchrotron
peak to frequencies above or equal to 1018Hz
Description:
In the present work, we report on the observations of a VHE
γ-ray are of 1ES 2344+514 in August 2016, detected by FACT
(First G-APD Cherenkov Telescope), and followed up by many
instruments, including the MAGIC (Major Atmospheric Gamma Imaging
Cherenkov) telescopes, the Fermi-LAT (Large Area Telescope), Swift-XRT
and Swift-UVOT, TCS (Telescope Carlos Sanchez), KAIT (Katzman
Automatic Imaging Telescope), KVA (Kungliga Vetenskapsakademien),
Stella, LX-200, AZT-8, NOT (Nordic Optical Telescope) IAC80 and OVRO
(Owens Valley Radio Observatory). We collected a dataset from
simultaneous and quasisimultaneous MWL observations of a flaring
state. FACT and MAGIC are both IACT devoted to the study of VHE
γ rays. It is worth to note that, for this source, the
combination of Fermi-LAT and MAGIC data for the first time offers an
unprecedented characterisation of the IC peak during a flaring state.
Other data underlying this article will be shared on reasonable
request to the corresponding authors.
Objects:
-------------------------------------------------------
RA (2000) DE Designation(s)
-------------------------------------------------------
23 47 04.84 +51 42 17.9 1ES 2344+514 = QSO B2344+514
-------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 74 6 Parameters of the power-law fit to the VHE
γ-ray spectra observed by MAGIC (this work)
fig1.dat 113 117 Multi-wavelength light curve of 1ES 2344+514
from MJD 57567 (28 June 2016) to MJD 57645
(14 September 2016)
fig5.dat 65 46 Observed and intrinsic spectra
fig6-7.dat 135 23 Broadband SED points
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See also:
J/A+A/549/A23 : MAGIC map of 1E 2259+586 (Aleksic+, 2013)
J/A+A/565/L12 : Crab pulsar 50-400GeV light curve (Aleksic+, 2014)
J/A+A/573/A50 : 2008 multiwavelength observations of Mrk 501 (Aleksic+, 2015)
J/A+A/578/A22 : Mrk421 in March 2010 (Aleksic+, 2015)
J/A+A/576/A126 : 2009 multiwavelength campaign on Mrk421 (Aleksic+, 2015)
J/A+A/619/A45 : S5 0716+714 multi-wavelength curves (MAGIC Coll., 2018)
J/ApJS/247/16 : Extreme high-frequency-peaked BL Lac objects (Acciari+, 2020)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Date MJD date (57611 or 57612) or combined
10- 18 A9 --- Note observed or intrinsic
20- 27 E8.2 1/cm2/s/TeV f0 Normalization constant
29- 37 E9.4 1/cm2/s/TeV e_f0 Statistical error on f0
39- 46 E8.2 1/cm2/s/TeV s_f0 Systematic error on f0
48- 51 F4.2 --- GAMMA Spectral index
53- 56 F4.2 --- e_GAMMA Statistical error on GAMMA
58- 61 F4.2 --- s_GAMMA Systematic error on GAMMA
63- 67 F5.2 --- chi2 χ2 value
68 A1 --- --- [/]
69 I1 --- DOF Degree of freedom
71- 74 F4.1 % Prob Probability
--------------------------------------------------------------------------------
Byte-by-byte Description of file: fig1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 A14 --- Inst Instrument (1)
15- 38 E24.19 d MJD Observation date
40- 63 E24.19 d e_MJD ? rms uncertainty on MJD
65- 88 E24.19 1/cm2/s Flux Flux in instrument band
90-113 E24.19 1/cm2/s e_Flux rms uncertainty on Flux
--------------------------------------------------------------------------------
Note (1): The observations were carried out using (from top to bottom)
FACT (energy threshold ∼810GeV), MAGIC (>300GeV),
Fermi-LAT (0.3GeV-300GeV), Swift-XRT (2keV-10keV),
Swift-UVOT (W1, M2 and W2 filter), KVA, NOT, IAC80 and Stella at Teide,
AZT-8 at Crimean Observatory, LX-200 at St. Petersburg (R band),
KAIT (optical, clear filter), TCS at Teide (J, H, K filters), and
OVRO (15GHz).
In the Fermi-LAT light curve we quote an upper limit at 95% C.L. for
time bins having TS<4.
The shadowed band represents the VHE γ-ray activity window. The
band is centred on MJD 57610 (10 August 2016), which is the night in
which FACT sent the alert which triggered MWL observations. The night
of MJD 57613 (13 August 2016) is the night chosen for building the
broadband SED. HE and VHE γ-ray panels show the flux in number
of photons, while the other panels show the flux density in the
respective energy bands.
Optical and NIR data from 1ES 2344+514 shown here are corrected for
the host galaxy contribution and Galactic reddening.
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Byte-by-byte Description of file: fig5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Title Title for the following data (1)
3- 10 A8 --- Date MJD date (57611 or 57612) or combined
12- 20 F9.4 GeV E Energy
22- 30 F9.4 GeV Emin Lower value of Energy
32- 40 F9.4 GeV Emax Upper value of Energy
42- 52 E11.6 1/TeV/cm2/s dN/dE Spectrum
55- 65 E11.6 1/TeV/cm2/s e_dN/dE rms uncertainty on spectrum
--------------------------------------------------------------------------------
Note (1): Titles as follows:
A = MAGIC observed differential spectrum MJD 57611 + MJD57612 forward folding
(Fig. 5a)
B = MAGIC EBL corrected differential spectrum MJD 57611 + MJD57612
forward folding (Fig. 5a)
C = MAGIC observed differential spectrum MJD 57611 + MJD57612 data points
tikhonov unfolding(Fig. 5a)
D = MAGIC EBL corrected differential spectrum MJD 57611 + MJD57612 data points
tikhonov unfolding(Fig. 5a)
E = MAGIC EBL corrected differential spectrum MJD 57611 forward folding
corrected for EBL absorption by 2011MNRAS.410.2556D 2011MNRAS.410.2556D) (Fig. 5b)
F = MAGIC EBL corrected differential spectrum MJD 57612 forward folding
corrected for EBL absorption by 2011MNRAS.410.2556D 2011MNRAS.410.2556D) (Fig. 5b)
G = MAGIC EBL corrected differential spectrum MJD 57611 data points tikhonov
unfolding corrected for EBL absorption by 2011MNRAS.410.2556D 2011MNRAS.410.2556D) (Fig. 5b)
H = MAGIC EBL corrected diff spectrum MJD 57612 data points tikhonov unfolding
corrected for EBL absorption by 2011MNRAS.410.2556D 2011MNRAS.410.2556D) (Fig. 5b)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: fig6-7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Inst Instrument (1)
12- 35 E24.19 Hz nu Frequency
37- 60 E24.19 mW/m2 nuFnu Flux density
62- 85 E24.19 Hz e_nu Error on nu, lower value
87-110 E24.19 Hz E_nu Error on nu, upper value
112-135 E24.19 mW/m2 e_nuFnu rms uncertainty on nuFnu
--------------------------------------------------------------------------------
Note (1):
Swift-XRT (MJD 57613)
Fermi-LAT (from MJD57596.5 to MJD 57626.5)
MAGIC (MJD 57612)
--------------------------------------------------------------------------------
Acknowledgements:
M. Manganaro (marina.manganaro(at)phy.uniri.hr),
A. Arbet Engels (aaxel(at)phys.ethz.ch),
D. Dorner(dorner(at)astro.uni-wuerzburg.de)
(End) Marina Manganaro [UniRI, Croatia], Patricia Vannier [CDS] 30-Jun-2020