J/ApJS/248/29 Simultaneous X-ray & gamma obs. of Mrk421 in 2013 (Acciari+, 2020)
Unraveling the complex behavior of Mrk 421 with simultaneous X-ray and VHE
observations during an extreme flaring activity in 2013 April.
Acciari V.A., Ansoldi S., Antonelli L.A., Engels A.A., Baack D., Babic A.,
Banerjee B., Barres de Almeida U., Barrio J.A., Becerra Gonzalez J.,
Bednarek W., Bellizzi L.K., Bernardini E., Berti A., Besenrieder J.,
Bhattacharyya W., Bigongiari C., Biland A., Blanch O., Bonnoli G.,
Bosnjak Z., Busetto G., Carosi R., Ceribella G., Cerruti M., Chai Y.,
Chilingarian 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., Del Puppo F., Delfino M., Delgado J.,
Depaoli D., Di Pierro F., Di Venere L., Do Souto Espineira E.,
Dominis Prester D., Donini A., Dorner D., Doro M., Elsaesser D.,
Fallah Ramazani V., Fattorini A., Ferrara G., Foffano L., Fonseca M.V.,
Font L., Fruck C., Fukami S., Garcia Lopez R.J., Garczarczyk M.,
Gasparyan S., Gaug M., Giglietto N., Giordano F., Gliwny P., Godinovic N.,
Green D., Hadasch D., Hahn A., Hassan T., Herrera J., Hoang J., Hrupec D.,
Hutten 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.,
Mannheim K., Maraschi L., Mariotti M., Martinez 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., Penil P., Peresano M., Persic M., Prada Moroni P.G.,
Prandini E., Puljak I., Rhode W., 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., Vasquez Acosta M.,
Ventura S., Verguilov V., Vigorito C.F., Vitale V., Vovk I., Will M.,
Zaric D. (The MAGIC Collaboration), Petropoulou M., Finke J.,
D'Ammando F., Balokovic M., Madejski G., Mori K., Puccetti S., Leto C.,
Perri M., Verrecchia F., Villata M., Raiteri C.M., Agudo I., Bachev R.,
Berdyugin A., Blinov D.A., Chanishvili R., Chen W.P., Chigladze R.,
Damljanovic G., Eswaraiah C., Grishina T.S., Ibryamov S., Jordan B.,
Jorstad S.G., Joshi M., Kopatskaya E.N., Kurtanidze O.M., Kurtanidze S.O.,
Larionova E.G., Larionova L.V., Larionov V.M., Latev G., Lin H.C.,
Marscher A.P., Mokrushina A.A., Morozova D.A., Nikolashvili M.G., Semkov E.,
Smith P.S., Strigachev A., Troitskaya Y.V., Troitsky I.S., Vince O.,
Barnes J., Guver T., Moody J.W., Sadun A.C., Hovatta T., Richards J.L.,
Max-Moerbeck W., Readhead A.C.S., Lahteenmaki A., Tornikoski M., Tammi J.,
Ramakrishnan V., Reinthal R.
<Astrophys. J. Suppl. Ser., 248, 29 (2020)>
=2020ApJS..248...29A 2020ApJS..248...29A
ADC_Keywords: Active gal. nuclei; X-ray sources; Gamma rays; Polarization;
Optical; Radio sources
Keywords: BL Lacertae objects ; Blazars ; Active galaxies ; Markarian galaxies ;
Gamma-ray detectors ; Gamma-rays ; Relativistic jets ;
High energy astrophysics ; Observational astronomy
Abstract:
We report on a multiband variability and correlation study of the TeV
blazar Mrk 421 during an exceptional flaring activity observed from
2013 April 11 to 19. The study uses, among others, data from
GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope
(WEBT), Swift, Nuclear Spectroscopic Telescope Array (NuSTAR), Fermi
Large Area Telescope, Very Energetic Radiation Imaging Telescope Array
System (VERITAS), and Major Atmospheric Gamma Imaging Cherenkov
(MAGIC). The large blazar activity and the 43hr of simultaneous
NuSTAR and MAGIC/VERITAS observations permitted variability studies on
15 minute time bins over three X-ray bands (3-7keV, 7-30keV, and
30-80keV) and three very-high-energy (VHE; >0.1TeV) gamma-ray bands
(0.2-0.4TeV, 0.4-0.8TeV, and >0.8TeV). We detected substantial flux
variations on multi-hour and sub-hour timescales in all of the X-ray
and VHE gamma-ray bands. The characteristics of the sub-hour flux
variations are essentially energy independent, while the multi-hour
flux variations can have a strong dependence on the energy of the
X-rays and the VHE gamma-rays. The three VHE bands and the three X-ray
bands are positively correlated with no time lag, but the strength and
characteristics of the correlation change substantially over time and
across energy bands. Our findings favor multi-zone scenarios for
explaining the achromatic/chromatic variability of the fast/slow
components of the light curves, as well as the changes in the
flux-flux correlation on day- long timescales. We interpret these
results within a magnetic reconnection scenario, where the multi-hour
flux variations are dominated by the combined emission from various
plasmoids of different sizes and velocities, while the sub-hour flux
variations are dominated by the emission from a single small plasmoid
moving across the magnetic reconnection layer.
Description:
The observations presented here are part of the multi-instrument
campaign for Mrk 421 that has occurred yearly since 2009
(Abdo+ 2011ApJ...736..131A 2011ApJ...736..131A).
The instruments that participated in the 2013 campaign, as well as
their performances and data analysis strategies, were reported in
Balokovic+ (2016ApJ...819..156B 2016ApJ...819..156B), which is our first publication with
the 2013 multi-instrument data set, and it focused on the low
X-ray/very-high-energy (VHE; >0.1TeV) activity observed in 2013
January-March.
During the first observations in 2013 April, Mrk 421 showed high X-ray
and VHE gamma-ray activity, which triggered daily few-hour-long
multi-instrument observations that lasted from April 10 (MJD 56392) to
April 19 (MJD 56401). Among other instruments, this data set contains
an exceptionally deep temporal coverage at VHE gamma-rays above
0.2TeV, as the source was observed with the Major Atmospheric Gamma
Imaging Cherenkov (MAGIC) during nine consecutive nights, and with the
Very Energetic Radiation Imaging Telescope Array System (VERITAS)
during six nights.
A key characteristic of this data set is the extensive and
simultaneous coverage in the X-ray bands provided by Swift and,
especially, by the Nuclear Spectroscopic Telescope Array (NuSTAR).
See Section 2 for further details.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
11 04 27.31 +38 12 31.8 Mrk 421 = SWIFT J1104.5+3813
----------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
fig1flux.dat 102 1134 Multiwavelength fluxes for Mrk421 during
the bright flaring activity in 2013 April
fig1pol.dat 54 267 Polarization data for Mrk421 during
the bright flaring activity in 2013 April
fig2.dat 85 1764 Light curves in various VHE and X-ray energy bands
-- Data behind Figure 2
fig3int.dat 59 31 Fractional variability vs energy for the 9-day
interval -- Data behind Figure 3
fig3nt.dat 70 45 Night-wise fractional variability vs energy
-- Data behind Figure 3
fig4.dat 64 227 Light curves from 2013 April 15 in three X-ray
bands and three VHE gamma-ray bands
fig5.dat 58 220 X-ray and VHE hardness (flux) ratios for
several X-ray and VHE bands -- Data behind Fig 5
fig6.dat 73 1524 VHE flux vs. X-ray flux in three X-ray and
three VHE energy bands -- Data behind Figure 6
fig7.dat 73 276 VHE flux vs. X-ray flux in three X-ray and
three VHE energy bands for April 15
-- Data behind Figure 7
fig12_11.dat 63 615 Normalized VHE and X-ray light curves with 15-min
time bins for 2013 April 11
-- Data behind Figure 12 (B1) (11 April)
fig12_12.dat 63 705 Normalized VHE and X-ray light curves with 15-min
time bins for 2013 April 12
-- Data behind Figure 12 (B1) (12 April)
fig12_13.dat 63 474 Normalized VHE and X-ray light curves with 15-min
time bins for 2013 April 13
-- Data behind Figure 12 (B1) (13 April)
fig12_14.dat 63 654 Normalized VHE and X-ray light curves with 15-min
time bins for 2013 April 14
-- Data behind Figure 12 (B1) (14 April)
fig12_15.dat 63 681 Normalized VHE and X-ray light curves with 15-min
time bins for 2013 April 15
-- Data behind Figure 12 (B1) (15 April)
fig12_16.dat 63 432 Normalized VHE and X-ray light curves with 15-min
time bins for 2013 April 16
-- Data behind Figure 12 (B1) (16 April)
fig12_17.dat 63 216 Normalized VHE and X-ray light curves with 15-min
time bins for 2013 April 17
-- Data behind Figure 12 (B1) (17 April)
fig12_18.dat 63 360 Normalized VHE and X-ray light curves with 15-min
time bins for 2013 April 18
-- Data behind Figure 12 (B1) (18 April)
fig12_19.dat 63 225 Normalized VHE and X-ray light curves with 15-min
time bins for 2013 April 19
-- Data behind Figure 12 (B1) (19 April)
figc1.dat 64 205 Light curves from 2013 April 11 in three X-ray
bands and three VHE gamma-ray bands
-- Data behind Figure C1
figc2.dat 64 235 Light curves from 2013 April 12 in three
X-ray bands and three VHE gamma-ray bands
-- Data behind Figure C2
figc3.dat 64 158 Light curves from 2013 April 13 in three
X-ray bands and three VHE gamma-ray bands
-- Data behind Figure C3
figc4.dat 64 218 Light curves from 2013 April 14 in three
X-ray bands and three VHE gamma-ray bands
-- Data behind Figure C4
figc5.dat 64 144 Light curves from 2013 April 16 in three
X-ray bands and three VHE gamma-ray bands
-- Data behind Figure C5
--------------------------------------------------------------------------------
See also:
J/A+A/545/A117 : Monitoring of Mrk 421 at 15 and 24 GHz (Lico+, 2012)
J/A+A/559/A75 : 43GHz observation of the blazar Mrk 421 (Blasi+, 2013)
J/A+A/573/A50 : Multiwavelength obs. of Mrk 501 in 2008 (Aleksic+, 2015)
J/A+A/576/A126 : The 2009 multiwavelength campaign on Mrk421 (Aleksic+, 2015)
J/A+A/578/A22 : Mrk421 in March 2010 (Aleksic+, 2015)
J/A+A/593/A91 : Mrk 421 multi-wavelength variability, 2007-2009 (Ahnen+, 2016)
J/ApJ/831/102 : Swift and NuSTAR obs. of the BL Lac Mrk 421 (Kapanadze+, 2016)
J/ApJS/222/6 : 4.5yr obs. of Mrk421 with ARGO-YBJ + Fermi (Bartoli+, 2016)
J/ApJS/232/7 : 8yr R-band photopolarimetric data of Mrk421 (Fraija+, 2017)
J/ApJ/851/33 : Multi-wavelength analysis of CGRaBS blazars (Paliya+, 2017)
J/ApJ/858/68 : Mrk421 with Swift in selected epochs. II. (Kapanadze+, 2018)
J/ApJ/874/43 : MOJAVE. XVII. Jet kinematics of AGNs (Lister+, 2019)
J/ApJS/247/27 : Mrk 421 Swift obs. III. 2015 Dec-2018 Apr (Kapanadze+, 2020)
J/ApJS/247/33 : The Fermi LAT fourth source catalog (4FGL) (Abdollahi+, 2020)
Byte-by-byte Description of file: fig1flux.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 F11.5 d MJDl ? Modified Julian date, bin low
13- 23 F11.5 d MJDc Modified Julian date, bin center
25- 35 F11.5 d MJDh ? Modified Julian date, bin high
37- 45 E9.3 --- Flux Flux with instrument in energy range
47- 55 E9.3 --- e_Flux Uncertainty in Flux
57- 78 A22 --- Inst Instrument
80- 92 A13 --- Energy Energy range / Filter
94-102 A9 --- x_Flux Flux units (erg/cm2/s, mJy or ph/cm2/s)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: fig1pol.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 F11.5 d MJD Modified Julian Date of observation (JD-2400000.5)
13- 17 F5.3 % Pol [0.89/9.62] Polarization degree
19- 23 F5.3 % e_Pol [0.015/0.6] Error in Pol
25- 31 F7.3 deg EVPA [-90.1/47.2] Electric vector position angle
33- 37 F5.3 deg e_EVPA [0.1/5.1] Error in EVPA
39- 47 A9 --- Inst Instrument
49- 54 A6 --- Filt Energy range / Filter (R-band ; or 86GHz
(1 occurrence for IRAM))
--------------------------------------------------------------------------------
Byte-by-byte Description of file: fig2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 F11.5 d MJDl Modified Julian date, bin low
13- 23 F11.5 d MJDc Modified Julian date, bin center
25- 35 F11.5 d MJDh Modified Julian date, bin high
37- 45 E9.3 --- Flux Flux with Instrument in Energy Range having Unit
47- 55 E9.3 --- e_Flux Uncertainty in Flux
57- 63 A7 --- Inst Instrument (NuSTAR, MAGIC, VERITAS or Swift)
65- 75 A11 --- Energy Energy range / Filter
77- 85 A9 --- x_Flux Flux units (erg/cm2/s or ph/cm2/s)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: fig3int.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 F7.4 [Hz] logE [10.17/26.99] log Energy range center
9- 13 F5.3 [Hz] logdE [0.01/1.5] log Energy range halfwidth
15- 24 F10.7 --- Fvar [-0.02/1.06] Fractional variability
26- 35 F10.8 --- e_Fvar [0.0008/0.13] Uncertainty in Fvar
37- 59 A23 --- Label Observation label
--------------------------------------------------------------------------------
Byte-by-byte Description of file: fig3nt.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 F7.4 [Hz] logE [18.04/27] log Energy range center
9- 13 F5.3 [Hz] logdE [0.15/0.7] log Energy range halfwidth
15- 22 F8.6 --- Fvar [0.049/0.47] Fractional variability
24- 31 F8.6 --- e_Fvar [0.002/0.12] Uncertainty in Fvar
33- 53 A21 --- Inst Instrument (NuStar or "VHE (MAGIC & VERITAS)")
55- 64 A10 "D/M/Y" Date Observation date
66- 70 I5 d MJD Modified Julian Date (JD-2400000.5)
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Byte-by-byte Description of file: fig4.dat figc[1-5].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 F7.4 h Time [-3.2/9.8] Time in hours from MJD 56397
9- 14 F6.4 h dT [0.018/0.14] Time bin halfwidth
16- 24 E9.3 --- Flux Flux with Instrument in Energy Range having Unit
26- 34 E9.3 --- e_Flux Uncertainty in Flux
36- 42 A7 --- Inst Instrument (NuSTAR, MAGIC or VERITAS)
44- 54 A11 --- Energy Energy range / Filter
56- 64 A9 --- x_Flux Flux units (erg/cm2/s or ph/cm2/s)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: fig5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 F7.4 h Time [-2.45/8.5] Time in hours from MJD 56397
9- 14 F6.4 h dT [0.018/0.14] Time bin halfwidth
16- 21 F6.4 --- Ratio [0.18/1.3] Flux Ratio
23- 28 F6.4 --- e_Ratio [0.009/0.3] Error in Ratio
30- 58 A29 --- Energy Energy ranges of Ratio
--------------------------------------------------------------------------------
Byte-by-byte Description of file: fig[67].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 F11.5 d MJDc Modified Julian date, bin center
13- 21 E9.3 mW/m2 FluxX [3.8e-12/2.2e-09] Xray Flux, erg/cm2/s
23- 31 E9.3 mW/m2 e_FluxX [1e-12/1.5e-10] Uncertainty in Xray Flux
33- 41 E9.3 ph/cm2/s FluxV [6.7e-12/1.3e-09] VHE flux
43- 51 E9.3 ph/cm2/s e_FluxV [2.6e-12/9.1e-11] Uncertainty in VHE flux
53- 61 A9 --- EnergyX Energy range, Xray
63- 73 A11 --- EnergyV Energy range, VHE
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Byte-by-byte Description of file: fig12_1[1-9].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 F7.4 h Time [-3.2/9.8] Time in hours from midnight
9- 14 F6.4 h dT [0.01/0.14] Time bin halfwidth
16- 21 F6.4 --- Flux [0.3/2.4] Normalized Flux (1)
23- 28 F6.4 --- e_Flux [0.004/0.8] Uncertainty in normalized flux
30- 36 A7 --- Inst Instrument (NuSTAR, MAGIC or VERITAS)
38- 48 A11 --- Energy Energy band
50- 60 A11 --- Comp Complementary band
62- 63 I2 --- Sim [0/1] Simultaneity (2)
--------------------------------------------------------------------------------
Note (1): Normalisation factors (from Table B1) are the following --
-------------------------------------------------------------------------
Day 3-7keV 7-30keV 30-80keV 0.2-0.4TeV 0.4-0.8TeV >0.8 TeV
-------------------------------------------------------------------------
2013 Apr 11 0.2657 0.1670 0.02437 3.872 1.312 0.4375
2013 Apr 12 0.7881 0.6725 0.1291 8.431 3.683 1.834
2013 Apr 13 1.119 0.9506 0.1737 10.23 4.889 2.713
2013 Apr 14 0.4043 0.2806 0.04366 5.758 2.286 0.9662
2013 Apr 15 1.021 1.194 0.3437 7.373 3.493 2.326
2013 Apr 16 0.4054 0.3498 0.07931 4.211 1.561 0.6639
2013 Apr 17 0.3190 0.3397 0.1042 2.706 0.9845 0.37643
2013 Apr 18 0.08387 0.05741 0.007850 2.053 0.5959 0.2168
2013 Apr 19 0.07172 0.03977 0.005220 1.175 0.3813 0.09668
-------------------------------------------------------------------------
Mean X-ray fluxes are given in units 10-9erg/cm2/s, and
VHE gamma-ray fluxes are given in 10-10ph/cm2/s
-------------------------------------------------------------------------
Note (2): informs whether the reported flux for the (primary) energy band is
simultaneous (1) or not (0) to that of the complementary band.
In Figure B1, this information is depicted with filled and open
markers, respectively.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 06-Nov-2020