J/ApJS/238/13 Spectral and timing results of 1ES 1959+650 (Kapanadze+, 2018)
Strong X-ray and multiwavelength flaring activity for 1ES 1959+650,
2016 August-2017 November.
Kapanadze B., Dorner D., Vercellone S., Romano P., Hughes P., Aller M.,
Aller H., Reynolds M., Tabagari L.
<Astrophys. J. Suppl. Ser., 238, 13 (2018)>
=2018ApJS..238...13K 2018ApJS..238...13K
ADC_Keywords: BL Lac objects; X-ray sources; Photometry, UBV; Ultraviolet;
Gamma rays
Keywords: BL Lacertae objects: individual (1ES 1959+650)
Abstract:
We present the detailed timing and spectral results obtained during
the Swift observations of the TeV-detected blazar 1ES 1959+650 in 2016
August-2017 November. The source continued its trend of gradually
enhancing X-ray flaring activity in the 0.3-10keV energy range,
starting in 2015 August, and a new highest historical brightness state
was recorded twice. A long-term high state was superimposed by both
weak and strong flares, and we detected 32 instances of intraday X-ray
flux variability, including several occasions of extremely fast
fluctuations with fractional amplitudes of 5.4%-7.5% within 1ks
exposures. The 0.3-10keV spectra generally showed a best fit with the
log-parabolic model, yielding a very wide range of the curvature
parameter b and the photon index at 1keV. The position of the
synchrotron SED peak Ep showed an extreme variability on various
timescales between energies less than 0.1keV and 7.7±0.7keV, with
25% of the spectra peaking at hard X-rays. In 2017 May-November, the
source mostly showed lower spectral curvature and an anticorrelation
b-Ep, expected in the case of efficient stochastic acceleration of
X-ray-emitting electrons. The 0.3-100GeV and optical-UV fluxes also
attained their highest historical values in this period, although the
latter showed an anticorrelation with the 0.3-10keV emission, which is
explained by the stochastic acceleration of electrons with a narrow
initial energy distribution, having an average energy significantly
higher than the equilibrium energy.
Description:
In this paper, we report the results of the intensive Swift-XRT
observations of 1ES 1959+650 during 2016 August-2017 November. The
source was targeted 93 times by the XRT during 2016 August 6 and 2017
November 12. The information about each XRT observation and the
measurement results are provided in Table 1.
Along with these data, we have analyzed the lower-energy data
simultaneously obtained with the Ultraviolet/Optical Telescope (UVOT)
on board the same satellite; see Table 2.
We also constructed light curves for the same period using the
publicly available data obtained with (i) the Burst Alert Telescope
(BAT) on board Swift, (ii) the Monitor of All Sky X-ray Image (MAXI)
device (Matsuoka+, 2009PASJ...61..999M 2009PASJ...61..999M), (iii) the Large Area
Telescope (LAT) on board Fermi, (iv) the First G-APD Cherenkov
Telescope (FACT), (v) the 40m telescope of Owens Valley Radio
Observatory (OVRO , and (vi) the long-term monitoring program MOJAVE
(Lister+ 2011, J/AJ/137/3718).
The FACT telescope observed 1ES 1959+650 during 237 nights for a total
of 591hr in 2016 August-2017 November.
See section 2 for further details.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
19 59 59.85 +65 08 54.7 1ES 1959+650 = 1ES 1959+65.0
----------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 92 90 The XRT observations of 1ES 1959+650 in
2016 August-2017 November
table2.dat 138 91 The results of the UVOT observations
table4.dat 117 160 Results of the spectral analysis with the
log-parabolic model
table9.dat 148 34 Summary of the 0.3-10keV intraday variabilities
(IDVs) in 2016 August-2017 November
table10.dat 84 33 The results from 2-week binned LAT data in
the 0.3-2GeV and 2-300GeV
--------------------------------------------------------------------------------
See also:
B/swift : Swift Master Catalog (HEASARC, 2004-)
B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2014)
VIII/76 : Leiden/Argentine/Bonn (LAB) Survey of Galactic HI (Kalberla+ 2005)
J/A+AS/109/267 : Radio to X-Ray distribution of BL Lac Objects (Giommi+, 1995)
J/A+AS/144/481 : BVRI photometry of 5 X-ray selected BL Lacs (Villata+, 2000)
J/A+A/406/L9 : TeV Gamma-Rays from 1ES1959+650 (Aharonian+, 2003)
J/A+A/433/1163 : Spectral catalog of BeppoSAX blazars (Donato+, 2005)
J/ApJ/626/95 : Gamma-ray blazar candidates (Sowards-Emmerd+, 2005)
J/A+A/445/441 : SED of BL Lacertae objects (Nieppola+, 2006)
J/A+A/466/63 : VLBI observations of BL Lac objects (Wu+, 2007)
J/ApJ/681/113 : Swift BAT survey of AGNs (Tueller+, 2008)
J/ApJ/696/580 : Properties of weak emission-line QSOs (WLQ) (Shemmer+, 2009)
J/ApJ/706/L7 : The Fermi LAT sky as seen by INTEGRAL/IBIS (Ubertini+, 2009)
J/ApJ/707/L56 : VLBI and bright Fermi/LAT sources (Kovalev, 2009)
J/AJ/137/3718 : 15GHz monitoring of AGN jets with VLBA (Lister+, 2009)
J/A+A/520/A47 : Blazars in the Swift-BAT hard X-ray sky (Maselli+, 2010)
J/ApJ/709/1407 : SED of the Fermi blazars (Li+, 2010)
J/ApJ/716/30 : SED of Fermi bright blazars (Abdo+, 2010)
J/ApJ/722/520 : Gamma-ray light curves of Fermi blazars (Abdo+, 2010)
J/ApJ/722/L7 : Fermi/LAT detected MOJAVE AGNs (Pushkarev+, 2010)
J/ApJ/741/30 : Radio/γ-ray correlation in AGN (Ackermann+, 2011)
J/ApJ/742/27 : 15GHz and jet properties of MOJAVE blazars (Lister+, 2011)
J/ApJS/194/29 : Observations of blazars at 15GHz (Richards+, 2011)
J/MNRAS/410/2690 : CRATES sources at 30 GHz (Peel+, 2011)
J/A+A/541/A160 : Planck + X/γ observations of blazars (Giommi+, 2012)
J/ApJ/744/177 : VLBA 5GHz observations of Fermi/LAT AGNs (Linford+, 2012)
J/ApJ/751/52 : AGN cand. from the WISE, 2MASS, RASS (W2R) (Edelson+, 2012)
J/ApJ/754/23 : Blazar (sub-)mm+γ-ray luminosities (Leon-Tavares+, 2012)
J/ApJ/757/25 : Fermi/LAT AGN at 5GHz (Linford+, 2012)
J/ApJ/761/125 : X and γ spectral indexes of Fermi blazars (Fan+, 2012)
J/AJ/145/31 : Catalog of X-ray selected BL Lac objects (Kapanadze+, 2013)
J/AJ/146/120 : MOJAVE. X. Parsec-scale kinematics of AGNs (Lister+, 2013)
J/ApJS/206/12 : Blazars with γ-ray counterparts. I. (D'Abrusco+, 2013)
J/ApJS/207/16 : BL Lac candidates for TeV observations (Massaro+, 2013)
J/ApJS/209/14 : The Swift/BAT hard X-ray transient monitor (Krimm+, 2013)
J/ApJS/212/15 : Polarized NVSS sources SEDs (Farnes+, 2014)
J/A+A/563/A57 : Long-term variability of AGN at hard X-rays (Soldi+, 2014)
J/other/RAA/14.1135 : Doppler factor for a Fermi blazar sample (Fan+, 2014)
J/MNRAS/438/3058 : 15GHz variability of γ-ray blazars (Richards+, 2014)
J/MNRAS/439/690 : Optical/γ-ray variability in blazars (Hovatta+, 2014)
J/MNRAS/442/1693 : Gamma-ray-loud blazars opt. polarization (Pavlidou+, 2014)
J/ApJ/810/14 : Third catalog of LAT-detected AGNs (3LAC) (Ackermann+, 2015)
J/A+A/576/A126 : The 2009 multiwavelength campaign on Mrk421 (Aleksic+, 2015)
J/AJ/150/67 : Optical photometry for 1ES 1959+650 (Yuan+, 2015)
J/other/AstBu/70.264 : Sample of 877 blazars (Mingaliev+, 2015)
J/MNRAS/458/56 : TeV gamma-ray blazar X-ray studies (Wierzcholska+,2016)
J/A+A/587/A93 : MeV-GeV counterparts of TeV sources (Rappoldi+, 2016)
J/A+A/596/A78 : R-band polarization curves of 48 BL Lacs (Hovatta+, 2016)
J/ApJS/223/15 : 8yr INTEGRAL/IBIS soft gamma-ray source obs. (Bird+, 2016)
J/ApJS/224/26 : SEDs of Roma BZCAT blazars (Mao+, 2016)
J/ApJS/226/20 : X-ray, opt. + radio SEDs of Fermi blazars (Fan+, 2016)
J/ApJ/833/77 : gamma-ray bright blazars optical polarization (Itoh+, 2016)
J/AJ/152/12 : MOJAVE. XIII. New 15GHz obs. on 1994-2013 (Lister+, 2016)
J/A+A/608/A68 : TeV BL Lacs multi-lambda fluxes (Fallah Ramazani+, 2017)
J/ApJ/848/103 : ∼1.5yr Swift observations of Mrk 421 (Kapanadze+, 2017)
J/ApJ/851/33 : Multi-wavelength analysis of CGRaBS blazars (Paliya+, 2017)
J/ApJS/233/17 : Swift/BAT AGN spectroscopic survey. V. X-ray (Ricci+, 2017)
J/MNRAS/467/4565 : Bimodal radio variability in OVRO blazars (Liodakis+, 2017)
J/ApJS/234/12 : MOJAVE XV. VLBA 15GHz obs. of AGNs 1996-2016 (Lister+, 2018)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- ObsID [34588023/93251014] Observation identifier
10- 19 A10 "Y/M/D" st.date UTC date of observation start
21- 28 A8 "h:m:s" st.time UTC time of observation start
30- 39 A10 "Y/M/D" end.date UTC date of observation end
41- 48 A8 "h:m:s" end.time UTC time of observation end
50- 53 I4 s Exp [415/1814] Exposure time
55- 62 F8.2 d MJD [57618.2/58069.8] Modified Julian Date
of observation start
64- 68 F5.2 ct/s CR [5.3/39.2] Mean 0.3-10keV count rate
70- 73 F4.2 ct/s e_CR [0.07/0.5] Uncertainty in CR
75- 80 F6.2 --- chi2 [0.4/436.2] Reduced χ2 of model fit
82- 83 I2 --- dof [1/26] Degrees of fit
85- 89 A5 --- Bin Time bin
91- 92 A2 --- Var Existence of flux variability (1)
--------------------------------------------------------------------------------
Note (1): Variability as follows:
V = variable (21 occurrences);
PV = possibly variable (4 occurrences);
NV = non-variable (65 occurrences).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- ObsID [34588023/93251014] Observation identifier
10- 14 F5.2 mag Vmag [13.4/14.3]? Swift/UVOT V band magnitude
16- 19 F4.2 mag e_Vmag [0.03/0.06]? Uncertainty in Vmag
21- 25 F5.2 mJy FV [7.1/15.2]? Swift/UVOT V band flux density
27- 30 F4.2 mJy e_FV [0.03/0.6]? Uncertainty in FV
32- 36 F5.2 mag Bmag [7.2/14.7]? Swift/UVOT B band magnitude
38- 41 F4.2 mag e_Bmag [0.02/0.3]? Uncertainty in Bmag
43- 47 F5.2 mJy FB [4.1/13.5]? Swift/UVOT B band flux density
49- 52 F4.2 mJy e_FB [0.04/0.4]? Uncertainty in FB
54- 58 F5.2 mag Umag [6/13.8]? Swift/UVOT U band magnitude
60- 63 F4.2 mag e_Umag [0.03/0.3]? Uncertainty in Umag
65- 69 F5.2 mJy FU [4.7/13.3]? Swift/UVOT U band flux density
71- 74 F4.2 mJy e_FU [0.03/0.3]? Uncertainty in FU
76- 80 F5.2 mag UVW1mag [4.2/13.6]? Swift/UVOT UVW1 band magnitude
82- 85 F4.2 mag e_UVW1mag [0.03/0.3]? Uncertainty in UVW1mag
87- 90 F4.2 mJy FUVW1 [3.4/7.6]? Swift/UVOT UVW1 band flux density
92- 95 F4.2 mJy e_FUVW1 [0.1/0.4]? Uncertainty in FUVW1
97-101 F5.2 mag UVM2mag [12.4/13.5]? Swift/UVOT UVM2 band magnitude
103-106 F4.2 mag e_UVM2mag [0.03/0.2]? Uncertainty in UVM2mag
108-112 F5.2 mJy FUVM2 [3.3/13.1]? Swift/UVOT UVM2 band flux density
114-117 F4.2 mJy e_FUVM2 [0.04/0.6]? Uncertainty in FUVM2
119-123 F5.2 mag UVW2mag [4.6/13.6]? Swift/UVOT UVW2 band magnitude
125-128 F4.2 mag e_UVW2mag [0.03/0.2]? Uncertainty in UVW2mag
130-133 F4.2 mJy FUVW2 [2.8/7.7]? Swift/UVOT UVW2 band flux density
135-138 F4.2 mJy e_FUVW2 [0.1/0.3]? Uncertainty in FUVW2
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- ObsID Observation identifier
10- 23 A14 --- m_ObsID Or=orbit; S=segment
25- 28 F4.2 --- a [1.5/2.5] The photon index at E1
30- 33 F4.2 --- e_a [0.02/0.07] Uncertainty in a
35- 38 F4.2 --- b [0.1/0.9] The curvature parameter
40- 43 F4.2 --- e_b [0.04/0.2] Uncertainty in b
45- 48 F4.2 keV Ep [0.1/7.8] Peak energy
50- 53 F4.2 keV e_Ep [0.05/0.8] Uncertaint in Ep
55- 59 F5.2 --- 100K [3.3/27.4] Normalization factor times 100
61- 64 F4.2 --- e_100K [0.08/0.5] Uncertainty in 100K
66- 69 F4.2 --- chi2 [0.8/1.2] Reduced χ2 of model fit
71- 73 I3 --- dof [76/292] Degrees of Freedom
75- 79 F5.2 10-14W/m2 F0.3-2 [8.9/76.8] De-absorbed 0.3-2keV flux (1)
81- 84 F4.2 10-14W/m2 e_F0.3-2 [0.3/1.7] Uncertainty in F0.3-2 (1)
86- 90 F5.2 10-14W/m2 F2-10 [4.6/88.6] De-absorbed 2-10keV flux (1)
92- 95 F4.2 10-14W/m2 e_F2-10 [0.1/3.2] Uncertainty in F2-10 (1)
97-102 F6.2 10-14W/m2 F0.3-10 [17.5/158.2] De-absorbed 0.3-10keV flux (1)
104-107 F4.2 10-14W/m2 e_F0.3-10 [0.4/3.3] Uncertainty in F0.3-10 (1)
109-112 F4.2 --- HR [0.2/1.3] Hardness ratio (HR=F2-10/F0.3-2)
114-117 F4.2 --- e_HR [0.01/0.2] Uncertainty in HR
--------------------------------------------------------------------------------
Note (1): In units of 10-11erg/s/cm2.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table9.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 21 A21 --- ObsID Observation identifier(s)
23- 32 A10 "Y/M/D" Date1 UT first date of the observation
33 A1 --- --- [/]
34- 35 I2 d Date2 ? Second day of observation if any
37- 41 F5.2 h DelT [0.1/23.6] Total observation duration
43- 48 F6.2 --- chi2 [1.9/502.3] Reduced χ2 of model fit
50- 51 I2 --- dof [1/33] Degrees of fit
53- 56 A4 --- Bin Time bin; Or = Orbit
58- 61 F4.1 % Fvar [3/34] Fractional amplitude
63- 66 F4.2 % e_Fvar [0.5/2] Uncertainty in Fvar
67- 70 F4.2 --- alow [1.5/2.5] Lower value of the photon index
at E1 (1)
72- 75 F4.2 --- e_alow [0.02/0.06] Uncertainty in alow
77- 80 F4.2 --- aup [1.6/2.4]? Upper value of the photon index
at E1 (1)
82- 85 F4.2 --- e_aup [0.02/0.05]? Uncertainty in aup
87- 88 A2 --- Model Model code (PL = Power law or
LP = log-parabolic model)
90- 93 F4.2 --- blow [0.1/0.7]? Lower value of the curvature
parameter (1)
95- 98 F4.2 --- e_blow [0.04/0.1]? Uncertainty in blow
100-103 F4.2 --- bup [0.2/0.9]? Upper value of the curvature
parameter (1)
105-108 F4.2 --- e_bup [0.05/0.2]? Uncertainty in bup
110-113 F4.2 --- Eplow [0.1/4]? Lower value of the peak energy (1)
115-118 F4.2 --- e_Eplow [0.05/0.4]? Uncertainty in Eplow
120-123 F4.2 --- Epup [0.7/4.7]? Upper value of the peak energy (1)
125-128 F4.2 --- e_Epup [0.08/0.5]? Uncertainty in Epup
130-133 F4.2 --- HRlow [0.2/1.2]? Lower value in the hardness ratio (1)
135-138 F4.2 --- e_HRlow [0.01/0.04]? Uncertainty in HRlow
140-143 F4.2 --- HRup [0.4/1.2]? Upper value in the hardness ratio (1)
145-148 F4.2 --- e_HRup [0.02/0.05]? Uncertainty in HRup
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Note (1): When a upper value is not provided the lower value is the
measured value.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table10.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "Y/M/D" stDate UTC date of observation start
12- 21 A10 "Y/M/D" EndDate UTC date of observation end
23- 27 F5.1 --- TS0.3-2GeV [17.3/103.7] Test-statistic for
the 0.3-2GeV energy range
29- 32 F4.1 ph N0.3-2GeV [19.9/68.6] Number of model predicted
photons for the 0.3-2GeV energy range
34- 37 F4.2 10-8ph/cm/s F0.3-2GeV [1.4/5.3] 0.3-2GeV photon flux
39- 42 F4.2 10-8ph/cm/s e_F0.3-2GeV [0.1/1.1] Uncertainty in F0.3-2GeV
44- 47 F4.2 --- G0.3-2GeV [1.1/2.9] 0.3-2GeV photon index
49- 52 F4.2 --- e_G0.3-2GeV [0.1/0.3] Uncertainty in G0.3-2GeV
54- 58 F5.1 --- TS2-300GeV [43.6/218.2] Test-statistic for
the 2-300GeV energy range
60- 64 F5.2 ph N2-300GeV [8.7/25.4] Number of model predicted
photons for the 2-300GeV energy range
66- 69 F4.2 10-8ph/cm/s F2-300GeV [0.4/1.6] 2-300GeV photon flux
71- 74 F4.2 10-8ph/cm/s e_F2-300GeV [0.09/0.3] Uncertainty in F2-300GeV
76- 79 F4.2 --- G2-300GeV [1.3/2.5] 2-300GeV photon index
81- 84 F4.2 --- e_G2-300GeV [0.08/0.2] Uncertainty in G2-300GeV
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 23-Oct-2018