J/ApJ/889/142 Swift/XRT and NICER timing study of MAXI J1820+070 (Stiele+, 2020)
A timing study of MAXI J1820+070 based on Swift/XRT and NICER monitoring in
2018/19.
Stiele H., Kong A.K.H.
<Astrophys. J., 889, 142 (2020)>
=2020ApJ...889..142S 2020ApJ...889..142S
ADC_Keywords: Binaries, X-ray; Black holes; X-ray sources
Keywords: Stellar mass black holes ; Low-mass X-ray binary stars ;
Close binary stars ; Transient sources
Abstract:
We present a detailed timing analysis of the bright black hole X-ray
binary MAXI J1820+070 (ASASSN-18ey), during its first detected
outburst lasting from 2018 March until 2019 October based on Swift/XRT
window timing mode observations, corresponding UVOT data and NICER
observations. The light curves clearly show four outbursts, with the
source remaining in the hard state during its first outburst, while
the rise of the second outburst corresponds with the transition to the
soft state. A similar double outburst of GX339-4 has been observed in
2004. Here it is followed by two hard-state only outbursts. In many
observations the power density spectra showed type-C quasi-periodic
oscillations (QPOs) with characteristic frequencies below 1Hz, which
suggests that the source stayed in a state of low effective accretion
for large parts of its outburst. The absence of other types of QPOs
hinders a precise determination of the state transitions, but from
combining NICER and Swift/XRT data, we find that MAXI J1820+070 went
from the hard-intermediate to the soft state in less than one day. The
covariance ratios derived from NICER data show an increase toward
lower energies, which indicate that the source should make a
transition to the soft state. This transition finally took place,
after MAXI J1820+070 stayed in the hard state at rather constant
luminosity for about 116 days. The steepness of the increase of the
covariance ratios is not correlated with the amount of rms variability
and it does not show a monotonic evolution along the outburst.
Description:
All Swift/XRT monitoring data of MAXI J1820+070 obtained in window
timing mode between 2018 March 11 (MJD 58188) and 2019 September 28
are analyzed in this study.
NICER (Neutron star Interior Composition Explorer) observed
MAXIJ1820+070 between 2018 March 12 and 2018 July 5, where
observations with an exposure of less than 1ks have been excluded from
our study. NICER resumed observing this source on 2018 September 25
and followed it until 2019 October 25.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
18 20 21.94 +07 11 07.3 MAXI J1820+070 = ASASSN -18ey
----------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 78 88 Parameters of the band-limited noise (BLN) components
of the power density spectra (PDS)
derived from Swift/XRT data
table2.dat 75 101 Parameters of the quasi-periodic oscillations (QPOs)
of the PDS derived from Swift/XRT
table3.dat 135 196 Parameters of the noise components of
the PDS derived from NICER data
table4.dat 77 212 Parameters of the QPOs of the PDS derived
from NICER data
table5.dat 73 39 Additional Lorentzian needed to fit QPO
at higher frequency in NICER data
table6.dat 73 6 Additional QPOs or peaked noise features
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See also:
B/gcvs : General Catalogue of Variable Stars (Samus+, 2007-2017)
B/swift : Swift Master Catalog (HEASARC, 2004-)
J/A+A/407/1039 : X-ray power spectra of Cygnus X-1 (Pottschmidt+, 2003)
J/ApJS/222/15 : WATCHDOG: all-sky database of Gal. BHXBs (Tetarenko+, 2016)
J/MNRAS/496/L96 : Polarization of LMXB MAXI J1820+070 (Kosenkov+, 2020)
J/A+A/645/A18 : SVOM-ECLAIRs known X-ray sources catalogue (Dagoneau+, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 F6.2 d Time [2.74/545.05] Days since 2018 March 11th
8- 12 F5.3 Hz numaxBLN1 [0.002/4.6] Characteristic frequency of first
band limited noise component
14- 18 F5.3 Hz e_numaxBLN1 [0.002/0.9] Lower error on numaxBLN1
20- 24 F5.3 Hz E_numaxBLN1 [0.003/1.7] Upper error on numaxBLN1
26- 30 F5.3 -- rmsBLN1 [0.066/0.4] RMS of first BLN component
32- 36 F5.3 -- e_rmsBLN1 [0/0.08] Lower error on rmsBLN1
38- 42 F5.3 -- E_rmsBLN1 [0.002/1] Upper error on rmsBLN1
44- 48 F5.3 Hz numaxBLN2 [0.01/8.4]? Characteristic frequency of
second band limited noise component
50- 54 F5.3 Hz e_numaxBLN2 [0.003/1.7]? Lower error on numaxBLN2
56- 60 F5.3 Hz E_numaxBLN2 [0.004/2.5]? Upper error on numaxBLN2
62- 66 F5.3 -- rmsBLN2 [0.048/0.7]? RMS of second BLN component
68- 72 F5.3 -- e_rmsBLN2 [0/0.2]? Lower error on rmsBLN2
74- 78 F5.3 -- E_rmsBLN2 [0.003/1]? Upper error on rmsBLN2
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 F6.2 d Time [23.8/536.02] Days since 2018 March 11th
8- 12 F5.3 Hz nu0 [0.06/6.2] QPO centroid frequency
14- 18 F5.3 Hz e_nu0 [0/0.11] Lower uncertainty in nu0
20- 24 F5.3 Hz E_nu0 [0/0.09] Upper uncertainty in nu0
26 A1 --- l_Delta Upper limit flag on Delta
27- 31 F5.3 Hz Delta [0.001/0.54] QPO half width at half maximum
33- 37 F5.3 Hz e_Delta [0.001/0.12]? Lower uncertainty in Delta
39- 43 F5.3 Hz E_Delta [0.003/0.14]? Upper uncertainty in Delta
45 A1 --- l_rms Lower limit flag on rms
46- 50 F5.3 --- rms [0.019/0.15] QPO root mean square
52- 56 F5.3 --- e_rms [0.003/0.03]? Lower uncertainty in rms
58- 62 F5.3 --- E_rms [0.003/0.03]? Upper uncertainty in rms
64- 68 F5.2 --- Q [0.6/50.8] QPO quality factor (G1)
70- 73 F4.2 --- sigma [1.3/6.3] Detection significance of the QPO
75 I1 --- Num [1/4] QPO component number
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 F6.2 d Time [1.58/552.02] Days since 2018 March 11th
8 A1 --- l_nuBLN1 Upper limit flag on nuBLN1
9- 14 F6.3 Hz nuBLN1 [0/29.4] Characteristic frequency of 1st band
limited noise component
16- 20 F5.3 Hz e_nuBLN1 [0/6.2]? Lower uncertainty in nuBLN1
22- 27 F6.3 Hz E_nuBLN1 [0/12.3]? Upper uncertainty in nuBLN1
29 A1 --- l_rmsBLN1 Lower limit flag on rmsBLN1
30- 34 F5.3 --- rmsBLN1 [0.03/1.22] First band limited noise component
root mean square
36- 40 F5.3 --- e_rmsBLN1 [0.001/1.1]? Lower uncertainty in rmsBLN1
42- 46 F5.3 --- E_rmsBLN1 [0.001/6.1]? Upper uncertainty in rmsBLN1
48- 53 F6.3 Hz nuBLN2 [0.007/25]? Characteristic frequency of 2nd band
limited noise component
55- 59 F5.3 Hz e_nuBLN2 [0.001/5.6]? Lower uncertainty in nuBLN2
61- 66 F6.3 Hz E_nuBLN2 [0/12.6]? Upper uncertainty in nuBLN2
68 A1 --- l_rmsBLN2 Lower limit flag on rmsBLN2
69- 73 F5.3 --- rmsBLN2 [0.018/0.43]? Second band limited noise component
root mean square
75- 79 F5.3 --- e_rmsBLN2 [0.001/0.09]? Lower uncertainty in rmsBLN2
81- 85 F5.3 --- E_rmsBLN2 [0.001/0.08]? Upper uncertainty in rmsBLN2
87 A1 --- l_nuPN1 Upper limit flag on nuPN1
88- 92 F5.3 Hz nuPN1 [0.002/8.6]? Characteristic frequency of 1st peak
noise component
94- 98 F5.3 Hz e_nuPN1 [0.001/2.9]? Lower uncertainty in nuPN1
100-104 F5.3 Hz E_nuPN1 [0.001/2.6]? Upper uncertainty in nuPN1
106 A1 --- l_rmsPN1 Lower limit flag on rmsPN1
107-111 F5.3 --- rmsPN1 [0.005/1]? First peak noise component
root mean square
113-117 F5.3 --- e_rmsPN1 [0.001/0.3]? Lower uncertainty in rmsPN1
119-123 F5.3 --- E_rmsPN1 [0.001/0.6]? Upper uncertainty in rmsPN1
125-129 F5.2 --- QPN1 [0.39/11.82]? First PN component quality factor
(G1)
131-135 F5.2 --- sigma [0.85/34.53]? Detection significance of the QPO1
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 F6.2 d Time [10.39/551.57] Days since 2018 March 11th
8- 13 F6.3 Hz nu0 [0.018/13.75] QPO centroid frequency
15- 19 F5.3 Hz e_nu0 [0/0.32] Lower uncertainty in nu0
21- 25 F5.3 Hz E_nu0 [0/0.45] Upper uncertainty in nu0
27 A1 --- l_Delta Upper limit flag on Delta
28- 32 F5.3 Hz Delta [0.001/2.17] QPO half width at half maximum
34- 38 F5.3 Hz e_Delta [0.001/0.5]? Lower uncertainty in Delta
40- 44 F5.3 Hz E_Delta [0/0.5]? Upper uncertainty in Delta
46 A1 --- l_rms Lower limit flag on rms
47- 51 F5.3 --- rms [0.01/0.2] QPO root mean square
53- 57 F5.3 --- e_rms [0.001/0.05]? Upper uncertainty in rms
59- 63 F5.3 --- E_rms [0.001/0.04]? Upper uncertainty in rms
65- 69 F5.2 --- Q [0.07/76.83] QPO quality factor (G1)
71- 75 F5.2 --- sigma [0.88/18] Detection significance of the QPO
77- 77 I1 --- Num [1/2] QPO component number
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 F6.2 d Time [23.32/115.88] Days since 2018 March 11th
8- 12 F5.3 Hz nu0 [0.16/3.52] QPO centroid frequency
14- 18 F5.3 Hz e_nu0 [0.008/0.34] Lower uncertainty in nu0
20- 24 F5.3 Hz E_nu0 [0.008/0.41] Upper uncertainty in nu0
26 A1 --- l_Delta Upper limit flag on Delta
27- 31 F5.3 Hz Delta [0.048/1.98] QPO half width at half maximum
33- 37 F5.3 Hz e_Delta [0.007/0.3]? Lower uncertainty in Delta
39- 43 F5.3 Hz E_Delta [0.002/0.3]? Upper uncertainty in Delta
45 A1 --- l_rms Lower limit flag on rms
46- 50 F5.3 --- rms [0.009/0.13] QPO root mean square
52- 56 F5.3 --- e_rms [0.005/0.04]? Upper uncertainty in rms
58- 62 F5.3 --- E_rms [0.004/0.04]? Upper uncertainty in rms
64- 68 F5.2 --- Q [0.8/75.4] QPO quality factor (G1)
70- 73 F4.2 --- sigma [1.18/6.6] Detection significance of the QPO
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 F6.2 d Time [85.26/525.05] Days since 2018 March 11th
8- 12 F5.3 Hz nu0 [0.08/1.41] QPO centroid frequency
14- 18 F5.3 Hz e_nu0 [0.006/0.06] Lower uncertainty in nu0
20- 24 F5.3 Hz E_nu0 [0.001/0.05] Upper uncertainty in nu0
26 A1 --- l_Delta Upper limit flag on Delta
27- 31 F5.3 Hz Delta [0.014/0.4] QPO half width at half maximum
33- 37 F5.3 Hz e_Delta [0.01/0.07]? Lower uncertainty in Delta
39- 43 F5.3 Hz E_Delta [0.007/0.09]? Upper uncertainty in Delta
45- 49 F5.3 --- rms [0.024/0.22] QPO root mean square
51- 55 F5.3 --- e_rms [0.003/0.02] Upper uncertainty in rms
57- 61 F5.3 --- E_rms [0.003/0.01] Upper uncertainty in rms
63- 67 F5.2 --- Q [0.69/12.6] QPO quality factor (G1)
69- 73 F5.2 --- sigma [2.4/25.4] Detection significance of the QPO
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Global notes:
Note (G1): The quality factor (Q) = v0/(2Δ), where v0 is the centroid
frequency, and Δ is the half width at half maximum.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 20-Oct-2021