J/ApJ/840/41 X-ray/UV Swift monitoring of NGC 4151 (Edelson+, 2017)
Swift monitoring of NGC 4151: evidence for a second X-Ray/UV reprocessing.
Edelson R., Gelbord J., Cackett E., Connolly S., Done C., Fausnaugh M.,
Gardner E., Gehrels N., Goad M., Horne K., McHardy I., Peterson B.M.,
Vaughan S., Vestergaard M., Breeveld A., Barth A.J., Bentz M., Bottorff M.,
Brandt W.N., Crawford S.M., Bonta E.D., Emmanoulopoulos D., Evans P.,
Jaimes R.F., Filippenko A.V., Ferland G., Grupe D., Joner M., Kennea J.,
Korista K.T., Krimm H.A., Kriss G., Leonard D.C., Mathur S., Netzer H.,
Nousek J., Page K., Romero-Colmenero E., Siegel M., Starkey D.A., Treu T.,
Vogler H.A., Winkler H., Zheng W.
<Astrophys. J., 840, 41 (2017)>
=2017ApJ...840...41E 2017ApJ...840...41E
ADC_Keywords: Active gal. nuclei ; Photometry, UBV ; Photometry, ultraviolet ;
X-ray sources
Keywords: galaxies: active; galaxies: individual (NGC 4151); galaxies: nuclei;
galaxies: Seyfert
Abstract:
Swift monitoring of NGC 4151 with an ∼6hr sampling over a total of
69days in early 2016 is used to construct light curves covering five
bands in the X-rays (0.3-50keV) and six in the ultraviolet
(UV)/optical (1900-5500Å). The three hardest X-ray bands (>2.5keV)
are all strongly correlated with no measurable interband lag, while
the two softer bands show lower variability and weaker correlations.
The UV/optical bands are significantly correlated with the X-rays,
lagging ∼3-4days behind the hard X-rays. The variability within the
UV/optical bands is also strongly correlated, with the UV appearing to
lead the optical by ∼0.5-1days. This combination of ≳3day lags
between the X-rays and UV and ≲1day lags within the UV/optical
appears to rule out the "lamp-post" reprocessing model in which a hot,
X-ray emitting corona directly illuminates the accretion disk, which
then reprocesses the energy in the UV/optical. Instead, these results
appear consistent with the Gardner & Done (2017MNRAS.470.3591G 2017MNRAS.470.3591G)
picture in which two separate reprocessings occur: first, emission
from the corona illuminates an extreme-UV-emitting toroidal component
that shields the disk from the corona; this then heats the extreme-UV
component, which illuminates the disk and drives its variability.
Description:
During 2016 February 20 through April 29, Swift executed an intensive
monitoring campaign on NGC 4151, consisting of 319 separate visits of
at least 120s, an average of nearly five visits per day.
These Swift observations were coordinated with intensive monitoring
with numerous ground-based telescopes including the Las Cumbres
Observatory Global Telescope network and the Liverpool Telescope at La
Palma. Those data will be presented in subsequent papers (K. Horne et
al. 2017, in preparation; M. Goad et al. 2017, in preparation).
Objects:
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RA (ICRS) DE Designation(s)
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12 10 32.58 +39 24 21.0 NGC 4151 = SWIFT J1210.5+3924
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 40 1684 Swift/UVOT data
table4.dat 83 319 Swift/XRT data
table5.dat 34 69 Swift/BAT data
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See also:
J/ApJ/613/682 : AGN masses & broad-line region sizes (Peterson+, 2004)
J/ApJ/622/129 : Lag-luminosity relationship in AGN (Sergeev+, 2005)
J/ApJ/681/113 : Swift BAT survey of AGNs (Tueller+, 2008)
J/MNRAS/397/1177 : Swift-XRT observations of GRBs (Evans+, 2009)
J/ApJ/713/L11 : X-ray properties of Seyfert 1 galaxies (Zhou+, 2010)
J/ApJ/753/104 : AGN identifications from AKARI and Swift (Matsuta+, 2012)
J/ApJ/754/45 : IR properties of Swift/BAT X-ray AGNs (Ichikawa+, 2012)
J/MNRAS/433/1709 : PKS 0558-504 UVOT and XRT monitoring (Gliozzi+, 2013)
J/ApJS/209/14 : The Swift/BAT hard X-ray transient monitor (Krimm+, 2013)
J/A+A/563/A57 : Long-term variability of AGN at hard X-rays (Soldi+, 2014)
J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)
J/ApJ/806/129 : Space telescope RM project. II. Swift data (Edelson+, 2015)
J/ApJ/821/56 : Space telescope RM project. III. NGC 5548 (Fausnaugh+, 2016)
J/A+A/588/A70 : Hard X-ray view of the soft excess in AGN (Boissay+, 2016)
http://swift.gsfc.nasa.gov/results/transients/weak/NGC4151.lc.txt : Swift-BAT
daily average light curve for NGC 4151
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 11 F11.5 d MJD Modified Julian Date of mid-exposure
13- 23 F11.9 10-14cW/m2/nm Flux [2.9/7] Measured flux in Filt (1)
25- 35 F11.9 10-14cW/m2/nm e_Flux [0.05/0.2] 1σ error in Flux (1)
37- 40 A4 --- Filt Filter used
(u, b, v, uvw1, uvm2 or uvw2) (2)
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Note (1): In units of 1e-14 erg/s/cm2/Angstrom.
Note (2): The data are sorted first by filter, then by MJD.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 11 F11.5 d MJD Modified Julian Date of mid-exposure
13- 20 F8.6 ct/s X1 [0.04/0.3] Measured 0.3-1.25keV flux
22- 29 F8.6 ct/s e_X1 The 1σ error in X1
31- 38 F8.6 ct/s X2 [0.04/0.2] Measured 1.25-2.5keV flux
40- 47 F8.6 ct/s e_X2 The 1σ error in X2
49- 56 F8.6 ct/s X3 [0.1/1.2] Measured 2.5-5keV flux
58- 65 F8.6 ct/s e_X3 The 1σ error in X3
67- 74 F8.6 ct/s X4 [0.1/0.9] Measured 5-10keV flux
76- 83 F8.6 ct/s e_X4 The 1σ error in X4
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 7 F7.1 d MJD Modified Julian Date
13- 22 F10.8 ct/s Flux [0.003/0.01] Measured 15-50keV flux
25- 34 F10.8 ct/s e_Flux [0.0006/0.003] The 1σ error in Flux
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History:
From electronic version of the journal
Table 5 has been cut to 69 rows to match only the Swift/BAT data.
Acknowledgements:
Rick Edelson [University of Maryland; e-mail: redelson
followed by {at}astro.umd.edu]
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 11-Dec-2017