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J/ApJ/806/129    Space telescope RM project. II. Swift data    (Edelson+, 2015)

Space telescope and optical reverberation mapping project. II. Swift and HST reverberation mapping of the accretion disk of NGC 5548. Edelson R., Gelbord J.M., Horne K., McHardy I.M., Peterson B.M., Arevalo P., Breeveld A.A., De Rosa G., Evans P.A., Goad M.R., Kriss G.A., Brandt W.N., Gehrels N., Grupe D., Kennea J.A., Kochanek C.S., Nousek J.A., Papadakis I., Siegel M., Starkey D., Uttley P., Vaughan S., Young S., Barth A.J., Bentz M.C., Brewer B.J., Crenshaw D.M., Dalla Bonta E., De Lorenzo-Caceres A., Denney K.D., Dietrich M., Ely J., Fausnaugh M.M., Grier C.J., Hall P.B., Kaastra J., Kelly B.C., Korista K.T., Lira P., Mathur S., Netzer H., Pancoast A., Pei L., Pogge R.W., Schimoia J.S., Treu T., Vestergaard M., Villforth C., Yan H., Zu Y. <Astrophys. J., 806, 129 (2015)> =2015ApJ...806..129E (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Photometry, UBV ; Ultraviolet ; X-ray sources Keywords: galaxies: active; galaxies: individual: NGC 5548; galaxies: nuclei; galaxies: Seyfert Abstract: Recent intensive Swift monitoring of the Seyfert 1 galaxy NGC 5548 yielded 282 usable epochs over 125 days across six UV/optical bands and the X-rays. This is the densest extended active galactic nucleus (AGN) UV/optical continuum sampling ever obtained, with a mean sampling rate <0.5 day. Approximately daily Hubble Space Telescope UV sampling was also obtained. The UV/optical light curves show strong correlations (rmax=0.57-0.90) and the clearest measurement to date of interband lags. These lags are well-fit by a τ∝λ4/3 wavelength dependence, with a normalization that indicates an unexpectedly large disk radius of ∼0.35±0.05lt-day at 1367Å, assuming a simple face-on model. The U band shows a marginally larger lag than expected from the fit and surrounding bands, which could be due to Balmer continuum emission from the broad-line region as suggested by Korista and Goad. The UV/X-ray correlation is weaker (rmax<0.45) and less consistent over time. This indicates that while Swift is beginning to measure UV/optical lags in general agreement with accretion disk theory (although the derived size is larger than predicted), the relationship with X-ray variability is less well understood. Combining this accretion disk size estimate with those from quasar microlensing studies suggests that AGN disk sizes scale approximately linearly with central black hole mass over a wide range of masses. Description: In 2014 February-June, Swift executed a monitoring campaign on NGC5548 that was ground-breaking in two respects: 1) it was comprised of 360 separate visits over a ∼4 month period, of which 282 successful visits were obtained, for a sampling rate (after removing bad data) better than one visit every ∼0.5day, and 2) it utilized all six UVOT filters in each visit, with 239 (84%) providing usable measurements in all six filters. The Swift XRT data were gathered in photon counting mode (see table 3). In addition, a parallel HST emission-line reverberation mapping (RM) campaign yielded daily UV spectroscopic monitoring of NGC 5548 over a slightly longer period (see Paper I, De Rosa+, 2015, J/ApJ/806/128). Objects: --------------------------------------------------- RA (ICRS) DE Designation(s) --------------------------------------------------- 14 17 59.51 +25 08 12.5 NGC 5548 = LEDA 51074 --------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 28 2606 Swift/UVOT data table3.dat 35 725 Swift/XRT data
See also: J/ApJ/806/128 : Space telescope RM project. I. NGC5548 (De Rosa+, 2015) J/ApJ/798/95 : HE1104-1805 BVRIJ light curves (Blackburne+, 2015) J/ApJ/779/109 : Long-term monitoring of NGC 5548 (Peterson+, 2013) J/MNRAS/433/1709 : PKS 0558-504 UVOT and XRT monitoring (Gliozzi+, 2013) J/ApJ/753/104 : AGN identifications from AKARI and Swift (Matsuta+, 2012) J/MNRAS/397/1177 : Swift-XRT observations of GRBs (Evans+, 2009) J/ApJ/622/129 : Lag-luminosity relationship in AGN (Sergeev+, 2005) J/ApJ/613/682 : AGN central masses & broad-line reg. sizes (Peterson+, 2004) Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 11 F11.3 d HJD Heliocentric Julian Date (1) 13- 16 A4 --- Filt Swift/UVOT filter used (UBV, UVM2, UVW1, or UVW2) (1) 18- 22 F5.3 10-14cW/m2/nm Flux [0.5/4.4] Measured flux; in 1e-14erg/s/cm2/Å unit 24- 28 F5.3 10-14cW/m2/nm e_Flux [0.01/0.2] Measured 1σ error in Flux
Note (1): Note that this table includes all usable Swift observations of NGC 5548, not just those from the intensive monitoring period. The data are sorted first by filter, then by HJD.
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 11 F11.3 D HJD Heliocentric Julian Date (1) 13- 17 F5.3 ct/s HX [0.1/2.2] Measured Swift 0.8-10keV X-ray count rate 19- 23 F5.3 ct/s e_HX [0.01/0.3] Measured 1σ error in HX 25- 29 F5.3 ct/s SX [0.006/0.5] Measured Swift 0.3-0.8keV X-ray count rate 31- 35 F5.3 ct/s e_SX [0.003/0.2] Measured 1σ error in SX
Note (1): Note that this table includes all usable Swift observations of NGC 5548, not just those from the intensive monitoring period, sorted by HJD.
History: From electronic version of the journal References: De Rosa et al. Paper I. 2015ApJ...806..128D Cat. J/ApJ/806/128 Fausnaugh et al. Paper III. 2016ApJ...821...56F Cat. J/ApJ/821/56 Goad et al. Paper IV. 2016ApJ...824...11G
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 16-Oct-2015
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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