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J/ApJ/788/48      X-ray through NIR photometry of NGC 2617      (Shappee+, 2014)

The man behind the curtain: X-rays drive the UV through NIR variability in the 2013 active galactic nucleus outburst in NGC 2617. Shappee B.J., Prieto J.L., Grupe D., Kochanek C.S., Stanek K.Z., De Rosa G., Mathur S., Zu Y., Peterson B.M., Pogge R.W., Komossa S., Im M., Jencson J., Holoien T.W-S., Basu U., Beacom J.F., Szczygiel D.M., Brimacombe J., Adams S., Campillay A., Choi C., Contreras C., Dietrich M., Dubberley M., Elphick M., Foale S., Giustini M., Gonzalez C., Hawkins E., Howell D.A., Hsiao E.Y., Koss M., Leighly K.M., Morrell N., Mudd D., Mullins D., Nugent J.M., Parrent J., Phillips M.M., Pojmanski G., Rosing W., Ross R., Sand D., Terndrup D.M., Valenti S., Walker Z., Yoon Y. <Astrophys. J., 788, 48 (2014)> =2014ApJ...788...48S (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Galaxies, Seyfert ; X-ray sources ; Photometry, UBVRIJKLMNH ; Photometry, SDSS Keywords: galaxies: active - galaxies: nuclei - galaxies: Seyfert - line: formation - line: profiles Abstract: After the All-Sky Automated Survey for SuperNovae discovered a significant brightening of the inner region of NGC 2617, we began a ∼70 day photometric and spectroscopic monitoring campaign from the X-ray through near-infrared (NIR) wavelengths. We report that NGC 2617 went through a dramatic outburst, during which its X-ray flux increased by over an order of magnitude followed by an increase of its optical/ultraviolet (UV) continuum flux by almost an order of magnitude. NGC 2617, classified as a Seyfert 1.8 galaxy in 2003, is now a Seyfert 1 due to the appearance of broad optical emission lines and a continuum blue bump. Such "changing look active galactic nuclei (AGNs)" are rare and provide us with important insights about AGN physics. Based on the Hβ line width and the radius-luminosity relation, we estimate the mass of central black hole (BH) to be (4±1)x107 M. When we cross-correlate the light curves, we find that the disk emission lags the X-rays, with the lag becoming longer as we move from the UV (2-3 days) to the NIR (6-9 days). Also, the NIR is more heavily temporally smoothed than the UV. This can largely be explained by a simple model of a thermally emitting thin disk around a BH of the estimated mass that is illuminated by the observed, variable X-ray fluxes. Description: On 2013 April 10.27, a transient source alert was triggered by the brightening of the central region of NGC 2617. Follow-up observations confirmed that the nucleus was the source of the outburst and a follow-up spectrum showed that the source now has the strong broad emission lines and continuum shape characteristic of a Seyfert 1. Given the strong outburst and dramatic change in the spectral properties, we requested and obtained Swift (Gehrels et al. 2004ApJ...611.1005G) target of opportunity (ToO) observations to monitor NGC 2617 in the optical, UV, and X-rays, which found that NGC 2617 continued to brighten. During this outburst we were able to obtain an extensive time series of optical spectroscopy and NIR/optical/UV/X-ray photometry that are presented in this paper. Objects: ---------------------------------------------------------------- RA (ICRS) DE Designation(s) ---------------------------------------------------------------- 08 35 38.78 -04 05 17.3 NGC 2617 = 2MASX J08353877-0405172 ---------------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 52 528 Photometric Observations
See also: VII/173 : Catalogue of Seyfert Galaxies (Lipovetsky+, 1988) II/339 : Swift/UVOT Serendipitous Source Catalog (Yershov, 2015) J/ApJ/705/14 : Seyfert galaxies in the mid-IR (Deo+, 2009) J/ApJ/713/L11 : X-ray properties of Seyfert 1 galaxies (Zhou+, 2010) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 8 F8.3 d JD Julian Date of the observation (JD-2450000) 10- 21 A12 --- Band Observational band 23- 27 F5.2 mag mag ? Observed magnitude (1) 29- 32 F4.2 mag e_mag ? Uncertainty in mag 34- 37 F4.2 10-14W/m2 FX ? X-ray flux (2) 39- 42 F4.2 10-14W/m2 e_FX ? Uncertainty in FX 44- 47 F4.2 --- Gamma ? Photon Index; X-ray data only 49- 52 F4.2 --- e_Gamma ? Uncertainty in Gamma
Note (1): Magnitudes with the Swift, U, B, V, R, I, Z, Y, J, H, and K-band photometry are calibrated in the Vega magnitude system. u, g, r, and i-band photometry are calibrated in the AB magnitude system. Note (2): The units of the Swift 0.3-10 keV X-ray fluxes (first 41 data rows) are in 10-11 erg/s/cm2.
History: From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 06-Jul-2017
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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