J/ApJ/795/38 Photometry/spectroscopic measurements for KA1858+4850 (Pei+, 2014)
Reverberation mapping of the Kepler field AGN KA1858+4850.
Pei L., Barth A.J., Aldering G.S., Briley M.M., Carroll C.J., Carson D.J.,
Cenko S.B., Clubb K.I., Cohen D.P., Cucchiara A., Desjardins T.D.,
Edelson R., Fang J.J., Fedrow J.M., Filippenko A.V., Fox O.D., Furniss A.,
Gates E.L., Gregg M., Gustafson S., Horst J.C., Joner M.D., Kelly P.L.,
Lacy M., Laney C.D., Leonard D.C., Li W., Malkan M.A., Margon B.,
Neeleman M., Nguyen M.L., Prochaska J.X., Ross N.R., Sand D.J.,
Searcy K.J., Shivvers I.S., Silverman J.M., Smith G.H., Suzuki N.,
Smith K.L., Tytler D., Werk J.K., Worseck G.
<Astrophys. J., 795, 38 (2014)>
=2014ApJ...795...38P 2014ApJ...795...38P (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Photometry, hydrogen-line ; Spectroscopy
Keywords: galaxies: active - galaxies: individual: 1RXSJ185800.9+485020 -
galaxies: nuclei
Abstract:
KA1858+4850 is a narrow-line Seyfert 1 galaxy at redshift 0.078 and is
among the brightest active galaxies monitored by the Kepler mission.
We have carried out a reverberation mapping campaign designed to
measure the broad-line region size and estimate the mass of the black
hole in this galaxy. We obtained 74 epochs of spectroscopic data using
the Kast Spectrograph at the Lick 3 m telescope from 2012 February to
November, and obtained complementary V-band images from five other
ground-based telescopes. We measured the Hβ light curve lag with
respect to the V-band continuum light curve using both
cross-correlation techniques (CCF) and continuum light curve
variability modeling with the JAVELIN method and found rest-frame lags
of τCCF=13.53-2.32+2.03 days and
τJAVELIN=13.15-1.00+1.08 days. The Hβ rms line profile
has a width of σline=770±49 km/s. Combining these two
results and assuming a virial scale factor of f=5.13, we obtained a
virial estimate of MBH=8.06-1.72+1.59x106M☉ for the
mass of the central black hole and an Eddington ratio of
L/LEdd~0.2. We also obtained consistent but slightly shorter
emission-line lags with respect to the Kepler light curve. Thanks to
the Kepler mission, the light curve of KA1858+4850 has among the
highest cadences and signal-to-noise ratios ever measured for an
active galactic nucleus; thus, our black hole mass measurement will
serve as a reference point for relations between black hole mass and
continuum variability characteristics in active galactic nuclei.
Description:
We employed the Lick Observatory 3 m Shane telescope with the Kast
Spectrograph and five other ground-based telescopes to
spectroscopically and photometrically monitor KA1858+4850 from 2012
February to November. Reverberation mapping requires a continuum light
curve with high sampling cadence and S/N. To achieve this, we obtained
V-band images from ground-based telescopes and used aperture
photometry to construct a light curve for KA1858+4850 that has nearly
nightly sampling for a span of 290 days. For several reasons, we chose
to use the V-band light curve rather than the Kepler light curve for
reverberation measurements.
Objects:
---------------------------------------------------------
RA (ICRS) DE Designation(s)
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18 58 01.11 +48 50 23.4 KA1858+4850 = KIC 11178007
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 34 376 Photometry measurements for KA1858+4850
table4.dat 66 74 Spectroscopic measurements for KA1858+4850
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See also:
J/other/ChJAA/2.501 : Seyfert 1 galaxies (Zhou+, 2002)
J/ApJS/166/128 : Narrow line Seyfert 1 galaxies from SDSS-DR3
(Zhou+, 2006)
J/ApJ/755/60 : Reverberation mapping for five Seyfert 1 galaxies
(Grier+, 2012)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 I10 "date" Date UT Date of the observation
12 A1 --- TCode [FKMNW] Telescope code (1)
14- 21 F8.3 d HJD Heliocentric Julian Date of observation
(HJD-2450000)
23- 28 F6.3 mag Vmag The V band magnitude
30- 34 F5.3 mag e_Vmag Uncertainty in Vmag
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Note (1): Code as follows:
N = 1-m Nickel telescope at Lick Observatory;
M = Mount Laguna Observatory (MLO);
F = Faulkes Telescope North (FTN);
K = Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory;
W = Brigham Young University West Mountain Observatory (WMO).
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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- 10 I10 "date" Date UT Date of the observation
12- 19 F8.3 d HJD Heliocentric Julian Date of observation
(HJD-2450000)
21- 22 I2 --- SNR Signal-to-Noise ratio
24- 28 F5.2 10-18W/m2 fHb Integrated Hβ line flux (1)
30- 33 F4.2 10-18W/m2 e_fHb Uncertainty in fHb (1)
35- 39 F5.2 10-18W/m2 fHg Integrated Hγ line flux (1)
41- 44 F4.2 10-18W/m2 e_fHg Uncertainty in fHg (1)
46- 50 F5.2 10-18W/m2 fHd Integrated Hδ line flux (1)
52- 55 F4.2 10-18W/m2 e_fHd Uncertainty in fHd (1)
57- 61 F5.2 10-18W/m2 fHeII Integrated He II line flux (1)
63- 66 F4.2 10-18W/m2 e_fHeII Uncertainty in fHeII (1)
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Note (1): In units of 1e-15 erg/s/cm2.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 18-May-2017