J/ApJ/756/73 gri light curves of the low-luminosity AGN NGC 4395 (Edri+, 2012)
Broadband photometric reverberation mapping of NGC 4395.
Edri H., Rafter S.E., Chelouche D., Kaspi S., Behar E.
<Astrophys. J., 756, 73 (2012)>
=2012ApJ...756...73E 2012ApJ...756...73E
ADC_Keywords: Active gal. nuclei ; Photometry, ugriz
Keywords: galaxies: active; galaxies: fundamental parameters; galaxies: Seyfert;
methods: observational; quasars: individual: NGC 4395;
techniques: photometric
Abstract:
We present results of broadband photometric reverberation mapping (RM)
to measure the radius of the broad-line region, and subsequently the
black hole mass (MBH), in the nearby, low-luminosity active galactic
nuclei NGC 4395. Using the Wise Observatory's 1m telescope equipped
with the Sloan Digital Sky Survey g', r', and i' broadband filters, we
monitored NGC 4395 for nine consecutive nights and obtained three
light curves each with over 250 data points. The g' and r' bands
include time variable contributions from Hβ and Hα,
respectively, plus continuum. The i' band is free of broad lines and
covers exclusively continuum. We show that by looking for a peak in
the difference between the cross-correlation and the auto-correlation
functions for all combinations of filters, we can get a reliable
estimate of the time lag necessary to compute MBH. We measure the
time lag for Hα to be 3.6±0.8hr, comparable to previous
studies using the line-resolved spectroscopic RM method. We argue that
this lag implies a black hole mass of MBH=(4.9±2.6)x104M☉.
Description:
We observed NGC 4395 for nine nights during 2011, from February 23 to
March 6, with the Wise Observatory's 1m telescope that is equipped
with the Sloan Digital Sky Survey (SDSS) g', r', and i' filters.
Objects:
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RA (ICRS) DE Designation(s)
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12 25 48.92 +33 32 48.3 NGC 4395 = MCG+06-27-053
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 28 823 Photometric light curves for NGC 4395
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See also:
J/ApJ/753/L2 : Reverberation mapping of AGNs (Assef+, 2012)
J/A+A/529/A25 : Phot. of star clusters in 5 nearby gal. (Silva-Villa+, 2011)
J/AJ/142/122 : SDSS DR7 galaxy/QSOs pairs (Cherinka+, 2011)
J/MNRAS/407/2399 : AGN activity and black hole mass (McKernan+, 2010)
J/ApJ/650/88 : NGC4395 light curves. III. (Desroches+, 2006)
J/ApJ/641/L21 : Black hole mass & velocity dispersion relation (Greene+, 2006)
J/ApJ/632/799 : NGC4395 light curves (Peterson+, 2005)
J/ApJ/613/682 : AGN central masses & broad-line region sizes (Peterson+, 2004)
J/A+A/391/809 : HII regions in NGC 5457 and NGC 4395 (Cedres+, 2002)
J/A+A/390/863 : CCD R Photometry of WHISP Dwarf Galaxies (Swaters, 2002)
J/ApJS/143/257 : AGN emission line properties (Kuraszkiewicz+, 2002)
J/ApJS/112/315 : Spectroscopic parameters of Seyfert nuclei (Ho+ 1997)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 A1 --- Filt SDSS filter used in the observation (g, r, i)
3- 15 F13.5 d JD Julian Date of the observation
17- 22 F6.3 mag mag [16.14/17.37] Observed magnitude in Filt
24- 28 F5.3 mag e_mag [0.01/0.06] Uncertainty in mag
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 25-Mar-2014