J/ApJ/959/25 LCO continuum and emission line LCs of NGC 3227 (Bentz+, 2023)
Velocity-resolved reverberation mapping of NGC 3227.
Bentz M.C., Markham M., Rosborough S., Onken C.A., Street R., Valluri M.,
Treu T.
<Astrophys. J., 959, 25 (2023)>
=2023ApJ...959...25B 2023ApJ...959...25B
ADC_Keywords: Galaxies, Seyfert; Photometry; Optical
Keywords: Seyfert galaxies ; Supermassive black holes ; Reverberation mapping
Abstract:
We describe the results of a new reverberation mapping program focused
on the nearby Seyfert galaxy NGC 3227. Photometric and spectroscopic
monitoring was carried out from 2022 December to 2023 June with the
Las Cumbres Observatory network of telescopes. We detected time delays
in several optical broad emission lines, with Hβ having the
longest delay at τcent=4.0-0.9+0.9 days and HeII having the
shortest delay with τcent=0.9-0.8+1.1days. We also detect
velocity-resolved behavior of the Hβ emission line, with
different line-of-sight velocities corresponding to different observed
time delays. Combining the integrated Hβ time delay with the
width of the variable component of the emission line and a standard
scale factor suggests a black hole mass of
MBH=1.1-0.3+0.2x107M☉. Modeling of the full
velocity-resolved response of the Hβ emission line with the
phenomenological code CARAMEL finds a similar mass of
MBH=1.2-0.7+1.5x107M☉ and suggests that the
Hβ-emitting broad-line region (BLR) may be represented by a
biconical or flared disk structure that we are viewing at an
inclination angle of θi∼33° and with gas motions that are
dominated by rotation. The new photoionization-based BLR modeling tool
BELMAC finds general agreement with the observations when assuming the
best-fit CARAMEL results; however, BELMAC prefers a thick-disk
geometry and kinematics that are equally composed of rotation and
inflow. Both codes infer a radially extended and flattened BLR that is
not outflowing.
Description:
Broadband photometric monitoring of NGC 3227 began on 2022 December 1
and continued through 2023 June 4 under programs LCO-2022B-003 and
LCO-2023A-004. Observations were collected on the 1m telescope network
of Las Cumbres Observatory (LCO) using the Sinistro imagers equipped
with Johnson V filters. Exposures were scheduled to occur every ∼8hr,
with a typical exposure time of 60s. Each image covers a field of view
of 26.5'x26.5', with a pixel scale of 0.389".
A total of 376 images were collected from five different observatory
sites over the course of the monitoring program: 93 at Siding Spring
Observatory (SSO), 85 at South African Astronomical Observatory
(SAAO), 84 at McDonald Observatory, 65 at Cerro Tololo Inter-American
Observatory (CTIO), and 49 at Teide Observatory.
See Section 2.1.
Spectroscopic monitoring was carried out on the LCO 2m telescope
network between UT dates 2023 February 2 and 2023 June 1 under
programs LCO-2023A-004 and ANU-2023A-002. The FLOYDS cross-dispersed
spectrographs provided wavelength coverage of 5400Å-1.0um with a
dispersion of 3.51Å/pixel in the first order and wavelength
coverage of 3200-5700Å with a dispersion of 1.74Å/pixel in the
second order.
A total of 51 spectra were acquired over the course of the program,
with 42 acquired by Faulkes Telescope South and 9 by Faulkes Telescope
North.
see Section 2.2.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
10 23 30.57 +19 51 54.2 NGC 3227 = MCG+03-27-016
----------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 81 203 Continuum and emission-line light curves
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See also:
VII/248 : Quasars and Active Galactic Nuclei (12th Ed.) (Veron+ 2006)
J/MNRAS/327/1004 : Early-type galaxy parameters (Blakeslee+, 2001)
J/AJ/128/1761 : HATNET variability survey (Hartman+, 2004)
J/ApJ/613/682 : AGN masses and broad-line region sizes (Peterson+, 2004)
J/ApJ/666/674 : ESSENCE supernova survey (Miknaitis+, 2007)
J/ApJ/761/123 : KELT-1 photometry and spectroscopy follow-up (Siverd+, 2012)
J/ApJ/779/109 : Long-term monitoring of NGC 5548 (Peterson+, 2013)
J/ApJ/821/56 : Space telescope RM project. III. NGC 5548 (Fausnaugh+, 2016)
J/MNRAS/463/3813 : ASASSN-15oi UBVI M2W1W2 light curves (Holoien+, 2016)
J/ApJ/866/133 : Continuum-Hβ light curves of 5 Sy1 (De Rosa+, 2018)
J/ApJ/905/77 : AGNs with Hβ Asymmetry. II. (Brotherton+, 2020)
J/ApJ/944/29 : Reverberation mapping of IC 4329A (Bentz+, 2023)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 F10.4 d HJDc [59914.6/60099.5] Heliocentric Julian
date, continuum, HJDc-2400000
12- 16 F5.3 10-15cW/m2/nm FV [4.8/7.6] V-band flux density,
10-15erg/s/cm2/Å
18- 22 F5.3 10-15cW/m2/nm e_FV [0.04/0.2] FV uncertainty
24- 33 F10.4 d HJDe [59978.1/60096.9]? Heliocentric Julian
date, emission lines, HJDe-2400000
35- 39 F5.3 10-13mW/m2 FHb [3.67/6.4]? Hβ integrated flux,
10-13erg/s/cm2
41- 45 F5.3 10-13mW/m2 e_FHb [0.047/0.2]? Hβ integrated flux
uncertainty, 10-13erg/s/cm2
47- 51 F5.3 10-13mW/m2 FHg [1.29/2.82]? Hγ integrated flux,
10-13erg/s/cm2
53- 57 F5.3 10-13mW/m2 e_FHg [0.04/0.11]? Hγ integrated flux
uncertainty, 10-13erg/s/cm2
59- 63 F5.3 10-13mW/m2 FHd [0.13/1.24]? Hδ integrated flux,
10-13erg/s/cm2
65- 69 F5.3 10-13mW/m2 e_FHd [0.04/0.12]? Hδ integrated flux
uncertainty, 10-13erg/s/cm2
71- 75 F5.3 10-13mW/m2 FHeII [0.84/3.61]? HeII integrated flux,
10-13erg/s/cm2
77- 81 F5.3 10-13mW/m2 e_FHeII [0.05/0.14]? HeII integrated flux
uncertainty, 10-13erg/s/cm2
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 28-Jan-2026