J/ApJ/958/127 SEAMBH in AGNs. XIII. Mrk142 GMOS and LJT spectra (Khatu+, 2023)
Supermassive black holes with high accretion rates in active galactic nuclei.
XIII. Ultraviolet time lag of Hβ emission in Mrk 142.
Khatu V.C., Gallagher S.C., Horne K., Cackett E.M., Hu C., Pasquini S.,
Hall P., Wang J.-M., Bian W.-H., Li Y.-R., Bai J.-M., Chen Y.-J., Du Pu,
Goad M., Jiang B.-W., Li S.-S., Songsheng Y.-Y., Wang C., Xiao M., Yu Z.
<Astrophys. J., 958, 127 (2023)>
=2023ApJ...958..127K 2023ApJ...958..127K
ADC_Keywords: Active gal. nuclei; Spectra, optical
Keywords: Active galactic nuclei ; Accretion ; Spectroscopy
Abstract:
We performed a rigorous reverberation-mapping analysis of the
broad-line region (BLR) in a highly accreting (L/LEdd=0.74-3.4)
active galactic nucleus, Markarian 142 (Mrk 142), for the first time
using concurrent observations of the inner accretion disk and the BLR
to determine a time lag for the Hβλ4861 emission relative
to the ultraviolet (UV) continuum variations. We used continuum data
taken with the Niel Gehrels Swift Observatory in the UVW2 band, and
the Las Cumbres Observatory, Dan Zowada Memorial Observatory, and
Liverpool Telescope in the g band, as part of the broader Mrk 142
multiwavelength monitoring campaign in 2019. We obtained new
spectroscopic observations covering the Hβ broad emission line in
the optical from the Gemini North Telescope and the Lijiang 2.4m
Telescope for a total of 102 epochs (over a period of 8 months)
contemporaneous to the continuum data. Our primary result states a
UV-to-Hβ time lag of 8.68-0.72+0.75 days in Mrk 142 obtained
from light-curve analysis with a Python-based running optimal average
algorithm. We placed our new measurements for Mrk 142 on the optical
and UV radius-luminosity relations for NGC 5548 to understand the
nature of the continuum driver. The positions of Mrk 142 on the
scaling relations suggest that UV is closer to the "true" driving
continuum than the optical. Furthermore, we obtain
log(M•/M☉)=6.32±0.29 assuming UV as the primary
driving continuum.
Description:
We obtained concurrent observations of Mrk 142 with multiple
telescopes to perform reverberation-mapping (RM) analysis of the
accretion disk and broad-line region (BLR) simultaneously.
We obtained new observations of Mrk 142 long-slit spectra taken with
the Gemini Multi-Object Spectrograph (GMOS) on the 8.1m Gemini North
Telescope (Gemini) on Maunakea, Hawai'i with 33 epochs from
2019-Feb-06 through Jun-01. These spectral observations are concurrent
with the Mrk 142 photometric data from the Swift telescope comprising
180 epochs of 1ks exposures at X-ray, UV, and optical wavelengths from
2019 January 1 through April 30 (P.I.: E. Cackett) as well as with the
photometric g-band data from LCO (P.I.: R. Edelson), Zowada
(P.I.: E.Cackett), and Liverpool (P.I.: M. Goad); the photometric data
are presented in Cackett+ (2020ApJ...896....1C 2020ApJ...896....1C).
The spectra were taken with the GMOS-North Hamamatsu detector and a
single grating, B600 with two different slits, 0.75" (narrow slit) and
5.00" (wide slit), in the two-target acquisition mode, where Mrk 142
and a comparison star were observed in the same slit.
The narrow 0.75" slit was selected to obtain a spectral resolution of
∼1125 (narrow-slit data) required to study the velocity structure of
Hβ. We used the wide slit at a resolution of ∼170 (wide-slit
data) to correct for slit losses due to the narrow slit.
A summary of the GMOS-North science observations is provided in Table 1.
To complement the short observing period of 33 epochs with Gemini, we
incorporated supporting observations of Mrk 142 for our study. We
observed Mrk 142 with the Yunnan Faint Object Spectrograph and Camera
on the Lijiang 2.4m Telescope (LJT).
We obtained long-slit spectra of the target at 69 epochs from
2018-Nov-01 through 2019-Jun-21, contemporaneously with the Swift,
LCO+Zowada+Liverpool, and Gemini observing campaigns. Two exposures of
1200s each were taken for each epoch.
See Section 2.2.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
10 25 31.27 +51 40 34.8 Mrk 142 = PG 1022+519
----------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 47 66 *Summary of Mrk 142 GMOS observations
from 2019 February to June
table4.dat 36 33 [OIII]λ5008 emission-line measurements
for Gemini spectra
table5.dat 57 33 Hβλ4861 emission-line measurements
for Gemini spectra
table6.dat 55 33 HeIλ5877 emission-line measurements for
Gemini spectra
table7.dat 38 69 [OIII]λ5008 emission-line measurements for
LJT spectra
table8.dat 58 69 Hβλ4861 emission-line measurements for
LJT spectra
table9.dat 58 69 HeIλ5877 emission-line measurements for LJT
spectra
sp/* . 33 Individual GMOS spectra in ASCII format
(Data behind Figure 2)
--------------------------------------------------------------------------------
Note on table1.dat: Observations were done with the GMOS-North Hamamatsu
detector in the two-target acquisition mode (Mrk 142 and a comparison
star in the same slit) positioning the slit at 155.20° east of
north, with the B600 grating (covering the broad Hβ emission line
at ∼4862Å) and two slits, 0.75" (narrow slit) and 5.00" (wide
slit). Two exposures were taken with every grating/slit combination,
each 90s long. A data quality flag (DQF) of "P" (passable) or "U"
(usable) was assigned to all data at the time of observing. Unless
stated otherwise, all science spectra were assigned a DQF of "P".
SpectroPhotometric CALibration Flag (SPCALF) indicates whether the
science spectra were calibrated ("1") or not calibrated ("0") during
spectral reduction (see Section 3.1.4 for more details).
SpectroPhotometric CALibration Grade (SPCALG) indicates the grade
assigned to the spectrophotometric calibration based on the epoch and
exposure of the calibration star spectrum used for calibrating the
science spectra (see Section 3.1.4 for more details). All science
spectra were assigned an SPCALF of 1 and an SPCALG of "A" unless
indicated otherwise.
--------------------------------------------------------------------------------
See also:
J/ApJS/115/185 : 3C 390.3 BVRI and H photometry (Dietrich+, 1998)
J/ApJ/755/60 : Reverberation mapping for 5 Seyfert 1 galaxies (Grier+, 2012)
J/ApJ/782/45 : SEAMBHs. I. Mrk 142, Mrk 335, and IRAS F12397+3333 (Du+, 2014)
J/ApJ/795/38 : Phot./spectroscopic measurements for KA1858+4850 (Pei+, 2014)
J/ApJ/795/149 : Reverberation mapping of the Sy1 NGC 7469 (Peterson+, 2014)
J/ApJ/793/108 : SEAMBHs. II. Continuum and Hbeta LCs (Wang+, 2014)
J/ApJ/806/22 : SEAMBHs IV. Hβ time lags (Du+, 2015)
J/ApJ/825/126 : SEAMBHs. V. The third year (Du+, 2016)
J/ApJ/827/118 : A new reverberation mapping campaign on NGC 5548 (Lu+, 2016)
J/ApJ/837/131 : Space telescope RM project. V. NGC5548 sp. (Pei+, 2017)
J/ApJ/866/133 : Continuum-Hβ light curves of 5 Seyfert 1 (De Rosa+, 2018)
J/ApJ/856/6 : SEAMBHs IX. 10 new Hβ light curves (Du+, 2018)
J/ApJ/870/123 : Swift optical & UV flux of four AGNs (Edelson+, 2019)
J/ApJ/876/49 : A 10yr reverberation mapping campaign for 3C273 (Zhang+, 2019)
J/ApJ/896/1 : SEAMBHs. XI. Mrk 142 X-ray to optical LCs (Cackett+, 2020)
J/ApJ/901/133 : Supermassive BH masses of AGNs (Yu+, 2020)
J/ApJ/920/9 : YFOSC light curves of PG 0923+201 and PG 1001+291 (Li+, 2021)
J/ApJS/263/10 : 2015, 2018-2021 sp. monitoring of NGC 5548 (Lu+, 2022)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 yr Epoch [1/33] Epoch number
4- 13 A10 "Y/M/D" Date Date of observation (UT)
15- 23 F9.3 d MJD Modified Julian Date at the start
of the observations, 0.75" slit
24 A1 --- f_MJD Flag on MJD (1)
26- 34 F9.3 d MJD5 Modified Julian Date at the start
of the observations, 5.00" slit
35 A1 --- f_MJD5 Flag on MJD5 (1)
37- 41 F5.3 --- Airmass [1.175/1.7] Airmass, 0.75" slit
43- 47 F5.3 --- Airmass5 [1.176/1.75] Airmass, 5.00" slit
--------------------------------------------------------------------------------
Note (1): Flag as follows:
c = Science spectrum assigned SPCALF, DQF = 0 (not calibrated).
d = Science spectrum calibrated with the narrow-slit standard star
spectrum from exposure 1 and hence assigned SPCALG, DQF = B.
e = Science spectrum likely had a calibration issue and hence was not
used for further analysis (see Appendix for details).
f = Science spectrum assigned DQF = U (usable).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Epoch [1/33] Gemini Spectrum Epoch
4- 10 F7.2 0.1nm lambda [5008.11/5008.34] Position of [OIII]5008A,
Angstroms
12- 15 F4.2 0.1nm e_lambda [0.03/0.07] Uncertainty in lambda
17- 19 I3 km/s FWHM [292/338] FWHM, [OIII]5008Å
21- 22 I2 km/s e_FWHM [2/10] Uncertainty in FWHM
24- 27 F4.1 10-18W/m2 Flux [15.3/16.4] Flux, [OIII]5008Å,
10-15erg/s/cm2
29- 31 F3.1 10-18W/m2 e_Flux [0.2/0.5] Uncertainty in Flux
33- 36 F4.2 --- chi2v [0.97/1.35] Reduced χ^2/dof model
statistic
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Epoch [1/33] Gemini Spectrum Epoch
4- 7 I4 km/s FWHM-b [1499/1830] FWHM, Hβ4861Å, broad
component
9- 11 I3 km/s e_FWHM-b [43/132] Uncertainty in FWHM-b
13- 17 F5.1 10-18W/m2 Flux-b [94.9/140.4] Flux, Hβ4861Å, broad
component, 10-15erg/s/cm2
19- 21 F3.1 10-18W/m2 e_Flux-b [2.1/5.8] Uncertainty in flux-b
23- 25 I3 km/s FWHM-n [291/337] FWHM, Hβ4861Å, narrow
component
27- 28 I2 km/s e_FWHM-n [1/10] Uncertainty in FWHM-n
30- 32 F3.1 10-18W/m2 Flux-n [3.1/6.1] Flux, Hβ4861Å, narrow
component, 10-15erg/s/cm2
34- 36 F3.1 10-18W/m2 e_Flux-n [0.4/0.8] Uncertainty in flux-n
38- 41 I4 km/s FWHM-t [1235/1603] FWHM, Hβ4861A, total
43- 45 I3 km/s e_FWHM-t [30/165] Uncertainty in FWHM-t
47- 51 F5.1 10-18W/m2 Flux-t [99.2/146.3] Flux, Hβ4861Å, total,
10-15erg/s/cm2
53- 55 F3.1 10-18W/m2 e_Flux-t [2.1/5.8] Uncertainty in Flux-t
57 A1 --- f_Epoch Epoch rejection flags (G1)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Epoch [1/33] Gemini Spectrum Epoch
4 A1 --- f_Epoch Epoch rejection flags (G1)
6- 9 I4 km/s FWHM-b [34/1870] FWHM, HeI5877Å, broad component
11- 13 I3 km/s e_FWHM-b [25/654] Uncertainty in FWHM-b
15- 18 F4.1 10-18W/m2 Flux-b [31.4/55.6] Flux, HeI5877Å, broad
component, 10-15erg/s/cm2
20- 22 F3.1 10-18W/m2 e_Flux-b [0.7/1.4] Uncertainty in Flux-b
24- 26 I3 km/s FWHM-n [291/337] FWHM, HeI5877Å,
narrow component
28- 29 I2 km/s e_FWHM-n [1/10] Uncertainty in FWHM-n
31- 33 F3.1 10-18W/m2 Flux-n [0.0/0.9] Flux, HeI5877Å, narrow
component, 10-15 erg/s/cm2
35- 37 F3.1 10-18W/m2 e_Flux-n [0.1/0.2] Uncertainty in Flux-n
39- 42 I4 km/s FWHM-t [34/1962] FWHM, HeI5877A, total
44- 46 I3 km/s e_FWHM-t [20/682] Uncertainty in FWHM-t
48- 51 F4.1 10-18W/m2 Flux-t [32.0/55.7] Flux, HeI5877Å, total,
10-15erg/s/cm2
53- 55 F3.1 10-18W/m2 e_Flux-t [0.7/1.4] Uncertainty in Flux-t
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Epoch [1/69] LJT Spectrum Epoch
4 A1 --- f_Epoch Epoch rejection flags (G2)
6- 12 F7.2 0.1nm lambda [5007.16/5008.33] Position of [OIII]5008Å,
Angstroms
14- 17 F4.2 0.1nm e_lambda [0.06/0.24] Uncertainty in lambda
19- 21 I3 km/s FWHM [634/880] FWHM, [OIII]5008Å
23- 24 I2 km/s e_FWHM [0/49]? Uncertainty in FWHM
26- 29 F4.1 10-18W/m2 Flux [14.5/19.6] Flux, [OIII]5008Å,
10-15erg/s/cm2
31- 33 F3.1 10-18W/m2 e_Flux [0.2/1.0] Uncertainty in Flux
35- 38 F4.2 --- chi2v [1.05/4.65] Reduced χ^2/dof model
statistic
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table8.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Epoch [1/69] LJT Spectrum Epoch
4- 7 I4 km/s FWHM-b [1802/2129] FWHM, Hβ4861Å, broad
component
9- 11 I3 km/s e_FWHM-b [29/133] Uncertainty in FWHM-b
13- 16 F4.1 10-18W/m2 Flux-b [75.4/98.8] Flux, Hβ4861Å, broad
component, 10-15erg/s/cm2
18- 21 F4.1 10-18W/m2 e_Flux-b [0.7/21.5] Uncertainty in Flux-b
23- 25 I3 km/s FWHM-n [634/880] FWHM, Hβ4861Å, narrow
component
27- 28 I2 km/s e_FWHM-n [0/49]? Uncertainty in FWHM-n
30- 32 F3.1 10-18W/m2 Flux-n [4.2/5.7] Flux, Hβ4861Å, narrow
component, 10-15erg/s/cm2
34- 36 F3.1 10-18W/m2 e_Flux-n [0.0/0.3] Uncertainty in Flux-n
38- 41 I4 km/s FWHM-t [1536/1848] FWHM, Hβ4861Å, total
43- 45 I3 km/s e_FWHM-t [29/127] Uncertainty in FWHM-t
47- 51 F5.1 10-18W/m2 Flux-t [80.6/103.0] Flux, Hβ4861Å, total,
10-15erg/s/cm2
53- 56 F4.1 10-18W/m2 e_Flux-t [0.7/21.5] Uncertainty in Flux-t
58 A1 --- f_Epoch Epoch rejection flags (G2)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table9.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Epoch [1/69] LJT Spectrum Epoch
4 A1 --- f_Epoch Epoch rejection flags (G2)
6- 9 I4 km/s FWHM-b [1713/5320] FWHM, HeI5877Å,
broad component
11- 14 I4 km/s e_FWHM-b [224/1067] Uncertainty in FWHM-b
16- 19 F4.1 10-18W/m2 Flux-b [45.0/61.1] Flux, HeI5877Å, broad
component, 10-15erg/s/cm2
21- 23 F3.1 10-18W/m2 e_Flux-b [0.9/4.1] Uncertainty in Flux-b
25- 27 I3 km/s FWHM-n [634/880] FWHM, HeI5877Å,
narrow component
29- 30 I2 km/s e_FWHM-n [0/49]? Uncertainty in FWHM-n
32- 35 F4.2 10-18W/m2 Flux-n [0.49/0.67] Flux, HeI5877Å, narrow
component, 10-15erg/s/cm2
37- 40 F4.2 10-18W/m2 e_Flux-n [0.01/0.03] Uncertainty in Flux-n
42- 45 I4 km/s FWHM-t [1708/4224] FWHM, HeI5877Å, total
47- 49 I3 km/s e_FWHM-t [203/876] Uncertainty in FWHM-t
51- 54 F4.1 10-18W/m2 Flux-t [45.6/61.7] Flux, HeI5877Å, total,
10-15erg/s/cm2
56- 58 F3.1 10-18W/m2 e_Flux-t [0.9/4.1] Uncertainty in Flux-t
--------------------------------------------------------------------------------
Byte-by-byte Description of file: sp/*
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 F7.2 0.1nm lambda [4399.97/6299.52] Wavelength,
Rest-frame, Angstroms
9- 12 F4.2 10-15cW/m2/nm Flambda [1.1/7.22] Flux,
10-15erg/s/cm2/Angstrom
14- 17 F4.2 10-15cW/m2/nm e_Flambda [0.03/0.7] Error in flambda
--------------------------------------------------------------------------------
Global notes:
Note (G1): Epoch rejection flags as follows:
a = Because the noisy region blueward of the Hβ emission
line was unable to well constrain the broad, blue wing of
Hβ4861Å, this epoch was excluded from further analysis.
b = Due to a calibration issue at the location of the Hβ
emission line, the Hβ profile appeared unusually broader
and brighter than in other spectra. Therefore, this epoch was
excluded from further analysis.
Note (G2): Epoch rejection flags as follows:
a = This spectrum appeared very noisy likely due to some
disturbance in the field of view at the time of observation.
Therefore, we excluded this epoch from further analysis.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
License: CC-BY-4.0
References:
Du et al. Paper I. 2014ApJ...782...45D 2014ApJ...782...45D Cat. J/ApJ/782/45
Wang et al. Paper II. 2014ApJ...793..108W 2014ApJ...793..108W Cat. J/ApJ/793/108
Hu et al. Paper III. 2015ApJ...804..138H 2015ApJ...804..138H
Du et al. Paper IV. 2015ApJ...806...22D 2015ApJ...806...22D Cat. J/ApJ/806/22
Du et al. Paper V. 2016ApJ...825..126D 2016ApJ...825..126D Cat. J/ApJ/825/126
Du et al. Paper VI. 2016ApJ...820...27D 2016ApJ...820...27D
Xiao et al. Paper VII. 2018ApJ...864..109X 2018ApJ...864..109X
Li et al. Paper VIII. 2018ApJ...869..137L 2018ApJ...869..137L
Du et al. Paper IX. 2018ApJ...856....6D 2018ApJ...856....6D Cat. J/ApJ/856/6
Lu et al. Paper X. 2019ApJ...877...23L 2019ApJ...877...23L Cat. J/ApJ/877/23
Cackett et al. Paper XI. 2020ApJ...896....1C 2020ApJ...896....1C Cat. J/ApJ/896/1
Hu et al. Paper XII. 2021ApJS..253...20H 2021ApJS..253...20H Cat. J/ApJS/253/20
Khatu et al. Paper XIII. 2023ApJ...958..127K 2023ApJ...958..127K This catalog
Hu et al. Paper XIV. 2025ApJS..278...61H 2025ApJS..278...61H Cat. J/ApJS/278/61
Bai et al. Paper XV. 2026ApJS..282...56B 2026ApJS..282...56B
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 07-May-2026