J/ApJ/901/55 SDSS-RM project: MgII lags from 4yrs monitoring (Homayouni+, 2020)
The Sloan Digital Sky Survey Reverberation Mapping project: MgII lag results
from four years of monitoring.
Homayouni Y., Trump J.R., Grier C.J., Horne K., Shen Y., Brandt W.N.,
Dawson K.S., Fonseca Alvarez G., Green P.J., Hall P.B.,
Hernandez Santisteban J.V., Ho L.C., Kinemuchi K., Kochanek C.S.,
Li J.I.-H., Peterson B.M., Schneider D.P., Starkey D.A., Bizyaev D.,
Pan K., Oravetz D., Simmons A.
<Astrophys. J., 901, 55 (2020)>
=2020ApJ...901...55H 2020ApJ...901...55H
ADC_Keywords: QSOs; Redshifts; Photometry, SDSS
Keywords: Active galaxies ; Galaxy nuclei ; Quasars ; Active galactic nuclei
Abstract:
We present reverberation mapping results for the MgIIλ2800Å
broad emission line in a sample of 193 quasars at 0.35<z<1.7 with
photometric and spectroscopic monitoring observations from the Sloan
Digital Sky Survey Reverberation Mapping project during 2014-2017. We
find significant time lags between the MgII and continuum lightcurves
for 57 quasars, and define a "gold sample" of 24 quasars with the most
reliable lag measurements. We estimate false-positive rates for each
lag that range from 1% to 24%, with an average false-positive rate of
11% for the full sample and 8% for the gold sample. There are an
additional ∼40 quasars with marginal MgII lag detections, which may
yield reliable lags after additional years of monitoring. The MgII
lags follow a radius-luminosity relation with a best-fit slope that is
consistent with α=0.5, but with an intrinsic scatter of 0.36dex
that is significantly larger than found for the Hβ
radius-luminosity relation. For targets with SDSS-RM lag measurements
of other emission lines, we find that our MgII lags are similar to the
Hβ lags and ∼2-3 times larger than the CIV lags. This work
significantly increases the number of MgII broad-line lags and
provides additional reverberation-mapped black hole masses, filling
the redshift gap at the peak of supermassive black hole growth between
the Hβ and CIV emission lines in optical spectroscopy.
Description:
Our sample is drawn from the 849 quasars monitored by the Sloan
Digital Sky Survey Reverberation Mapping (SDSS-RM) project, with
spectroscopy and photometry in a single 7deg2 field observed every
year from January-July since 2014 (see Shen+ 2015, J/ApJS/216/4 &
2019, J/ApJS/241/34).
The SDSS-RM monitoring includes multi-epoch spectroscopy from the BOSS
spectrograph mounted on the 2.5m SDSS telescope, covering wavelengths
of 3650-10400Å with a spectral resolution of R∼2000. We use four
years of SDSS-RM spectroscopic observations, obtained annually during
dark/gray observing windows from 2014 January to 2017 July, for a
total of 68 spectroscopic epochs.
SDSS-RM is supported by ground-based photometry from the 3.6m
Canada-France-Hawaii Telescope (CFHT) MegaCam and the 2.3m Steward
Observatory Bok telescope 90" imagers. Photometry was obtained in the
g and i filters over the full SDSS-RM field, with the same
January-July time coverage over 2014-2017 and a faster cadence than
the spectroscopy.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 105 57 *MgII significant lag results
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Note on table1.dat: We measure lags from the SDSS-RM lightcurves following
the same approach as Grier+ (2019, J/ApJ/887/38), with two widely used
time series analysis methods adapted for multiyear observations:
JAVELIN (Zu+ 2011ApJ...735...80Z 2011ApJ...735...80Z) and CREAM (Starkey+ 2016MNRAS.456.1960S 2016MNRAS.456.1960S).
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See also:
J/ApJ/632/799 : NGC4395 light curves (Peterson+, 2005)
J/ApJ/698/895 : Variations in QSOs optical flux (Kelly+, 2009)
J/ApJ/699/800 : Mass functions of active black holes (Vestergaard+, 2009)
J/ApJ/716/993 : LAMP: reverberation mapping of H and He lines (Bentz+, 2010)
J/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)
J/ApJ/746/169 : Luminosity function of broad-line quasars (Shen+, 2012)
J/ApJ/755/60 : Reverberation mapping for 5 Seyfert 1 galaxies (Grier+, 2012)
J/A+A/562/A34 : UV FeII template from LBQS 2113-4538 (Hryniewicz+, 2014)
J/ApJS/216/4 : SDSS-RM project: technical overview (Shen+, 2015)
J/ApJS/217/26 : Lick AGN monitoring 2011: light curves (Barth+, 2015)
J/ApJ/806/22 : SEAMBHs IV. Hβ time lags (Du+, 2015)
J/ApJ/806/128 : Space telescope RM project. I. NGC5548 (De Rosa+, 2015)
J/ApJ/805/96 : SDSS-RM project: velocity dispersions of QSOs (Shen+, 2015)
J/ApJ/811/91 : SDSS-RM project: z<1 QSO host galaxies (Matsuoka+, 2015)
J/ApJ/818/30 : Lag measurements for 15 z<0.8 QSOs from SDSS-RM (Shen+, 2016)
J/ApJ/821/56 : Space telescope RM project. III. NGC5548 LCs (Fausnaugh+, 2016)
J/ApJ/824/130 : SDSS/BOSS/TDSS CIV BAL quasars (Grier+, 2016)
J/ApJ/825/126 : SEAMBHs. V. The third year (Du+, 2016)
J/ApJ/831/7 : SDSS-RM project: peak velocities of QSOs (Shen+, 2016)
J/ApJ/837/131 : Space telescope RM project. V. NGC5548 sp. (Pei+, 2017)
J/ApJ/851/21 : SDSS RM project first year of observations (Grier+, 2017)
J/ApJ/865/56 : Emission line & R-band continuum LCs of 17 QSOs (Lira+, 2018)
J/ApJ/872/21 : SDSS RM project: <10day CIV BAL variability (Hemler+, 2019)
J/ApJ/880/46 : Spectroscopy & V-band monitoring of CTS C30.10 (Czerny+, 2019)
J/ApJ/880/126 : SDSS RM project: continuum lags (Homayouni+, 2019)
J/ApJ/881/153 : Space telescope RM project VIII. NGC5548 HST sp. (Kriss+, 2019)
J/ApJ/882/4 : SDSS-RM project: Hα, Hβ & MgII lines (Wang+, 2019)
J/ApJ/886/42 : Reverberation mapping & opt. spectra data of AGNs (Du+, 2019)
J/ApJ/887/38 : SDSS RM Project: CIV lags & LCs from 4yrs obs. (Grier+, 2019)
J/ApJS/241/34 : The SDSS Reverberation Mapping (SDSS-RM) project (Shen+, 2019)
J/ApJS/242/28 : MgII-BAL quasar variability in SDSS spectra (Yi+, 2019)
J/ApJS/250/10 : SDSS-RM AGNs CFHT & Bok photometry over 4yrs (Kinemuchi+, 2020)
http://www.sdss3.org/ : SDSS-III home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- RMID [18/848] Object ID of SDSS-RM quasars (1)
5- 9 F5.3 --- z [0.36/1.7] Improved systemic redshift (1)
11- 19 F9.5 deg RAdeg [211.47/216.06] Right Ascension (J2000) (1)
21- 28 F8.5 deg DEdeg [51.8/54.2] Declination (J2000) (1)
30- 34 F5.2 mag imag [17.73/21.64] i band PSF magnitude (1)
36- 40 F5.1 --- SNR2 [20/190] signal-to-noise-ratio of
the MgII variability
(SNR2=(χ2-DOF))0.5)
42- 45 F4.1 [10-7W] logL3000 [43.5/46.1] log of continuum luminosity
at rest-frame 3000Å, in erg/s (1)
47- 51 F5.1 d tau-JAV [17/388] Rest-frame lag with JAVELIN
53- 56 F4.1 d E_tau-JAV [3/31] Upper uncertainty on tau-JAV
58- 61 F4.1 d e_tau-JAV [2.6/74.3] Lower uncertainty on tau-JAV
63- 66 F4.1 % fpeak [60/97.6] Fraction of the lag posterior
within the primary peak
68- 71 F4.1 % FPR [1/24] False-positive rate
73- 78 F6.1 d tau-CREAM [-579/367] Rest-frame lag with CREAM
80- 83 F4.1 d E_tau-CREAM [1/31.5] Upper uncertainty on tau-CREAM
85- 88 F4.1 d e_tau-CREAM [1.3/48.3] Lower uncertainty on tau-CREAM
90- 93 F4.2 [Msun] logMBH [7.7/9.6] Log of MgII-based black hole mass
95- 98 F4.2 [Msun] E_logMBH [0.16/0.42] Upper uncertainty on logMBH
100-103 F4.2 [Msun] e_logMBH [0.16/0.22] Lower uncertainty on logMBH
105-105 I1 --- Gold [0/1] Gold flag (2)
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Note (1): Identifiers, positions, magnitudes, and redshifts from
Shen+ 2019, J/ApJS/241/34
Note (2): Gold flag as follows:
1 = a member of the "gold sample" of 24 significant and positive lags
with false-positive rates of ≤10%.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 06-Jan-2022