THE LICK AGN MONITORING PROJECT: REVERBERATION MAPPING OF OPTICAL HYDROGEN AND HELIUM RECOMBINATION LINES
By M. Bentz, Jonelle L. Walsh, A. Barth, Y. Yoshii, J. Woo, Xiaofeng Wang, T. Treu, C. E. Thornton, R. Street, T. Steele and 16 more. 2010
139 citations recorded by the source corpus.
We have recently completed a 64-night spectroscopic monitoring campaign at the Lick Observatory 3 m Shane telescope with the aim of measuring the masses of the black holes in 12 nearby (z < 0.05) Seyfert 1 galaxies with expected masses in the range ∼106–107 M☉ and also the well-studied nearby active galactic nucleus (AGN) NGC 5548. Nine of the objects in the sample (including NGC 5548) showed optical variability of sufficient strength during the monitoring campaign to allow for a time lag to be measured between the continuum fluctuations and the response to these fluctuations in the broad Hβ emission, which we have previously reported. We present here the light curves for the Hα, Hγ, He ii λ4686, and He i λ5876 emission lines and the time lags for the emission-line responses relative to changes in the continuum flux. Combining each emission-line time lag with the measured width of the line in the variable part of the spectrum, we determine a virial mass of the central supermassive black hole from several independent emission lines. We find that the masses are generally consistent within the uncertainties. The time-lag response as a function of velocity across the Balmer line profiles is examined for six of the AGNs. We find similar responses across all three Balmer lines for Arp 151, which shows a strongly asymmetric profile, and for SBS 1116+583A and NGC 6814, which show a symmetric response about zero velocity. For the other three AGNs, the data quality is somewhat lower and the velocity-resolved time-lag response is less clear. Finally, we compare several trends seen in the data set against the predictions from photoionization calculations as presented by Korista & Goad. We confirm several of their predictions, including an increase in responsivity and a decrease in the mean time lag as the excitation and ionization level for the species increases. Specifically, we find the time lags of the optical recombination lines to have weighted mean ratios of τ(Hα):τ(Hβ):τ(Hγ):τ(He i):τ(He ii) = 1.54:1.00:0.61:0.36:0.25. Further confirmation of photoionization predictions for broad-line gas behavior will require additional monitoring programs for these AGNs while they are in different luminosity states.
Subfields: Astronomy and Astrophysics, Instrumentation
View Paper: https://www.semanticscholar.org/paper/7af9c8d474b28b6ac66596f49e4b848f36daa609
How researchers see this paper
The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.
In Astronomy and Astrophysics
In Instrumentation
Citations in the corpus
- THE LOW-LUMINOSITY END OF THE RADIUS–LUMINOSITY RELATIONSHIP FOR ACTIVE GALACTIC NUCLEI (2013, background): “A subset of objects in the reverberation sample have measurements for several different emission lines throughout the ultraviolet and optical portions of their spectra, and the multiple emission lines show a virial behavior (e.g., Peterson & Wandel 1999, 2000; Kollatschny 2003; Bentz et al. 2010).”
- THE LICK AGN MONITORING PROJECT 2011: SPECTROSCOPIC CAMPAIGN AND EMISSION-LINE LIGHT CURVES (2015, methodology): “…Silva, Michele Fumagalli, Jessica Werk, Michael Gregg, Chelsea Harris, Jeffrey Lee, Liliana Lopez, 33 The Lick AGN Monitoring Project 2008 spectroscopic dataset (Bentz et al. 2009b, 2010a) has been recently released for public use, and is currently available at the web site of A.J.B. at UC Irvine.”
- The Sloan Digital Sky Survey Reverberation Mapping Project: Hα and Hβ Reverberation Measurements from First-year Spectroscopy and Photometry (2017, methodology): “We see that in all cases, the Hα lag is consistent with or larger than the Hβ lag — this was also reported in previous studies (e.g., Kaspi et al. 2000; Bentz et al. 2010).”
- PS1-10jh: THE DISRUPTION OF A MAIN-SEQUENCE STAR OF NEAR-SOLAR COMPOSITION (2013, methodology): “…line regions (BLRs) of steadily-accreting AGN, we predict that the helium lines that are observed in PS1-10jh are produced much closer to the black hole (Korista et al. 1995; Bentz et al. 2010), and the debris has sufficient time to reach this distance by the time the first spectrum was observed.”
- A ∼50,000 M⊙ SOLAR MASS BLACK HOLE IN THE NUCLEUS OF RGG 118 (2015, methodology): “Assuming the broad emission is indeed the signature of gas rotat- ing around a nuclear BH, we can estimate the BH mass using standard virial techniques which assume the gas in the broad line region surrounding the BH is in virial equilibrium (Peterson et al. 2004; Bentz et al. 2010).”
- THE STRUCTURE OF THE BROAD-LINE REGION IN ACTIVE GALACTIC NUCLEI. I. RECONSTRUCTED VELOCITY-DELAY MAPS (2012, methodology): “More recent spectroscopic monitoring campaigns for reverberationmapping have been specifically designed to, among other things, recover velocity-delay maps (e.g., Bentz et al. 2010a, Denney et al. 2011).”
- Measuring the Masses of Supermassive Black Holes (2014, methodology): “It is only relatively recently that reliable velocity–delay maps have begun to appear in the literature (Bentz et al. 2010b; Grier et al. 2013), with examples shown in Figures 4 and 5.”
- THE SLOAN DIGITAL SKY SURVEY REVERBERATION MAPPING PROJECT: TECHNICAL OVERVIEW (2014, methodology): “This is an updated version of the PrepSpec procedure which has been used in earlier RM studies (e.g., Bentz et al. 2010b).”