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Title: THE LICK AGN MONITORING PROJECT 2011: DYNAMICAL MODELING OF THE BROAD-LINE REGION IN Mrk 50

Abstract

We present dynamical modeling of the broad-line region (BLR) in the Seyfert 1 galaxy Mrk 50 using reverberation mapping data taken as part of the Lick AGN Monitoring Project (LAMP) 2011. We model the reverberation mapping data directly, constraining the geometry and kinematics of the BLR, as well as deriving a black hole mass estimate that does not depend on a normalizing factor or virial coefficient. We find that the geometry of the BLR in Mrk 50 is a nearly face-on thick disk, with a mean radius of 9.6{sup +1.2}{sub -0.9} light days, a width of the BLR of 6.9{sup +1.2}{sub -1.1} light days, and a disk opening angle of 25 {+-} 10 deg above the plane. We also constrain the inclination angle to be 9{sup +7}{sub -5} deg, close to face-on. Finally, the black hole mass of Mrk 50 is inferred to be log{sub 10}(M{sub BH}/M{sub Sun }) = 7.57{sup +0.44}{sub -0.27}. By comparison to the virial black hole mass estimate from traditional reverberation mapping analysis, we find the normalizing constant (virial coefficient) to be log{sub 10} f = 0.78{sup +0.44}{sub -0.27}, consistent with the commonly adopted mean value of 0.74 based on aligning the M{sub BH}-{sigma}* relation formore » active galactic nuclei and quiescent galaxies. While our dynamical model includes the possibility of a net inflow or outflow in the BLR, we cannot distinguish between these two scenarios.« less

Authors:
; ; ; ;  [1]; ;  [2];  [3]; ; ; ;  [4];  [5];  [6];  [7]; ;  [8];  [9];  [10];  [11] more »; « less
  1. Department of Physics, University of California, Santa Barbara, CA 93106 (United States)
  2. Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California, Irvine, CA 92697-4575 (United States)
  3. Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States)
  4. Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)
  5. Lick Observatory, P.O. Box 85, Mount Hamilton, CA 95140 (United States)
  6. Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)
  7. Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States)
  8. Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Boulevard, Pasadena, CA 91109 (United States)
  9. Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of)
  10. Department of Astronomy and Center for Galaxy Evolution Research, Yonsei University, Seoul 120-749 (Korea, Republic of)
  11. Department of Physics and Astronomy, N283 ESC, Brigham Young University, Provo, UT 84602-4360 (United States)
Publication Date:
OSTI Identifier:
22039294
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 754; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTRONOMY; ASTROPHYSICS; BLACK HOLES; COMPARATIVE EVALUATIONS; GALAXY NUCLEI; INCLINATION; MAPPING; MASS; MONITORING; SEYFERT GALAXIES; VISIBLE RADIATION

Citation Formats

Pancoast, Anna, Brewer, Brendon J., Treu, Tommaso, Bennert, Vardha N., Sand, David J., Barth, Aaron J., Cooper, Michael C., Canalizo, Gabriela, Filippenko, Alexei V., Li, Weidong, Cenko, S. Bradley, Clubb, Kelsey I., Gates, Elinor L., Greene, Jenny E., Malkan, Matthew A., Stern, Daniel, Assef, Roberto J., Woo, Jong-Hak, Bae, Hyun-Jin, Buehler, Tabitha, E-mail: pancoast@physics.ucsb.edu, and and others. THE LICK AGN MONITORING PROJECT 2011: DYNAMICAL MODELING OF THE BROAD-LINE REGION IN Mrk 50. United States: N. p., 2012. Web. doi:10.1088/0004-637X/754/1/49.
Pancoast, Anna, Brewer, Brendon J., Treu, Tommaso, Bennert, Vardha N., Sand, David J., Barth, Aaron J., Cooper, Michael C., Canalizo, Gabriela, Filippenko, Alexei V., Li, Weidong, Cenko, S. Bradley, Clubb, Kelsey I., Gates, Elinor L., Greene, Jenny E., Malkan, Matthew A., Stern, Daniel, Assef, Roberto J., Woo, Jong-Hak, Bae, Hyun-Jin, Buehler, Tabitha, E-mail: pancoast@physics.ucsb.edu, & and others. THE LICK AGN MONITORING PROJECT 2011: DYNAMICAL MODELING OF THE BROAD-LINE REGION IN Mrk 50. United States. doi:10.1088/0004-637X/754/1/49.
Pancoast, Anna, Brewer, Brendon J., Treu, Tommaso, Bennert, Vardha N., Sand, David J., Barth, Aaron J., Cooper, Michael C., Canalizo, Gabriela, Filippenko, Alexei V., Li, Weidong, Cenko, S. Bradley, Clubb, Kelsey I., Gates, Elinor L., Greene, Jenny E., Malkan, Matthew A., Stern, Daniel, Assef, Roberto J., Woo, Jong-Hak, Bae, Hyun-Jin, Buehler, Tabitha, E-mail: pancoast@physics.ucsb.edu, and and others. Fri . "THE LICK AGN MONITORING PROJECT 2011: DYNAMICAL MODELING OF THE BROAD-LINE REGION IN Mrk 50". United States. doi:10.1088/0004-637X/754/1/49.
@article{osti_22039294,
title = {THE LICK AGN MONITORING PROJECT 2011: DYNAMICAL MODELING OF THE BROAD-LINE REGION IN Mrk 50},
author = {Pancoast, Anna and Brewer, Brendon J. and Treu, Tommaso and Bennert, Vardha N. and Sand, David J. and Barth, Aaron J. and Cooper, Michael C. and Canalizo, Gabriela and Filippenko, Alexei V. and Li, Weidong and Cenko, S. Bradley and Clubb, Kelsey I. and Gates, Elinor L. and Greene, Jenny E. and Malkan, Matthew A. and Stern, Daniel and Assef, Roberto J. and Woo, Jong-Hak and Bae, Hyun-Jin and Buehler, Tabitha, E-mail: pancoast@physics.ucsb.edu and and others},
abstractNote = {We present dynamical modeling of the broad-line region (BLR) in the Seyfert 1 galaxy Mrk 50 using reverberation mapping data taken as part of the Lick AGN Monitoring Project (LAMP) 2011. We model the reverberation mapping data directly, constraining the geometry and kinematics of the BLR, as well as deriving a black hole mass estimate that does not depend on a normalizing factor or virial coefficient. We find that the geometry of the BLR in Mrk 50 is a nearly face-on thick disk, with a mean radius of 9.6{sup +1.2}{sub -0.9} light days, a width of the BLR of 6.9{sup +1.2}{sub -1.1} light days, and a disk opening angle of 25 {+-} 10 deg above the plane. We also constrain the inclination angle to be 9{sup +7}{sub -5} deg, close to face-on. Finally, the black hole mass of Mrk 50 is inferred to be log{sub 10}(M{sub BH}/M{sub Sun }) = 7.57{sup +0.44}{sub -0.27}. By comparison to the virial black hole mass estimate from traditional reverberation mapping analysis, we find the normalizing constant (virial coefficient) to be log{sub 10} f = 0.78{sup +0.44}{sub -0.27}, consistent with the commonly adopted mean value of 0.74 based on aligning the M{sub BH}-{sigma}* relation for active galactic nuclei and quiescent galaxies. While our dynamical model includes the possibility of a net inflow or outflow in the BLR, we cannot distinguish between these two scenarios.},
doi = {10.1088/0004-637X/754/1/49},
journal = {Astrophysical Journal},
number = 1,
volume = 754,
place = {United States},
year = {Fri Jul 20 00:00:00 EDT 2012},
month = {Fri Jul 20 00:00:00 EDT 2012}
}
  • The prominent broad Fe II emission blends in the spectra of active galactic nuclei have been shown to vary in response to continuum variations, but past attempts to measure the reverberation lag time of the optical Fe II lines have met with only limited success. Here we report the detection of Fe II reverberation in two Seyfert 1 galaxies, NGC 4593 and Mrk 1511, based on data from a program carried out at Lick Observatory in Spring 2011. Light curves for emission lines including Hβ and Fe II were measured by applying a fitting routine to decompose the spectra intomore » several continuum and emission-line components, and we use cross-correlation techniques to determine the reverberation lags of the emission lines relative to V-band light curves. In both cases, the measured lag (τ{sub cen}) of Fe II is longer than that of Hβ, although the inferred lags are somewhat sensitive to the choice of Fe II template used in the fit. For spectral decompositions done using the Fe II template of Véron-Cetty et al., we find τ{sub cen}(Fe II)/τ{sub cen}(Hβ) = 1.9 ± 0.6 in NGC 4593 and 1.5 ± 0.3 in Mrk 1511. The detection of highly correlated variations between Fe II and continuum emission demonstrates that the Fe II emission in these galaxies originates in photoionized gas, located predominantly in the outer portion of the broad-line region.« less
  • 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 approx10{sup 6}-10{sup 7} M {sub sun} 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 themore » broad Hbeta emission. We present here the light curves for all the objects in this sample and the subsequent Hbeta time lags for the nine objects where these measurements were possible. The Hbeta lag time is directly related to the size of the broad-line region (BLR) in AGNs, and by combining the Hbeta lag time with the measured width of the Hbeta emission line in the variable part of the spectrum, we determine the virial mass of the central supermassive black hole in these nine AGNs. The absolute calibration of the black hole masses is based on the normalization derived by Onken et al., which brings the masses determined by reverberation mapping into agreement with the local M {sub BH}-sigma{sub *}relationship for quiescent galaxies. We also examine the time lag response as a function of velocity across the Hbeta line profile for six of the AGNs. The analysis of four leads to rather ambiguous results with relatively flat time lags as a function of velocity. However, SBS 1116+583A exhibits a symmetric time lag response around the line center reminiscent of simple models for circularly orbiting BLR clouds, and Arp 151 shows an asymmetric profile that is most easily explained by a simple gravitational infall model. Further investigation will be necessary to fully understand the constraints placed on the physical models of the BLR by the velocity-resolved response in these objects.« less
  • It is now possible to estimate black hole (BH) masses across cosmic time, using broad emission lines in active galaxies. This technique informs our views of how galaxies and their central BHs coevolve. Unfortunately, there are many outstanding uncertainties associated with these 'virial' mass estimates. One of these comes from using the accretion luminosity to infer a size for the broad-line region (BLR). Incorporating the new sample of low-luminosity active galaxies from our recent monitoring campaign at Lick Observatory, we recalibrate the radius-luminosity relation with tracers of the accretion luminosity other than the optical continuum. We find that the radiusmore » of the BLR scales as the square root of the X-ray and H{beta} luminosities, in agreement with recent optical studies. On the other hand, the scaling appears to be marginally steeper with narrow-line luminosities. This is consistent with a previously observed decrease in the ratio of narrow-line to X-ray luminosity with increasing total luminosity. The radius of the BLR correlates most tightly with H{beta} luminosity, while the X-ray and narrow-line relations both have comparable scatter of a factor of 2. These correlations provide useful alternative virial BH masses in objects with no detectable optical/UV continuum emission, such as high-redshift galaxies with broad emission lines, radio-loud objects, or local active galaxies with galaxy-dominated continua.« less
  • The Lick AGN Monitoring Project 2011 observing campaign was carried out over the course of 11 weeks in spring 2011. Here we present the first results from this program, a measurement of the broad-line reverberation lag in the Seyfert 1 galaxy Mrk 50. Combining our data with supplemental observations obtained prior to the start of the main observing campaign, our data set covers a total duration of 4.5 months. During this time, Mrk 50 was highly variable, exhibiting a maximum variability amplitude of a factor of {approx}4 in the U-band continuum and a factor of {approx}2 in the H{beta} line.more » Using standard cross-correlation techniques, we find that H{beta} and H{gamma} lag the V-band continuum by {tau}{sub cen} = 10.64{sup +0.82}{sub -0.93} and 8.43{sup +1.30}{sub -1.28} days, respectively, while the lag of He II {lambda}4686 is unresolved. The H{beta} line exhibits a symmetric velocity-resolved reverberation signature with shorter lags in the high-velocity wings than in the line core, consistent with an origin in a broad-line region (BLR) dominated by orbital motion rather than infall or outflow. Assuming a virial normalization factor of f = 5.25, the virial estimate of the black hole mass is (3.2 {+-} 0.5) Multiplication-Sign 10{sup 7} M{sub Sun }. These observations demonstrate that Mrk 50 is among the most promising nearby active galaxies for detailed investigations of BLR structure and dynamics.« less
  • In the Spring of 2011 we carried out a 2.5 month reverberation mapping campaign using the 3 m Shane telescope at Lick Observatory, monitoring 15 low-redshift Seyfert 1 galaxies. This paper describes the observations, reductions and measurements, and data products from the spectroscopic campaign. The reduced spectra were fitted with a multicomponent model in order to isolate the contributions of various continuum and emission-line components. We present light curves of broad emission lines and the active galactic nucleus (AGN) continuum, and measurements of the broad Hβ line widths in mean and rms spectra. For the most highly variable AGNs wemore » also measured broad Hβ line widths and velocity centroids from the nightly spectra. In four AGNs exhibiting the highest variability amplitudes, we detect anticorrelations between broad Hβ width and luminosity, demonstrating that the broad-line region “breathes” on short timescales of days to weeks in response to continuum variations. We also find that broad Hβ velocity centroids can undergo substantial changes in response to continuum variations; in NGC 4593, the broad Hβ velocity shifted by ∼250 km s{sup −1} over a 1 month period. This reverberation-induced velocity shift effect is likely to contribute a significant source of confusion noise to binary black hole searches that use multi-epoch quasar spectroscopy to detect binary orbital motion. We also present results from simulations that examine biases that can occur in measurement of broad-line widths from rms spectra due to the contributions of continuum variations and photon-counting noise.« less