scholarly journals Space Telescope and Optical Reverberation Mapping Project: A Leap Forward in Reverberation Mapping

2016 ◽  
Vol 12 (S324) ◽  
pp. 215-218 ◽  
Author(s):  
Bradley M. Peterson
Keyword(s):  
World Wide ◽  
Hubble Space Telescope ◽  
Line Emission ◽  
Broad Line ◽  
Space Telescope ◽  
Reverberation Mapping ◽  
Significant Challenge ◽  
Past Behavior ◽  
Line Region ◽  
Mapping Program

AbstractIn 2014, a 179-orbit allocation of Hubble Space Telescope time anchored a massive reverberation-mapping program on the well-studied Seyfert 1 galaxy NGC 5548. Supporting imaging and spectrophotometric observations were provided by Swift, Chandra, Spitzer, and a world-wide network of ground-based telescopes. Understanding the data remains a significant challenge, partly because the level of detail is far beyond what has been seen before and partly because the behavior of the AGN was not typical of its past behavior. Based on analysis to date, the following conclusions can be reached: (1) the AGN accretion disk has a temperature profile that is consistent with that predicted by the Shakura–Sunyaev model, but is about three times larger than expected; (2) at least part of the broad-line region appears to be a Keplerian disk seen at intermediate inclination, and (3) the broad-line emission response from the far side of the disk is weaker than expected.

scholarly journals Hubble Space Telescope observations of BALQSO Ton 34 reveal a connection between the broad-line region and the BAL outflow

2017 ◽  
Vol 468 (3) ◽  
pp. 3607-3614 ◽  
Author(s):  
Y. Krongold ◽  
L. Binette ◽  
R. Bohlin ◽  
L. Bianchi ◽  
A. L. Longinotti ◽  
...  
Keyword(s):  
Hubble Space Telescope ◽  
Broad Line ◽  
Space Telescope ◽  
Broad Line Region ◽  
Line Region

scholarly journals The Structure of the Broad Emission Line Region as Shown by Variability Monitoring

1994 ◽  
Vol 159 ◽  
pp. 163-172
Author(s):  
Julian H. Krolik
Keyword(s):  
Line Emission ◽  
Published Data ◽  
Broad Line ◽  
Linear Inversion ◽  
Reverberation Mapping ◽  
Physical Conditions ◽  
Broad Emission ◽  
Line Region ◽  
Broad Emission Line ◽  
Basic Concepts

The various methods used to infer the physical conditions and location of the material responsible for broad line emission in AGN are reviewed. Recent efforts have focussed on reverberation mapping, whose basic concepts and experimental constraints are discussed. A new method for analyzing the results of monitoring experiments, regularized linear inversion, is presented. This method is then applied to published data from the 1989 IUE campaign on NGC 5548, and the results found contrasted with those obtained by the previous standard method, maximum entropy.

scholarly journals The dynamics of the broad-line region in NGC 3227

2020 ◽  
Vol 500 (1) ◽  
pp. 786-794
Author(s):  
Nick Devereux
Keyword(s):  
Emission Line ◽  
Hubble Space Telescope ◽  
Outer Radius ◽  
Short Time Scale ◽  
Broad Line ◽  
Fall Velocity ◽  
Space Telescope ◽  
X Ray ◽  
Broad Line Region ◽  
Line Region

ABSTRACT Archival Hubble Space Telescope (HST) observations of the Seyfert 1 nucleus of NGC 3227 obtained with the Space Telescope Imaging Spectrograph (STIS) are re-examined in order to constrain a viable photoionization model for the broad-line region (BLR). The results imply that the BLR is a partially ionized, dust-free, spherical shell that is collapsing, supersonically, at the free-fall velocity due to its proximity to a supermassive black hole. The BLR is ionization bounded at the outer radius, coincident with the dust reverberation radius, and transforms into an X-ray emitting plasma inside the Balmer reverberation radius as the central UV–X-ray source is approached. Only 40 M⊙ of Hydrogen are required to explain the Balmer emission-line luminosity, but it is compressed by gravity into a column measuring 5.5 × 1024 atoms cm−2. Assuming radiatively inefficient accretion, the X-ray luminosity requires ∼10−2 M⊙ yr−1. However, the mass inflow rate required to explain the luminosity of the broad H α emission line is ∼1 M⊙ yr−1. The very large disparity between these two estimates indicates that 99 per cent of the inflowing gas must be re-directed into an outflow, and on a very short time-scale corresponding to ∼40 yr. Alternatively, the radiative efficiency of the inflow has been overestimated, or the X-ray luminosity has been underestimated, a distinct possibility if the BLR is indeed Compton-thick.

scholarly journals Space Telescope and Optical Reverberation Mapping Project. XII. Broad-line Region Modeling of NGC 5548

2020 ◽  
Vol 902 (1) ◽  
pp. 74
Author(s):  
P. R. Williams ◽  
A. Pancoast ◽  
T. Treu ◽  
B. J. Brewer ◽  
B. M. Peterson ◽  
...  
Keyword(s):  
Broad Line ◽  
Space Telescope ◽  
Reverberation Mapping ◽  
Broad Line Region ◽  
Line Region ◽  
Ngc 5548

scholarly journals Hubble Space Telescope observations of Europa in and out of eclipse

2010 ◽  
Vol 9 (4) ◽  
pp. 265-271 ◽  
Author(s):  
W.B. Sparks ◽  
M. McGrath ◽  
K. Hand ◽  
H.C. Ford ◽  
P. Geissler ◽  
...  
Keyword(s):  
Hubble Space Telescope ◽  
Broad Band ◽  
Line Emission ◽  
Optical Emission ◽  
High Energy ◽  
High Energy Particle ◽  
Wide Field ◽  
Particle Radiation ◽  
Space Telescope ◽  
Solar Blind

AbstractEuropa is a prime target for astrobiology and has been prioritized as the next target for a National Aeronautics and Space Administration flagship mission. It is important, therefore, that we advance our understanding of Europa, its ocean and physical environment as much as possible. Here, we describe observations of Europa obtained during its orbital eclipse by Jupiter using the Hubble Space Telescope. We obtained Advanced Camera for Surveys Solar Blind Channel far ultraviolet low-resolution spectra that show oxygen line emission both in and out of eclipse. We also used the Wide-Field and Planetary Camera-2 and searched for broad-band optical emission from fluorescence of the surface material, arising from the very high level of incident energetic particle radiation on ices and potentially organic substances. The high-energy particle radiation at the surface of Europa is extremely intense and is responsible for the production of a tenuous oxygen atmosphere and associated FUV line emission. Approximately 50% of the oxygen emission lasts at least a few hours into the eclipse. We discuss the detection limits of the optical emission, which allow us to estimate the fraction of incident energy reradiated at optical wavelengths, through electron-excited emission, Cherenkov radiation in the ice and fluorescent processes.

scholarly journals Reverberation Mapping and Broad-Line Region Models

1997 ◽  
Vol 159 ◽  
pp. 138-145
Author(s):  
D. Maoz
Keyword(s):  
Broad Line ◽  
Future Directions ◽  
Reverberation Mapping ◽  
Broad Line Region ◽  
Line Region ◽  
Mapping Point

AbstractI review what we have learned about the BLR from reverberation mapping, point to some problems and complications that have emerged, and outline some future directions.

A Photoionization Method for Estimating Black Hole Masses in Quasars

2018 ◽  
Vol 14 (S342) ◽  
pp. 270-271
Author(s):  
C. Alenka Negrete ◽  
Deborah Dultzin ◽  
Paola Marziani ◽  
Jack W. Sulentic ◽  
M. L. Martínez-Aldama
Keyword(s):  
Black Hole ◽  
High Redshift ◽  
Broad Line ◽  
Reverberation Mapping ◽  
Physical Conditions ◽  
Broad Line Region ◽  
Supermassive Black Hole ◽  
Line Region ◽  
Black Hole Masses

AbstractWe present a method that uses photoionization codes (CLOUDY) to estimate the supermassive black hole masses (MBH) for quasars at low and high redshift. This method is based on the determination of the physical conditions of the broad line region (BLR) using observational diagnostic diagrams from line ratios in the UV. We also considered that the density and metallicity of the BLR in quasars at high z could be different from those at the nearby Universe. The computed black hole masses obtained using this method are in agreement with those derived from the method of reverberation mapping.

scholarly journals High redshift quasars monitoring campaign

2013 ◽  
Vol 9 (S304) ◽  
pp. 409-410
Author(s):  
Ismael Botti ◽  
Paulina Lira ◽  
Jorge Martinez ◽  
Hagai Netzer ◽  
Shai Kaspi
Keyword(s):  
Cross Correlation ◽  
High Redshift ◽  
Mapping Technique ◽  
Broad Line ◽  
Black Hole Mass ◽  
Massive Black Holes ◽  
Monitoring Campaign ◽  
Reverberation Mapping ◽  
Line Region ◽  
Cross Correlation Analysis

AbstractWe present an update of the monitoring campaign we have undertaken to probe the most massive black holes in powerful quasars at high redshift through the reverberation mapping technique. Once this campaign has finished, we will be able to directly measure broad line region (BLR) sizes of quasars at z ~ 2−3, improving dramatically the BLR size-luminosity relation, and therefore, black hole mass estimates based on this relationship. So far, we have identified a dozen highly variable sources suitable for future cross-correlation analysis and reverberation measurements.

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