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 ◽  
...  
2020 ◽  
Vol 500 (1) ◽  
pp. 786-794
Author(s):  
Nick Devereux

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.


2016 ◽  
Vol 12 (S324) ◽  
pp. 215-218 ◽  
Author(s):  
Bradley M. Peterson

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.


2020 ◽  
Vol 902 (1) ◽  
pp. 74
Author(s):  
P. R. Williams ◽  
A. Pancoast ◽  
T. Treu ◽  
B. J. Brewer ◽  
B. M. Peterson ◽  
...  

Author(s):  
MARKOS GEORGANOPOULOS ◽  
AMANDA DOTSON ◽  
DEMOSTHENES KAZANAS ◽  
ERIC PERLMAN

This work presents a method for settling the following ongoing debate: is the GeV emission of powerful blazars produced inside the sub-pc size broad line region (BLR) or further out at scales of ~ 10 pc where the IR photon field of the dusty molecular torus dominates over that the UV field of the BLR? In the first case the GeV emission is most probably external Compton (EC) scattering of the ~ 10 eV BLR photons21, while in the second the seed photons for the EC GeV emission are the ~ 0.1 eV photons of the dust9 in the molecular torus8. The issue of the energy dissipation location is connected to the jet formation and collimation process25 and, as we argue here, can be resolved with Fermi spectral variability observations.


2022 ◽  
Vol 21 (12) ◽  
pp. 305
Author(s):  
Ze-Rui Wang ◽  
Rui Xue

Abstract In addition to neutrino event IceCube-170922A which is observed to be associated with a γ-ray flare from blazar TXS 0506+056, there are also several neutrino events that may be associated with blazars. Among them, PKS B1424-418, GB6 J1040+0617 and PKS 1502+106 are low synchrotron peaked sources, which are usually believed to have the broad line region in the vicinity of the central black hole. They are considered as counterparts of IceCube event 35, IceCube-141209A and IceCube-190730A, respectively. By considering the proton-proton (pp) interactions between the dense gas clouds in the broad line region and the relativistic protons in the jet, we show that the pp model that is applied in this work can not only reproduce the multi-waveband spectral energy distribution but also suggest a considerable annual neutrino detection rate. We also discuss the emission from the photopion production and Bethe-Heitler pair production with a sub-Eddington jet power that is suggested in our model and find that it has little effect on the spectrum of total emission for all of three sources.


1997 ◽  
Vol 112 (2) ◽  
pp. 271-283 ◽  
Author(s):  
M. Santos‐Lleo ◽  
E. Chatzichristou ◽  
C. Mendes de Oliveira ◽  
C. Winge ◽  
D. Alloin ◽  
...  

2018 ◽  
Vol 865 (2) ◽  
pp. 97 ◽  
Author(s):  
J. M. Miller ◽  
E. Cackett ◽  
A. Zoghbi ◽  
D. Barret ◽  
E. Behar ◽  
...  

2006 ◽  
pp. 1-11 ◽  
Author(s):  
L.C. Popovic

In this paper a discussion of kinematics and physics of the Broad Line Region (BLR) is given. The possible physical conditions in the BLR and problems in determination of the physical parameters (electron temperature and density) are considered. Moreover, one analyses the geometry of the BLR and the probability that (at least) a fraction of the radiation in the Broad Emission Lines (BELs) originates from a relativistic accretion disk.


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