scholarly journals Unification of Radio Galaxies

1998 ◽  
Vol 164 ◽  
pp. 81-82
Author(s):  
M.H. Cohen ◽  
P.M. Ogle ◽  
H.D. Iran ◽  
R.W. Goodrich
Keyword(s):  
Radio Galaxies ◽  
Broad Line ◽  
Narrow Line ◽  
Spectral Classification ◽  
Broad Line Region ◽  
Line Region ◽  
Direct View

AbstractMany FR 2 narrow-line radio galaxies also display polarized broad lines. The broad-line region is hidden from direct view and is seen by reflection (ie scattering). In these objects the spectral classification is controlled by the aspect at which they are viewed.

scholarly journals Near-IR Spectroscopy of High-z QSOs: Relating the Broad and Narrow-Line Regions

1997 ◽  
Vol 159 ◽  
pp. 258-259
Author(s):  
M.S. Brotherton
Keyword(s):  
Simple Model ◽  
Broad Line ◽  
Narrow Line ◽  
Strong Correlations ◽  
Broad Line Region ◽  
Near Ir ◽  
Line Region ◽  
Derived Properties ◽  
Narrow Line Region ◽  
Line Widths

Recent investigations of the broad UV lines in luminous QSOs identified strong correlations involving emission-line widths, shifts, equivalent widths, and ratios (Francis et al. 1992; Wills et al. 1993; Brotherton et al. 1994a, b). A simple model developed to explain these trends approximates UV broad lines as emission from two regions, an intermediate-line region (ILR), and a very broad-line region (VBLR), together comprising the traditional broad-line region (BLR). The observed and derived properties for the ILR and VBLR are summarized in Table 1, along with typical values for the narrow-line region (NLR).

scholarly journals A REVERBERATION LAG FOR THE HIGH-IONIZATION COMPONENT OF THE BROAD-LINE REGION IN THE NARROW-LINE SEYFERT 1 Mrk 335

2011 ◽  
Vol 744 (1) ◽  
pp. L4 ◽  
Author(s):  
C. J. Grier ◽  
B. M. Peterson ◽  
R. W. Pogge ◽  
K. D. Denney ◽  
M. C. Bentz ◽  
...  
Keyword(s):  
Broad Line ◽  
Narrow Line ◽  
Broad Line Region ◽  
Line Region ◽  
High Ionization

scholarly journals A REVISED BROAD-LINE REGION RADIUS AND BLACK HOLE MASS FOR THE NARROW-LINE SEYFERT 1 NGC 4051

2009 ◽  
Vol 702 (2) ◽  
pp. 1353-1366 ◽  
Author(s):  
K. D. Denney ◽  
L. C. Watson ◽  
B. M. Peterson ◽  
R. W. Pogge ◽  
D. W. Atlee ◽  
...  
Keyword(s):  
Black Hole ◽  
Broad Line ◽  
Narrow Line ◽  
Black Hole Mass ◽  
Broad Line Region ◽  
Line Region ◽  
Ngc 4051

scholarly journals Prospects for γ-ray observations of narrow-line Seyfert 1 galaxies with the Cherenkov Telescope Array – II. γ–γ absorption in the broad-line region radiation fields

2020 ◽  
Vol 494 (1) ◽  
pp. 411-424 ◽  
Author(s):  
P Romano ◽  
M Böttcher ◽  
L Foschini ◽  
C Boisson ◽  
S Vercellone ◽  
...  
Keyword(s):  
High Energy ◽  
Emission Region ◽  
Broad Line ◽  
Narrow Line ◽  
Telescope Array ◽  
Cherenkov Telescope ◽  
Broad Line Region ◽  
Radiation Fields ◽  
Line Region ◽  
Γ Ray

ABSTRACT Gamma-ray emitting narrow-line Seyfert 1 (γ-NLS1) galaxies possibly harbour relatively low-mass black holes (106–108 M⊙) accreting close to the Eddington limit, and share many characteristics with their sibling sources, flat-spectrum radio quasars. Although they have been detected in the MeV–GeV band with Fermi–LAT, they have never been seen in the very high energy band with current imaging atmospheric Cherenkov telescopes (IACTs). Thus, they are key targets for the next-generation IACT, the Cherenkov Telescope Array (CTA). In a previous work we selected, by means of extensive simulations, the best candidates for a prospective CTA detection (SBS 0846+513, PMN J0948+0022, and PKS 1502+036) taking into account the effects of both the intrinsic absorption (approximated with a cut-off at 30 GeV), and the extragalactic background light on the propagation of γ-rays. In this work, we simulate the spectra of these three sources by adopting more realistic broad-line region (BLR) absorption models. In particular, we consider the detailed treatment of γ–γ absorption in the radiation fields of the BLR as a function of the location of the γ-ray emission region with parameters inferred from observational constraints. We find that, due to the energy range extent and its sensitivity, CTA is particularly well suited to locate the γ-ray emitting region in γ-NLS1. In particular CTA will be able not only to distinguish whether the γ-ray emitting region is located inside or outside the BLR, but also where inside the BLR it may be.

LOCATING THE BLAZAR EMISSION SITE WITH FERMI VARIABILITY

2012 ◽  
Vol 08 ◽  
pp. 37-42
Author(s):  
MARKOS GEORGANOPOULOS ◽  
AMANDA DOTSON ◽  
DEMOSTHENES KAZANAS ◽  
ERIC PERLMAN
Keyword(s):  
Energy Dissipation ◽  
Broad Line ◽  
Jet Formation ◽  
Spectral Variability ◽  
Ongoing Debate ◽  
Broad Line Region ◽  
Photon Field ◽  
First Case ◽  
Line Region

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.

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