scholarly journals Extended Emission Line Gas in Radio Galaxies: PKS 0349−27

1999 ◽  
Vol 521 (1) ◽  
pp. 121-133 ◽  
Author(s):  
B. I. Grimberg ◽  
E. M. Sadler ◽  
S. M. Simkin
Keyword(s):  
Emission Line ◽  
Radio Galaxies ◽  
Extended Emission

scholarly journals Dynamical Models of Emission-Line Gas in Radio Galaxies

1996 ◽  
Vol 175 ◽  
pp. 471-472
Author(s):  
A. M. Koekemoer ◽  
G. V. Bicknell
Keyword(s):  
Emission Line ◽  
Dynamical Evolution ◽  
Radio Galaxies ◽  
Disk Galaxy ◽  
Trace Gas ◽  
Dynamical Models ◽  
Velocity Amplitude ◽  
Wide Range ◽  
Large Velocity ◽  
Extended Emission

Extended emission-line regions (EELRs) in radio ellipticals are generally thought to trace gas acquired externally, eg. through interaction with a gas-rich disk galaxy (Athanassoula and Bosma 1985, Barnes and Hernquist 1992, Hernquist and Mihos 1995). We examine here the dynamical evolution of gas in mergers, focussing on the conditions required for collisions between streams of gas. We find that such collisions can occur over a relatively wide range of encounter geometries, producing large-velocity-amplitude kinematic signatures characteristic of those observed in EELRs. This is relevant to the formation of shocks, which can account for the ionization properties of EELRs (Koekemoer and Bicknell, this conference).

scholarly journals Weak Radio Galaxies: Narrow-Band Optical Imaging

1996 ◽  
Vol 175 ◽  
pp. 236-237
Author(s):  
René Carrillo ◽  
Irene Cruz-González
Keyword(s):  
Emission Line ◽  
Narrow Band ◽  
Radio Galaxies ◽  
Convincing Evidence ◽  
Host Galaxy ◽  
Ultraviolet Continuum ◽  
Physical Relationship ◽  
Radio Jets ◽  
Extended Radio ◽  
Extended Emission

Previous studies show that: a) radio galaxies and radio-loud quasars have emission-line gas (ELG) which is extended on scales of tenths of kiloparsecs; b) there is convincing evidence that the kinematics and excitation of the very extended emission-line gas is governed by its interaction with the outflowing radio plasma; c) the evidence for an interaction is weaker in some radio galaxies. It is argued that the ionization of the ELG may be predominantly produced by the nuclear ultraviolet continuum and the kinematics of the gas due to the gravitational potential of the host galaxy, but it is not yet known whether there is a physical relationship between the ELG and the extended radio jets.

Extended Emission-Line Gas in Distant 3CR Radio Galaxies

1988 ◽  
pp. 325-329 ◽  
Author(s):  
Patrick J. McCarthy ◽  
Hyron Spinrad ◽  
Wil Breugel ◽  
S. Djorgovski ◽  
Michael A. Strauss ◽  
...  
Keyword(s):  
Emission Line ◽  
Radio Galaxies ◽  
Extended Emission

scholarly journals A Powerful Jet/Cloud Interaction in the Radio Galaxy PKS 2250-41

1996 ◽  
Vol 175 ◽  
pp. 227-229
Author(s):  
R. Morganti ◽  
C.N. Tadhunter ◽  
N. Clark ◽  
N. Killeen
Keyword(s):  
Emission Line ◽  
Strong Evidence ◽  
Radio Galaxy ◽  
High Redshift ◽  
Radio Galaxies ◽  
Radio Sources ◽  
Excitation Mechanism ◽  
Powerful Radio ◽  
Radio Jets ◽  
Extended Emission

Extended emission line regions aligned with the radio axis are a common feature of powerful radio galaxies and there is much interest in the origin of the extended gas and excitation mechanism. One model that can produce this alignment is photoionization by anisotropic nuclear continuum radiation. However, strong evidence exists, especially in high redshift radio galaxies, for powerful interactions between the relativistic radio jets and the ISM/IGM. Here we present the results of our study of the southern radio galaxy PKS 2250–41 (z = 0.308). This object is the most spectacular found in a sample of southern radio sources studied by Tadhunter et al. (1993) and it displays particularly clear evidence for such an interaction (Tadhunter et al. 1994; Dickson et al. 1995).

scholarly journals Gaia-assisted discovery of a detached low-ionisation BAL quasar with very large ejection velocities

2020 ◽  
Vol 634 ◽  
pp. A111 ◽  
Author(s):  
J. P. U. Fynbo ◽  
P. Møller ◽  
K. E. Heintz ◽  
J. N. Burchett ◽  
L. Christensen ◽  
...  
Keyword(s):  
Emission Line ◽  
Absorption Line ◽  
Emission Lines ◽  
Broad Absorption ◽  
Broad Absorption Line ◽  
Red Edge ◽  
First Case ◽  
Bl Lac ◽  
Spatially Extended ◽  
Extended Emission

We report on the discovery of a peculiar broad absorption line (BAL) quasar identified in our Gaia-assisted survey of red quasars. The systemic redshift of this quasar was difficult to establish because of the absence of conspicuous emission lines. Based on deep and broad BAL troughs of at least Si IV, C IV, and Al III, a redshift of z = 2.41 was established under the assumption that the systemic redshift can be inferred from the red edge of the BAL troughs. However, we observe a weak and spatially extended emission line at 4450 Å that is most likely due to Lyman-α emission, which implies a systemic redshift of z = 2.66 if correctly identified. There is also evidence for the onset of Lyman-α forest absorption bluewards of 4450 Å and evidence for Hα emission in the K band consistent with a systemic redshift of z = 2.66. If this redshift is correct, the quasar is an extreme example of a detached low-ionisation BAL quasar. The BALs must originate from material moving with very large velocities ranging from 22 000 km s−1 to 40 000 km s−1. To our knowledge, this is the first case of a systemic-redshift measurement based on extended Lyman-α emission for a BAL quasar. This method could also be useful in cases of sufficiently distant BL Lac quasars without systemic-redshift information.

scholarly journals The ionization of the emission-line gas in young radio galaxies

2009 ◽  
Vol 400 (2) ◽  
pp. 589-602 ◽  
Author(s):  
J. Holt ◽  
C. N. Tadhunter ◽  
R. Morganti
Keyword(s):  
Emission Line ◽  
Radio Galaxies
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