Emission-Line Properties of 3CR Radio Galaxies. II. Velocity Fields in the Extended Emission Lines

1996 ◽  
Vol 106 ◽  
pp. 281 ◽  
Author(s):  
Patrick J. McCarthy ◽  
Stefi A. Baum ◽  
Hyron Spinrad
Keyword(s):  
Emission Line ◽  
Radio Galaxies ◽  
Velocity Fields ◽  
Emission Lines ◽  
Extended Emission

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 Shock Excitation of Emission Lines in Radio Galaxies

1996 ◽  
Vol 175 ◽  
pp. 473-474
Author(s):  
A. M. Koekemoer ◽  
G. V. Bicknell
Keyword(s):  
Physical Mechanism ◽  
Radio Galaxies ◽  
Emission Lines ◽  
Line Of Sight ◽  
Ionization Mechanism ◽  
Unknown Parameters ◽  
Radio Lobe ◽  
Axis Alignment ◽  
Gas Interactions ◽  
Extended Emission

We present evidence for the viability of “auto-ionizing” shocks as the dominant ionization mechanism in extended emission-line regions (EELRs) in two radio galaxies, PKS 0349–27 and PKS 2356–61. The application of this model, rather than the nuclear photoionization hypothesis of unified schemes (Barthel 1989), is motivated by observed EELR properties: large line-of-sight velocity widths (up to δv ≃ 500 km s–1 for nearby objects and ≳ 1000kms–1 at higher z); kinematics/excitation relationships (Baum et al. 1992); the EELR/radio axis alignment (Chambers et al. 1987, McCarthy et al. 1987); and the correspondence between the brighter EELR and the shorter radio lobe (McCarthy et al. 1991), suggestive of jet/gas interactions. We show that the flux, excitation and kinematics across the gas is self-consistently accounted for in terms of shocks as a single physical mechanism, requiring fewer unknown parameters than nuclear photoionization.

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 High-resolution emission line profiles in blue luminous stars

1989 ◽  
Vol 113 ◽  
pp. 279-280
Author(s):  
Rino Bandiera ◽  
Paola Focardi ◽  
Aldo Altamore ◽  
Corinne Rossi ◽  
Otmar Stahl
Keyword(s):  
High Resolution ◽  
Emission Line ◽  
High Velocity ◽  
Large Scale ◽  
Velocity Fields ◽  
Emission Lines ◽  
Line Profiles ◽  
High Luminosity ◽  
Stellar Envelopes ◽  
Η Car

Emission lines are often observed in high luminosity stars and provide evidence of the presence of extended stellar envelopes. Ha is the most frequently observed across the H-R diagram, but lines of Hel or Fell are also found in emission in these stars. They could be used as diagnostics of the structure of their outer atmospheres and winds. High resolution (1/dl ~ 105) high S/N profiles of Ha and Hel 5876 in the galactic LBVs η Car, AG and HR Car, and in the LMC star S22 have been obtained with the ESO CAT-CES during 1984-87, and are described in Figs.1-5. We find that these stars show a large variety of profiles with narrow and broad emissions, wide or multiple blue-shifted absorptions. The profiles are largely variable. Once, a kind of inverse P Cyg profile was observed in HR Car (Fig.4). These results indicate the presence of large scale phenomena and high velocity fields which are dramatically variable in time. Continuous HIRES monitoring of these stars is urgently needed.

An Extended Emission Line Region around Mrk 1172

2019 ◽  
Vol 15 (S359) ◽  
pp. 438-440
Author(s):  
Augusto Lassen ◽  
Rogério Riffel ◽  
Ana L. Chies-Santos ◽  
Evelyn Johnston ◽  
Boris Haeussler ◽  
...  
Keyword(s):  
Emission Line ◽  
Stellar Population ◽  
Emission Lines ◽  
Gas Content ◽  
Early Type ◽  
Strong Emission ◽  
Line Region ◽  
Hard Radiation ◽  
Star Formation Activity ◽  
Extended Emission

AbstractWe serendipitously found an intriguing Extended Emission Line Region (EELR) near the quiescent and massive early-type Mrk 1172, with a projected extension of approximately 14 × 14 kpc. Its irregular shape, high gas content, strong emission lines and proximity to an isolated possible faded quasar raise questions about the ionization of this gas and the nature of this object. Analyzing the stellar population in both objects we observe that the EELR has a dominance of young-intermediate and intermediate stellar populations (200 Myr < t < 1 Gyr) with significant star formation activity, while Mrk 1172 is dominated by old stellar population (t > 5 Gyr). BPT diagnostic diagrams indicate that the gas in the EELR is photoionized by hot massive stars rather than by a hard radiation field or by shocks. Further analysis on abundances of the gas and its kinematics shall be performed to better comprehend the nature of this object and how it is interacting with Mrk 1172.

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.

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 Impact of nuclear activity on extended emission line regions of nearby galaxies

1995 ◽  
Vol 149 ◽  
pp. 269-273
Author(s):  
E. Pécontal ◽  
P. Ferruit ◽  
A.S. Wilson
Keyword(s):  
Emission Line ◽  
Seyfert Galaxies ◽  
Emission Lines ◽  
Nuclear Activity ◽  
Central Engine ◽  
Nearby Galaxies ◽  
The Impact ◽  
Integral Field ◽  
Extended Emission ◽  
Narrow Emission

AbstractWe used the integral field TIGER to map the intensity ratios of emission lines and the velocity field over the narrow emission line of a few nearby Seyfert galaxies. Our aim is to study the impact of nuclear activity on galaxies, which will hopefully help us to probe the central engine. We present here some results for two objects: M 51 and NGC 5929.

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