The impact of compact radio sources on their host galaxies: observations

2016 ◽  
Vol 337 (1-2) ◽  
pp. 159-166 ◽  
Author(s):  
C. Tadhunter
Keyword(s):  
Radio Sources ◽  
Host Galaxies ◽  
The Impact

scholarly journals The Impact of the Early Stages of Radio Source Evolution on the ISM of the Host Galaxies

2003 ◽  
Vol 20 (1) ◽  
pp. 129-133 ◽  
Author(s):  
R. Morganti ◽  
C. N. Tadhunter ◽  
T. A. Oosterloo ◽  
J. Holt ◽  
A. Tzioumis ◽  
...  
Keyword(s):  
Radio Source ◽  
Radio Galaxy ◽  
Optical Emission ◽  
The Other ◽  
Emission Lines ◽  
Radio Sources ◽  
Host Galaxies ◽  
Cygnus A ◽  
Intermediate Size ◽  
The Impact

AbstractThe study of both neutral and ionised gas in young radio sources is providing key information on the effect the radio plasma has on the ISM of these objects. We present results obtained for the compact radio sources PKS 1549–79, 4C 12.50 and PKS 1814–63 and for the intermediate-size radio galaxy 3C 459. At least in the first two, low ionisation optical emission lines and HI absorption appear to be associated with the extended, but relatively quiescent, dusty cocoon surrounding the nucleus. The [OIII] lines are, on the other hand, mostly associated with the region of interaction between the radio plasma and the ISM, indicating a fast outflow from the centre. A case of fast outflow (up to ∼1000 km s-1) is also observed in HI in the radio source 4C 12.50. As the radio source evolves, any obscuring material along the radio axis is swept aside until, eventually, cavities (of the same kind as observed e.g. in Cygnus A) are hollowed out on either side of the nucleus. We may witness this phase in the evolution of a radio source in the radio galaxy 3C 459.

scholarly journals X-ray properties of reverberation-mapped AGNs with super-Eddington accreting massive black holes

2019 ◽  
Vol 15 (S356) ◽  
pp. 143-143
Author(s):  
Jaya Maithil ◽  
Michael S. Brotherton ◽  
Bin Luo ◽  
Ohad Shemmer ◽  
Sarah C. Gallagher ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Accretion Rate ◽  
Time Lags ◽  
Black Hole Mass ◽  
Host Galaxies ◽  
Massive Black Holes ◽  
X Ray ◽  
Photon Index ◽  
The Impact

AbstractActive Galactic Nuclei (AGN) exhibit multi-wavelength properties that are representative of the underlying physical processes taking place in the vicinity of the accreting supermassive black hole. The black hole mass and the accretion rate are fundamental for understanding the growth of black holes, their evolution, and the impact on the host galaxies. Recent results on reverberation-mapped AGNs show that the highest accretion rate objects have systematic shorter time-lags. These super-Eddington accreting massive black holes (SEAMBHs) show BLR size 3-8 times smaller than predicted by the Radius-Luminosity (R-L) relationship. Hence, the single-epoch virial black hole mass estimates of highly accreting AGNs have an overestimation of a factor of 3-8 times. SEAMBHs likely have a slim accretion disk rather than a thin disk that is diagnostic in X-ray. I will present the extreme X-ray properties of a sample of dozen of SEAMBHs. They indeed have a steep hard X-ray photon index, Γ, and demonstrate a steeper power-law slope, ασx.

scholarly journals AGN radiative feedback in the early growth of massive black holes

2019 ◽  
Vol 489 (4) ◽  
pp. 5225-5230
Author(s):  
W Ishibashi
Keyword(s):  
Black Holes ◽  
Early Universe ◽  
Radiation Pressure ◽  
Early Growth ◽  
Host Galaxies ◽  
Massive Black Holes ◽  
Black Hole Growth ◽  
Hole Growth ◽  
The Impact ◽  
Very High

ABSTRACT Growing observational evidence confirms the existence of massive black holes ($M_{\rm BH} \sim 10^9 \, \mathrm{M}_{\odot }$), accreting at rates close to the Eddington limit, at very high redshifts ($z \gtrsim 6\!-\!7$) in the early Universe. Recent observations indicate that the host galaxies of the first quasars are chemically evolved systems, containing unexpectedly large amounts of dust. Such a combination of high luminosities and large dust content should form favourable physical conditions for radiative dusty feedback. We explore the impact of the active galactic nucleus (AGN) feedback, driven by radiation pressure on dust, on the early growth of massive black holes. Assuming Eddington-limited exponential black hole growth, we find that the dynamics and energetics of the radiation pressure-driven outflows also follow exponential trends at late times. We obtain modest outflow energetics (with momentum flux $\dot{p} \lesssim L/c$ and kinetic power $\dot{E}_{\rm k} \lesssim 10^{-3} L$), comparable with available observations of quasar-driven outflows at very high redshifts, but significantly lower than typically observed in local quasars and predicted by wind energy-driven models. AGN radiative dusty feedback may thus play an important role in powering galactic outflows in the first quasars in the early Universe.

Density diagnostics of photoionized outflows in active galactic nuclei

2019 ◽  
Vol 15 (S350) ◽  
pp. 274-277
Author(s):  
Junjie Mao
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
State Of The Art ◽  
Density Measurement ◽  
Galactic Nuclei ◽  
Next Generation ◽  
Host Galaxies ◽  
Current Generation ◽  
X Ray ◽  
The Impact

AbstractPhotoionized outflows in active galactic nuclei (AGNs) are thought to influence their circumnuclear and host galactic environment. However, the distance of the outflow with respect to the black hole is poorly constrained, which limits our understanding of the kinetic power by the outflow. Therefore, the impact of AGN outflows on their host galaxies is uncertain. If the density of the outflow is known, its distance can be derived. Density measurement via variability studies and density sensitive lines have been used, albeit not very effective in the X-ray band. Good measurements are rather demanding or challenging for the current generation of (grating) spectrometers. The next generation of spectrometers will certainly provide data with better quality and large quantity, leading to tight constraints on the location and the kinetic power of AGN outflows. This contribution summarizes the state-of-the-art in this field.

scholarly journals An Extragalactic Reference Frame From DSN VLBI Measurements–1989

1990 ◽  
Vol 141 ◽  
pp. 261-270 ◽  
Author(s):  
O. J. Sovers
Keyword(s):  
Reference Frame ◽  
Systematic Errors ◽  
Radio Sources ◽  
Dual Frequency ◽  
Source Position ◽  
Deep Space Network ◽  
Space Network ◽  
Data Analyses ◽  
Accuracy Level ◽  
The Impact

Assessment of the impact of recent improvements in Deep Space Network (DSN) instrumentation, as well as of joint data analyses, provide a prognosis for the accuracy level to be expected in future realizations of an inertial radio reference frame. Intercontinental dual-frequency radio interferometric measurements during 68 sessions (including two recent sessions employing Mark III instrumentation) from 1978 to 1989 using NASA's DSN stations in California, Spain, and Australia give 8900 pairs of delay and delay rate observations. Analysis yields a catalog of positions of 200 extragalactic radio sources north of —45° declination. The resulting source position formal uncertainty distributions peak below 1 milliarcsecond, with three fourths being smaller than 2 mas. Comparison with independent measurements shows some evidence for systematic errors at the milliarcsecond level.

scholarly journals Statistics of Giant Radio Sources

2002 ◽  
Vol 199 ◽  
pp. 203-206
Author(s):  
J. Machalski ◽  
M. Jamrozy
Keyword(s):  
Time Evolution ◽  
Cosmological Evolution ◽  
Analytical Models ◽  
Radio Sources ◽  
Host Galaxies

An important aspects of the studies of giant radio sources is that they can constrain models of the cosmological evolution of radio sources (e.g. Condon 1984, ApJ, 287, 461; Dunlop & Peacock 1990, MNRAS, 247, 19) and their host galaxies, as well as the recent analytical models of time evolution of these sources (e.g. Kaiser, Dennett—Thorpe & Alexander 1997, MNRAS, 292, 723; Blundell et al. 1999, AJ, 117, 677). In order to achieve these goals, we undertook the following tasks:

scholarly journals Radio Source Environments at Redshifts > 0.5

1996 ◽  
Vol 175 ◽  
pp. 321-322
Author(s):  
M. Lacy ◽  
S. Rawlings ◽  
M. Wold ◽  
A. Bunker ◽  
K.M. Blundell ◽  
...  
Keyword(s):  
Radio Source ◽  
High Redshift ◽  
Elliptical Galaxies ◽  
Radio Sources ◽  
Powerful Radio ◽  
Host Galaxies ◽  
Local Universe ◽  
Wide Range ◽  
Age Of The Universe ◽  
The Universe

The most powerful radio sources in the local Universe are found in giant elliptical galaxies. Looking back to a redshift of 0.5 (≈ half the age of the Universe for ω = 1), we see that these host galaxies are increasingly found in moderately rich clusters. This fact gives us hope that radio sources can be used as tracers of high density environments at high redshift. By exploiting radio source samples selected over a wide range in luminosity (Blundell et al., these proceedings), we will also be able to test whether the luminosities of radio sources are correlated with their environments.

scholarly journals 9.10. The cause of the spectral turnover in the GPS source 0108+388: free-free absorption or SSA?

1998 ◽  
Vol 184 ◽  
pp. 401-402
Author(s):  
J. M. Marr ◽  
F. Crawford ◽  
G. B. Taylor
Keyword(s):  
Magnetic Fields ◽  
Radio Source ◽  
High Frequency ◽  
Radio Sources ◽  
Host Galaxies ◽  
Ionized Gas ◽  
High Frequencies ◽  
Extragalactic Radio Sources ◽  
Competing Models ◽  
Frequency Radiation

The radio source 0108 + 388 is a canonical example of a class of extragalactic radio sources, referred to as Gigahertz-Peaked Spectrum (GPS) sources, whose spectra peak at high frequencies. There are two competing models for the cause of the high frequency turnover: free-free absorption (f-f) of the lower frequency radiation by ionized gas in the host galaxies (e.g. van Breugel 1984), or synchrotron self-absorption (SSA) due to exceptionally large magnetic fields, (e.g. Hodges, Mutel, & Phillips 1984).

scholarly journals Quasar outflows at z ≥ 6: the impact on the host galaxies

2017 ◽  
Vol 473 (3) ◽  
pp. 4003-4020 ◽  
Author(s):  
Paramita Barai ◽  
Simona Gallerani ◽  
Andrea Pallottini ◽  
Andrea Ferrara ◽  
Alessandro Marconi ◽  
...  
Keyword(s):  
Host Galaxies ◽  
The Impact

scholarly journals Optically faint radio sources: reborn AGN?

2011 ◽  
Vol 7 (S284) ◽  
pp. 231-233
Author(s):  
Mercedes E. Filho ◽  
Jarle Brinchmann ◽  
Catarina Lobo ◽  
Sonia Antón
Keyword(s):  
Black Hole ◽  
Large Scale ◽  
High Redshift ◽  
Radio Sources ◽  
Host Galaxies

AbstractWe have discovered eight relatively strong radio sources that have no optical counterparts. A NIR follow-up has detected faint (17–20 mag) host galaxies in all targets. In general, the radio properties are similar to those observed in 3CRR sources but the optical-radio slopes are consistent with moderate to high redshift (z < 4) GHz-peaked spectrum sources. Our results suggest that these are galaxies whose black hole has been recently re-ignited into activity but that retain large-scale radio structures, signatures of previous AGN activity.

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