The intermediate-power population of radio galaxies: morphologies and interactions

2018 ◽  
Vol 14 (A30) ◽  
pp. 90-93
Author(s):  
Diana M. Worrall ◽  
Ryan T. Duffy ◽  
Mark Birkinshaw
Keyword(s):  
Luminosity Function ◽  
Full Range ◽  
Radio Galaxies ◽  
Power Sources ◽  
X Ray ◽  
Power Injection ◽  
Work Done ◽  
The Universe ◽  
Radio Luminosity Function ◽  
Radio Power

AbstractRadio galaxies of intermediate power dominate the radio-power injection in the Universe as a whole, due to the break in the radio luminosity function, and so are of special interest. The population spans FR I, FR II, and hybrid morphologies, resides in a full range of environmental richness, and sources of all ages are amenable to study. We describe structures and interactions, with emphasis on sources with deep high-resolution Chandra X-ray data. As compared with low-power sources there is evidence that the physics changes, and the work done in driving shocks can exceed that in evacuating cavities. A range of morphologies and phenomena is identified.

scholarly journals Jet-gas interactions at crucial jet power for feedback

2014 ◽  
Vol 10 (S313) ◽  
pp. 260-265
Author(s):  
D. M. Worrall ◽  
M. Birkinshaw
Keyword(s):  
Gas Flows ◽  
Rich Cluster ◽  
Power Sources ◽  
X Ray ◽  
Wide Range ◽  
Higher Power ◽  
Radiative Power ◽  
Gas Interactions ◽  
Work Done ◽  
Radio Luminosity Function

AbstractMost X-ray studies of radio-mode feedback have concentrated on locally-abundant low-power radio sources in relatively rich cluster environments. But the scaling found between mechanical and radiative power, when combined with the radio luminosity function, means that half of the heating in the local Universe is expected from higher-power sources, which lie within a factor of about three of the FRI/II transition, and these sources encounter a wide range of atmosphere properties. We summarize what is observed at FRI/II transition powers from a complete sample observed with modest Chandra exposure times. We then discuss two systems with deep Chandra data. In one we find that the work done in driving shocks exceeds that in evacuating cavities. This source also displays a remarkable jet-cloud interaction, and revealing hotspot X-ray emission. In the second we find evidence of radio-emitting plasma running along boundaries between gas of different temperature, apparently lubricating the gas flows and inhibiting heat transfer, and itself being heavily structured by the process.

scholarly journals Feedback from AGN: The Kinetic/Radio Luminosity Function

2009 ◽  
Vol 5 (S267) ◽  
pp. 402-402
Author(s):  
Gabriele Melini ◽  
Fabio La Franca ◽  
Fabrizio Fiore
Keyword(s):  
Galaxy Formation ◽  
Probability Distribution Function ◽  
Luminosity Function ◽  
Complete Sample ◽  
X Ray ◽  
Galaxy Formation And Evolution ◽  
Formation And Evolution ◽  
Radio Luminosity Function ◽  
Radio Power ◽  
Good Agreement

We have measured the probability distribution function of the ratio RX = log L1.4/LX, where L1.4/LX = ν Lν(1.4 GHz)/LX(2–10 keV), between the 1.4 GHz and the unabsorbed 2–10 keV luminosities and its dependence on LX and z. We have used a complete sample of ~1800 hard X-ray selected AGN, observed in the 1.4 GHz band, cross-correlated in order to exclude FR II-type objects, and thus obtain a contemporaneous measure of the radio and X-ray emission. The distribution P(RX|LX,z) is shown in Figure 1. Convolution of the distribution P(RX|LX,z) with the 2–10 keV X-ray AGN luminosity function from La Franca et al. (2005) and the relations between radio power and kinetic energy from Best et al. (2006) and Willott et al. (1999) allows us to derive the AGN kinetic power and its evolution. As shown in Figure 1, our results are in good agreement with the predictions of the most recent models of galaxy formation and evolution (e.g., Croton et al. 2006), where AGN radio feedback is required to quench the star formation.

scholarly journals High-Redshift Milli-Jansky Radio Galaxies

1996 ◽  
Vol 175 ◽  
pp. 581-582
Author(s):  
J. Dunlop ◽  
J. Peacock ◽  
R. Windhorst ◽  
H. Spinrad ◽  
A. Dey ◽  
...  
Keyword(s):  
Luminosity Function ◽  
High Redshift ◽  
Radio Galaxies ◽  
Elliptical Galaxies ◽  
Observational Cosmology ◽  
Redshift Distribution ◽  
Flux Limit ◽  
Formation And Evolution ◽  
Radio Luminosity Function ◽  
Radio Power

The study of radio galaxies selected at mJy flux levels has the potential to resolve two important issues in observational cosmology provided redshifts can be determined or reliably estimated for complete samples of such sources. First, the deep flux limit, combined with the shape of the radio luminosity function means that the redshift distribution of such samples provides a much more powerful test of the existence of a high-redshift cutoff for radio sources (Dunlop & Peacock 1990) than can be provided by further studies of brighter radio samples. Second, as a consequence of selection from bright radio surveys, the detailed study of galaxies at z > 2 has to date been confined to objects of extreme radio power (e.g. 4C41.17, Chambers et al. 1990; B2 0902+34, Eales et al. 1993), and it has now become clear that the ultraviolet-infrared properties of such sources are strongly contaminated by processes connected to the AGN (Eales & Rawlings 1993; Dunlop & Peacock 1993). Being 100-1000 times less radio luminous than these extreme sources, mJy radio galaxies at comparable redshifts should provide much more representative probes of the formation and evolution of elliptical galaxies in general.

scholarly journals The High Mass X-ray binaries in star-forming galaxies

2018 ◽  
Vol 14 (S346) ◽  
pp. 332-336
Author(s):  
M. Celeste Artale ◽  
Nicola Giacobbo ◽  
Michela Mapelli ◽  
Paolo Esposito
Keyword(s):  
Luminosity Function ◽  
High Mass ◽  
Population Synthesis ◽  
Host Galaxies ◽  
X Ray ◽  
Star Forming ◽  
Star Formation In Galaxies ◽  
Binary Evolution ◽  
X Ray Binaries ◽  
The Universe

AbstractThe high mass X-ray binaries (HMXBs) provide an exciting framework to investigate the evolution of massive stars and the processes behind binary evolution. HMXBs have shown to be good tracers of recent star formation in galaxies and might be important feedback sources at early stages of the Universe. Furthermore, HMXBs are likely the progenitors of gravitational wave sources (BH–BH or BH–NS binaries that may merge producing gravitational waves). In this work, we investigate the nature and properties of HMXB population in star-forming galaxies. We combine the results from the population synthesis model MOBSE (Giacobbo & Mapelli 2018a) together with galaxy catalogs from EAGLE simulation (Schaye et al. 2015). Therefore, this method describes the HMXBs within their host galaxies in a self-consistent way. We compute the X-ray luminosity function (XLF) of HMXBs in star-forming galaxies, showing that this methodology matches the main features of the observed XLF.

scholarly journals Probing restarting activity in hard X-ray selected giant radio galaxies

2018 ◽  
Vol 14 (A30) ◽  
pp. 66-69
Author(s):  
G. Bruni ◽  
F. Ursini ◽  
F. Panessa ◽  
L. Bassani ◽  
A. Bazzano ◽  
...  
Keyword(s):  
Radio Galaxies ◽  
High Luminosity ◽  
X Ray ◽  
The Universe ◽  
Multiple Episodes ◽  
Individual Objects

AbstractWith their sizes larger than 0.7 Mpc, Giant Radio Galaxies (GRGs) are the largest individual objects in the Universe. To date, the reason why they reach such enormous extensions is still unclear. One of the proposed scenarios suggests that they are the result of multiple episodes of jet activity. Cross-correlating the INTEGRAL+Swift AGN population with radio catalogues (NVSS, FIRST, SUMSS), we found that 22% of the sources are GRG (a factor four higher than those selected from radio catalogues). Remarkably, all of the sources in the sample show signs of restarting radio activity. The X-ray properties are consistent with this scenario, the sources being in a high-accretion, high-luminosity state with respect to the previous activity responsible for the radio lobes.

scholarly journals The radio luminosity function of the NEP distant cluster radio galaxies

2006 ◽  
Vol 446 (1) ◽  
pp. 97-111 ◽  
Author(s):  
M. Branchesi ◽  
I. M. Gioia ◽  
C. Fanti ◽  
R. Fanti ◽  
R. Perley
Keyword(s):  
Luminosity Function ◽  
Radio Galaxies ◽  
Radio Luminosity ◽  
Distant Cluster ◽  
Radio Luminosity Function

scholarly journals Radio Source Evolution Derived from Low Frequency Surveys

2002 ◽  
Vol 199 ◽  
pp. 50-53
Author(s):  
C.A. Jackson ◽  
J.V. Wall
Keyword(s):  
Radio Source ◽  
Luminosity Function ◽  
Low Frequency ◽  
Radio Galaxies ◽  
Parametric Models ◽  
Radio Luminosity ◽  
Space Density ◽  
Radio Data ◽  
Radio Luminosity Function

We find simple parametric models to describe the space density evolution of radio-loud AGN, treating FRI and FRII radio galaxies separately as the two parent populations in our dual-population unified scheme. In this we use low frequency radio data (v < 500 MHz), where radio samples are unbiased by Doppler beaming. Incorporated into this latest analysis is a new determination of the local radio luminosity function at 1.4 GHz from galaxies common to both the 2dFGRS and NVSS surveys.

scholarly journals Quasar Surveys

1986 ◽  
Vol 119 ◽  
pp. 17-32
Author(s):  
M. G. Smith
Keyword(s):  
Luminosity Function ◽  
Seyfert Galaxies ◽  
Radio Sources ◽  
Selection Effects ◽  
Spectral Evolution ◽  
X Ray ◽  
Spectrum Radio ◽  
Show Evidence ◽  
Optical Surveys ◽  
Radio Luminosity Function

A review is given of progress in surveys for quasars at frequencies from radio to x-ray. Radio results show evidence for a decline in the radio luminosity function for flat-spectrum radio sources at redshifts z > 2. The IRAS survey is uncovering hitherto unknown dusty Seyfert galaxies. Optical surveys, which yield the largest number of QSOs per square degree, may suffer from selection effects which depend on intrinsic luminosity, redshift, and spectral evolution - particularly above redshift 2. Below redshifts of about 2.3, the optical magnitude-redshift plane is being filled in to the point where the evolution of the luminosity function can be seen directly. The statistics of quasar pair separations provide the best evidence so far for quasar clustering.The existence of many potentially significant selection effects means that a multi-frequency approach to quasar surveys is likely to prove essential to an understanding of the evolutionary behaviour of the quasar population as a whole.

The radio-luminosity function for radio galaxies

Astrophysics ◽  
1973 ◽  
Vol 6 (4) ◽  
pp. 297-300
Author(s):  
Yu. K. Melik-Alaverdyan
Keyword(s):  
Luminosity Function ◽  
Radio Galaxies ◽  
Radio Luminosity ◽  
Radio Luminosity Function

scholarly journals AGN jets versus accretion as reionization sources

2020 ◽  
Vol 635 ◽  
pp. A57 ◽  
Author(s):  
Núria Torres-Albà ◽  
Valentí Bosch-Ramon ◽  
Kazushi Iwasawa
Keyword(s):  
Accretion Disks ◽  
Luminosity Function ◽  
Massive Star ◽  
Minor Role ◽  
X Ray ◽  
Star Forming ◽  
Low Mass ◽  
A Minor ◽  
Favorable Conditions ◽  
The Universe

Context. Cosmic reionization put an end to the dark ages that came after the recombination era. Observations seem to favor the scenario of massive-star photons generated in low-mass galaxies being responsible for the bulk of reionization and, whereas a possible contribution from AGN accretion disks has been widely considered, they are currently thought to have had a minor role in reionization. Aims. We aim to study the possibility of AGN having contributed to reionization not only through their accretion disks, but also through ionizing photons coming from the AGN jets interacting with the intergalactic medium. Methods. We adopt an empirically derived AGN luminosity function at z ≃ 6, use X-ray observations to correct it for the presence of obscured sources, and estimate the density of jetted AGN. We then use analytical calculations to derive the fraction of jet energy that goes into ionizing photons. Finally, we compute the contribution of AGN jets to the H II volume filling factor at redshifts z ≃ 15−5. Results. We show that the contribution of the AGN jet lobes to the reionization of the Universe at z ∼ 6 might have been as high as ≳10% of that of star-forming galaxies, under the most favorable conditions of jetted and obscuration fraction. Conclusions. The contribution of AGN to the reionization, while most likely not dominant, could have been higher than previously assumed, thanks to the radiation originated in the jet lobes.

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