scholarly journals The Origins of X‐Ray Emission from the Hot Spots of FR II Radio Sources

2004 ◽  
Vol 612 (2) ◽  
pp. 729-748 ◽  
Author(s):  
M. J. Hardcastle ◽  
D. E. Harris ◽  
D. M. Worrall ◽  
M. Birkinshaw
Keyword(s):  
Hot Spots ◽  
Radio Sources ◽  
X Ray

scholarly journals The 3C Chandra snapshot survey

2014 ◽  
Vol 10 (S313) ◽  
pp. 305-306
Author(s):  
Alessandro Paggi ◽  
F. Massaro ◽  
D. E. Harris
Keyword(s):  
Spectral Analysis ◽  
Detailed Analysis ◽  
Hot Spots ◽  
Column Density ◽  
Radio Sources ◽  
Energy Bands ◽  
Complete Sample ◽  
X Ray ◽  
Pile Up ◽  
Best Fit

AbstractWe present a uniform analysis of Chandra archival observations of a complete sample of ~ 200 3C sources at z < 0.5. We measured the X-ray intensity of the nuclei and of any radio hot spots and jet features with associated X-ray emission. X-ray fluxes in three energy bands, i.e., soft, medium, and hard, for all the sources analyzed are also reported. For the stronger nuclei, we also applied the standard spectral analysis, which provides the best-fit values of the X-ray spectral index and absorbing column density. In addition, a detailed analysis of bright X-ray nuclei that could be affected by pile-up has been performed. X-ray emission was detected for all the nuclei of the radio sources in our sample.

scholarly journals Active Nuclei and Redshift Problems

1983 ◽  
Vol 6 ◽  
pp. 531-533
Author(s):  
Geoffrey Burbidge
Keyword(s):  
Galactic Nuclei ◽  
Seyfert Galaxies ◽  
Radio Sources ◽  
Powerful Radio ◽  
Radiation Mechanism ◽  
X Ray ◽  
Major Interest ◽  
Relativistic Particles

More than 20 years ago V. A. Ambartsumian proposed that much of the activity in galaxies was dominated and even generated by their nuclei. Subsequent observational work in radio, optical and x-ray frequencies has borne out his prophecy, and major interest has centered about the nature of the machine in the galactic nucleus. The major characteristic of this machine is that it releases energy rapidly and often spasmodically by processes which are not thermonuclear in origin.The original studies which led to the conclusion that nuclei were all important were observations of the powerful radio sources and Seyfert galaxies, and evidence for the ejection of gas from galaxies of many types. The realization that the synchrotron mechanism was the dominant radiation mechanism and the later studies of Compton radiation were fundamental in leading to the conclusion that large fluxes of relativistic particles must be generated in galactic nuclei.

Supermassive Black Hole feedback in early type galaxies

2020 ◽  
Vol 15 (S359) ◽  
pp. 119-125
Author(s):  
W. Forman ◽  
C. Jones ◽  
A. Bogdan ◽  
R. Kraft ◽  
E. Churazov ◽  
...  
Keyword(s):  
Dark Matter Halo ◽  
Scaling Relations ◽  
Radio Sources ◽  
Early Type ◽  
X Ray ◽  
Galaxy Groups ◽  
Sufficient Energy ◽  
The Galaxy ◽  
Simple Scaling ◽  
Halo Masses

AbstractOptically luminous early type galaxies host X-ray luminous, hot atmospheres. These hot atmospheres, which we refer to as coronae, undergo the same cooling and feedback processes as are commonly found in their more massive cousins, the gas rich atmospheres of galaxy groups and galaxy clusters. In particular, the hot coronae around galaxies radiatively cool and show cavities in X-ray images that are filled with relativistic plasma originating from jets powered by supermassive black holes (SMBH) at the galaxy centers. We discuss the SMBH feedback using an X-ray survey of early type galaxies carried out using Chandra X-ray Observatory observations. Early type galaxies with coronae very commonly have weak X-ray active nuclei and have associated radio sources. Based on the enthalpy of observed cavities in the coronae, there is sufficient energy to “balance” the observed radiative cooling. There are a very few remarkable examples of optically faint galaxies that are 1) unusually X-ray luminous, 2) have large dark matter halo masses, and 3) have large SMBHs (e.g., NGC4342 and NGC4291). These properties suggest that, in some galaxies, star formation may have been truncated at early times, breaking the simple scaling relations.

scholarly journals A Multi-Frequency Study of the Milky Way-Like Spiral Galaxy NGC 6744

2018 ◽  
Vol 35 ◽  
Author(s):  
Miranda Yew ◽  
Miroslav D. Filipović ◽  
Quentin Roper ◽  
Jordan D. Collier ◽  
Evan J. Crawford ◽  
...  
Keyword(s):  
Black Hole ◽  
Milky Way ◽  
Formation Rate ◽  
Radio Continuum ◽  
Starburst Galaxy ◽  
Radio Sources ◽  
Wide Field ◽  
Central Black Hole ◽  
X Ray ◽  
Continuum Data

AbstractWe present a multi-frequency study of the intermediate spiral SAB(r)bc type galaxy NGC 6744, using available data from the Chandra X-Ray telescope, radio continuum data from the Australia Telescope Compact Array and Murchison Widefield Array, and Wide-field Infrared Survey Explorer infrared observations. We identify 117 X-ray sources and 280 radio sources. Of these, we find nine sources in common between the X-ray and radio catalogues, one of which is a faint central black hole with a bolometric radio luminosity similar to the Milky Way’s central black hole. We classify 5 objects as supernova remnant (SNR) candidates, 2 objects as likely SNRs, 17 as H ii regions, 1 source as an AGN; the remaining 255 radio sources are categorised as background objects and one X-ray source is classified as a foreground star. We find the star-formation rate (SFR) of NGC 6744 to be in the range 2.8–4.7 M⊙~yr − 1 signifying the galaxy is still actively forming stars. The specific SFR of NGC 6744 is greater than that of late-type spirals such as the Milky Way, but considerably less that that of a typical starburst galaxy.

scholarly journals Improvement of Spatial Modeling of Cr, Pb, Cd, As and Ni in Soil Based on Portable X-ray Fluorescence (PXRF) and Geostatistics: A Case Study in East China

2019 ◽  
Vol 16 (15) ◽  
pp. 2694 ◽  
Author(s):  
Xia ◽  
Hu ◽  
Shao ◽  
Xu ◽  
Zhou ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Hot Spots ◽  
Ordinary Kriging ◽  
Eastern China ◽  
Indicator Kriging ◽  
Polluted Water ◽  
X Ray ◽  
Soil Heavy Metals ◽  
Metals Pollution ◽  
Heavy Metals Pollution

To verify the feasibility of portable X-ray fluorescence (PXRF) for rapidly analyzing, assessing and improving soil heavy metals mapping, 351 samples were collected from Fuyang District, Hangzhou City, in eastern China. Ordinary kriging (OK) and co-ordinary kriging (COK) combined with PXRF measurements were used to explore spatial patterns of heavy metals content in the soil. The Getis-Ord index was calculated to discern hot spots of heavy metals. Finally, multi-variable indicator kriging was conducted to obtain a map of multi-heavy metals pollution. The results indicated Cd is the primary pollution element in Fuyang, followed by As and Pb. Application of PXRF measurements as covariates in COK improved model accuracy, especially for Pb and Cd. Heavy metals pollution hot spots were mainly detected in northern Fuyang and plains along the Fuchun River in southern Fuyang because of mining, industrial and traffic activities, and irrigation with polluted water. Area with high risk of multi-heavy metals pollution mainly distributed in plain along the Fuchun River and the eastern Fuyang. These findings certified the feasibility of using PXRF as an efficient and reliable method for soil heavy metals pollution assessment and mapping, which could contribute to reduce the cost of surveys and pollution remediation.

scholarly journals Soft X-Ray Properties of a Complete Sample of Radio Sources

1996 ◽  
pp. 263-264
Author(s):  
J. Siebert ◽  
W. Brinkmann ◽  
R. Morganti ◽  
C. N. Tadhunter ◽  
I. J. Danziger ◽  
...  
Keyword(s):  
Radio Sources ◽  
Complete Sample ◽  
X Ray

Radio Sources, X-ray Sources, Cosmic Radiation

1981 ◽  
pp. 508-548
Author(s):  
Siegfried Böhme ◽  
Walter Fricke ◽  
Inge Heinrich ◽  
Wilfried Hofmann ◽  
Dietlinde Krahn ◽  
...  
Keyword(s):  
Cosmic Radiation ◽  
Radio Sources ◽  
X Ray

Study on Linear Segregation of ZL205A Alloy

2021 ◽  
Vol 1020 ◽  
pp. 8-12
Author(s):  
Wu Hu ◽  
Ke Zhu ◽  
Meng Wang ◽  
Wei Dong Huang ◽  
Jian Min Zeng
Keyword(s):  
Aluminum Alloy ◽  
Wall Thickness ◽  
Hot Spots ◽  
Energy Dispersive Spectrometer ◽  
High Strength ◽  
X Ray ◽  
Thermal Cracks ◽  
Zl205a Alloy ◽  
Solidification Speed ◽  
Scanning Electron

Linear segregation of high strength aluminum alloy ZL205A castings were studied by X-ray Nondestructive testing, scanning electron microscope and energy dispersive spectrometer. It is found that the linear segregation occurs at the large wall thickness of the casting and/or at the place where the wall thickness is in transition. Segregation element is mainly Cu, which exists as compound θ (Al2Cu) phase. The formation of linear segregation is related to the flow of Cu-rich melt in the late solidification period, while the occurrence of thermal cracks promotes the formation of linear segregation. The formation of linear segregation of the casting can be effectively prevented by eliminating hot spots of the casting, refining crystal grains and increasing solidification speed of the casting.

Radio Sources, X-ray Sources, Cosmic Radiation

1983 ◽  
pp. 538-569
Author(s):  
S. Böhme ◽  
Walter Fricke ◽  
H. Hefele ◽  
I. Heinrich ◽  
W. Hofmann ◽  
...  
Keyword(s):  
Cosmic Radiation ◽  
Radio Sources ◽  
X Ray

Radio Sources, X-ray Sources, Cosmic Rays

1990 ◽  
pp. 896-943
Author(s):  
G. Burkhardt ◽  
U. Esser ◽  
H. Hefele ◽  
I. Heinrich ◽  
W. Hofmann ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Radio Sources ◽  
X Ray
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