Radio Jets as a Probe of the Cooling Flow Environment

1988 ◽  
pp. 257-261 ◽  
Author(s):  
D. M. Sumi ◽  
M. L. Norman ◽  
L. L. Smarr
Keyword(s):  
Flow Environment ◽  
Cooling Flow ◽  
Radio Jets

scholarly journals High Frequency Observations of a Large Faraday Rotation Galaxy in a Cluster

1990 ◽  
Vol 140 ◽  
pp. 486-486
Author(s):  
M. Inoue ◽  
H. Tabara ◽  
T. Kato ◽  
K. Aizu
Keyword(s):  
Faraday Rotation ◽  
Hot Spots ◽  
High Frequency ◽  
Intracluster Medium ◽  
X Ray ◽  
Cooling Flow ◽  
Radio Jets ◽  
Rotation Measure ◽  
Dominant Member

We present 22 and 49 GHz interferometric observations of Hyd A (3C218). The source was found to have a very large Faraday rotation measure (RM) (Kato et al. 1987), and to be a dominant member of a luminous X-ray cluster with a large cooling flow (David et al. 1988). These characteristics are very similar to those of Cyg A which is suggested to produce a large RM within a dense sheath around the radio lobes as a result of somehow an interaction between dense intracluster medium (ICM) and radio jets and/or lobes (Dreher et al. 1987). Hyd A is the second example of Cyg A type source. In case of Cyg A, hot spots are the place where the interaction between jets and ICM occurs (Carilli et al. 1988). We then expect in Hyd A that similar interaction also occurs to form hot spots, and consequently that high frequency observations reveal structures of the interaction.

scholarly journals Discovery of radio jets in the Phoenix galaxy cluster center

2020 ◽  
Vol 72 (4) ◽  
Author(s):  
Takuya Akahori ◽  
Tetsu Kitayama ◽  
Shutaro Ueda ◽  
Takuma Izumi ◽  
Kianhong Lee ◽  
...  
Keyword(s):  
Radio Emission ◽  
Dust Emission ◽  
Galaxy Cluster ◽  
Cluster Center ◽  
Cluster Galaxy ◽  
Cooling Flow ◽  
Radio Jets ◽  
Spatially Resolved ◽  
Extended Radio ◽  
The Phoenix

Abstract We report the results of the Australia Telescope Compact Array (ATCA) 15 mm observation of the Phoenix galaxy cluster possessing an extreme star-burst brightest cluster galaxy (BCG) at the cluster center. We spatially resolved radio emission around the BCG, and found diffuse bipolar and bar-shape structures extending from the active galactic nucleus (AGN) of the BCG. They are likely radio jets/lobes, whose sizes are ∼10–20 kpc and locations are aligned with X-ray cavities. If we assume that the radio jets/lobes expand with the sound velocity, their ages are estimated to be ∼10 Myr. We also found compact radio emissions near the center and suggest that they are more young bipolar jets ∼1 Myr in age. Moreover, we found extended radio emission surrounding the AGN and discussed the possibility that the component is a product of the cooling flow, by considering synchrotron radiation partially absorbed by molecular clumps, free–free emission from the warm ionized gas, and the spinning dust emission from the dusty circumgalactic medium.

Propagation and Stability Properties of Radio Jets in Cluster Cooling Flow Atmospheres

1993 ◽  
Vol 417 ◽  
pp. 515 ◽  
Author(s):  
Chris Loken ◽  
Jack O. Burns ◽  
Michael L. Norman ◽  
David A. Clarke
Keyword(s):  
Stability Properties ◽  
Cooling Flow ◽  
Radio Jets

scholarly journals The role of AGN jets and intracluster magnetic fields in the formation and acceleration of cosmic rays

2010 ◽  
Vol 6 (S275) ◽  
Author(s):  
Nectaria A. B. Gizani
Keyword(s):  
Cosmic Rays ◽  
Magnetic Fields ◽  
Radio Emission ◽  
Radio Galaxies ◽  
Powerful Radio ◽  
X Ray ◽  
Cooling Flow ◽  
The Core ◽  
Radio Jets

AbstractUsing radio and X-ray data of two powerful radio galaxies, we attempt to find out the role that radio jets (in terms of composition and power), as well as intracluster magnetic fields, play in the formation, propagation, and acceleration of cosmic rays. For this study we have selected the powerful radio galaxies Hercules A and 3C 310 because of the presence of ring-like features in their kpc-scale radio emission instead of the usual hotspots. These two FR1.5 lie at the center of galaxy cooling flow clusters in a dense environment. We observed the unique jets of Hercules both in kpc-scales (multifrequency VLA data) and pc-scales (EVN observations at 18 cm). We have also observed the core and inner jets of 3C310 at 18 cm using global VLBI. We report on the work in progress.

Multiphysics Computational Analysis of a Perforated Plate Cooling Flow

2021 ◽  
Author(s):  
Justin M. Pesich ◽  
Nicholas J. Georgiadis ◽  
Mark P. Wernet
Keyword(s):  
Computational Analysis ◽  
Perforated Plate ◽  
Cooling Flow

Fundamental Issues and Recent Advancements in Analysis of Aircraft Brake Natural Convective Cooling

1998 ◽  
Vol 120 (4) ◽  
pp. 840-857 ◽  
Author(s):  
M. P. Dyko ◽  
K. Vafai
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Flow Field ◽  
Three Dimensional ◽  
Convective Cooling ◽  
Cooling Flow ◽  
Physical Mechanisms ◽  
Braking System ◽  
Flow And Heat Transfer ◽  
Convection Cooling

A heightened awareness of the importance of natural convective cooling as a driving factor in design and thermal management of aircraft braking systems has emerged in recent years. As a result, increased attention is being devoted to understanding the buoyancy-driven flow and heat transfer occurring within the complex air passageways formed by the wheel and brake components, including the interaction of the internal and external flow fields. Through application of contemporary computational methods in conjunction with thorough experimentation, robust numerical simulations of these three-dimensional processes have been developed and validated. This has provided insight into the fundamental physical mechanisms underlying the flow and yielded the tools necessary for efficient optimization of the cooling process to improve overall thermal performance. In the present work, a brief overview of aircraft brake thermal considerations and formulation of the convection cooling problem are provided. This is followed by a review of studies of natural convection within closed and open-ended annuli and the closely related investigation of inboard and outboard subdomains of the braking system. Relevant studies of natural convection in open rectangular cavities are also discussed. Both experimental and numerical results obtained to date are addressed, with emphasis given to the characteristics of the flow field and the effects of changes in geometric parameters on flow and heat transfer. Findings of a concurrent numerical and experimental investigation of natural convection within the wheel and brake assembly are presented. These results provide, for the first time, a description of the three-dimensional aircraft braking system cooling flow field.

scholarly journals Large Bent Jets in the Inner Region of CSS

1996 ◽  
Vol 175 ◽  
pp. 71-72
Author(s):  
F. Mantovani ◽  
W. Junor ◽  
M. Bondi ◽  
L. Padrielli ◽  
W. Cotton ◽  
...  
Keyword(s):  
Velocity Structure ◽  
Radio Sources ◽  
Ambient Media ◽  
The Core ◽  
Gaseous Environment ◽  
Radio Jets ◽  
Large Size ◽  
Superluminal Motion ◽  
Inner Region ◽  
Quasars And Radio Galaxies

Recently we focussed our attention on a sample of Compact Steep-spectrum Sources (CSSs) selected because of the large bent radio jets seen in the inner region of emission. The largest distortions are often seen in sources dominated by jets, and there are suggestions that this might to some extent be due to projection effects. However, superluminal motion is rare in CSSs. The only case we know of so far is 3C147 (Alef at al. 1990) with a mildly superluminal speed of ≃ 1.3v/c. Moreover, the core fractional luminosity in CSSs is ≃ 3% and ≤ 0.4% for quasars and radio galaxies respectively. Similar values are found for large size radio sources i.e. both boosting and orientations in the sky are similar for the two classes of objects. An alternative possibility is that these bent-jet sources might also be brightened by interactions with the ambient media. There are clear indications that intrinsic distortions due to interactions with a dense inhomogeneous gaseous environment play an important role. Observational support comes from the large RMs found in CSSs (Taylor et al. 1992; Mantovani et al. 1994; Junor et al. these proc.) and often associated with strong depolarization (Garrington & Akujor, t.p.). The CSSs also have very luminous Narrow Line Regions emission, with exceptional velocity structure (Gelderman, t.p.).

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