scholarly journals The different flavors of extragalactic jets: The role of relativistic flow deceleration

2020 ◽  
Vol 642 ◽  
pp. A69 ◽  
Author(s):  
P. Rossi ◽  
G. Bodo ◽  
S. Massaglia ◽  
A. Capetti
Keyword(s):  
Ambient Medium ◽  
Three Dimensional ◽  
Lorentz Factor ◽  
Uniform Density ◽  
Radio Sources ◽  
Extragalactic Jets ◽  
The Galaxy ◽  
Relativistic Flow ◽  
Flow Deceleration

We perform three-dimensional numerical simulations of relativistic (with a Lorentz factor of 10), non-magnetized jets propagating in a uniform density environment in order to study the effect of the entrainment and the consequent deceleration. Our simulations investigate the jet propagation inside the galaxy core, where the deceleration most likely occurs more efficiently. We compare cases with different density and pressure ratios with respect to the ambient medium and find that low density jets are efficiently decelerated and reach a quasi-steady state in which, over a length of 600 jet radii, they slow down from highly relativistic to sub-relativistic velocities. Conversely, denser jets keep highly relativistic velocities over the same length. We discuss these results in relation to the Faranoff Riley (FR) radio source classification. We infer that lower density jets can give rise to FR 0 and FR I radio sources, while higher density jets may be connected to FR II radio sources.

scholarly journals Making Faranoff-Riley I radio sources

2019 ◽  
Vol 621 ◽  
pp. A132 ◽  
Author(s):  
S. Massaglia ◽  
G. Bodo ◽  
P. Rossi ◽  
S. Capetti ◽  
A. Mignone
Keyword(s):  
Low Power ◽  
Constant Pressure ◽  
Three Dimensional ◽  
Stratified Medium ◽  
Radio Sources ◽  
Wide Angle ◽  
Mhd Simulations ◽  
The Universe ◽  
Nonrelativistic Velocity

Radio sources of low power are the most common in the universe. Their jets typically move at nonrelativistic velocity and show plume-like morphologies that in many instances appear distorted and bent. We investigate the role of magnetic field on the propagation and evolution of low-power jets and the connection between the field intensity and the resulting morphology. The problem is addressed by means of three-dimensional magnetohydrodynamic (MHD) simulations. We consider supersonic jets that propagate in a stratified medium. The ambient temperature increases with distance from the jet origin maintaining constant pressure. Jets with low magnetization show an enhanced collimation at small distances with respect to hydrodynamic (HD) cases studied in a previous paper. These jets eventually evolve in a way similar to the HD cases. Jets with higher magnetization are affected by strong nonaxisymmetric modes that lead to the sudden jet energy release. From there on, distorted plumes of jet material move at subsonic velocities. This transition is associated with the formation of structures reminiscent of the “warm spots” observed in wide-angle-tail (WAT) sources.

scholarly journals Numerical Simulations of Extragalactic Jets in an Inhomogeneous Environment

1996 ◽  
Vol 175 ◽  
pp. 467-468
Author(s):  
Steve Higgins ◽  
TIM O'BRIEN ◽  
James Dunlop
Keyword(s):  
Numerical Simulations ◽  
Three Dimensional ◽  
Second Order ◽  
Godunov Method ◽  
Radio Sources ◽  
Cartesian Coordinates ◽  
Extragalactic Radio Sources ◽  
Extragalactic Jets ◽  
Hydrodynamic Code

We have simulated the passage of an extragalactic jet through a medium containing an ensemble of cool, dense clouds. The hydrodynamic code uses the second-order Godunov method of Falle (Falle 1991, van Leer 1979) in three-dimensional, cartesian coordinates. We have estimated the synchrotron emissivity and used this to produce synthetic radio maps. The results are reminiscent of structures seen in many extragalactic radio sources.

scholarly journals Boundary Layers in Extragalactic Jets

1996 ◽  
Vol 175 ◽  
pp. 461-462
Author(s):  
DAVID S. DE YOUNG
Keyword(s):  
Energy Transfer ◽  
Ambient Medium ◽  
Surrounding Medium ◽  
Essential Elements ◽  
Energy Requirements ◽  
Radio Sources ◽  
Radio Luminosity ◽  
Central Engine ◽  
Extragalactic Jets ◽  
Loss Term

The radio morphology of extragalactic radio sources, in particular the FR I objects, has long been recognized to be suggestive of an outflow which is undergoing a strong interaction with the surrounding medium. Two essential elements must be noted in considering this interaction. First, it is inevitable. Second, the interaction will always provide mass and energy transfer from the jet to the ambient medium, and thus it is a loss term in the overall energy balance of the radio source. As will be seen, these losses can be comparable to the overall radio luminosity and hence are a nontrivial constraint on the energy requirements placed on the central engine.

The Role of Three-Dimensional Imaging in Evaluation of the Sinonasal Mass

1996 ◽  
Vol 34 (1) ◽  
pp. 27
Author(s):  
Sue Yon Shim ◽  
Ki Joon Sung ◽  
Young Ju Kim ◽  
In Soo Hong ◽  
Myung Soon Kim ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Three Dimensional Imaging ◽  
Sinonasal Mass

Homogenization and Mass Identity vs. Individual Identity. An Analysis in the Light of the Theory of “The Three Dimensional Spiral of Sense

2016 ◽  
Vol 2 (2) ◽  
pp. 40
Author(s):  
Miriam Aparicio
Keyword(s):  
Three Dimensional ◽  
Individual Identity ◽  
Cognitive Effects ◽  
The Media

This study tests some hypotheses included in the psycho-social-communicational paradigm, which emphasizes the cognitive effects of the media and the role of the psychosocial subject as the recipient

Dysregulation of HOX as a Potential Therapeutic Target in Breast Cancer

2020 ◽  
Vol 27 ◽  
Author(s):  
Ji-Yeon Lee ◽  
Myoung Hee Kim
Keyword(s):  
Breast Cancer ◽  
Hox Genes ◽  
Therapeutic Potential ◽  
Expression Patterns ◽  
Genome Structure ◽  
Control Cell ◽  
Three Dimensional ◽  
Cellular Processes ◽  
Hox Protein

: HOX genes belong to the highly conserved homeobox superfamily, responsible for the regulation of various cellular processes that control cell homeostasis, from embryogenesis to carcinogenesis. The abnormal expression of HOX genes is observed in various cancers, including breast cancer; they act as oncogenes or as suppressors of cancer, according to context. In this review, we analyze HOX gene expression patterns in breast cancer and examine their relationship, based on the three-dimensional genome structure of the HOX locus. The presence of non-coding RNAs, embedded within the HOX cluster, and the role of these molecules in breast cancer have been reviewed. We further evaluate the characteristic activity of HOX protein in breast cancer and its therapeutic potential.

Central ossifying fibroma of mandible

2020 ◽  
Vol 13 (12) ◽  
pp. e239286
Author(s):  
Kumar Nilesh ◽  
Prashant Punde ◽  
Nitin Shivajirao Patil ◽  
Amol Gautam
Keyword(s):  
Fibrous Tissue ◽  
Three Dimensional ◽  
Facial Asymmetry ◽  
Ossifying Fibroma ◽  
Mandible Reconstruction ◽  
Three Dimensional Printing ◽  
Osseous Lesion ◽  
Large Size ◽  
Dimensional Printing

Ossifying fibroma (OF) is a rare, benign, fibro-osseous lesion of the jawbone characterised by replacement of the normal bone with fibrous tissue. The fibrous tissue shows varying amount of calcified structures resembling bone and/or cementum. The central variant of OF is rare, and shows predilection for mandible among the jawbone. Although it is classified as fibro-osseous lesion, it clinically behaves as a benign tumour and can grow to large size, causing bony swelling and facial asymmetry. This paper reports a case of large central OF of mandible in a 40-year-old male patient. The lesion was treated by segmental resection of mandible. Reconstruction of the surgical defect was done using avascular fibula bone graft. Role of three-dimensional printing of jaw and its benefits in surgical planning and reconstruction are also highlighted.

scholarly journals Charge algebra in Al(A)dSn spacetimes

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Adrien Fiorucci ◽  
Romain Ruzziconi
Keyword(s):  
Boundary Conditions ◽  
Dirichlet Boundary ◽  
Three Dimensional ◽  
Dirichlet Boundary Conditions ◽  
Boundary Structure ◽  
Asymptotic Symmetry ◽  
Renormalization Procedure ◽  
Field Dependent ◽  
Odd Dimensions

Abstract The gravitational charge algebra of generic asymptotically locally (A)dS spacetimes is derived in n dimensions. The analysis is performed in the Starobinsky/Fefferman-Graham gauge, without assuming any further boundary condition than the minimal falloffs for conformal compactification. In particular, the boundary structure is allowed to fluctuate and plays the role of source yielding some symplectic flux at the boundary. Using the holographic renormalization procedure, the divergences are removed from the symplectic structure, which leads to finite expressions. The charges associated with boundary diffeomorphisms are generically non-vanishing, non-integrable and not conserved, while those associated with boundary Weyl rescalings are non-vanishing only in odd dimensions due to the presence of Weyl anomalies in the dual theory. The charge algebra exhibits a field-dependent 2-cocycle in odd dimensions. When the general framework is restricted to three-dimensional asymptotically AdS spacetimes with Dirichlet boundary conditions, the 2-cocycle reduces to the Brown-Henneaux central extension. The analysis is also specified to leaky boundary conditions in asymptotically locally (A)dS spacetimes that lead to the Λ-BMS asymptotic symmetry group. In the flat limit, the latter contracts into the BMS group in n dimensions.

scholarly journals Learning by Doing: The Use of Distance, Corners and Length in Rewarded Geometric Tasks by Zebrafish (Danio rerio)

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 2001
Author(s):  
Greta Baratti ◽  
Angelo Rizzo ◽  
Maria Elena Miletto Petrazzini ◽  
Valeria Anna Sovrano
Keyword(s):  
Danio Rerio ◽  
Three Dimensional ◽  
Reference Memory ◽  
Spatial Abilities ◽  
Learning By Doing ◽  
Surface Distance ◽  
Extended Surfaces ◽  
Unequal Length ◽  
Over Time

Zebrafish spontaneously use distance and directional relationships among three-dimensional extended surfaces to reorient within a rectangular arena. However, they fail to take advantage of either an array of freestanding corners or an array of unequal-length surfaces to search for a no-longer-present goal under a spontaneous cued memory procedure, being unable to use the information supplied by corners and length without some kind of rewarded training. The present study aimed to tease apart the geometric components characterizing a rectangular enclosure under a procedure recruiting the reference memory, thus training zebrafish in fragmented layouts that provided differences in surface distance, corners, and length. Results showed that fish, besides the distance, easily learned to use both corners and length if subjected to a rewarded exit task over time, suggesting that they can represent all the geometrically informative parts of a rectangular arena when consistently exposed to them. Altogether, these findings highlight crucially important issues apropos the employment of different behavioral protocols (spontaneous choice versus training over time) to assess spatial abilities of zebrafish, further paving the way to deepen the role of visual and nonvisual encodings of isolated geometric components in relation to macrostructural boundaries.

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