scholarly journals ICL light in a z~0.5 cluster: the MUSE perspective

2016 ◽  
Vol 11 (S321) ◽  
pp. 336-338
Author(s):  
E. Pompei ◽  
C. Adami ◽  
Keyword(s):  
Ram Pressure ◽  
History Of ◽  
Intracluster Light ◽  
Interaction History ◽  
Intermediate Redshift

AbstractIntracluster light is contributed by both stars and gas and it is an important tracer of the interaction history of galaxies within a cluster. We present here the results obtained from MUSE observations of an intermediate redshift (z~ 0.5) cluster taken from the XXL survey and we conclude that the most plausible process responsible for the observed amount of ICL is ram pressure stripping.

scholarly journals The Evolution of Tidal Debris

2004 ◽  
Vol 217 ◽  
pp. 390-399 ◽  
Author(s):  
J. Christopher Mihos
Keyword(s):  
Galaxy Clusters ◽  
Large Scale ◽  
Dwarf Galaxies ◽  
Galactic Disks ◽  
Galaxy Interactions ◽  
Surrounding Environment ◽  
History Of ◽  
Formation And Evolution ◽  
Intracluster Light ◽  
Interaction History

Galaxy interactions expel a significant amount of stars and gas into the surrounding environment. I review the formation and evolution of the tidal debris spawned during these collisions, and describe how this evolution depends on the large scale environment in which the galaxies live. In addition to acting as a long-lived tracer of the interaction history of galaxies, the evolution of this material - on both large scales and small - has important ramifications for galactic recycling processes, the feeding of the intracluster light and intracluster medium within galaxy clusters, and the delayed formation of galactic disks and dwarf galaxies.

scholarly journals Impact of the Metal Evaporation Rate in Vacuum Interrupters on Vapor Expansion and Deposition in Vacuum

2019 ◽  
Vol 6 (2) ◽  
pp. 165-169
Author(s):  
A. E. Geisler ◽  
N. Wenzel
Keyword(s):  
Ceramic Surface ◽  
High Current ◽  
Extended Version ◽  
Metal Vapour ◽  
Current Case ◽  
Vacuum Interrupter ◽  
Ceramic Surfaces ◽  
Metal Evaporation ◽  
History Of ◽  
Interaction History

The emission of contact material into vacuum after switching operation of a vacuum interrupter is crucial for the metallisation of the ceramic surfaces. This work focuses on the simulation of various regimes of metal vapour pressure using an extended version of an existing DSMC code that now allows the visualisation of the interaction types and locations during the vapour expansion. The model was applied to a typical vacuum interrupter geometry at different current levels between 3 A and 100 kA. The simulations show that in the low current case the likelihood for a particle hitting a ceramic surface can be more than a factor of 5 higher than in the high current case. An explanation of this observation will be given by analysing the interaction history of the respective particles.

scholarly journals Stellar substructures in the periphery of the magellanic clouds with the VISTA hemisphere survey from the red clump and other tracers

2021 ◽  
Author(s):  
Dalal El Youssoufi ◽  
Maria-Rosa L Cioni ◽  
Cameron P M Bell ◽  
Richard de Grijs ◽  
Martin A T Groenewegen ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Imaging ◽  
Magellanic Clouds ◽  
Imaging Data ◽  
The North ◽  
The Galaxy ◽  
History Of ◽  
Northern Side ◽  
Red Clump ◽  
Interaction History

Abstract We study the morphology of the stellar periphery of the Magellanic Clouds in search of substructure using near–infrared imaging data from the VISTA Hemisphere Survey (VHS). Based on the selection of different stellar populations using the (J − Ks, Ks) colour–magnitude diagram, we confirm the presence of substructures related to the interaction history of the Clouds and find new substructures on the eastern side of the LMC disc which may be owing to the influence of the Milky Way, and on the northern side of the SMC, which is probably associated to the ellipsoidal structure of the galaxy. We also study the luminosity function of red clump stars in the SMC and confirm the presence of a bi–modal distance distribution, in the form of a foreground population. We find that this bi–modality is still detectable in the eastern regions of the galaxy out to a 10○ distance from its centre. Additionally, a background structure is detected in the North between 7○ and 10○ from the centre which might belong to the Counter Bridge, and a foreground structure is detected in the South between 6○ and 8○ from the centre which might be linked to the Old Bridge.

scholarly journals Star Formation in Isolated LIRGs: Clues to Star-forming Processes at Higher z

2010 ◽  
Vol 6 (S277) ◽  
pp. 195-198
Author(s):  
Isaura Fuentes-Carrera ◽  
Lorenzo Olguín ◽  
Patricia Ambrocio-Cruz ◽  
Simon Verley ◽  
Margarita Rosado ◽  
...  
Keyword(s):  
Star Formation ◽  
Large Fraction ◽  
Formation Rate ◽  
Local Universe ◽  
Star Forming ◽  
Luminous Infrared Galaxies ◽  
History Of ◽  
Observational Techniques ◽  
Intermediate Redshift ◽  
Very High

AbstractLuminous infrared galaxies (LIRGs) are galaxies with LIR > 1011 L⊙. For a star-forming galaxy to emit at a LIRG level, it must have a very high star formation rate (SFR). In the local Universe, the star formation (SF) is primarily triggered by interactions. However, at intermediate redshift, a large fraction of LIRGs are disk galaxies with little sign of recent merger activity. The question arises whether the intermediate redshift LIRGs are “triggered” or experiencing “normal”, if elevated, SF. Understanding these SF processes is important since this type of systems may have contributed to 20% or more of the cosmic SFR in the early Universe. In order to address this issue we study similar systems in the Local Universe, that is isolated late-type galaxies displaying LIRG activity. We use different observational techniques in order to trace the star-forming history of these systems. Here we present preliminary results.

scholarly journals Absorption Line Surveys at Intermediate Redshift

2011 ◽  
Vol 7 (S280) ◽  
pp. 339-350 ◽  
Author(s):  
Sébastien Muller
Keyword(s):  
Fundamental Constants ◽  
Molecular Absorption ◽  
Chemical Enrichment ◽  
Distant Galaxies ◽  
Absorption Studies ◽  
History Of ◽  
Spectral Survey ◽  
Intermediate Redshift ◽  
The Universe ◽  
Compact Array

AbstractThe z=0.89 spiral galaxy located on the line of sight to the quasar PKS1830-211 is right now the extragalactic object with the largest number of detected molecular species (34, plus isotopic variants). This remarkable molecular inventory was recently built after an unbiased spectral survey of molecular absorption lines with the Australia Telescope Compact Array in the 7 mm band. We present the results of this survey, as a showcase of the various interests of molecular absorption studies at intermediate redshift: chemical inventory and gas properties in distant galaxies, chemical enrichment history of the Universe, measurements of the CMB temperature as a function of z, and constraints on the constancy of fundamental constants.

scholarly journals Trust Based Authentication Mechanism in Wireless Sensor Networks

2016 ◽  
Vol 12 (1) ◽  
pp. 58
Author(s):  
Li Ru Ping
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Data Exchange ◽  
Wireless Sensor ◽  
Network Nodes ◽  
Authentication Mechanism ◽  
Efficiency And Effectiveness ◽  
Evaluation Algorithm ◽  
History Of ◽  
Interaction History

Authentication mechanism is the basis of access control and data exchange. In wireless sensor networks, the vulnerability of network nodes and complexity of communication protocols pose a huge challenge for designing authentication mechanism in such environment. In this paper, we study the authentication mechanism in wireless sensor networks based on trust between nodes. We use the interaction history of nodes for recommendation trust computation, and the interaction history comes from the interactions between nodes. We design a penalty mechanism for hostile nodes based on the TCP congestion control protocol, and present a loyalty based trust recommendation evaluation algorithm. Massive experiments validate the efficiency and effectiveness of the proposed approach.

scholarly journals The distinct stellar metallicity populations of simulated Local Group dwarfs

2019 ◽  
Vol 488 (2) ◽  
pp. 2312-2331 ◽  
Author(s):  
Anna Genina ◽  
Carlos S Frenk ◽  
Alejandro Benítez-Llambay ◽  
Shaun Cole ◽  
Julio F Navarro ◽  
...  
Keyword(s):  
Star Formation ◽  
Local Group ◽  
Dwarf Galaxies ◽  
Mass Range ◽  
Spatial Segregation ◽  
Ram Pressure ◽  
History Of ◽  
Hydrodynamical Simulations ◽  
Two Populations ◽  
Poor Population

ABSTRACT A number of Local Group dwarf galaxies are known to have two spatially segregated stellar metallicity populations, a centrally concentrated metal-rich population, and a more extended metal-poor population. In this work we discuss mechanisms that lead to the formation of two spatially segregated metallicity populations. Using a set of high-resolution hydrodynamical simulations of Local Group-like environments, we select a sample of satellite and field galaxies, spanning the stellar mass range 106–109 M⊙, that exhibit bimodality in their metallicity distributions. Among those, we identify a subsample with a strong spatial segregation in the two populations. We find three distinct mechanisms for their formation. In field dwarfs and in a small fraction of satellites, a merger causes the metal-poor stars to migrate to larger radii and encourages the available gas to sink to the centre of the dwarf. Most of the gas is subsequently blown out of the halo through star formation feedback, but the remaining gas is consumed in the formation of a metal-rich population. In the exclusive case of satellites that have retained some of their gas at infall, it is the compression of this gas by ram pressure near pericentre that triggers the formation of metal-rich stars, whilst simultaneously preventing star formation at larger radii through stripping. Additionally, in a small number of field and satellite dwarfs, interactions with gaseous filaments and other galaxies can result in the formation of a metal-rich population. Regardless of the formation mechanism, a history of mergers typically enhances the spatial segregation.

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