scholarly journals How Special Are Brightest Cluster Galaxies? The Impact of Near-Infrared Luminosities on Scaling Relations for BCGs

2007 ◽  
Vol 663 (2) ◽  
pp. L85-L88 ◽  
Author(s):  
Dan Batcheldor ◽  
Alessandro Marconi ◽  
David Merritt ◽  
David J. Axon
Keyword(s):  
Near Infrared ◽  
Scaling Relations ◽  
Cluster Galaxies ◽  
Brightest Cluster Galaxies ◽  
The Impact

scholarly journals Excitation mechanism in the intracluster filaments surrounding the Brightest Cluster Galaxies

2019 ◽  
Vol 15 (S359) ◽  
pp. 185-187
Author(s):  
Fiorella L. Polles
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Elliptical Galaxies ◽  
Cluster Galaxies ◽  
Cooling Flow ◽  
Submillimeter Wavelengths ◽  
Hot Plasma ◽  
Brightest Cluster Galaxies ◽  
Multi Phase ◽  
The Impact

AbstractMulti-phase filamentary structures surrounding giant elliptical galaxies at the center of cool-core clusters, the Brightest Cluster Galaxies (BCGs), have been detected from optical to submillimeter wavelengths. The source of the ionisation in the filaments is still debated. Studying the excitation of these structures is key to our understanding of Active Galactic Nuclei (AGN) feedback in general, and more precisely of the impact of environmental and local effects on star formation. One possible contributor to the excitation of the filaments is the thermal radiation from the cooling of the hot plasma surrounding the BCGs, the so-called cooling flow.

scholarly journals Near-infrared evolution of brightest cluster galaxies in the most X-ray luminous clusters since z = 1

2008 ◽  
Vol 384 (4) ◽  
pp. 1502-1510 ◽  
Author(s):  
J. P. Stott ◽  
A. C. Edge ◽  
G. P. Smith ◽  
A. M. Swinbank ◽  
H. Ebeling
Keyword(s):  
Near Infrared ◽  
X Ray ◽  
Cluster Galaxies ◽  
Brightest Cluster Galaxies

scholarly journals Fossil Galaxy Groups; Scaling Relations, Galaxy Properties and Formation of BCGs

2006 ◽  
Vol 2 (S235) ◽  
pp. 214-214
Author(s):  
Habib G. Khosroshahi ◽  
T. J. Ponman
Keyword(s):  
Scaling Relations ◽  
X Ray ◽  
Cluster Galaxies ◽  
Galaxy Groups ◽  
Hot Gas ◽  
Early Formation ◽  
Central Galaxy ◽  
Brightest Cluster Galaxies ◽  
The Galaxy

AbstractWe study fossil galaxy groups, their hot gas and the galaxy properties. Fossils are more X-ray luminous than non-fossil groups, however, they fall comfortably on the conventional L-T relation of galaxy groups and clusters indicating that their X-ray luminosity and temperature are both boosted, arguably, as a result of their early formation. The central dominant galaxy in fossils have optical luminosity comparable to the brightest cluster galaxies (BCGs), however, the isophotal shapes of the central galaxy in fossils are non-boxy in contrast to the isophotes of majority of the BCGs.

scholarly journals Brightest cluster galaxies: the centre can(not?) hold

2020 ◽  
Vol 500 (1) ◽  
pp. 310-318
Author(s):  
Roberto De Propris ◽  
Michael J West ◽  
Felipe Andrade-Santos ◽  
Cinthia Ragone-Figueroa ◽  
Elena Rasia ◽  
...  
Keyword(s):  
Dark Matter ◽  
Local Environment ◽  
Major Axis ◽  
Theoretical Models ◽  
Dark Matter Halo ◽  
Gas Distribution ◽  
X Ray ◽  
Cluster Galaxies ◽  
Peculiar Velocities ◽  
Brightest Cluster Galaxies

ABSTRACT We explore the persistence of the alignment of brightest cluster galaxies (BCGs) with their local environment. We find that a significant fraction of BCGs do not coincide with the centroid of the X-ray gas distribution and/or show peculiar velocities (they are not at rest with respect to the cluster mean). Despite this, we find that BCGs are generally aligned with the cluster mass distribution even when they have significant offsets from the X-ray centre and significant peculiar velocities. The large offsets are not consistent with simple theoretical models. To account for these observations BCGs must undergo mergers preferentially along their major axis, the main infall direction. Such BCGs may be oscillating within the cluster potential after having been displaced by mergers or collisions, or the dark matter halo itself may not yet be relaxed.

scholarly journals Impact of Incorporating NIR Reflective Pigments in Finishing Coatings of ETICS

2021 ◽  
Vol 6 (6) ◽  
pp. 79
Author(s):  
Nuno M. M. Ramos ◽  
Joana Maia ◽  
Andrea R. Souza ◽  
Ricardo M. S. F. Almeida ◽  
Luís Silva
Keyword(s):  
Surface Layer ◽  
Surface Temperature ◽  
Near Infrared ◽  
Building Performance ◽  
Colour Difference ◽  
Colour Perception ◽  
Composite Systems ◽  
Solar Reflectance ◽  
Building Cooling ◽  
The Impact

Near-infrared (NIR) reflective materials are being developed for mitigating building cooling needs. Their use contributes to broadening the range of colours, responding to the urban aesthetic demand without compromising the building performance. Despite the increase in NIR reflective pigments investigation, there is still a knowledge gap in their applicability, impact, and durability in multilayer finishing coatings of External Thermal Insulation Composite Systems (ETICS). Hence, the main goal of this work consists of evaluating the impact of incorporating NIR reflective pigments (NRP) in the solar reflectance of the surface layer of ETICS, without affecting the colour perception, as well as their influence on the colour durability and surface temperature. As such, colour, solar reflectance, and surface temperature were monitored for 2 years in dark-coloured specimens of ETICS, with and without NRP and a primer layer. It was confirmed that the main contribution of NRP is the increase of solar reflectance and, consequently, the decrease in surface temperature, especially for high exterior temperatures (around 30 ºC). Moreover, these pigments highly increase the NIR reflectance without affecting the visible colour. In addition, they contribute to maintaining the colour characteristics. The application of primer increased the surface temperature, especially for higher exterior temperatures. However, it contributes to a lower colour difference and solar reflectance variation, which is an important achievement for durability purposes.

scholarly journals A Precise Benchmark for Cluster Scaling Relations: Fundamental Plane, Mass Plane and IMF in the Coma Cluster from Dynamical Models

2020 ◽  
Author(s):  
Shravan Shetty ◽  
Michele Cappellari ◽  
Richard M McDermid ◽  
Davor Krajnović ◽  
P T de Zeeuw ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Scaling Relations ◽  
Coma Cluster ◽  
Dynamical Models ◽  
Fundamental Plane ◽  
Cluster Galaxies ◽  
Dynamical Scaling ◽  
Small Uncertainty ◽  
Cluster Distance ◽  
Using Data

Abstract We study a sample of 148 early-type galaxies in the Coma cluster using SDSS photometry and spectra, and calibrate our results using detailed dynamical models for a subset of these galaxies, to create a precise benchmark for dynamical scaling relations in high-density environments. For these galaxies, we successfully measured global galaxy properties, modeled stellar populations, and created dynamical models, and support the results using detailed dynamical models of 16 galaxies, including the two most massive cluster galaxies, using data taken with the SAURON IFU. By design, the study provides minimal scatter in derived scaling relations due to the small uncertainty in the relative distances of galaxies compared to the cluster distance. Our results demonstrate low (≤55% for 90th percentile) dark matter fractions in the inner 1Re of galaxies. Owing to the study design, we produce the tightest, to our knowledge, IMF-σe relation of galaxies, with a slope consistent with that seen in local galaxies. Leveraging our dynamical models, we transform the classical Fundamental Plane of the galaxies to the Mass Plane. We find that the coefficients of the mass plane are close to predictions from the virial theorem, and have significantly lower scatter compared to the Fundamental plane. We show that Coma galaxies occupy similar locations in the (M* - Re) and (M* - σe) relations as local field galaxies but are older. This, and the fact we find only three slow rotators in the cluster, is consistent with the scenario of hierarchical galaxy formation and expectations of the kinematic morphology-density relation.

scholarly journals The Improvement on the Performance of DMD Hadamard Transform Near-Infrared Spectrometer by Double Filter Strategy and a New Hadamard Mask

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 149 ◽  
Author(s):  
Zifeng Lu ◽  
Jinghang Zhang ◽  
Hua Liu ◽  
Jialin Xu ◽  
Jinhuan Li
Keyword(s):  
Near Infrared ◽  
Signal To Noise Ratio ◽  
Nonuniform Distribution ◽  
Stray Light ◽  
Spectral Energy ◽  
Hadamard Transform ◽  
Digital Micromirror Device ◽  
Infrared Spectrometer ◽  
Near Infrared Spectrometer ◽  
The Impact

In the Hadamard transform (HT) near-infrared (NIR) spectrometer, there are defects that can create a nonuniform distribution of spectral energy, significantly influencing the absorbance of the whole spectrum, generating stray light, and making the signal-to-noise ratio (SNR) of the spectrum inconsistent. To address this issue and improve the performance of the digital micromirror device (DMD) Hadamard transform near-infrared spectrometer, a split waveband scan mode is proposed to mitigate the impact of the stray light, and a new Hadamard mask of variable-width stripes is put forward to improve the SNR of the spectrometer. The results of the simulations and experiments indicate that by the new scan mode and Hadamard mask, the influence of stray light is restrained and reduced. In addition, the SNR of the spectrometer also is increased.

scholarly journals Radial gradients in initial mass function sensitive absorption features in the Coma brightest cluster galaxies

2016 ◽  
Vol 465 (1) ◽  
pp. 192-212 ◽  
Author(s):  
Simon Zieleniewski ◽  
Ryan C. W. Houghton ◽  
Niranjan Thatte ◽  
Roger L. Davies ◽  
Sam P. Vaughan
Keyword(s):  
Mass Function ◽  
Initial Mass Function ◽  
Initial Mass ◽  
Cluster Galaxies ◽  
Brightest Cluster Galaxies ◽  
Absorption Features
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