The Enrichment History of Hot Gas in Poor Galaxy Groups

1999 ◽  
Vol 511 (1) ◽  
pp. 34-40 ◽  
Author(s):  
David S. Davis ◽  
John S. Mulchaey ◽  
Richard F. Mushotzky
Keyword(s):  
Galaxy Groups ◽  
Hot Gas ◽  
History Of

scholarly journals Evidence for AGN Feedback in Galaxy Clusters and Groups

2012 ◽  
Vol 2012 ◽  
pp. 1-24 ◽  
Author(s):  
Myriam Gitti ◽  
Fabrizio Brighenti ◽  
Brian R. McNamara
Keyword(s):  
Galaxy Clusters ◽  
Galaxy Evolution ◽  
Large Scale ◽  
Current Knowledge ◽  
Dynamical Evolution ◽  
Large Scale Structures ◽  
Hot Gas ◽  
History Of ◽  
Initial Idea ◽  
Scale Structures

The current generation of flagship X-ray missions,ChandraandXMM-Newton, has changed our understanding of the so-called “cool-core” galaxy clusters and groups. Instead of the initial idea that the thermal gas is cooling and flowing toward the center, the new picture envisages a complex dynamical evolution of the intracluster medium (ICM) regulated by the radiative cooling and the nongravitational heating from the active galactic nucleus (AGN). Understanding the physics of the hot gas and its interplay with the relativistic plasma ejected by the AGN is key for understanding the growth and evolution of galaxies and their central black holes, the history of star formation, and the formation of large-scale structures. It has thus become clear that the feedback from the central black hole must be taken into account in any model of galaxy evolution. In this paper, we draw a qualitative picture of the current knowledge of the effects of the AGN feedback on the ICM by summarizing the recent results in this field.

scholarly journals Dark matter and X-ray halo in early-type galaxies and clusters of galaxies

2009 ◽  
Vol 5 (H15) ◽  
pp. 89-90
Author(s):  
Takaya Ohashi
Keyword(s):  
Dark Matter ◽  
Clusters Of Galaxies ◽  
Large Scatter ◽  
Early Type ◽  
Matter Distribution ◽  
X Ray ◽  
Galaxy Groups ◽  
Hot Gas ◽  
Luminous Galaxies ◽  
Dark Matter Distribution

X-ray observations reveal extended halos around early-type galaxies which enable us to trace the dark matter distribution around the galaxies (see Mathews and Brighenti 2003 for a review). X-ray luminosities, LX of massive early-type galaxies are 1040−1042 erg s−1 in 0.3–2 keV. The correlation plot between LX and B-band luminosity LB shows a large scatter in the sense that LX varies by 2 orders of magnitudes for the same LB, in the brightest end (log LB ≳ 10.5). The amount of the X-ray hot gas in early-type galaxies is typically a few % of the stellar mass, in contrast to clusters of galaxies which hold ~5 times more massive gas than stars. Matsushita (2001) showed that X-ray luminous galaxies are characterized by extended X-ray halo with a few tens of re, similar to the scale of galaxy groups, so the presence of group-size potentials would be strongly linked with the problem of large LX scatter.

scholarly journals Metal abundances in the hot ISM of early-type galaxies

2009 ◽  
Vol 5 (H15) ◽  
pp. 283-283
Author(s):  
Philip J. Humphrey ◽  
David A. Buote
Keyword(s):  
Mass Range ◽  
Point Sources ◽  
Early Type ◽  
X Ray ◽  
Object A ◽  
Galaxy Groups ◽  
History Of ◽  
Solar Abundances ◽  
Entire History ◽  
Metal Abundances

Understanding the process of metal enrichment is one of the key problems for our picture of structure formation and evolution, in which early-type galaxies are a crucial ingredient. X-ray observations provide a powerful tool for measuring the metal distributions in their hot ISM, which is shaped by their entire history of star-formation, evolution and feedback. In Fig 1 (left panel), we summarize the results of a Chandra survey of metals in early-type galaxies, supplemented with Suzaku data (Humphrey & Buote 2006, P. Humphrey et al., in prep.). Chandra is particularly suited to this study, as it enables temperature gradients and X-ray point sources to be resolved, mitigating two important sources of bias (e.g., Buote & Fabian 1998; Fabbiano et al. 1994). We found on average that the ISM is at least as metal-rich as the stars, and we did not find the problematical, highly sub-solar, abundances historically reported. The abundance ratios of O, Ne, Mg, Si and S with respect to Fe are similar to the centres of massive groups and clusters, suggesting homology in the enrichment process over a wide mass range. Finally, using high-quality Suzaku data, we were able to resolve, for the first time in a galaxy-scale (≲1013M⊙) object, a radial abundance gradient similar to those seen in some bright galaxy groups (Fig. 1, right panel).

scholarly journals Acoustic Agglomeration of Power Plant Fly Ash for Environmental and Hot Gas Clean-up

1988 ◽  
Vol 110 (4) ◽  
pp. 552-557 ◽  
Author(s):  
G. Reethof
Keyword(s):  
Fly Ash ◽  
Power Plant ◽  
Pollution Control ◽  
Flue Gases ◽  
Analytical Models ◽  
Particle Removal ◽  
Air Pollution Control ◽  
Hot Gas ◽  
History Of ◽  
Viable Method

Acoustic agglomeration of power plant fly ash is an intermediate treatment of the flue gases to increase the size of the small micron (1–5) and submicron (0.1–1) particulates to large micron sizes (5–10) so that the conventional particle removal devices such as bag houses, electrostatic precipitators, and scrubbers can operate more efficiently. This paper provides a brief history of the topic, introduces some of the fundamental issues and gives some recent results of analytical models of the processes. The experimental facility is briefly described and some analytical results are shown which compare well with the experimental results. Most important of all, the paper shows that acoustic agglomeration is a technically and potentially economically viable method to improve air pollution control.

scholarly journals DETECTION OF HOT GAS IN GALAXY GROUPS VIA THE THERMAL SUNYAEV-ZEL'DOVICH EFFECT

2009 ◽  
Vol 697 (2) ◽  
pp. 1392-1409 ◽  
Author(s):  
K. Moodley ◽  
R. Warne ◽  
N. Goheer ◽  
H. Trac
Keyword(s):  
Galaxy Groups ◽  
Hot Gas ◽  
Sunyaev Zel'dovich Effect

A study of breakdown delay in electrically pumped laser gases

1977 ◽  
Vol 55 (4) ◽  
pp. 325-336 ◽  
Author(s):  
P. Savic ◽  
M. M. Kekez
Keyword(s):  
Roughness Element ◽  
Surface Phenomena ◽  
Cathode Sheath ◽  
Sheath Region ◽  
Hot Gas ◽  
Deposited Energy ◽  
History Of ◽  
Laser Development ◽  
Time Required ◽  
Experimental Findings

When a steep-fronted voltage step is applied to the electrodes in a preionized gas, the high electric field in the cathode sheath, together with current continuity across the sheath causes preferential heating and pressure increase of the gas in the sheath region. The situation is somewhat analogous to that in a shock tube at the instant of diaphragm rupture. However, owing to the current, the cathode sheath goes unstable, forming filaments of hot gas from the sheath. Expressions are derived for the breakdown delay in the two extreme cases of high and low power deposited in the gas, in terms of four time constants, i.e. the relaxation time, the 'power time', being the time required for the electric power to raise the pressure level of the gas to ambient, the 'asperity time', i.e. the time taken by a sound wave to traverse a roughness element or asperity of the electrode surface, and the 'sheath time', being the time of the wave's traverse of the sheath thickness. It is shown that the theory is in substantial agreement with existing experimental findings, including those of the authors. It is further indicated to what extent the new theory goes beyond older concepts, namely in that not only thermoacoustic but also surface phenomena are taken into account.The history of gas laser development is illustrated graphically in the theoretical and experimental curves of breakdown delay vs. surface asperity and deposited energy.

scholarly journals A SYSTEMATIC SEARCH FOR X-RAY CAVITIES IN THE HOT GAS OF GALAXY GROUPS

2010 ◽  
Vol 712 (2) ◽  
pp. 883-900 ◽  
Author(s):  
Ruobing Dong ◽  
Jesper Rasmussen ◽  
John S. Mulchaey
Keyword(s):  
Systematic Search ◽  
X Ray ◽  
Galaxy Groups ◽  
Hot Gas

scholarly journals First detection of stacked X-ray emission from cosmic web filaments

2020 ◽  
Vol 643 ◽  
pp. L2
Author(s):  
H. Tanimura ◽  
N. Aghanim ◽  
A. Kolodzig ◽  
M. Douspis ◽  
N. Malavasi
Keyword(s):  
Point Sources ◽  
Sloan Digital Sky Survey ◽  
Gas Temperature ◽  
Astrophysical Plasma ◽  
X Ray ◽  
Galaxy Groups ◽  
Hot Gas ◽  
Code Model ◽  
Sky Survey ◽  
Statistical Detection

We report the first statistical detection of X-ray emission from cosmic web filaments in ROSAT data. We selected 15 165 filaments at 0.2 <  z <  0.6 ranging from 30 Mpc to 100 Mpc in length, identified in the Sloan Digital Sky Survey survey. We stacked the X-ray count-rate maps from ROSAT around the filaments, excluding resolved galaxy groups and clusters above the mass of ∼3 × 1013 M⊙ as well as the detected X-ray point sources from the ROSAT, Chandra, and XMM-Newton observations. The stacked signal results in the detection of the X-ray emission from the cosmic filaments at a significance of 4.2σ in the energy band of 0.56−1.21 keV. The signal is interpreted, assuming the Astrophysical Plasma Emission Code model, as an emission from the hot gas in the filament-core regions with an average gas temperature of 0.9−0.6+1.0 keV and a gas overdensity of δ ∼ 30 at the center of the filaments. Furthermore, we show that stacking the SRG/eROSITA data for ∼2000 filaments only would lead to a ≳5σ detection of their X-ray signal, even with an average gas temperature as low as ∼0.3 keV.

scholarly journals The role of cold and hot gas flows in feeding early-type galaxy formation

2014 ◽  
Vol 11 (S308) ◽  
pp. 394-397
Author(s):  
Peter H. Johansson
Keyword(s):  
Galaxy Formation ◽  
Gas Flows ◽  
Early Type ◽  
Gas Streams ◽  
Hot Gas ◽  
Stellar Component ◽  
The Galaxy ◽  
History Of ◽  
Gas Accretion ◽  
Low Entropy

AbstractWe study the evolution of the gaseous components in massive simulated galaxies and show that their early formation is fuelled by cold, low entropy gas streams. At lower redshifts of z ≲ 3 the simulated galaxies are massive enough to support stable virial shocks resulting in a transition from cold to hot gas accretion. The gas accretion history of early-type galaxies is directly linked to the formation of their stellar component in the two phased formation scenario, in which the central parts of the galaxy assemble rapidly through in situ star formation and the later assembly is dominated primarily by minor stellar mergers.

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