scholarly journals X-Ray Large Scale Structure and XMM

1998 ◽  
Vol 188 ◽  
pp. 177-180
Author(s):  
M. Pierre
Keyword(s):  
Large Scale ◽  
Initial Conditions ◽  
Data Set ◽  
X Ray ◽  
Large Scale Structures ◽  
The Galaxy ◽  
Optical Wavelengths ◽  
Analytical Approaches ◽  
The Universe ◽  
Additional Constraints

The formation of Large Scale Structures (LSS) in the universe was first studied at optical wavelengths as the galaxy spatial distribution appeared to be far from homogeneous. Considerable effort has been invested in semi-analytical approaches and in numerical simulations (DM + hot gas) to explain the observed structures, given some set of initial conditions and using additional constraints provided by the COBE results. It is now clear however, that these two extreme data set are not sufficient to discriminate between the possible remaining cosmological scenarios. It is thus timely to investigate LSS at a much higher redshift than the present survey limits both in the optical and in other wavebands. In this context, the X-ray band will certainly become a hot field with the advent of the XMM observatory. The next section briefly summarizes what is known about LSS from optical wavelengths and simulations. Sect. 3 reviews the particular points that can be addressed in the X-ray band. Last section presents realistic prospects for mapping LSS with XMM.

Spectroscopic Observations of Baryons in the Local Universe

2005 ◽  
Vol 216 ◽  
pp. 274-289
Author(s):  
Kenneth R. Sembach
Keyword(s):  
Large Scale ◽  
Intergalactic Gas ◽  
Local Universe ◽  
X Ray ◽  
Spectroscopic Observations ◽  
Spectral Diagnostics ◽  
The Galaxy ◽  
X Ray Absorption ◽  
The Universe ◽  
Velocity Cloud

There is increasing observational evidence that hot, highly-ionized interstellar and intergalactic gas plays a significant role in the evolution of galaxies in the local universe. Recent observations from several ultraviolet and X-ray observatories have been used to study the highly ionized high velocity cloud system in the vicinity of the Galaxy, the hot gaseous corona of the Galaxy, and highly ionized absorption-line systems at low redshift. The primary spectral diagnostics of this warm-hot interstellar/intergalactic medium are ultraviolet and X-ray absorption lines of O vi and O vii. The observational data fit well into the framework of current theories for the evolution of large-scale structure in the universe, which predict that a significant fraction of the baryonic material at low redshift is contained in highly ionized intergalactic gas. In this paper, I summarize some of the recent highlights of spectroscopic observations of the hot baryons in the local universe.

scholarly journals Segmenting the Universe into dynamically coherent basins

2020 ◽  
Vol 493 (3) ◽  
pp. 3513-3520
Author(s):  
Alexandra Dupuy ◽  
Hélène M Courtois ◽  
Noam I Libeskind ◽  
Daniel Guinet
Keyword(s):  
Large Scale ◽  
Basins Of Attraction ◽  
Data Set ◽  
Density Profiles ◽  
Large Scale Structures ◽  
Unique Definition ◽  
Scale Structures ◽  
Definition Of ◽  
Previous Letter ◽  
The Universe

ABSTRACT This paper explores in depth a watershed concept to partition the Universe, introduced in a previous Letter and applied to the Cosmicflows-3 observational data set. We present a series of tests conducted with cosmological dark matter simulations. In particular, we are interested in quantifying the evolution with redshift of large-scale structures when defined as segmented basins of attraction. This new dynamical definition in the field of measuring standard rulers demonstrates robustness since all basins show a density contrast δ above 1 (mean Universe density) independently of the simulation spatial resolution or the redshift. Another major finding is that density profiles of the basins show universality in slope. Consequently, there is a unique definition of what is a gravitational watershed at a large scale, which can be further used as a probe for cosmology studies.

scholarly journals How complex is the cosmic web?

2019 ◽  
Vol 491 (4) ◽  
pp. 5447-5463 ◽  
Author(s):  
F Vazza
Keyword(s):  
Large Scale ◽  
Initial Conditions ◽  
Magnetic Energy ◽  
Large Scale Structures ◽  
Dominant Component ◽  
Statistical Complexity ◽  
Statistical Sense ◽  
Scale Structures ◽  
Physical Laws ◽  
The Universe

ABSTRACT The growth of large-scale cosmic structure is a beautiful exemplification of how complexity can emerge in our Universe, starting from simple initial conditions and simple physical laws. Using enzo cosmological numerical simulations, I applied tools from Information Theory (namely, ‘statistical complexity’) to quantify the amount of complexity in the simulated cosmic volume, as a function of cosmic epoch and environment. This analysis can quantify how much difficult to predict, at least in a statistical sense, is the evolution of the thermal, kinetic, and magnetic energy of the dominant component of ordinary matter in the Universe (the intragalactic medium plasma). The most complex environment in the simulated cosmic web is generally found to be the periphery of large-scale structures (e.g. galaxy clusters and filaments), where the complexity is on average ∼10–102 times larger than in more rarefied regions, even if the latter dominate the volume-integrated complexity of the simulated Universe. If the energy evolution of gas in the cosmic web is measured on a ≈100 ${\rm kpc}\, h^{-1}$ resolution and over a ≈200 $\rm Myr$ time-scale, its total complexity is in the range of $\sim 10^{16}\!-\!10^{17} \rm \,bits$, with little dependence on the assumed gas physics, cosmology, or cosmic variance.

scholarly journals A Possible Connection Between the Diffuse X-Ray Background and Large Scale Structures in the Universe

1988 ◽  
Vol 130 ◽  
pp. 540-540
Author(s):  
Ruth A. Daly
Keyword(s):  
Emission Spectrum ◽  
Large Scale ◽  
X Ray ◽  
Large Scale Structures ◽  
Bremsstrahlung Emission ◽  
Scale Structures ◽  
X Ray Background ◽  
The Universe ◽  
Thermal Bremsstrahlung

The diffuse x-ray background extends from about five to 200 keV. The spectrum is very well fit by a thermal bremsstrahlung emission spectrum characterized by a temperature of about (25–40)(l+z) keV, where z is the redshift at which the emission is produced.

scholarly journals Mapping the active Universe with eROSITA

2013 ◽  
Vol 9 (S304) ◽  
pp. 421-421
Author(s):  
Mara Salvato
Keyword(s):  
Black Holes ◽  
Large Scale ◽  
Gamma Ray ◽  
Galactic Nuclei ◽  
Binary Black Holes ◽  
X Ray ◽  
Wide Range ◽  
The Galaxy ◽  
Deep Survey ◽  
The Universe

AbstracteROSITA (extended Röntgen Survey with an Imaging Telescope Array) is the core instrument on the Russian Spektrum-Röntgen-Gamma (SRG) mission which is current scheduled for launch in Q4 2014. eROSITA will perform a deep survey of the entire X-ray sky. In the soft band (0.5–2 keV), it will be about 30 times more sensitive than ROSAT, while in the hard band (2–8 keV) it will provide the first ever true imaging survey of the sky. The design driving science is the detection of large samples of galaxy clusters up to redshifts z ~ 1, in order to study the large scale structure in the Universe and test cosmological models including Dark Energy. In addition, eROSITA is expected to yield a sample of about 3 million active galactic nuclei, which is bound to revolutionize our view of the evolution of supermassive black holes and their impact on the process of structure formation in the Universe. The survey will also provide new insights into a wide range of astrophysical phenomena, including isolated Neutron Stars and Black Holes, X-ray binaries, active stars and diffuse emission within the Galaxy, as well as more exotic ones such as gamma-ray bursts, tidal disruption of stars in galactic nuclei and binary black holes. In this talk I presented the main characteristics of the mission and focus on the scientific drivers for extragalactic all-sky surveys of AGN. All what was presented at the Symposium (plots, simulations, expected numbers of various kind of sources –QSO, obscured and CT AGN– their properties and evolution with redshift) can be found in the official eROSITA Science Book (Merloni et al., 2012).

scholarly journals X-Ray and Radio Emissions of AWM and MKW Clusters

2012 ◽  
Author(s):  
Michael Ramuta
Keyword(s):  
Large Scale ◽  
Life Cycles ◽  
Sloan Digital Sky Survey ◽  
X Ray ◽  
Large Scale Structures ◽  
Sky Survey ◽  
Scale Structures ◽  
Using Data ◽  
And Behavior ◽  
The Universe

A grasp of the life-cycles of large-scale structures is critical to understanding the Universe. This can be accomplished through the study of poor clusters-- that is, younger clusters that are likely evolving to another state. The selected clusters are significant in that they are poor but also possess a type-cD galaxy. This brighter central galaxy suggests that these clusters may be dynamically evolved and are potential candidates for fossil groups. In order to more fully understand the structure and behavior of poor galaxy clusters, 12 clusters were selected and analyzed. Using data from the Sloan Digital Sky Survey, Chandra X-Ray Archive, and the VLA FIRST Survey, we present x-ray profiles and radio observations of these 12 galaxy clusters. 

scholarly journals Introductory Review

2003 ◽  
Vol 209 ◽  
pp. 3-14 ◽  
Author(s):  
Sun Kwok
Keyword(s):  
Solid State ◽  
Stellar Evolution ◽  
Large Scale ◽  
Dynamical Models ◽  
Infrared Observations ◽  
X Ray ◽  
Current State ◽  
The Galaxy ◽  
The Universe ◽  
Introductory Review

Our current state of understanding of the planetary nebulae (PNe) phenomenon is reviewed in the context of modern stellar evolution and dynamical models. Also discussed are a number of new problems that have emerged as the result of recent space (x-ray, UV, optical, and infrared) observations. The roles of PNe in the chemical (atomic, molecular, and solid-state) enrichment of the galaxy and as tracers of the large scale structure of the Universe are also discussed.

scholarly journals Investigating the properties of a galaxy group at z = 0.6

2020 ◽  
Vol 15 (S359) ◽  
pp. 188-189
Author(s):  
Daniela Hiromi Okido ◽  
Cristina Furlanetto ◽  
Marina Trevisan ◽  
Mônica Tergolina
Keyword(s):  
Large Scale ◽  
The Other ◽  
Numerical Density ◽  
Spectroscopy Data ◽  
Stellar Kinematics ◽  
Galaxy Groups ◽  
The Galaxy ◽  
The Difference ◽  
The Impact ◽  
The Universe

AbstractGalaxy groups offer an important perspective on how the large-scale structure of the Universe has formed and evolved, being great laboratories to study the impact of the environment on the evolution of galaxies. We aim to investigate the properties of a galaxy group that is gravitationally lensing HELMS18, a submillimeter galaxy at z = 2.39. We obtained multi-object spectroscopy data using Gemini-GMOS to investigate the stellar kinematics of the central galaxies, determine its members and obtain the mass, radius and the numerical density profile of this group. Our final goal is to build a complete description of this galaxy group. In this work we present an analysis of its two central galaxies: one is an active galaxy with z = 0.59852 ± 0.00007, while the other is a passive galaxy with z = 0.6027 ± 0.0002. Furthermore, the difference between the redshifts obtained using emission and absorption lines indicates an outflow of gas with velocity v = 278.0 ± 34.3 km/s relative to the galaxy.

scholarly journals Relativistic Cosmology with an Introduction to Inflation

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 276
Author(s):  
Muhammad Zahid Mughal ◽  
Iftikhar Ahmad ◽  
Juan Luis García Guirao
Keyword(s):  
Standard Model ◽  
Early Universe ◽  
Large Scale ◽  
Initial Conditions ◽  
Big Bang ◽  
Relativistic Cosmology ◽  
The Standard Model ◽  
Big Bang Model ◽  
The Big Bang ◽  
The Universe

In this review article, the study of the development of relativistic cosmology and the introduction of inflation in it as an exponentially expanding early phase of the universe is carried out. We study the properties of the standard cosmological model developed in the framework of relativistic cosmology and the geometric structure of spacetime connected coherently with it. The geometric properties of space and spacetime ingrained into the standard model of cosmology are investigated in addition. The big bang model of the beginning of the universe is based on the standard model which succumbed to failure in explaining the flatness and the large-scale homogeneity of the universe as demonstrated by observational evidence. These cosmological problems were resolved by introducing a brief acceleratedly expanding phase in the very early universe known as inflation. The cosmic inflation by setting the initial conditions of the standard big bang model resolves these problems of the theory. We discuss how the inflationary paradigm solves these problems by proposing the fast expansion period in the early universe. Further inflation and dark energy in fR modified gravity are also reviewed.

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