scholarly journals Filament profiles from WISExSCOS galaxies as probes of the impact of environmental effects

2020 ◽  
Vol 638 ◽  
pp. A75 ◽  
Author(s):  
V. Bonjean ◽  
N. Aghanim ◽  
M. Douspis ◽  
N. Malavasi ◽  
H. Tanimura
Keyword(s):  
Galaxy Evolution ◽  
Large Scale ◽  
Value Added ◽  
Gas Content ◽  
Large Scale Structures ◽  
A Value ◽  
The Galaxy ◽  
Scale Structures ◽  
Isothermal Gas ◽  
The Impact

The role played by large-scale structures in galaxy evolution is not very well understood yet. In this study, we investigated properties of galaxies in the range 0.1 <  z <  0.3 from a value-added version of the WISExSCOS catalogue around cosmic filaments detected with DisPerSE. We fitted a profile of galaxy over-density around cosmic filaments and found a typical radius of rm = 7.5 ± 0.2 Mpc. We measured an excess of passive galaxies near to the spine of the filament that was higher than the excess of transitioning and active galaxies. We also detected star formation rates (SFR) and stellar mass (M⋆) gradients pointing towards the spine of the filament. We investigated this result and found an M⋆ gradient for each type of galaxy, that is active, transitioning, and passive; we found a positive SFR gradient for passive galaxies. We also linked the galaxy properties and gas content in the cosmic web. To do so, we investigated the quiescent fraction fQ profile of galaxies around the cosmic filaments. Based on recent studies about the effect of the gas and the cosmic web on galaxy properties, we modelled fQ with a β model of gas pressure. The slope obtained in this work, β = 0.54 ± 0.18, is compatible with the scenario of projected isothermal gas in hydrostatic equilibrium (β = 2/3) and with the profiles of gas fitted in Sunyaev-Zel’dovich data from the Planck satellite.

scholarly journals The impact of AGN feedback on galaxy intrinsic alignments in the Horizon simulations

2020 ◽  
Vol 492 (3) ◽  
pp. 4268-4282 ◽  
Author(s):  
Adam Soussana ◽  
Nora Elisa Chisari ◽  
Sandrine Codis ◽  
Ricarda S Beckmann ◽  
Yohan Dubois ◽  
...  
Keyword(s):  
Galaxy Evolution ◽  
Gravitational Lensing ◽  
Large Scale ◽  
Galactic Nuclei ◽  
Three Dimensions ◽  
High Mass ◽  
Angular Momenta ◽  
The Galaxy ◽  
The Impact ◽  
The Universe

ABSTRACT The intrinsic correlations of galaxy shapes and orientations across the large-scale structure of the Universe are a known contaminant to weak gravitational lensing. They are known to be dependent on galaxy properties, such as their mass and morphologies. The complex interplay between alignments and the physical processes that drive galaxy evolution remains vastly unexplored. We assess the sensitivity of intrinsic alignments (shapes and angular momenta) to active galactic nuclei (AGN) feedback by comparing galaxy alignment in twin runs of the cosmological hydrodynamical Horizon simulation, which do and do not include AGN feedback, respectively. We measure intrinsic alignments in three dimensions and in projection at $z$ = 0 and $z$ = 1. We find that the projected alignment signal of all galaxies with resolved shapes with respect to the density field in the simulation is robust to AGN feedback, thus giving similar predictions for contamination to weak lensing. The relative alignment of galaxy shapes around galaxy positions is however significantly impacted, especially when considering high-mass ellipsoids. Using a sample of galaxy ‘twins’ across simulations, we determine that AGN changes both the galaxy selection and their actual alignments. Finally, we measure the alignments of angular momenta of galaxies with their nearest filament. Overall, these are more significant in the presence of AGN as a result of the higher abundance of massive pressure-supported galaxies.

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 Large-scale structure probes of modified gravity

2018 ◽  
Vol 27 (15) ◽  
pp. 1848005 ◽  
Author(s):  
Catherine Heymans ◽  
Gong-Bo Zhao
Keyword(s):  
Gravitational Lensing ◽  
Modified Gravity ◽  
Large Scale ◽  
Information Gain ◽  
Einstein Gravity ◽  
Large Scale Structures ◽  
Modified Gravity Theories ◽  
Scale Structures ◽  
The Impact ◽  
The Universe

Observations of the evolution of large-scale structures in the Universe provides unique tools to confront Einstein’s theory of General Relativity on cosmological scales. We review weak gravitational lensing and galaxy clustering studies, discussing how these can be used in combination in order to constrain a range of different modified gravity theories. We argue that in order to maximise the future information gain from these probes, theoretical effort will be required in order to model the impact of beyond-Einstein gravity in the nonlinear regime of structure formation.

scholarly journals The orientation of galaxy pairs with filamentary structures: dependence on morphology

2018 ◽  
Vol 619 ◽  
pp. A24 ◽  
Author(s):  
Valeria Mesa ◽  
Fernanda Duplancic ◽  
Sol Alonso ◽  
Maria Rosa Muñoz Jofré ◽  
Georgina Coldwell ◽  
...  
Keyword(s):  
Large Scale ◽  
Elliptical Galaxies ◽  
Sloan Digital Sky Survey ◽  
Morphological Classification ◽  
Large Scale Structures ◽  
Significant Alignment ◽  
Sky Survey ◽  
The Galaxy ◽  
High Fraction ◽  
Scale Structures

Aims. With the aim of performing an analysis of the orientations of galaxy pair systems with respect to the underlying large-scale structure, we study the alignment between the axis connecting the pair galaxies and the host cosmic filament where the pair resides. In addition, we analyze the dependence of the amplitude of the alignment on the morphology of pair members as well as filament properties. Methods. We build a galaxy pair catalog requiring rp < 100 h−1 kpc and ΔV < 500 km s−1 within redshift z < 0.1 from the Sloan Digital Sky Survey (SDSS). We divided the galaxy pair catalog taking into account the morphological classification by defining three pair categories composed by elliptical–elliptical (E–E), elliptical–spiral (E–S) and spiral–spiral (S–S) galaxies. We use a previously defined catalog of filaments obtained from SDSS and we select pairs located closer than 1 h−1 Mpc to the filament spine, which are considered as members of filaments. For these pairs, we calculate the relative angle between the axis connecting each galaxy, and the direction defined by the spine of the parent filament. Results. We find a statistically significant alignment signal between the pair axes and the spine of the host filaments consistent with a relative excess of ∼15% aligned pairs. We obtain that pairs composed by elliptical galaxies exhibit a stronger alignment, showing a higher alignment signal for pairs closer than 200 h−1 kpc to the filament spine. In addition, we find that the aligned pairs are associated with luminous host filaments populated with a high fraction of elliptical galaxies. The findings of this work show that large-scale structures play a fundamental role in driving galactic anisotropic accretion as induced by galaxy pairs exhibiting a preferred alignment along the filament direction.

scholarly journals Probing the azimuthal environment of galaxies around clusters

2020 ◽  
Vol 635 ◽  
pp. A195 ◽  
Author(s):  
C. Gouin ◽  
N. Aghanim ◽  
V. Bonjean ◽  
M. Douspis
Keyword(s):  
Galaxy Evolution ◽  
Large Scale ◽  
Harmonic Space ◽  
Star Forming ◽  
Large Scale Structures ◽  
Galaxy Distribution ◽  
Hydrodynamical Simulation ◽  
The Galaxy ◽  
Harmonic Decomposition ◽  
Formation And Evolution

Galaxy clusters are connected at their peripheries to the large-scale structures by cosmic filaments that funnel accreting material. These filamentary structures are studied to investigate both environment-driven galaxy evolution and structure formation and evolution. In the present work, we probe in a statistical manner the azimuthal distribution of galaxies around clusters as a function of the cluster-centric distance, cluster richness, and star-forming or passive galaxy activity. We performed a harmonic decomposition in large photometric galaxy catalogue around 6400 SDSS clusters with masses M >  1014 solar masses in the redshift range of 0.1 <  z <  0.3. The same analysis was performed on the mock galaxy catalogue from the light cone of a Magneticum hydrodynamical simulation. We used the multipole analysis to quantify asymmetries in the 2D galaxy distribution. In the inner cluster regions at R <  2R500, we confirm that the galaxy distribution traces an ellipsoidal shape, which is more pronounced for richest clusters. In the outskirts of the clusters (R = [2 − 8]R500), filamentary patterns are detected in harmonic space with a mean angular scale mmean = 4.2 ± 0.1. Massive clusters seem to have a larger number of connected filaments than lower-mass clusters. We also find that passive galaxies appear to trace the filamentary structures around clusters better. This is the case even if the contribution of star-forming galaxies tends to increase with the cluster-centric distance, suggesting a gradient of galaxy activity in filaments around clusters.

scholarly journals Explosive Origins of Large-Scale Structures

1988 ◽  
Vol 130 ◽  
pp. 321-329
Author(s):  
Jeremiah P. Ostriker
Keyword(s):  
Galaxy Formation ◽  
Large Scale ◽  
Cosmic Strings ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Energy Output ◽  
Galaxy Groups ◽  
Large Scale Structures ◽  
The Galaxy ◽  
Scale Structures

Large scale structures up to 5h−1 mpc, the galaxy-galaxy correlation length and the size of typical galaxy groups and clusters, can be produced quite naturally from explosions originating in young galaxies (Ostriker and Cowie, 1981: “OC”) or quasars (Ikeuchi, 1981: “I”) with energy output of 1061 ergs. But very large-scale structure in the 25 mpc −50 mpc range possibly indicated by cluster-cluster correlations (Bahcall, 1987a), can only be produced by much more energetic events of 1065 ergs which are far beyond the output of any objects currently known. This follows simply from the dimensional arguments which give R = c(Eσ/t2)0.2 implicit in the classic Seldov-Taylor solution and cosmological analogs (cf Ostriker, 1986). Thus very large scale structure can only be produced by explosions if many small ones can coalesce suitably at early epochs (OC) or single giant events are produced by exotic objects such as superconducting cosmic strings (Ostriker, Thompson and Witten 1986: “OTW”). If however these large events do occur, then many specific properties of very large-scale structures will be produced quite naturally (cf Bahcall, 1987b, Weinberg, Ostriker and Dekel, 1987 “WOD”). Before discussing these points, it is appropriate to say a few words on the importance of hydrodynamics in general and explosions in particular, since the latter will certainly be a consequence of galaxy formation even if they are not the primary cause.

scholarly journals Connection of large-scale structures of the galaxy distribution behind the southern Milky Way

1993 ◽  
Vol 262 (1) ◽  
pp. 79-84 ◽  
Author(s):  
Toru Yamada ◽  
Tadafumi Takata ◽  
Thomas Djamaluddin ◽  
Akihiko Tomita ◽  
Kentaro Aoki ◽  
...  
Keyword(s):  
Large Scale ◽  
Milky Way ◽  
Large Scale Structures ◽  
Galaxy Distribution ◽  
The Galaxy ◽  
Scale Structures

Some comments about observations and image processing of comet 29P/Schwassmann-Wachmann 1

1999 ◽  
Vol 173 ◽  
pp. 243-248
Author(s):  
D. Kubáček ◽  
A. Galád ◽  
A. Pravda
Keyword(s):  
Image Processing ◽  
Large Scale ◽  
Harvard College ◽  
Oak Ridge ◽  
Large Scale Structures ◽  
Short Period Comet ◽  
Short Period ◽  
Scale Structures ◽  
Harvard College Observatory ◽  
Period Comet

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.

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