Phase-Space Correlations among Systems of Satellite Galaxies

Driven by the increasingly complete observational knowledge of systems of satellite galaxies, mutual spatial alignments and relations in velocities among satellites belonging to a common host have become a productive field of research. Numerous studies have investigated different types of such phase-space correlations and were met with varying degrees of attention by the community. The Planes of Satellite Galaxies issue is maybe the best-known example, with a rich field of research literature and an ongoing, controversial debate on how much of a challenge it poses to the ΛCDM model of cosmology. Another type of correlation, the apparent excess of close pairs of dwarf galaxies, has received considerably less attention despite its reported tension with ΛCDM expectations. With the fast expansion of proper motion measurements in recent years, largely driven by the Gaia mission, other peculiar phase-space correlations have been uncovered among the satellites of the Milky Way. Examples are the apparent tangential velocity excess of satellites compared to cosmological expectations, and the unexpected preference of satellites to be close to their pericenters. At the same time, other kinds of correlations have been found to be more in line with cosmological expectations—specifically, lopsided satellite galaxy systems and the accretion of groups of satellite galaxies. The latter has mostly been studied in cosmological simulations thus far, but it offers the potential to address some of the other issues by providing a way to produce correlations among the orbits of a group’s satellite galaxy members. This review is the first to provide an introduction to the highly active field of phase-space correlations among satellite galaxy systems. The emphasis is on summarizing existing, recent research and highlighting interdependencies between the different, currently almost exclusively individually considered types of correlations. Future prospects in light of upcoming observational facilities and our ever-expanding knowledge of satellite galaxy systems beyond the Local Group are also briefly discussed.

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A whirling plane of satellite galaxies around Centaurus A challenges CDM cosmology

Proceedings of the International Astronomical Union ◽

10.1017/s1743921318005781 ◽

2018 ◽

Vol 14 (S344) ◽

pp. 473-476

Author(s):

Oliver Müller

Keyword(s):

Phase Space ◽

Structure Formation ◽

Milky Way ◽

Local Group ◽

Dwarf Galaxies ◽

Planar Structure ◽

Space Correlation ◽

Andromeda Galaxy ◽

Satellite Galaxies ◽

Centaurus A

AbstractThe phase-space correlation of dwarf galaxies around the Milky Way and the Andromeda galaxy pose a serious challenge to our understanding of structure formation. Recently, another planar structure was discovered around Cen A, the major galaxy of the Centaurus group. We have surveyed this galaxy group for new dwarf galaxies and presented the discovery of 57 new dwarf member candidates. Furthermore, we have studied the kinematics of previously known dwarfs and again found a kinematic coherence in their movement, similar to the Local Group satellites. In CDM simulations, such an alignment appears in less than 0.5 percent.

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The origin of lopsided satellite galaxy distribution in galaxy pairs

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz1917 ◽

2019 ◽

Vol 488 (3) ◽

pp. 3100-3108 ◽

Cited By ~ 2

Author(s):

Chen Chris Gong ◽

Noam I Libeskind ◽

Elmo Tempel ◽

Quan Guo ◽

Stefan Gottlöber ◽

...

Keyword(s):

Cold Dark Matter ◽

Local Group ◽

Sloan Digital Sky Survey ◽

Host Galaxies ◽

The Past ◽

Satellite Galaxy ◽

Galaxy Distribution ◽

Sky Survey ◽

Satellite Galaxies ◽

Set Up

ABSTRACT It is well known that satellite galaxies are not isotropically distributed among their host galaxies as suggested by most interpretations of the Λ cold dark matter (ΛCDM) model. One type of anisotropy recently detected in the Sloan Digital Sky Survey (and seen when examining the distribution of satellites in the Local Group and in the Centaurus group) is a tendency to be so-called lopsided. Namely, in pairs of galaxies (like Andromeda and the Milky Way) the satellites are more likely to inhabit the region in between the pair, rather than on opposing sides. Although recent studies found a similar set-up when comparing pairs of galaxies in ΛCDM simulations indicating that such a set-up is not inconsistent with ΛCDM, the origin has yet to be explained. Here we examine the origin of such lopsided set-ups by first identifying such distributions in pairs of galaxies in numerical cosmological simulations, and then tracking back the orbital trajectories of satellites (which at z = 0 display the effect). We report two main results: first, the lopsided distribution was stronger in the past and weakens towards z = 0. Secondly, the weakening of the signal is due to the interaction of satellite galaxies with the pair. Finally, we show that the z = 0 signal is driven primarily by satellites that are on first approach, who have yet to experience a ‘flyby’. This suggests that the signal seen in the observations is also dominated by dynamically young accretion events.

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Age and Mass of the Local Group from Satellite Galaxy Dynamics

Symposium - International Astronomical Union ◽

10.1017/s0074180900204440 ◽

1999 ◽

Vol 192 ◽

pp. 420-426

Author(s):

Alan B. Whiting

Keyword(s):

Time Scale ◽

Local Group ◽

Galaxy Dynamics ◽

Cosmological Time ◽

Satellite Galaxy ◽

Satellite Galaxies

The present kinematics of an unrelaxed system such as the Local Group can be used to investigate its dynamics on a cosmological time scale. In particular, the classical timing argument of Kahn & Woltjer may be extended to distant satellite galaxies of the Local Group whose distances and velocities are known with some accuracy. Including a correction for the fact that the Local Group was not always dynamically isolated, I derive a mass for the Group of about 1.6 x 1012M⊙ and an age of 1.0 to 1.2 x 1010 years.

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A Phase-Space Based Algorithm for Detecting Different Types of Artefacts

IFMBE Proceedings - XIII Mediterranean Conference on Medical and Biological Engineering and Computing 2013 ◽

10.1007/978-3-319-00846-2_148 ◽

2014 ◽

pp. 599-602

Author(s):

A. Brignol ◽

T. Al-ani

Keyword(s):

Phase Space ◽

Different Types

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Investigating the Stellar Mass Growth Histories of Satellite Galaxies as a Function of Infall Time Using Phase-space

The Astrophysical Journal ◽

10.3847/1538-4357/ab1917 ◽

2019 ◽

Vol 876 (2) ◽

pp. 145 ◽

Cited By ~ 7

Author(s):

Rory Smith ◽

Camilla Pacifici ◽

Anna Pasquali ◽

Paula Calderón-Castillo

Keyword(s):

Phase Space ◽

Stellar Mass ◽

Mass Growth ◽

Satellite Galaxies

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Democracy and Justice in Mathematics and Science Curriculum

Oxford Research Encyclopedia of Education ◽

10.1093/acrefore/9780190264093.013.126 ◽

2018 ◽

Author(s):

Paola Valero ◽

Auli Arvola Orlander

Keyword(s):

Science Curriculum ◽

Research Literature ◽

Economic Progress ◽

School Subjects ◽

Rational Science ◽

Different Types ◽

Science Curricula ◽

Mathematics And Science ◽

School Curricula ◽

Contemporary School

How mathematics and science curricula connect to democracy and justice is understood through the examination of different perspectives of mathematics and science education as political. Although frequently conceived of as neutral, these school subjects have been central in recent modern education for governing the making of rational, science-minded citizens who are necessary for social, political, and economic progress. Three main perspectives are identified in the existing research literature. A perspective of empowerment highlights the power that people can acquire by learning and using mathematics and science. A perspective of disadvantage focuses on how the pedagogies of mathematics and science intersect with categories such as ability, gender, class, ethnicity, and race to generate and reproduce marginalization. A perspective of subjectivation examines the effects of mathematics and science curricula within the context of historical and cultural processes for the making of desired modern, rational, and techno-scientific types of citizens, thus creating categories of inclusion and exclusion. All together, these perspectives point to the ways in which mathematics and science, as privileged forms of knowing in contemporary school curricula, simultaneously operate to include or exclude different types of students.

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Chaotic ray propagation in corrugated layers

Nonlinear Processes in Geophysics ◽

10.5194/npg-12-1003-2005 ◽

2005 ◽

Vol 12 (6) ◽

pp. 1003-1009 ◽

Cited By ~ 1

Author(s):

M. Bottiglieri ◽

S. De Martino ◽

M. Falanga ◽

C. Godano

Keyword(s):

Phase Space ◽

Power Law ◽

Chaotic Behaviour ◽

Kam Theorem ◽

Different Types ◽

Corrugated Wall

Abstract. The aim of this paper is to study the effects of a corrugated wall on the behaviour of propagating rays. Different types of corrugation are considered, using different distributions of the corrugation heights: white Gaussian, power law, self-affine perturbation. In phase space, a prevalent chaotic behaviour of rays, and the presence of a lot of caustics, are observed. These results entail that the KAM theorem is not fulfilled.

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WEAK DISSIPATION IN A HAMILTONIAN MAP

International Journal of Bifurcation and Chaos ◽

10.1142/s0218127494000654 ◽

1994 ◽

Vol 04 (04) ◽

pp. 921-932 ◽

Cited By ~ 1

Author(s):

RAÚL J. MONDRAGÓN C. ◽

PETER H. RICHTER

Keyword(s):

Phase Space ◽

Hamiltonian System ◽

Periodic Orbits ◽

Adiabatic Invariance ◽

Bifurcation Tree ◽

Bouncing Ball ◽

Different Types ◽

Weak Dissipation ◽

Hamiltonian Map

The dynamics of a bouncing ball reflected off a harmonic spring is investigated, with weak dissipation of three different types. The phase space is found to be organized into a system of tubes that wind around the branches of the bifurcation tree of periodic orbits of the Hamiltonian system. Instead of attraction towards special periodic orbits we observe a kind of piecewise adiabatic invariance of the tubes, with jumps occurring when the branches penetrate each other.

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-BOUNDS FOR PSEUDO-DIFFERENTIAL OPERATORS ON COMPACT LIE GROUPS

Journal of the Institute of Mathematics of Jussieu ◽

10.1017/s1474748017000123 ◽

2017 ◽

Vol 18 (3) ◽

pp. 531-559 ◽

Cited By ~ 4

Author(s):

Julio Delgado ◽

Michael Ruzhansky

Keyword(s):

Phase Space ◽

Vector Fields ◽

Differential Operators ◽

Compact Lie Group ◽

Compact Lie Groups ◽

Pseudo Differential Operators ◽

Different Types ◽

Unitary Dual ◽

Laplacian Operators ◽

Noncommutative Analogue

Given a compact Lie group$G$, in this paper we establish$L^{p}$-bounds for pseudo-differential operators in$L^{p}(G)$. The criteria here are given in terms of the concept of matrix symbols defined on the noncommutative analogue of the phase space$G\times \widehat{G}$, where$\widehat{G}$is the unitary dual of$G$. We obtain two different types of$L^{p}$bounds: first for finite regularity symbols and second for smooth symbols. The conditions for smooth symbols are formulated using$\mathscr{S}_{\unicode[STIX]{x1D70C},\unicode[STIX]{x1D6FF}}^{m}(G)$classes which are a suitable extension of the well-known$(\unicode[STIX]{x1D70C},\unicode[STIX]{x1D6FF})$ones on the Euclidean space. The results herein extend classical$L^{p}$bounds established by C. Fefferman on$\mathbb{R}^{n}$. While Fefferman’s results have immediate consequences on general manifolds for$\unicode[STIX]{x1D70C}>\max \{\unicode[STIX]{x1D6FF},1-\unicode[STIX]{x1D6FF}\}$, our results do not require the condition$\unicode[STIX]{x1D70C}>1-\unicode[STIX]{x1D6FF}$. Moreover, one of our results also does not require$\unicode[STIX]{x1D70C}>\unicode[STIX]{x1D6FF}$. Examples are given for the case of$\text{SU}(2)\cong \mathbb{S}^{3}$and vector fields/sub-Laplacian operators when operators in the classes$\mathscr{S}_{0,0}^{m}$and$\mathscr{S}_{\frac{1}{2},0}^{m}$naturally appear, and where conditions$\unicode[STIX]{x1D70C}>\unicode[STIX]{x1D6FF}$and$\unicode[STIX]{x1D70C}>1-\unicode[STIX]{x1D6FF}$fail, respectively.

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