scholarly journals Phase-space distribution of unbound dark matter near the Sun

2006 ◽  
Vol 74 (8) ◽  
Author(s):  
Moqbil S. Alenazi ◽  
Paolo Gondolo
Keyword(s):  
Dark Matter ◽  
Phase Space ◽  
Space Distribution ◽  
The Sun ◽  
Phase Space Distribution

scholarly journals Observationally inferred dark matter phase-space distribution and direct detection experiments

2019 ◽  
Vol 100 (2) ◽  
Author(s):  
Sayan Mandal ◽  
Subhabrata Majumdar ◽  
Vikram Rentala ◽  
Ritoban Basu Thakur
Keyword(s):  
Dark Matter ◽  
Phase Space ◽  
Direct Detection ◽  
Space Distribution ◽  
Phase Space Distribution ◽  
Matter Phase

scholarly journals Frequency maps as a probe of secular evolution in the Milky Way

2012 ◽  
Vol 10 (H16) ◽  
pp. 349-349
Author(s):  
Monica Valluri
Keyword(s):  
Dark Matter ◽  
Distribution Function ◽  
Phase Space ◽  
Milky Way ◽  
Space Distribution ◽  
Compact Representation ◽  
Phase Space Distribution ◽  
Secular Evolution ◽  
Halo Stars ◽  
Stellar Halo

AbstractThe frequency analysis of the orbits of halo stars and dark matter particles from a cosmological hydrodynamical simulation of a disk galaxy from the MUGS collaboration (Stinson et al. 2010) shows that even if the shape of the dark matter halo is nearly oblate, only about 50% of its orbits are on short-axis tubes, confirming a previous result: under baryonic condensation all orbit families can deform their shapes without changing orbital type (Valluri et al. 2010). Orbits of dark matter particles and halo stars are very similar reflecting their common accretion origin and the influence of baryons. Frequency maps provide a compact representation of the 6-D phase space distribution that also reveals the history of the halo (Valluri et al. 2012). The 6-D phase space coordinates for a large population of halo stars in the Milky Way that will be obtained from future surveys can be used to reconstruct the phase-space distribution function of the stellar halo. The similarity between the frequency maps of halo stars and dark matter particles (Fig. 1) implies that reconstruction of the stellar halo distribution function can reveal the phase space distribution of the unseen dark matter particles and provide evidence for secular evolution. MV is supported by NSF grant AST-0908346 and the Elizabeth Crosby grant.

scholarly journals Halo uncertainties in electron recoil events at direct detection experiments

2021 ◽  
Vol 81 (11) ◽  
Author(s):  
Tarak Nath Maity ◽  
Tirtha Sankar Ray ◽  
Sambo Sarkar
Keyword(s):  
Dark Matter ◽  
Phase Space ◽  
Direct Detection ◽  
Space Distribution ◽  
Semiconductor Detectors ◽  
Detection Rates ◽  
Phase Space Distribution ◽  
Electron Recoil ◽  
Highly Correlated ◽  
The Impact

AbstractThe dark matter direct detection rates are highly correlated with the phase space distribution of dark matter particles in our galactic neighbourhood. In this paper we make a systematic study of the impact of astrophysical uncertainties on electron recoil events at the direct detection experiments with Xenon and semiconductor detectors. We find that within the standard halo model there can be up to $$ \sim 50\%$$ ∼ 50 % deviation from the fiducial choice in the exclusion bounds from these observational uncertainties. For non-standard halo models we report a similar deviation from the fiducial standard halo model when fitted with recent cosmological N-body simulations while even larger deviations are obtained in case of the observational uncertainties.

scholarly journals Quantifying torque from the Milky Way bar using Gaia DR2

2020 ◽  
Vol 494 (3) ◽  
pp. 3358-3367 ◽  
Author(s):  
Rain Kipper ◽  
Peeter Tenjes ◽  
Taavi Tuvikene ◽  
Punyakoti Ganeshaiah Veena ◽  
Elmo Tempel
Keyword(s):  
Phase Space ◽  
Milky Way ◽  
Space Distribution ◽  
Gravitational Acceleration ◽  
The Sun ◽  
Solar Mass ◽  
Stellar Orbits ◽  
Phase Space Distribution ◽  
Acceleration Field ◽  
Gaia Dr2

ABSTRACT We determine the mass of the Milky Way bar and the torque it causes, using Gaia DR2, by applying the orbital arc method. Based on this, we have found that the gravitational acceleration is not directed towards the centre of our Galaxy but a few degrees away from it. We propose that the tangential acceleration component is caused by the bar of the Galaxy. Calculations based on our model suggest that the torque experienced by the region around the Sun is $\approx 2400\, {\rm km^2\, s^{-2}}$ per solar mass. The mass estimate for the bar is $\sim 1.6\pm 0.3\times 10^{10}\, \mathrm{M_\odot }$. Using greatly improved data from Gaia DR2, we have computed the acceleration field to great accuracy by adapting the orbital Probability Density Function (oPDF) method (Han et al. 2016) locally and used the phase space coordinates of ∼4 × 105 stars within a distance of 0.5 kpc from the Sun. In the orbital arc method, the first step is to guess an acceleration field and then reconstruct the stellar orbits using this acceleration for all the stars within a specified region. Next, the stars are redistributed along orbits to check if the overall phase space distribution has changed. We repeat this process until we find an acceleration field that results in a new phase space distribution that is the same as the one that we started with; we have then recovered the true underlying acceleration.

The phase-space distribution of infalling dark matter subhaloes

2005 ◽  
Vol 364 (2) ◽  
pp. 424-432 ◽  
Author(s):  
H. Y. Wang ◽  
Y. P. Jing ◽  
Shude Mao ◽  
Xi Kang
Keyword(s):  
Dark Matter ◽  
Phase Space ◽  
Space Distribution ◽  
Phase Space Distribution

A one-dimensional self-gravitating stellar gas

1966 ◽  
Vol 25 ◽  
pp. 46-48 ◽  
Author(s):  
M. Lecar
Keyword(s):  
Gravitational Field ◽  
Phase Space ◽  
Motion Picture ◽  
Space Distribution ◽  
Two Dimensional ◽  
One Dimensional ◽  
Phase Space Distribution ◽  
Dimensional Phase Space ◽  
The Mean

“Dynamical mixing”, i.e. relaxation of a stellar phase space distribution through interaction with the mean gravitational field, is numerically investigated for a one-dimensional self-gravitating stellar gas. Qualitative results are presented in the form of a motion picture of the flow of phase points (representing homogeneous slabs of stars) in two-dimensional phase space.

Simulation study of Landau damping near the persisting to arrested transition

2017 ◽  
Vol 83 (4) ◽  
Author(s):  
Alexander J. Klimas ◽  
Adolfo F. Viñas ◽  
Jaime A. Araneda
Keyword(s):  
Phase Space ◽  
Simulation Study ◽  
High Speed ◽  
Space Distribution ◽  
Landau Damping ◽  
Field Mode ◽  
Low Speed ◽  
Phase Space Distribution ◽  
Saturation Stage ◽  
First Time

A one-dimensional electrostatic filtered Vlasov–Poisson simulation study is discussed. The transition from persisting to arrested Landau damping that is produced by increasing the strength of a sinusoidal perturbation on a background Vlasov–Poisson equilibrium is explored. Emphasis is placed on observed features of the electron phase-space distribution when the perturbation strength is near the transition value. A single ubiquitous waveform is found perturbing the space-averaged phase-space distribution at almost any time in all of the simulations; the sole exception is the saturation stage that can occur at the end of the arrested damping scenario. This waveform contains relatively strong, very narrow structures in velocity bracketing $\pm v_{\text{res}}$ – the velocities at which electrons must move to traverse the dominant field mode wavelength in one of its oscillation periods – and propagating with $\pm v_{\text{res}}$ respectively. Local streams of electrons are found in these structures crossing the resonant velocities from low speed to high speed during Landau damping and from high speed to low speed during Landau growth. At the arrest time, when the field strength is briefly constant, these streams vanish. It is conjectured that the expected transfer of energy between electrons and field during Landau growth or damping has been visualized for the first time. No evidence is found in the phase-space distribution to support recent well-established discoveries of a second-order phase transition in the electric field evolution. While trapping is known to play a role for larger perturbation strengths, it is shown that trapping plays no role at any time in any of the simulations near the transition perturbation strength.

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