scholarly journals Modified dynamics (MOND) as a dark halo

1994 ◽  
Vol 266 (2) ◽  
pp. 360-366 ◽  
Author(s):  
R. H. Sanders ◽  
K. G. Begeman
Keyword(s):  
Dark Halo ◽  
Modified Dynamics

The Shape and Figure Rotation of the Dark Halo of NGC 2915

1999 ◽  
Vol 118 (5) ◽  
pp. 2158-2171 ◽  
Author(s):  
M. Bureau ◽  
K. C. Freeman ◽  
D. W. Pfitzner ◽  
G. R. Meurer
Keyword(s):  
Dark Halo ◽  
Figure Rotation

scholarly journals Resolving the Disk-Halo Degeneracy using Planetary Nebulae

2016 ◽  
Vol 12 (S323) ◽  
pp. 284-287
Author(s):  
S. Aniyan ◽  
K. C. Freeman ◽  
M. Arnaboldi ◽  
O. Gerhard ◽  
L. Coccato ◽  
...  
Keyword(s):  
Vertical Velocity ◽  
Velocity Dispersion ◽  
Mass Density ◽  
Planetary Nebulae ◽  
Disk Surface ◽  
Scale Height ◽  
Dark Halo ◽  
Surface Mass ◽  
Star Forming ◽  
Light Spectra

AbstractThe decomposition of the 21 cm rotation curve of galaxies into contribution from the disk and dark halo depends on the adopted mass to light ratio (M/L) of the disk. Given the vertical velocity dispersion (σz) of stars in the disk and its scale height (hz), the disk surface density and hence the M/L can be estimated. Earlier works have used this technique to conclude that galaxy disks are submaximal. Here we address an important conceptual problem: star-forming spirals have an old (kinematically hot) disk population and a young cold disk population. Both of these populations contribute to the integrated light spectra from which σz is measured. The measured scale height hz is for the old disk population. In the Jeans equation, σz and hz must pertain to the same population. We have developed techniques to extract the velocity dispersion of the old disk from integrated light spectra and from samples of planetary nebulae. We present the analysis of the disk kinematics of the galaxy NGC 628 using IFU data in the inner regions and planetary nebulae as tracers in the outer regions of the disk. We demonstrate that using the scale height of the old thin disk with the vertical velocity dispersion of the same population, traced by PNe, results in a maximal disk for NGC 628. Our analysis concludes that previous studies underestimate the disk surface mass density by ~ 2, sufficient to make a maximal disk for NGC 628 appear like a submaximal disk.

Halo-independent analysis of direct dark matter detection through electron scattering

2021 ◽  
Vol 2021 (12) ◽  
pp. 048
Author(s):  
Muping Chen ◽  
Graciela B. Gelmini ◽  
Volodymyr Takhistov
Keyword(s):  
Dark Matter ◽  
Direct Detection ◽  
Dark Matter Halo ◽  
Dark Halo ◽  
Sufficient Energy ◽  
Independent Analysis ◽  
Dark Matter Detection ◽  
Dark Matter Scattering ◽  
Matter Detection ◽  
Direct Dark Matter

Abstract Sub-GeV mass dark matter particles whose collisions with nuclei would not deposit sufficient energy to be detected, could instead be revealed through their interaction with electrons. Analyses of data from direct detection experiments usually require assuming a local dark matter halo velocity distribution. In the halo-independent analysis method, properties of this distribution are instead inferred from direct dark matter detection data, which allows then to compare different data without making any assumption on the uncertain local dark halo characteristics. This method has so far been developed for and applied to dark matter scattering off nuclei. Here we demonstrate how this analysis can be applied to scattering off electrons.

Galactic Spiral Pattern beyond the Optical Size Induced by the Triaxial Dark Halo

2015 ◽  
Vol 24 (2) ◽  
Author(s):  
M. Butenko ◽  
A. Khoperskov ◽  
S. Khoperskov
Keyword(s):  
Dark Halo ◽  
Spiral Pattern ◽  
Spiral Structures ◽  
Galactic Spiral

AbstractWe suggest a possible mechanism for the formation of non-tidal gaseous structures in galactic outskirts. According to recent observations, extended spiral structures are detected beyond the optical radii

scholarly journals Estimate of dark halo ellipticity by lensing flexion

2011 ◽  
Vol 528 ◽  
pp. A52 ◽  
Author(s):  
X. Er ◽  
P. Schneider
Keyword(s):  
Dark Halo

scholarly journals Excursion set peaks: a self-consistent model of dark halo abundances and clustering

2013 ◽  
Vol 431 (2) ◽  
pp. 1503-1512 ◽  
Author(s):  
Aseem Paranjape ◽  
Ravi K. Sheth ◽  
Vincent Desjacques
Keyword(s):  
Dark Halo ◽  
Consistent Model ◽  
Self Consistent ◽  
Excursion Set

scholarly journals Quantum Gravity Phenomenology from the Thermodynamics of Spacetime

Universe ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 50
Author(s):  
Ana Alonso-Serrano ◽  
Marek Liška
Keyword(s):  
Quantum Gravity ◽  
Big Bang ◽  
Einstein Equations ◽  
Logarithmic Term ◽  
Quantum Gravity Phenomenology ◽  
Gravity Effects ◽  
Energy Quantum ◽  
The Big Bang ◽  
Big Bang Singularity ◽  
Modified Dynamics

This work is based on the formalism developed in the study of the thermodynamics of spacetime used to derive Einstein equations from the proportionality of entropy within an area. When low-energy quantum gravity effects are considered, an extra logarithmic term in the area is added to the entropy expression. Here, we present the derivation of the quantum modified gravitational dynamics from this modified entropy expression and discuss its main features. Furthermore, we outline the application of the modified dynamics to cosmology, suggesting the replacement of the Big Bang singularity with a regular bounce.

scholarly journals The insight into the dark side – I. The pitfalls of the dark halo parameters estimation

2016 ◽  
Vol 463 (3) ◽  
pp. 2523-2541 ◽  
Author(s):  
Anna S. Saburova ◽  
Anastasia V. Kasparova ◽  
Ivan Yu. Katkov
Keyword(s):  
Parameters Estimation ◽  
Dark Side ◽  
Dark Halo ◽  
Insight Into
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