Peculiar dark matter halos inferred from gravitational lensing as a manifestation of modified gravity

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F24%3A00600802" target="_blank" >RIV/68378271:_____/24:00600802 - isvavai.cz</a>

Result on the web

<a href="https://hdl.handle.net/11104/0364556" target="_blank" >https://hdl.handle.net/11104/0364556</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202450154" target="_blank" >10.1051/0004-6361/202450154</a>

Result language

angličtina

Original language name

Peculiar dark matter halos inferred from gravitational lensing as a manifestation of modified gravity

Original language description

If modified gravity holds, but the weak lensing analysis is done in the standard way, we find that dark matter halos have peculiar shapes that do not follow the standard Navarro-Frenk-White profiles and which are fully predictable from the distribution of baryons. In this work, we study in detail the distribution of the apparent DM around point masses, approximating galaxies and galaxy clusters, along with their pairs for the QUMOND version of modified Newtonian dynamics, taking the external gravitational acceleration, g(e), into account. At large radii, the apparent halo of a point mass, M, is shifted against the direction of the external field. When averaged over all lines of sight, the halo has a hollow center. Using a(0) to denote the MOND acceleration constant, we find that its density follows rho(r)=root Ma(0)/G /(4 pi r(2)) between the galacticentric radii root GM/a(0) and root GMa(0) / g(e), and then rho proportional to r(-7)G(2)M(3)a(0)(3)/g(e)(5) at a greater distance. Between a pair of point masses, there is a region of a negative apparent DM density, whose mass can exceed the baryonic mass of the system. The density of the combined DM halo is not a sum of the densities of the halos of the individual points. The density has a singularity near the zero-acceleration point, but remains finite in projection. We computed maps of the surface density and the lensing shear for several configurations of the problem and derived formulas to scale them to further configurations. In general, for a large subset of MOND theories in their weak-field regime, for any configuration of the baryonic mass, M, with the characteristic size of d, the total lensing density scales as rho(x) = root Ma(0)/Gd(-2)f(alpha,x / d,g(e)d/ root GMa(0)) , where the vector alpha describes the geometry of the system.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astronomy & Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Volume of the periodical

690

Issue of the periodical within the volume

Oct

Country of publishing house

FR - FRANCE

Number of pages

21

Pages from-to

A364

UT code for WoS article

001340368800006

EID of the result in the Scopus database

2-s2.0-85207446610