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

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2024

Kód důvěrnosti údajů

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

Název periodika

Astronomy & Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Svazek periodika

690

Číslo periodika v rámci svazku

Oct

Stát vydavatele periodika

FR - Francouzská republika

Počet stran výsledku

21

Strana od-do

A364

Kód UT WoS článku

001340368800006

EID výsledku v databázi Scopus

2-s2.0-85207446610