TY - JOUR
T1 - The Effect of Adiabatic Compression on Dark Matter Halos and the Radial Acceleration Relation
AU - Li, Pengfei
AU - McGaugh, Stacy S.
AU - Lelli, Federico
AU - Tian, Yong
AU - Schombert, James M.
AU - Ko, Chung Ming
N1 - Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.
PY - 2022/3/1
Y1 - 2022/3/1
N2 - We use a semiempirical model to investigate the radial acceleration relation (RAR) in a cold dark matter (CDM) framework. Specifically, we build 80 model galaxies covering the same parameter space as the observed galaxies in the SPARC database, assigning them to dark matter (DM) halos using abundance-matching and halo mass-concentration relations. We consider several abundance-matching relations, finding some to be a better match to the kinematic data than others. We compute the unavoidable gravitational interactions between baryons and their DM halos, leading to an overall compression of the original Navarro-Frenk-White (NFW) halos. Before halo compression, high-mass galaxies lie approximately on the observed RAR, whereas low-mass galaxies display up-bending "hooks"at small radii due to DM cusps, making them deviate systematically from the observed relation. After halo compression, the initial NFW halos become more concentrated at small radii, making larger contributions to rotation curves. This increases the total accelerations, moving all model galaxies away from the observed relation. These systematic deviations suggest that the CDM model with abundance matching alone cannot explain the observed RAR. Further effects (e.g., feedback) would need to counteract the compression with precisely the right amount of halo expansion, even in high-mass galaxies with deep potential wells where such effects are generally predicted to be negligible.
AB - We use a semiempirical model to investigate the radial acceleration relation (RAR) in a cold dark matter (CDM) framework. Specifically, we build 80 model galaxies covering the same parameter space as the observed galaxies in the SPARC database, assigning them to dark matter (DM) halos using abundance-matching and halo mass-concentration relations. We consider several abundance-matching relations, finding some to be a better match to the kinematic data than others. We compute the unavoidable gravitational interactions between baryons and their DM halos, leading to an overall compression of the original Navarro-Frenk-White (NFW) halos. Before halo compression, high-mass galaxies lie approximately on the observed RAR, whereas low-mass galaxies display up-bending "hooks"at small radii due to DM cusps, making them deviate systematically from the observed relation. After halo compression, the initial NFW halos become more concentrated at small radii, making larger contributions to rotation curves. This increases the total accelerations, moving all model galaxies away from the observed relation. These systematic deviations suggest that the CDM model with abundance matching alone cannot explain the observed RAR. Further effects (e.g., feedback) would need to counteract the compression with precisely the right amount of halo expansion, even in high-mass galaxies with deep potential wells where such effects are generally predicted to be negligible.
UR - http://www.scopus.com/inward/record.url?scp=85127310529&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/ac52aa
DO - 10.3847/1538-4357/ac52aa
M3 - 期刊論文
AN - SCOPUS:85127310529
SN - 0004-637X
VL - 927
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 198
ER -