期刊
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
卷 521, 期 2, 页码 2227-2238出版社
OXFORD UNIV PRESS
DOI: 10.1093/mnras/stad646
关键词
galaxies: bar; galaxies: formation; galaxies: individual: NGC 4264; galaxies: individual: NGC 4277; galaxies: kinematics and dynamics; galaxies: structure
We examined the relationship between bar rotation rate and dark matter content in barred galaxies, focusing on NGC 4264 and NGC 4277. NGC 4264 has a fast bar that extends close to corotation, while the bar in NGC 4277 is slow and falls short of corotation. Using dynamical models and observational data, we found that NGC 4277 has a higher fraction of dark matter within the bar region compared to NGC 4264, in agreement with theoretical predictions and numerical simulations.
A B S T R A C T We investigate the link between the bar rotation rate and dark matter content in barred galaxies by concentrating on the cases of the lenticular galaxies NGC 4264 and NGC 4277. These two gas-poor galaxies have similar morphologies, sizes, and luminosities. But, NGC 4264 hosts a fast bar, which extends to nearly the corotation, while the bar embedded in NGC 4277 is slow and falls short of corotation. We derive the fraction of dark matter f(DM, bar) within the bar region from Jeans axisymmetric dynamical models by matching the stellar kinematics obtained with the MUSE integral-field spectrograph and using SDSS images to recover the stellar mass distribution. We build mass-follows-light models as well as mass models with a spherical halo of dark matter, which is not tied to the stars. We find that the inner regions of NGC 4277 host a larger fraction of dark matter ( f(DM , bar) = 0 . 53 +/- 0 . 02) with respect to NGC 4264 ( f(DM , bar) = 0 . 33 +/- 0 . 04) in agreement with the predictions of theoretical works and the findings of numerical simulations, which have found that fast bars live in baryon-dominated discs, whereas slow bars experienced a strong drag from the dynamical friction due to a dense DM halo. This is the first time that the bar rotation rate is coupled to fDM, bar derived from dynamical modelling.
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