A possible detection of gas rotation in galaxy groups via the kinetic Sunyaev-Zeldovich effect
Researchers used the kinetic Sunyaev-Zeldovich (kSZ) effect to measure gas rotation in galaxy groups using CMB data from SDSS groups. They found a tentative 2.3$\sigma$ detection of the dipolar rotational kSZ effect (rkSZ), estimating an average rotational velocity of about 100–200 km s$^{-1}$ within the group virial radii. This result is consistent with simulations, suggesting gas rotation in these structures.