Probing gaseous galactic halos through the rotational kinematic Sunyaev-Zeldovich effect

The rotational kinematic Sunyaev-Zeldovich (rkSZ) signal, imprinted on the cosmic microwave background (CMB) by the gaseous halos (spinning "atmospheres") of foreground galaxies, would be a novel probe of galaxy formation. Although the signal is too weak to detect in individual galaxies, we analyze the feasibility of its statistical detection via stacking CMB data on many galaxies for which the spin orientation can be estimated spectroscopically. We use an "optimistic" model, in which fully ionized atmospheres contain the cosmic baryon fraction and spin at the halo's circular velocity v(circ), and a more realistic model, based on hydrodynamical simulations, with multiphase atmospheres spinning at a fraction of v(circ). We incorporate realistic noise estimates into our analysis. Using low-redshift galaxy properties from the MaNGA spectroscopic survey (with median halo mass of 6.6 x 10(11) M-circle dot), and CMB data quality from Planck, we find that a 3 sigma detection would require a few x 10(4) galaxies, even in the optimistic model. This is too high for current surveys, but upcoming higher-angular resolution CMB experiments will significantly reduce the requirements: stacking CMB data on galaxy spins in a similar to 10 deg(2) can rule out the optimistic models, and approximate to 350 deg(2) will suffice for a 3 sigma detection with ACT. As a proof-of-concept, we stacked Planck data on the position of approximate to 2, 000 MaNGA galaxies, aligned with the galaxies' projected spin, and scaled to their halos' angular size. We rule out average temperature dipoles larger than approximate to 1.9 mu K around field spiral galaxies.