Planck data acquired during the first 15.4 months of observations toward both the disk and halo of the M 31 galaxy were analyzed. We confirm the temperature asymmetry that was previously detected by using the seven-year WMAP data in the direction of the rotation of M 31, which indicates that this is a Doppler-induced effect. The asymmetry extends to about 10° (≃130 kpc) from the center of M 31. We also investigated the recent problem raised in Rubin and Loeb (2014, JCAP, 01, 051) about the kinetic Sunyaev-Zel'dovich effect from the diffuse hot gas in the Local Group, which is predicted to generate a hot spot of a few degrees in size in the cosmic microwave background maps in the direction of M 31, where the free electron optical depth is highest. We also considered whether the same effect in the opposite direction with respect to the M 31 galaxy induces a minimum in temperature in the Planck maps of the sky. We find that the Planck data at 100 GHz show an even stronger effect than that expected.
Planck confirmation of the disk and halo rotation of M31
DE PAOLIS, Francesco;NUCITA, Achille;INGROSSO, Gabriele;VETRUGNO, DANIELE
2014-01-01
Abstract
Planck data acquired during the first 15.4 months of observations toward both the disk and halo of the M 31 galaxy were analyzed. We confirm the temperature asymmetry that was previously detected by using the seven-year WMAP data in the direction of the rotation of M 31, which indicates that this is a Doppler-induced effect. The asymmetry extends to about 10° (≃130 kpc) from the center of M 31. We also investigated the recent problem raised in Rubin and Loeb (2014, JCAP, 01, 051) about the kinetic Sunyaev-Zel'dovich effect from the diffuse hot gas in the Local Group, which is predicted to generate a hot spot of a few degrees in size in the cosmic microwave background maps in the direction of M 31, where the free electron optical depth is highest. We also considered whether the same effect in the opposite direction with respect to the M 31 galaxy induces a minimum in temperature in the Planck maps of the sky. We find that the Planck data at 100 GHz show an even stronger effect than that expected.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
