It has been recently found that a few galaxy clusters host diffuse radio halo emis- sion with very steep synchrotron spectra (α > 1.6), which may be classified as Ultra Steep Spectrum Radio Halos (USSRHs). USSRHs are expected in the turbulence re-acceleration model for the origin of cluster radio halos, and are best discovered and studied at low fre- quencies. We performed GMRT follow up observations of three galaxy clusters at 150 MHz, selected from the GMRT radio halo survey, which are known to host an USSRH or candi- date very steep spectrum diffuse emission. This project is aimed to characterize the low frequency spectrum of USSRHs for a detailed study of their origin and connection with cluster mergers. We present preliminary results at 150 MHz of the cluster A 697.
GMRT 150 MHz follow up of diffuse steep spectrum radio emission in galaxy clusters
MACARIO, GIULIA;DALLACASA, DANIELE;
2011
Abstract
It has been recently found that a few galaxy clusters host diffuse radio halo emis- sion with very steep synchrotron spectra (α > 1.6), which may be classified as Ultra Steep Spectrum Radio Halos (USSRHs). USSRHs are expected in the turbulence re-acceleration model for the origin of cluster radio halos, and are best discovered and studied at low fre- quencies. We performed GMRT follow up observations of three galaxy clusters at 150 MHz, selected from the GMRT radio halo survey, which are known to host an USSRH or candi- date very steep spectrum diffuse emission. This project is aimed to characterize the low frequency spectrum of USSRHs for a detailed study of their origin and connection with cluster mergers. We present preliminary results at 150 MHz of the cluster A 697.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
