We present HI data of the dwarf galaxy DDO 47, aimed at testing the hypothesis that dark halo triaxiality might induce non-circular motions resulting in rotation curves best fitted by cored halos, even if the dark matter halo is intrinsically cuspy. We performed a harmonic decomposition of the velocity field in order to search for alleged non-circular motions needed to ``hide'' a cusp: in DDO 47 non-circular motions are globally at a level of 2-3 km s−1, far from being sufficient to reconcile the observed rotation curve with the ΛCDM predictions. We conclude that the dark matter halo around DDO 47 is truly cored and that a cusp cannot be hidden by non-circular motions. More details are shown in Gentile et al.
The dwarf galaxy DDO 47: Testing cusps hiding in triaxial halos / Gentile, G; Burkert, Andreas Michael; Salucci, P; Klein, U; Walter, F.. - 20:(2006), pp. 279-280. (Intervento presentato al convegno 21st IAP Colloquium on Mass Profiles and Shapes of Cosmological Structures tenutosi a IAP , Parigi nel 4-9 Luglio, 2005) [10.1051/eas:2006089].
The dwarf galaxy DDO 47: Testing cusps hiding in triaxial halos
Gentile, G;Burkert, Andreas Michael;Salucci, P;
2006-01-01
Abstract
We present HI data of the dwarf galaxy DDO 47, aimed at testing the hypothesis that dark halo triaxiality might induce non-circular motions resulting in rotation curves best fitted by cored halos, even if the dark matter halo is intrinsically cuspy. We performed a harmonic decomposition of the velocity field in order to search for alleged non-circular motions needed to ``hide'' a cusp: in DDO 47 non-circular motions are globally at a level of 2-3 km s−1, far from being sufficient to reconcile the observed rotation curve with the ΛCDM predictions. We conclude that the dark matter halo around DDO 47 is truly cored and that a cusp cannot be hidden by non-circular motions. More details are shown in Gentile et al.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
