Spectroscopy of the Type Ic Supernova SN2017iuk Associated with Low-redshift GRB171205A

We here report a spectroscopic monitor for the supernova (SN) SN 2017iuk associated with the long-duration low-luminosity gamma-ray burst (GRB) GRB 171205A at a redshift of 0.037, which is up to now the third GRB-SN event away from us. Our spectroscopic observations and spectral analysis allow us to identify SN 2017iuk as a typical broad-line Type Ic SN. A comparison study suggests that the Type IcBL SN 2017iuk resembles SN 2006aj in the following aspects: (1) similar spectra at the nearby epochs, (2) comparable evolution of the photospheric velocity obtained from the measurements based on both the Si II lambda 6355 line and spectral modeling, and (3) comparable explosion parameters. This analogy could imply the formation of a neutron star in the core collapse of GRB 171205A/SN 2017iuk as previously suggested in GRB 060218/SN 2006aj. The properties of the host galaxy are discussed, which suggest that GRB 171205A/SN 2017iuk occurred in an early-type (S0), high-mass, star-forming galaxy with low specific star formation rate and solar metallicity.