High-resolution spectroscopy of SN2014J in M82

ATel #5797; N. L.J. Cox (KU Leuven); P. Davis, (Universite Libre de Bruxelles); F. Patat (ESO); Hans Van Winckel (KU Leuven)
on 23 Jan 2014; 16:59 UT
Credential Certification: Ferdinando Patat (fpatat@eso.org)

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We have observed SN2014J with the HERMES high-resolution spectrograph mounted at the Mercator Telescope (La Palma - Spain) on Jan 23.19 UT. The spectrum has a FWHM resolution of about 85,000 and a signal-to-noise ratio of about 25 at 5900A. A preliminary analysis reveals several inter-stellar atomic features (Ca II H&K, Na I D, K I) and Diffuse Inter-stellar Bands (DIBs). The most prominent absorption system is the Na I D doublet. In addition to weak components arising within the Milky Way (at barycentric velocities of -0.3 and +59 km/s, with a total equivalent width of 0.28A), a number of components likely arising within the host galaxy are detected at +149, +154, +170, +183, +202.5, +241.5, +252 km/s. A strongly saturated component (which may be the result of a blend) is present between +70 and +140 km/s. The total Na I D equivalent width (EW) is 5.1 A (D1: 2.4A, D2: 2.7A), indicating a relatively high reddening along the line of sight. DIB 5780.5 and 5796.9 are detected at + 130 km/s, coinciding with one of the strongly saturated Na I D systems. The equivalent widths are 0.57A (FWHM=4.1A) and 0.27A (FWHM=2.0A), respectively. The large FWHM for the DIBs are most probably caused by Doppler broadening due to multiple cloud velocity components along the line of sight in M82. Other DIBs are tentatively detected (e.g. 6196 and 6203). The relatively large DIB EWs imply a significant reddening [E(B-V)>1].