Diffuse interstellar bands in NGC 1448

We present spectroscopic VLT/UVES observations of two emerging supernovae, the Type Ia <ASTROBJ>SN 2001el</ASTROBJ> and the Type II <ASTROBJ>SN 2003hn</ASTROBJ>, in the spiral galaxy <ASTROBJ>NGC 1448</ASTROBJ>. Our high resolution and high signal-to-noise spectra display atomic lines of Ca II, Na I, Ti II and K I in the host galaxy. In the line of sight towards <ASTROBJ>SN 2001el</ASTROBJ>, we also detect over a dozen diffuse interstellar bands (DIBs) within <ASTROBJ>NGC 1448</ASTROBJ>. These DIBs have strengths comparable to low reddening galactic lines of sight, albeit with some variations. In particular, a good match is found with the line of sight towards the sigma type diffuse cloud (<ASTROBJ>HD 144217</ASTROBJ>). The DIBs towards <ASTROBJ>SN 2003hn</ASTROBJ> are significantly weaker, and this line of sight has also lower sodium column density. The DIB central velocities show that the DIBs towards <ASTROBJ>SN 2001el</ASTROBJ> are closely related to the strongest interstellar Ca II and Na I components, indicating that the DIBs are preferentially produced in the same cloud. The ratio of the lambda 5797 and lambda 5780 DIB strengths (r ~ 0.14) suggests a rather strong UV field in the DIB environment towards <ASTROBJ>SN 2001el</ASTROBJ>. We also note that the extinction estimates obtained from the sodium lines using multiple line fitting agree with reddening estimates based on the colors of the Type Ia <ASTROBJ>SN 2001el</ASTROBJ>.