%0 Generic %1 Ritchey2012 %A Ritchey, Adam M. %A Wallerstein, George %D 2012 %K SN absorption disk halo %T Interstellar Sodium and Calcium Absorption toward SN 2011dh in M51 %U http://arxiv.org/abs/1202.3156 %X We present high-resolution echelle observations of SN 2011dh, which exploded in the nearby, nearly face-on spiral galaxy M51. Our data, acquired on three nights when the supernova was near maximum brightness, reveal multiple absorption components in Na I D and Ca II H and K, which we identify with gaseous material in the Galactic disk or low halo and in the disk and halo of M51. The M51 components span a velocity range of over 140 km s^-1, extending well beyond the range exhibited by H I 21 cm emission at the position of the supernova. Since none of the prominent Na I or Ca II components appear to coincide with the peak in H I emission, the supernova may lie just in front of the bulk of the H I disk. The Na I/Ca II ratios for the components with the most extreme positive and negative velocities relative to the disk are ~1.0, similar to those for more quiescent components, suggesting that the absorption originates in relatively cool gas. Production scenarios involving a galactic fountain and/or tidal interactions between M51 and its companion would be consistent with these results. The overall weakness of Na I D absorption in the direction of SN 2011dh confirms a low foreground and host galaxy extinction for the supernova.

@misc{Ritchey2012, abstract = { We present high-resolution echelle observations of SN 2011dh, which exploded in the nearby, nearly face-on spiral galaxy M51. Our data, acquired on three nights when the supernova was near maximum brightness, reveal multiple absorption components in Na I D and Ca II H and K, which we identify with gaseous material in the Galactic disk or low halo and in the disk and halo of M51. The M51 components span a velocity range of over 140 km s^-1, extending well beyond the range exhibited by H I 21 cm emission at the position of the supernova. Since none of the prominent Na I or Ca II components appear to coincide with the peak in H I emission, the supernova may lie just in front of the bulk of the H I disk. The Na I/Ca II ratios for the components with the most extreme positive and negative velocities relative to the disk are ~1.0, similar to those for more quiescent components, suggesting that the absorption originates in relatively cool gas. Production scenarios involving a galactic fountain and/or tidal interactions between M51 and its companion would be consistent with these results. The overall weakness of Na I D absorption in the direction of SN 2011dh confirms a low foreground and host galaxy extinction for the supernova. }, added-at = {2012-02-16T19:32:52.000+0100}, author = {Ritchey, Adam M. and Wallerstein, George}, biburl = {https://www.bibsonomy.org/bibtex/2bc0ec816bcbd4a89e2f6c6d478f415c2/miki}, description = {[1202.3156] Interstellar Sodium and Calcium Absorption toward SN 2011dh in M51}, interhash = {b68d889c2936e562da23b9b016691fcb}, intrahash = {bc0ec816bcbd4a89e2f6c6d478f415c2}, keywords = {SN absorption disk halo}, note = {cite arxiv:1202.3156 Comment: 6 pages, 3 figures, emulateapj style, accepted for publication in ApJ Letters}, timestamp = {2012-02-16T19:32:52.000+0100}, title = {Interstellar Sodium and Calcium Absorption toward SN 2011dh in M51}, url = {http://arxiv.org/abs/1202.3156}, year = 2012 }