Abstract book - Prof. Per Jensen, Ph.D. - Bergische Universität ...

166 Poster session, J3Radio Search for H 2 CCC toward HD 183143 as a Candidate for aDiffuse Interstellar Band CarrierMitsunori Araki 1 , Shuro Takano 2 , Hiromichi Yamabe 1 , Koichi Tsukiyama 1 ,Nobuhiko Kuze 31 Department of Chemistry, Faculty of Science Division I, Tokyo University of Science,Japan, araki@rs.kagu.tus.ac.jp;2 Nobeyama Radio Observatory and Department of Astronomical Science,The Graduate University for Advanced Studies (Sokendai), Japan;3 Department of Materials and Life Sciences, Faculty of Science and Technology,Sophia University, JapanAraki M.Takano S.Yamabe H.Tsukiyama K.Kuze N.In order to clarify the authenticity of a recently proposed identification of H 2 CCC(linear-C 3 H 2 ) as a diffuse interstellar band carrier, 1 we searched for the rotationaltransition of H 2 CCC at a frequency of 103 GHz toward HD 183143 using a 45-mtelescope at the Nobeyama Radio Observatory. 2 Although an rms noise level of 32 mKin the antenna temperature, T * A , was achieved, detection of H 2 CCC was unsuccessful,producing a 3 σ upper limit corresponding to a column density of 2.0 × 10 13 cm −2 . Theupper limit indicates that the contribution of H 2 CCC to the diffuse interstellar band at5450 Å toward HD 183143 is less than 1/25; thus, it is unlikely that the laboratorybands of the B 1 B 1 –X 1 A 1 transition of H 2 CCC and the diffuse interstellar bands at 5450Å (and also 4881 Å) toward HD 183143 are related.Fig. 1: Spectrum at the line position of H 2 CCC searched toward HD 183143.Solid vertical lines indicate positions of the two velocity components of CH. Solidcurve shows a line profile of H 2 CCC simulated in arbitrary intensity. Two downwardconvex structures in this curve are frequency switching effects.References[1] J. P. Maier, G. A. H. Walker, D. A. Bohlender, F. J. Mazzotti, R. Raghunandan, J.Fulara, I. Garkusha, A. Nagy, ApJ, 726, 41 2011[2] M. Araki, S. Takano, H. Yamabe, K. Tsukiyama, N. Kuze, ApJL, submitted, 2012