Nobeyama 45 m telescope legacy project: Line survey (II)Takano, S. (NRO), Aikawa, Y. (Kobe U.), Chen, V. (NTHU), Hirano, N. (ASIAA), Hirota, T. (NAOJ),Kamegai, K. (JAXA), Kobayashi K. (Toyama U.), Kohno, K. (U. Tokyo), Kuan, Y-J. (NTNU), Liu, S.-Y.
(ASIAA), Nakajima, T. (NRO), Ohashi, N. (ASIAA), Ohishi, M. (NAOJ), Ozeki, H. (Toho U.), Sakai, N.
(U. Tokyo), Sakai, T. (U. Tokyo), Shiba, S. (U. Tokyo), Su, Y.-N. (ASIAA), Sugimura, M. (U. Tokyo),Takahashi, S. (ASIAA), Takakuwa, S. (ASIAA), Umemoto, T. (NAOJ), Wang, K.-S. (ASIAA), Yamada,M. (ASIAA), Yamamoto, S. (U. Tokyo), Zhang, Q.-Z. (CfA)

Line surveys are of fundamental importance in astronomy not only for complete
understanding of chemical compositions in representative sources, but also for finding out
new observing tools probing interstellar medium and star formation. We started the line
surveys toward a few new types of sources with the Nobeyama 45 m telescope in December
2007. The target sources include the low-mass star forming region L1527, the shocked regionof L1157, infrared dark clouds G28.34+0.06, and external galaxies Arp 220, NGC 1068 andNGC 253. Mainly with the new 3 mm receivers installed on the 45 m telescope [1], thefrequency range of ~84-115 GHz will be surveyed with much higher sensitivity than theprevious observations. The total observing time is expected to be about 1000 hours for fouryears. The results from the survey will be used for detailed studies on chemistry in eachsource, and will also provide us with useful templates for planning the observing strategy withALMA. The third year of the line surveys was finished. We report the preliminary results.
L1527 is a very interesting object, because the abundances of carbon-chain molecules are
high, though this source is a low-mass star-forming region [2]. We detected many lines
including high excitation lines of HC5N (e.g. J=41-40, upper state energy of 110 K), isotopic
species (D, 13C) of some carbon-chain molecules, HCO, C3O, cyclic-C3H, etc. These data
will be quite useful to understand chemistry in this warm environment.
In L1157, where interactions between an outflow and ambient clouds are prominent [3, 4], we
detected many lines including C2H, C34S, CCS, HCNO, CH3CN, CH3CHO, HCOOCH3, andNH2CHO. To study shock chemistry and gas-grain interaction, these results are rather
important information. After our observations, we noticed that HCOOCH3 is independently
detected with the IRAM 30 m telescope [5].
In G28.34+0.06 three interesting positions called mm1, mm4, and mm9 are selected. Towardmm1 and mm4 line wings were found in HCO+, HCN, SiO, CS, and CH3OH. These wings
indicate outflow activities. In addition, CH3CHO is detected only in mm1 and mm4. This
molecule is one of the probable grain related species. Therefore CH3CHO may be evaporated
from grain. Based on these results, mm1 and mm4 are thought to be high-mass protostellar
objects. Additional data supporting this view were obtained from DNC, DCO+, and N2D+.
About galaxies we are mainly observing NGC 1068, which is a nearby galaxy with Active
Galactic Nucleus (AGN). Our motivation is to study the effect of AGN on molecularabundances (cf. [6]). In addition a prototypical starburst galaxy NGC 253 is observed forcomparison. We detected C2H (N=1-0), H13CN (J=1-0), and cyclic-C3H2 for the first time inNGC 1068. The details will be presented in this workshop by Nakajima et al.
References [1] Nakajima et al. 2008, PASJ 60, 435. [2] Sakai et al. 2008, ApJ 672, 371. [3] Umemoto et al.
1992, ApJ 392, L83. [4] Mikami et al. 1992, ApJ 392, L87. [5] Arce et al. 2008, ApJ 681, L21. [6] Kohno et al.
2008, Ap&SS 313, 279.