Deep millimeter spectroscopy observations toward NGC 1068★
School of Astronomy and Space Science, Nanjing University,
210093, PR China
2 Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030, PR China
3 Key Laboratory of Radio Astronomy, Chinese Academy of Sciences, Nanjing 210008, PR China
4 Key Laboratory of Modern Astronomy and Astrophysics, Nanjing University, Ministry of Education, Nanjing 210093, PR China
5 Center For Astrophysics, GuangZhou University, GuangZhou 510006, PR China
6 Department of Astronomy, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA
7 University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing 100049, PR China
Accepted: 11 December 2017
Aims. We aim for a better understanding of gas properties in the circum-nuclear disk (CND) region of the nearby gas-rich Seyfert 2 galaxy NGC 1068. We focus on line identification and the basic physical parameters estimation of molecular gas in the CND region.
Methods. We used the IRAM 30 m telescope to conduct deep millimeter spectroscopy observations toward the center of NGC 1068.
Results. Thirty-two lines were detected in this galaxy, 15 lines of wich were detected for the first time. With a sensitivity better by about a factor of 4 than observations in the literature for this source at 3 mm band, we detected several weak lines for the first time in this source, such as lines from CH3CCH, CH3OCH3, and HC18O+. Column densities of these molecules were estimated based on line emissions. Some marginal detections in the literature, such as HN13C (1–0), were confirmed. CH3OCH3 was detected for the first time in external galaxies. Lines from several carbon chain molecules and shock-related molecules were also detected in this source.
Key words: ISM: molecules / galaxies: ISM / galaxies: individual: NGC 1068 / galaxies: nuclei / galaxies: active
The reduced spectrum (FITS file) is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (22.214.171.124) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/613/A3
© ESO 2018
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.