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IAU Commission 5, Documentation and Astronomical Data, continued its mission of promoting and supporting sound practices of data management, data dissemination, and data preservation over the past three years. The Commission also prepared its proposal for continuation, with some changes in emphasis, after the IAU's commission restructuring program. Below we report on the activities of the various Working Groups and the one Task Force in Commission 5.
We present result of the clustering analysis performed between AGNs and galaxies. AGN samples with redshift 0.1–1.0 were extracted from AGN properties catalogs which contain virial mass estimates of SMBHs. Galaxy samples were extracted from SDSS DR8 catalog and UKIDSS DR9 LAS catalog. The catalogs of SDSS and UKIDSS were merged and used to estimate the IR-opt color and IR magnitude in the rest frame by SED fitting. As we had no redshift information on the galaxy samples, stacking method was applied. We investigated the BH mass dependence of cross correlation length, red galaxy fraction at their environment, and luminosity function of galaxies. We found that the cross correlation length increase above MBH ≥ 108.2M⊙, and red galaxies dominate the environment of AGNs with MBH ≥ 109M⊙. This result indicates that the most massive SMBHs are mainly fueled by accretion of hot halo gas.
This will be the last triennial report from Commission 50 under that label, because of the reorganization of the IAU at the end of the triennial period. Fortunately, site protection was recognized as an important ongoing function of the IAU, and the work of the Commission is continuing as Commission C.B7. The Commission has its primary association with Division B because of the technical aspects of its work and association with ground-based facilities, while it has the support of Division C as an Inter-Division Commission because of the strong need for educating the public on the issues.
The International Astronomical Union's Commission 51 was established in 1982 as\break “Bioastronomy: Search for Extraterrestrial Life”. As the interests of Commission members expanded to include all aspects of the study of the origin, evolution, and distribution of life in the universe, C51 was renamed simply “Bioastronomy” in 2006. Thus, the term “bioastronomy” became for the Commission essentially synonymous with the NASA-coined term “astrobiology“. Since the latter term has been adopted by many scientific societies around the world with similar interests, under the new Division and Commission structure of the IAU the Commission has been again renamed and is now Commission F-3 “Astrobiology”.
IAU Commission 40 for Radio Astronomy (hereafter C40) brought together scientists and engineers who carry out observational and theoretical research in radio astronomy and who develop and operate the ground and space-based radio astronomy facilities and instrumentation. As of June 2015, the Commission had approximately 1,100 members from 49 countries, corresponding to nearly 10 per cent of the total IAU membership.
IAU Commission 5 (http://www.nao.ac.jp/IAU/Com5/) deals with data management issues, and its working groups and task group deal specifically with information handling, with data centers and networks, with technical aspects of collection, archiving, storage and dissemination of data, with designations and classification of astronomical objects, with library services, editorial policies, computer communications, ad hoc methodologies, and with various standards, reference frames, etc. FITS (Flexible Image Transport System), the major data exchange format in astronomy, has been standardized, maintained and updated by the FITS working group under Commission 5.
The activities of the Commission have continued to focus on controlling unwanted light and radio emissions at observatory sites, monitoring of conditions at observatory sites, and education and outreach. Commission members have been active in securing new legislation in several locations to further the protection of observatory sites as well as in the international regulation of the use of the radio spectrum and the protection of radio astronomical observations.
The IAU Working Group on Radio Frequency Interference (RFI) Mitigation was setup in the 2000 IAU GA in Manchester and its mandate was renewed at subsequent IAU GAs in 2003 and 2006. It was noted that that there are important issues related to RFI mitigation that extend beyond the regulatory function of IUCAF, and hence a more extended working group, which may include IUCAF members, was established.
The past President of Division XII, Malcolm Smith, took the chair of the business meeting of C50, in the absence of the past President of C50, Richard Wainscoat. He described the procedure of the election in 2006 of the then-time vice-president of C50, Richard Wainscoat, as President of C50, after the untimely deatch of the then-time C50 President, Hugo Schwarz. He also described the procedure for electing the incoming OC members and officers.
Commission 5 and its working groups have continued to operate at a high level of activity over the last three years. In an era when the volume of astronomical data generated by next-generation instruments continues to increase dramatically, and data centres and data tools become increasingly central to front-line astronomical research, the activities of Commission 5 are becoming even more significant. However, most of the activities of Commission 5 take place through its working groups. That was reflected in the meetings at the IAU GA, where there was only one short Business Meeting of the Commission as a whole, but several vigorous meetings of the working groups.
We present the results of a cross-correlation analysis of the projected positions of AGNs and galaxies at redshifts from 0.3 to 3.0. It is widely accepted that the origin of AGN activity is accretion of matter onto a massive black hole at the center of a galaxy (e.g., Lynden-Bell 1969). To explain the activity of AGNs, a large fraction of matter in the galaxy must be delivered to the inner region on a short timescale (Hopkins et al. 2008). One possible mechanism for causing rapid gas inflows into the central region is a major galaxy merger between gas-rich galaxies (e.g., Kauffmann & Haehnelt 2000). If this is the case, AGNs are expected to be found in an environment with higher galaxy density than that of typical galaxies. We investigated environments of ~ 750 AGNs, which is about a ten times larger sample than used in previous studies, and we find a significant excess of galaxies around the AGNs in the redshift range of 0.3 to 1.8. We used the Japanese Virtual Observatory (JVO) to obtain the Subaru Suprime-Cam images and UKIDSS data around known AGNs. The datasets accessed through the JVO are: Catalog of Quasars and Active Galactic Nuclei by Veron-Cetty et al. (2006), SDSS DR-5 Quasar Catalog by Schneider et al. (2007), Subaru Suprime-Cam Reduced Image Archive of JVO, and UKIDSS DR2 catalog by Warren et al. (2007). We divided all the AGN samples into four redshift groups, 0.3≲z ≲ 0.8, 0.8≲ z ≲ 1.5, 1.5≲ z ≲ 1.8, and 1.8≲ z ≲ 3.0. For each redshift group, the dataset was further divided into a fainter group (MV ≥ −25 mag) and a brighter group (MV < −25 mag). We found that the correlation length of the high-redshift bright sample (1.5≲ z ≲ 1.8) was larger than that of the low-redshift faint sample (0.3≲ z ≲ 0.8). We also found that the correlation length was larger for the faint group at redshift range 0.8≲ z ≲1.5. These results can be explained by downsizing of mass assembly. More details can be found in the paper by Shirasaki et al. (2009). Our result implies that the Japanese Virtual Observatory can be a powerful tool to investigate the co-evolution of central black holes and galaxies at the intermediate redshift universe.
IAU Commission 5 deals with data management issues, and its working groups and task groups deal specifically with information handling, with data centres and networks, with technical aspects of collection, archiving, storage and dissemination of data, with designations and classification of astronomical objects, with library services, editorial policies, computer communications, ad hoc methodologies, and with various standards, reference frames, etc., FITS, astronomys Flexible Image Transport System, the major data exchange format, is controlled, maintained and updated by the Working Group FITS.
It is known that more than 140 interstellar and circumstellar molecules have so far been detected, mainly by means of the radio astronomy observations. Many organic molecules are also detected, including alcohols, ketons, ethers, aldehydes, and others, that are distributed from dark clouds and hot cores in the giant molecular clouds. It is believed that most of the organic molecules in space are synthesized through the grain surface reactions, and are evaporated from the grain surface when they are heated up by the UV radiation from adjacent stars.
On the other hand the recent claim on the detection of glycine have raised an important issue how difficult it is to confirm secure detection of weak spectra from less abundant organic molecules in the interstellar molecular cloud.
I will review recent survey observations of organic molecules in the interstellar molecular clouds, including independent observations of glycine by the 45 m radio telescope in Japan, and will discuss the procedure to securely identify weak spectral lines from organic molecules and the importance of laboratory measurement of organic species.
Virtual Observatory (VO) is an emerging astronomical infrastructure for sharing the astronomical data set in the world. National Astronomical Observatory of Japan (NAOJ) started its VO project (Japanese Virtual Observatory – JVO) in 2002, and developed JVO portal prototypes. We have carried out several science use cases, such as cosmic string searches and QSO environment studies, by using the prototype system to examine the functionality of the system. This paper describes a preliminary result of the latter science use case.
The International Virtual Observatory Alliance is briefly introduced as a concensus-based group to construct International Virtual Observatory – a new, planet-wide research infrastructure for the 21st century astronomy. Standardized protocols by the IVOA were used to interconnect more than 10 astronomical obsrvatories and data centers to provide astronomers with multiwavelength astronomical data. The priority areas for technical development and planned developments are described.
Development of radio technologies will lead to a serious conflict between millimetre-wave astronomy and telecommunication services. I describe characteristics of millimetre-wave astronomy and technical aspects related to radio astronomical observations. Three examples of possible interference to millimetre-wave astronomy are described. It is very important to advertise what millimetre-wave astronomy contributes to human culture and to get support from the non-astronomical community to keep the radio windows open and clean.
Recent observational results toward the “Hot Core” sources (Orion KL, SgrB2, G34.3+0.15, W51, and so on) are summarized. Several saturated organic molecules are commonly observed among these sources, and these results favor formations on the grain mantles followed by evaporation. Some results of surveys in “hot core molecules” are presented. Such molecules may be used as diagnostics to establish the presence of “hot core” regions.
The Orion bright bar is a prominent ionization front located approximately 2’ southeast of the Trapezium stars. Because this ionization front is seen almost edge-on, it provides an opportunity to study the interaction between the HII region and the adjacent molecular cloud. The molecular bar has been thought to be a narrow layer of ~ 50” (0.1 pc) in width parallel to the ionization front with enhanced temperature, density and column density. The molecular gas outside the ionization front was redshifted with respect to the ambient molecular cloud by 1-2 kms−1 (Omodaka et al. 1984, 1986, 1992), suggesting that the expanding HII region generated by the Trapezium stars had driven a shock wave into the molecular cloud at the southeast of the bar. This layer is exposed to intense UV radiation from the Trapezium stars, resulting in the formation of photodissociated regions.
We have made aperture synthesis observations of CS(J=1-0) line and 49 GHz continuum in the Orion bright bar with the Nobeyama Millimeter Array. Figure 1, a map of integrated intensities of CS, clearly revealed fine structures of the molecular bar and more than six prominent features are confirmed. It is noted that these features are lined up at 30” from the ionization front inside the molecular cloud.
The latest table of molecular abundances in the cold, dark clouds TMC-1 and L134N is presented. Molecular abundance variations between TMC-1 and L134N, those within TMC-1 and L134N, and those among 49 dark cloud cores surveyed by Suzuki et al. (1991) are interpreted as an effect of chemical evolution.