The nearby (d = 19.7 Mpc) Seyfert galaxy NGC 3079 exhibits a prominent bubble emerging from the nucleus. In order to investigate the nuclear power source, we carried out ammonia observations toward the center of NGC 3079 with the Tsukuba 32-m telescope and the JVLA. The NH3 (J,K) = (1, 1) through (6, 6) lines were detected in absorption at the center of NGC 3079 with the JVLA, although the profile of NH3 (3, 3) was in emission in contrast to the other transitions. All ammonia absorption lines have two distinct velocity components: one is at the systemic velocity (Vsys ~ 1116 km s−1) and the other is blueshifted (Vsys ~ 1020 km s−1), and both components are aligned along the nuclear jets. The blueshifted NH3 (3, 3) emission can be regarded as ammonia masers associated with shocks by strong winds probably from newly formed massive stars or supernova explosions in the nuclear megamaser disk. The derived rotational temperature, Trot = 120 ± 12 K for the systemic component and Trot = 157 ± 19 K for the blueshifted component, and fractional abundance of NH3 relative to molecular hydrogen H2 are higher than those in other galaxies reported. The high temperature environment at the center may be mainly attributed to heating by the nuclear jets.

IAU Commission 28 (IAU C28: Galaxies) was founded in the late 1930s at which time it had only a small membership (see the historical notes by Sadler et al. 2007). When C28 ended its existence in 2015 there were well over 1000 members on its books. The membership had grown to the point where the effort to keep track of active participants had become a major task. During the C28s tenure 27 IAU Symposia have been devoted to galaxies, the third highest number (Mickaelian 2014)

Dome Fuji on the Antarctic high plateau may be a good site for terahertz astronomy because of its high altitude of 3,810 m and low average temperature of −54°C. We have demonstrated that the opacity at 220 GHz from Dome Fuji in summer is very good and stable; τ = 0.045 ± 0.007. We have developed a transportable 30 cm telescope to map the Milky Way in the CO (J=4–3) and the [CI] (3P1–3P0) lines at Dome Fuji from 2014. It has a 9′ beam. Physical conditions such as density and temperature of molecular clouds could be derived from a direct comparison of CO (J=4–3) and [CI] (3P1–3P0) with CO (J=1–0) taken by the Columbia–CfA survey. We are also developing a 1.2 m sub-millimeter telescope. It will be equipped with a dual superconducting device (SIS) receiver for 500/800 GHz. The 1.2 m telescope produces a 2.2′ beam at 492 GHz and could map a molecular cloud entirely. It could also observe nearby galaxies in the CO (J=4–3), CO (J=7–6), [CI] (3P1–3P0), [CI] (3P2–3P1) and in continuum emission between 460–810 GHz.

The membership of Commission 28 is so large, and the spread of research interests so broad, that the research highlights presented here of necessity represent just a small subset of the work carried out over the past three years. Progress in the area of galaxy evolution continues to be particularly rapid, driven by both the availability of new multi-wavelength survey data and the development of increasingly sophisticated simulations to model the complex behaviour of stars and gas (e.g. Agertz et al. 2011; Guo et al. 2011; Keres et al. 2009; Schaye et al. 2010).

This short report describes some highlights in extragalactic research over the past three years, and lists the main symposia and meetings in the domain.

We observed the H2O maser at the nucleus of the Seyfert 2, IC 2560, using the VLBA and the phased VLA. The systemic, red-shifted and blue-shifted maser features and a continuum component have been detected. We propose a maser disk in the nuclear region. The systemic and red-shifted features are emitted from a nearly edge-on disk with the position angle of PA = −47°. The thickness is 2H < 0.025 pc. The binding mass is 3.5 × 106M⊙. Assuming the Keplerian rotation, the radii at the disk are r = 0.087-0.335 pc and the rotation velocities are 213–418 km s−1. The mean density within the inner radius is 1.3 × 109M⊙ pc−3, suggesting a massive black hole at the center. A continuum component is considered as a jet ejected from the nucleus, with an angle of 70° from the disk. The blue-shifted maser feature is located on the continuum component, being interpreted to be a ‘jet maser’.

In an effort to achieve as high a storage capacity as possible on a disc format that is similar to conventional DVD using blue-violet laser, a number of new technologies have been implemented for the phase change rewritable media. The technologies include the ways to meet challenges in obtaining larger signal amplitude for shorter bit lengths and lowering the cross erase for narrower track pitches. Technologies developed for both the single layer and the dual layer discs are discussed.

Our observations of H2O masers have detected some high-velocity features and a secular velocity drift of the systemic features in the Seyfert 2 Galaxy IC 2560. The high-velocity features were blue- and red-shifted from the systemic velocity of 220-420 km s−1 and 210-350 km s−1, respectively. The velocity of the systemic features drifted at a secular rate of 2.62 km s−1 yr−1. Assuming the existence of a compact rotating disk as in NGC 4258, IC 2560 possesses a nuclear disk with inner and outer radii of 0.07 pc and 0.26 pc, respectively, and a confined mass of 2.8 × 106M⊙ at the center, making the central density > 2.1 × 109M⊙ pc−3. Such a dense object cannot be a cluster of stars, and this strongly suggests that the central mass is a super-massive black hole. Since the 2-10 keV luminosity of IC 2560 is 1 × 1041 erg s−1, the mass accretion rate of the suggested black hole must be 2 × 10−5M⊙ yr−1.

We present high resolution studies of the nuclear region in NGC 3079 with phase-referenced VLBI monitoring between its water maser and continuum emission. From results of the observations, NGC 3079 showed relative motion between core-jet-like continuum components. One of the components (A) relative to the reference maser feature moved with an apparent subluminal velocity along the SE-NW direction, almost parallel to alignment of the components. On the other hand, the position of the other component (B) did not show such a significant change. If the maser gas is associated with a rotating disk, the maser gas should be gravitationally bound to the central mass. This suggests that B and A are the nucleus and jet, respectively.

Knowledge of the distribution and excitation of gas close to the nuclei of starburst galaxies is an essential element in the construction of models dealing with intense, but short-lived, star forming events. Building a comprehensive picture of the concentrations of various gaseous components in such regions calls for a multi-wavelength approach: the principal cooling lines of cold (T≤200K) molecular gas fall in the millimetre waveband, those of hot (T~1−3×103K) excited molecular material in the near-IR, and those pinpointing starburst activity in the optical. In many cases the extents of the emitting regions are on the order of only a few arcseconds.

As part of such a study into the relationship between various near- and circum- nuclear gaseous components in starburst galaxies, we have obtained data on NGC 6764, a barred spiral classified as a LINER, at resolutions of 1″−4″ across the optical, near-infrared and millimetre wavelength regimes. In a previous paper (Eckart et al. 1991) we discussed extensive single dish millimetre and JHK near-IR measurements of the nucleus and disk of NGC 6764. Here we present new near-IR observations obtained with the MPE FAST instrument (Rotaciuc et al. 1991) at the William Herschel Telescope, along with 2″ resolution 12CO J=1-0 (115 GHz) interferometry measured with the Nobeyama millimeter array and 1″ optical spectroscopy from the 3.5m Calar Alto telescope.

12CO (J=1−0) emission has been detected in the extremely extinguished galaxy NGC4418 with a 15″ beam on the 45-m telescope at the Nobeyama Radio Observatory. The inferred molecular mass is 4 108 MO at a distance of 25 Mpc. The CO line profile is single peaked with the FWHM of 85 km/s, suggesting that molecular clouds highly concentrate towards the center. For the column density estimated from these observations to be consistent with the extinction value 55 < Av < 120 derived from the 10μm silicate absorption by Roche et al (1986), most of the clouds should be confined within a central region of 3.8″ (500pc) in diameter, through which beam Roche et al detected the 10 and 20μm fluxes comparable to the IRAS ones.

We present the kinematics and dynamics of molecular gas in the almost entire disk (>5′×5') of the grand-design spiral galaxy M51, derived from CO(J=1−0) observations with the Nobeyama 45-m telescope. The spatial resolution of 17″, which corresponds to 790pc at the distance of M51 (9.6 Mpc), is enough to distinguish between a spiral arm and an interarm; therefore a clear spiral structure (cf Nakai et al, this conference) and large streaming motions of the molecular gas were revealed.

A number of starburst galaxies are included in the Atlas of Peculiar Galaxies (Arp 1966) which is the collection of peculiar-morphology galaxies showing mutual tidal interaction. A scenario of starburst can be summarized as follows (e.g. Sofue 1987, Noguchi 1988). Tidal interaction between galaxies causes an oval disturbance in the gravitational potential of a galaxy. The oval disturbance causes a bar in the innermost region of the galaxy. By this bar a galactic shock wave is excited, which results in rapid accretion of gas toward the central region. The accreted gas produces a dense ring or a core of molecular gas in the central region, from which massive stars are born. Intense UV radiation from the stars heats dust in the dense molecular gas core/ring, and the dust emits strong FIR emission.

We have mapped the nuclear region of an Scd galaxy IC 342 in the CO (J = 1-0) emission with an angular resolution of 15″. This galaxy has a bright optical nucleus with a dark lane elongated in the north-south direction. A prominent molecular bar which has been discovered by Lo et al. (1984) using the Owens Valley Interferometer lies just on the dark lane. Their CO map was spatially limited by the primary beam pattern and the velocity coverage of their spectrometer was not sufficient. It is not known, therefore, whether the molecular bar is connected to the outer spiral arms or not. We made the highest resolution CO map accessible by a single-dish telescope with a sufficient velocity coverage.