Photometric studies on globular cluster systems in early-type galaxies are widely used to resolve stellar populations in these galaxies. The knowledge of the age and metalicity structure within the globular cluster systems allows to set constraints on the major star formation episodes in the galaxy. Here we present our method of detecting age sub-populations in globular cluster systems based on optical/near-infrared observations and Monte-Carlo simulations. It is based on the determination of the cumulative age distribution and its comparison to simulated globular cluster systems. On various galaxies we will demonstrate the ability of our method to detect age sub-populations and show how we use the derived age structure to find correlations between various galaxy parameters and the formation/evolution of a given galaxy.

We present the result of the analysis of the point-by-point correlation between the radio continuum (RC) and CO intensities from kpc to sub-kpc scales in 22 BIMA SONG galaxies and the point-by-point correlation at sub-kpc scales between the RC, CO and 24 μm-IR emissions in 6 galaxies for which Spitzer images have been recently released. We found that there is no significant variation of the slope and the scatter of the correlations at this spatial resolution. All three correlations are comparably tight with scatter of less than a factor of two.

Compact groups are highly isolated, dense galaxy systems, and therefore tidal interactions are expected to be continuous and dynamically important. For this reason they represent unique laboratories for studying interactions in extreme environments and tidally induced star formation as well as morphological and dynamical evolution of galaxies in general. This study is part of a broader investigation of the evolutionary status of HCGs. In order to explain the HI deficiency found in compact groups of galaxies we have proposed a broad evolutionary scenario in which the amount of HI decreases with the secular evolutionary state of a group. The fate of this gas is however not clear. In order to investigate the physical mechanisms responsible for these changes in the gas content of galaxies we have started a study to look for an intragroup medium (IGM). We have considered this IGM to be neutral (see e.g. reports of HI clouds within Virgo cluster (Oosterloo & Van Gorkom 2005), or hot gas (a higher X-ray detection rate of HI deficient groups is found relative to groups with a normal HI content, Verdes-Montenegro et al. 2001). Enhanced star formation activity might also be contributing to exhausting the gas supply. We have observed 25 HCGs with diverse HI content and distribution with the Green Bank radiotelescope, and performed VLA-HI as well as X-ray (XMM or Chandra) observations of the most HI deficient groups HCG 7, 15, 30, 37, 40, 44 and 97. We have also analysed FIR data from Verdes-Montenegro et al. (1998).

Our results are: (a) HI deficient groups show a larger amount of diffuse neutral and X-ray gas when compared to non-deficient ones, consistent with our evolutionary picture; (b) Most groups are still deficient after including diffuse gas. (c) A hot IGM is not detected in most of these systems, but the detection rate is higher for the high velocity dispersion groups, and in these cases ram pressure stripping could potentially cause the observed HI-deficiency. (d) In several of these groups we detect intragroup radio continuum emission, which is surprising since similar features were seen previously only in massive clusters (known as “relic” sources). (e) Star formation activity traced by FIR luminosity is not enhanced, contrary to the general expectation of tidally interacting systems.

Hence neither the presence of a hot or cold IGM nor star formation activity seem to be able to uniquely explain the HI deficiency found in compact groups of galaxies. We plan to explore the possibility that earlier starbursts could have contributed to the present HI deficiency.

We present Spitzer/MIPS far-infrared (FIR) mapping of O-rich AGB star, R Hya.

We present a star cluster population study in the interacting galaxy system M51 based on HST ACS BV I mosaic images taken by the Hubble Heritage Team to commemorate the HST's 15th anniversary. We have found and classified star clusters in M51 using SExtractor and visual inspection. We have derived the photometry, size, and age of the clusters. It is found that the companion SB0 galaxy NGC 5195 harbors about 50 faint fuzzy clusters and that the age distribution of star clusters appears to be correlated with the epochs of dynamical events in M51 system.

We have analyzed the level and type of nuclear activity in 720 galaxies belonging to a large complete sample of Compact Groups (UZC-CGs). We have found that most (67%) galaxies show emission lines and that the most frequent (43%) nuclear activity is AGN. AGNs are mainly hosted in bright early type galaxies and early spirals, at variance with HII which reside in late spirals of lower luminosity. CGs which have a dominant content of AGNs and TOs have larger σv and lower Rp than CGs dominated by HII.

We have recently obtained optical spectra for a large sample of young and intermediate-age star clusters in several nearby galaxies. The main aim of this programme is to carry out a detailed test of photometric and spectroscopic age- and metallicity indicators, but a first inspection of the data has also revealed emission lines in 3 clusters with ages of 30 Myrs or older. We identify these three objects as likely Planetary Nebula (PN) candidates and discuss their properties. Based on the cluster ages, the progenitor stars had initial masses in the range 3 to 7 M⊙, while the PN central stal luminosities and temperatures (estimated from emission line fluxes) are consistent with current masses close to 0.60 M⊙. These objects represent a rare opportunity to study PNe whose progenitor stars are known to be of intermediate masses, although detailed analysis is challenging because of the strong underlying stellar continuum from the cluster stars. Detection of 3 PNe in our sample appears consistent with expectations from stellar evolutionary theory.

This summary of JD13, Exploiting large surveys for Galactic astronomy, is based on the talks that were given during the meeting and/or submitted to the full proceedings which appeared in MemSAI 77 no. 4, 2006. The electronic version of this MemSAI volume also has the abstracts and images of the posters that were displayed and discussed during JD13. Here can only be listed their titles and authors. A panel discussion followed the talks, and a summary of the topics covered is added. Finally, there come the concluding remarks.

Methanol masers and UCHII regions trace massive star formation sites. We have undertaken a mid-IR survey of 17 regions containing methanol masers and UCHIIs in order to locate the young stellar sources associated with them. The images were obtained from 8.7 to 18.8 μm with the mid-IR camera CID (Salas et al. 2003) on the 2.1m telescope of the Observatorio Astronomico Nacional at San Pedro Martir (Baja California, Mexico). The images were taken with a scale 0.55″/pix and the mean PSF was 1.5-2.0″(FWHM) close to the diffraction limit. We report as an example in Fig. 1 (left panel) our 18.8μm contours of IRAS 06061+2151 superimposed to the 2MASS Ks image. A young cluster of at least 4 sources has been found centered on the IRAS source (Anandarao et al. 2004). We have found two mid-IR sources coinciding with the source #2 and #4 of Anandarao et al. (2004). The source #4 is at the center of two H2 knots and a high velocity molecular outflow. The mid-IR emission from #2 is extended and coincides with the UCHII and MSX source. The methanol maser is approximately 10″ south of the source #2. The SEDs of both sources are illustrated in Fig. 1 (right panel). The IR spectral indices of source #2 and #4 are α(IR)=1.9 and 2.2 respectively.

We present a powerful new tool to disentangle the 3-D geometry and kinematic structure of gaseous nebulae. The method consists of combining commercially available digital animation software to simulate the 3-D structure and expansion pattern of the nebula with a dedicated, purpose built rendering software and graphical user interface that produce the final images and long slit spectra which are compared to the real data.

The shaping of Pre-planetary nebulae (PPN) and Planetary Nebulae (PN) is believed to result from the interaction of a fast, collimated post-AGB wind (CFW) plowing into the slow, dense wind emitted during the AGB phase, followed by an isotropic tenuous wind during the PN phase (Sahai & Trauger 1998). The expanding shell which forms the PPN and later the PN is expected to produce extended X-ray emission due to the large speed of the fast wind and resulting high temperatures in the shocked gas. X-ray emission was only detected in 3 of 60 PNs observed with ROSAT, followed by a few more from CHANDRA and XMM (e.g. Guerrero et al. 2005). In the case of PPNs, there is so far only one confirmed X-ray detection (Sahai et al. 2003), although many have been observed with CHANDRA. The general problem of understanding the formation and shaping of PNs has been addressed analytically and numerically (see Balick & Frank 2002, and references therein). X-ray emission is one of the most direct probes of the fast wind and the interaction process which drives PN formation. However, this probe has not been fully exploited in previous modeling studies. Very recently, Akashi et al. (2006, hereafter ASB06) used analytical, self-similar, spherically symmetric models to address this problem. We are performing numerical simulations with the hydrodynamics code FLASH varying the basic parameters of the fast and slow wind over an extensive parameter grid and computing the X-ray emission as a function of these parameters and the time history of the fast wind.

We present the first results from a project to map Giant Molecular Clouds (GMCs) in the 12CO J=2-1, 13CO J=2-1, and 12CO J=3-2 lines using the Heinrich Hertz Submillimeter Telescope (HHT) at the University of Arizona. We mapped nearly 2.5 sq. deg of W3 and 1.0 sq. deg of W51 in the J=2-1 lines. We have begun mapping in the J=3-2 line. We achieve angular resolutions of 33″ and 24″ in the J=2-1 and J=3-2 lines with 1.3 and 0.9 km s−1 resolution.

Joint Discussion 14 was held at the General Assembly of the International Astronomical Union from August 17 until 23 in the beautiful Bohemian capital, Prague. The blueprints for this meeting were laid out during the MODEST-5 workshop, held in the Canadian city of Hamilton, Ontario in August 2004. We were sitting in a nice cafe with local brew and food, discussing the future of the MODEST community when we posed the idea for this Joint Discussion at the General Assembly. The meeting was then coined MODEST-7.

3-D Voronoi's tessellation method has been applied for identifying groups of galaxies in the structure of the Local Supercluster and evaluation of its properties.

We present preliminary results of a wide-field spectroscopic study on star clusters in the spiral galaxy M 33. We derive for 42 star clusters both age and metallicity using the principles of the Bayesian statistic and the Lick indices. We find that M 33 globular clusters in our sample are relatively young (∼8 – 9 Gyr), none of them being as old as the oldest Galactic counterparts. This implies that this galaxy started forming most of its star clusters after the main episode of star formation took place in the big Local Group galaxies (Milky Way, M 31 and LMC), possibly together with the SMC.

We studied ~ 2 deg2 region in the Shapley Supercluster (SSC) core at z~0.05 in two bands (B and R). By studying the galaxy luminosity function (LF) and the colour distribution of galaxies we find that processes directly related to the supercluster environment are responsible for transforming faint galaxies, rather than galaxy merging.

Bok globules, optically opaque small dark clouds, are classical examples of isolated star formation. However, the collapse mechanism for these cold, dense clouds of gas and dust is not well understood. Observations of Bok globules include some which appear to be starless while others harbor single stars, binaries and even small groups of forming stars. One example of a Bok globule forming a group of stars is CB 34, observed with both the IRAC and MIPS instruments as part of the Spitzer Young Cluster Survey. Based on initial analysis of 1-8 μm photometry from IRAC and the Two Micron All Sky Survey (2MASS), we identified 9 Class 0/I and 14 Class II young stellar objects within the small, 4.5′ × 4.5′ region encompassing CB 34. This unusually high number of protostars compared with Class II sources is intriguing because it implies a high rate of star formation. Therefore we have begun a larger study of this region in order to determine why and how CB 34 started forming stars at such a high rate. Is CB 34 embedded within a larger HII region which may have triggered its collapse or does it appear to have collapsed in isolation from outside influences?

Here we are reporting the detection of HCO$^+$ ($J=1\rightarrow 0$) emission as well as weak emission of CO($J=1\rightarrow 0$) toward the planetary nebula (PN) K 3-35 as a result of a molecular emission survey carried out toward this source. K 3-35 is remarkable because it is one of the two PNe that are known to exhibit water maser emission. In this nebula, the emission is present in the central region as well as at a distance of $\simeq$ 5000 AU away from the center. The presence of molecular emission reveals some clues that could lead to the understanding of the persistence of water molecules in its envelope. We also report new spectra of the CO ($J=2\rightarrow 1$) transition. From the CO emission we have obtained a value for the excitation temperature of the molecular gas of $\simeq$ 20 K. Using this result, we have estimated a molecular mass for the envelope of $\simeq$0.017 $M_{\odot}$, and that the abundance for the HCO$^{+}$ is 6.1 $\times 10^{-7}$.

I provide some background about recent efforts made in modeling dense stellar systems, within the context of the MODEST initiative. During the last four years, we have seen more than fifteen MODEST workshops, with an attendance between twenty and a hundred participants, and topics ranging from very specialized discussions to rather general overviews.