We stress the importance of Wolf-Rayet stars for the understanding of the AGN phenomenon in galaxies. WR stars provide an unique opportunity to explore from the ground whether non-thermal nuclear activity and circumnuclear starbursts are connected. We review the known reported WR signatures observed so far in AGNs and point out some intrincacies related to the analysis of the spectra, linked to reddening correction, the origin of the Hβ line, etc. Finally, we advocate that integral field spectroscopy is a very promising tool to study this problem and present preliminary results of a long-term project that have been obtained at the CFHT in 1998.

We present a 2D-hydrodynamical simulation of the gas flow generated by a starburst in a dwarf galaxy. We focus in particular on the ejection efficiency both of the ISM and of the metals produced during the burst. It turns out that while the galaxy is able to retain most of the ISM, a significant fraction of the metals is lost, supporting the differential wind scenario. A new burst may occur after ∼ 0.5-1 Gyr, when the central gas surface density approaches the critical value, during the post starburst gas replenishment.

In this work we study the very early phases of the evolution of our Galaxy by means of a chemical evolution model which reproduces most of the observational constraints in the solar vicinity and in the disk. We have restricted our analysis to the solar neighborhood and present the predicted abundances of several elements (C, N, 0, Mg, Si, S, Ca, Fe) over an extended range of metallicities [Fe/H] = −4.0 to 0.0 compared to previous models. We adopted the most recent yield calculations for massive stars taken from different authors (Woosley & Weaver 1995; Thielemann et al. 1996) and compared the results with a very large sample of data, one of the largest ever used to this purpose. We have obtained this by selecting the most rec.ent and higher quality abundance data from a number of sources and renormalizing them to the same solar abundances. These data have been analysed with a new and powerful statistical method which allows us to quantify the observational spread in measured elemental abundances and obtain a more meaningful comparison with the predictions from our chemical evolution model.

We present results of a panchromatic morphological study to determine how UV and Hα morphology relates to the underlying stellar populations, the ISM, and structure of nearby starbursts.

During their various evolutionary phases, stars enrich the interstellar gas (ISG) with chemical elements. In our study we investigate the effect of binaries on the chemical enrichment of the ISG. To derive the true yields for a population of single and binary stars we use a Population Number Synthesis code which is described in detail in Vanbeveren et al. (1998). We account for the enrichment through stellar wind (SW), supernova explosion (SN) of single and binary stars including type Ia, planetary nebula (PN), and through binary interaction (BI). When black hole (BH) formation occurs, it is assumed that all matter is swallowed by the hole. This happens for single stars with a mass larger than 25 M⊙ and for interacting binary components heavier than 40 M⊙. Type Ia SNe are treated according to the scenario of Li & van den Heuvel (1997). We conclude that including binaries: (a) increases the production of helium, up to a factor ∼ 1.8 for 100% binaries (note that the helium yield increases linearly with binary frequency); and (b) drastically changes the ratio of the relative helium to metallicity enrichment dY/dZ (even for Z = 0.02) resulting in values higher than 3.5 for binary frequencies ≥ 40%, which is in good agreement with the observations.

In order to study the influence of the environment in galaxies we have selected a sample from the catalog by Maia et al. (1994) which contains objects in low and high density areas of the Southern sky. These samples have been observed with the Brazilian-ESO 1.52m telescope and long-slit spectra are being analyzed. With our database we will be able to investigate the role of the environment in the galaxy population. We will be able to search for WR features and massive stars. It is our goal to compare the general properties of these galaxies with typical starburst galaxies which are dominated by episodes of massive star formation.

A detailed study of the stellar content of the giant H II region NGC 2363 and its surroundings in the Magellanic galaxy NGC 2366 is undertaken to understand the starburst phenomenon.

We investigate the kinematics of the luminous starburst galaxy NGC 7673 = Mrk 325, a nearby example of a ‘clumpy irregular galaxy’. Images with the WIYN 3.5m telescope reveal outer wisps associated with mergers, and we suggest NGC 7673 is the survivor of a minor merger. DensePak spectroscopy of the Hα kinematics shows that the H II regions are confined to a rotating disk. The Hα emission line velocity field indicates that although there is widespread star formation across the inner disk, it is still rotating smoothly. The Hα emission profiles over the brightest regions of the galaxy have two components: narrow, FWHM ≈ 50kms−1 lines, and broad, FWHMW ≈ 150 km s−1 lines. The width of the narrow lines is likely due to a combination of averaging effects, stellar winds and SNRs, and possibly gravitational motions within the disk. The origin of the broad component, which eclipses the narrow component in flux over much of the galaxy's inner regions, is still unclear. We may be looking at turbulent gas encased in bubbles carved out by massive stars and their descendants, or possibly some localized outflows from the disk.

We present spectroscopic mid-IR observations of prominent starburst galaxies obtained with the Short Wavelength Spectrometer onboard the Infrared Space Observatory. The wavelength range accessible by ISO-SWS (2.5–45 μm) contains a large number of emission lines of atomic and molecular hydrogen and several other atomic species. In this paper we discuss the interpretation of the [Ne III] 15.5 μm/[Ne II] 12.8 μm line-ratio, the faint [OIV]25.9 μm line and the pure rotational lines of molecular hydrogen observed in our target galaxies.

Star-formation in dwarf starburst galaxies can be quite intense for their sizes, especially in the very young ones characterized by Wolf-Rayet emission features. Since stars form out of molecular gas (H2), it is important to investigate in detail, where the molecular gas is relative to the star formation in such young starbursts. The molecular gas may also indicate what might have triggered the starburst. The ISM in dwarfs can be quite warm, is the molecular gas also warm? In an attempt to investigate the properties of molecular gas in WR galaxies we have obtained high resolution images of the J = 2–1 transitions of CO for two dwarf starbursts, NGC5253 and He2–10. Both galaxies are nearby dwarf starbursts with WR emission features (e.g., Conti 1991). NGC 5253 may be one of the youngest starbursts known (e.g., Rieke, Lebofsky & Walker 1988).

We present results of our optical spectroscopic observations and 12CO (J = 1 - 0) mapping of the Wolf-Rayet starburst galaxy Markarian 1259 with a superwind activity. We find that both the ionized gas and the molecular gas are associated with the superwind.

We present mid and far-infrared energy distributions of the CfA Seyfert sample, obtained with the Infrared Space Observatory photometer (ISO-PHOT). To analyse the CfA Seyfert SEDS, we apply an inversion method: the Inverse Planckian Transform, assuming that the mid- and far-IR emission is thermal. We obtain the spectral temperature distribution of sources that reproduces the observed SEDS. We compare the parameters of the spectral components found showing that there are not differences between Seyfert 1 and Seyfert 2 as for their temperatures while the emission between 12 and 25 μm is anisotropic.

A new radio image of the core of the starburst galaxy M82 is presented. A pair of probable galactic chimneys are evident. Such structures have been conjectured to result when a giant shell of ionized gas breaks out of the dense plane of a galaxy and ejects hot gas into the halo. In M 82, the starburst activity drives a galactic superwind and theoretical models of this process require a knowledge of the kinematics of the hot gas in the core of the galaxy. The results presented here imply that the ejection of material into the base of the superwind does not occur smoothly over the starburst region; instead, very localised venting of the hot gas appears to be taking place.

2D calculations of the evolution of the remnants generated by the strong mechanical energy produced by a central starburst in dwarf galaxies are presented. We show how the extended H I halos inhibit a galactic wind and thus the exit of metals from these galaxies.

The impact of chemical composition on the spectrum of stellar population formed in the starburst is studied. The range of metallicities Z = 0.0001–0.05–0.1 covers all the compositions observed; depending on age, wavelength region and IMF, the UV-fluxes differ between extreme compositions at least ten-fold or more. Independent of age, UV-fluxes shortwards of the Balmer jump monotonically decline with the growth of metallicity. The optical IR wavelenght region are also influenced, with fluxes at λ > 1 μm differing typically factors 10–50. In the IR the actually brightest emitting composition gets reversed with age.

We confirm the presence of compact H II regions in the center of the starburst in NGC 5253 through the detection of optically thick free-free emission. The number of O-type stars implied by the excitation of these nebulae is nearly two orders of magnitude larger than what is indicated by the radio continuum fluxes. The compact H II regions are located 70 pc to the north of the location of the Wolf-Rayet feature. Implied extinctions are extremely high. Not all WR galaxies can be identified as such due to extinction.

Starbursts, black holes and AGN have strong observational links, as discussed elsewhere in these proceedings. Perry & Dyson (1985 (PD), see also Perry 1994) studied the role of shocks around supernovae and stellar wind bubbles in the nuclei of active galaxies. Both the ejecta and the ambient ISM are initially shocked to high temperatures. PD found that while the shocked gas is maintained at high pressure by ram pressure, it cools rapidly, to then produce the observed optical and UV emission lines. The mass supply rate from the nuclear starburst, inferred from the strength of the emission lines, tallies well with that required by an accreting black hole to generate the observed luminosity. A symbiosis between a starburst stellar cluster and an accreting black hole naturally generates the observational features associated with QSOs.

By comparing the brightest red supergiants in IC 10 and IC 1613, we derive for IC 10 that EH-K = 0.24 ± 0.09mag (i.e., EB-v = 1.26 ± 0.19 mag) and a true distance modulus 24.0 ± 0.13 mag.

A personal perspective of the meeting is given.

On Monday before the regular meeting began, a group of 31 participants met for 5 hours to discuss HD 5980, a massive binary in which one of its components erupted in 1994 as a luminous blue variable (LBV). This made HD 5980 the most luminous star in all the SMC for about six months. The highlights of this session are presented here.