The Coma supercluster is one of the largest, nearby (∼100h−1Mpc) gravitationally bound structures known in the universe. It comprises two large clusters of galaxies and several galaxy groups intersected by a complex network of filaments, providing the perfect laboratory for studying the evolution of galaxies in a range of ‘continuous’ environments. We characterised the different components of the environment to study the properties of galaxies in the optical and ultraviolet (UV) wavebands. Our analysis shows that galaxies experience accelerated evolution as they approach the spine of the filament, suggesting that the intermediate-density environment prevalent in the filaments can accelerate the evolution of galaxies.

Simulations expect an enhanced star-formation and active galactic nuclei (AGN) activity during galaxy mergers, which can lead to formation of binary/dual AGN. AGN feedback can enhance or suppress star-formation. We have carried out a pilot study of a sample of ˜10 dual nuclei galaxies with AstroSat’s Ultraviolet Imaging Telescope (UVIT). Here, we present the initial results for two sample galaxies (Mrk 739, ESO 509) and deep multi-wavelength data of another galaxy (Mrk 212). UVIT observations have revealed signatures of positive AGN feedback in Mrk 739 and Mrk 212, and negative feedback in ESO 509. Deeper UVIT observations have recently been approved; these will provide better constraints on star-formation as well as AGN feedback in these systems.

The focus of this work is on two topics: (i) formation of complex organic molecules (COMs) and (ii) isotope fractionation. Various COMs, which are C, H-containing molecules consisting of 6 atoms and more, have been detected in the central warm region of protostellar cores. Most of this review is about gas-grain chemical models, which have been constructed to evaluate the mechanisms and efficiency of the COM formation. The relevant physical and chemical processes are investigated in laboratory experiments, as reported in other articles in this volume.

The isotope fractionation of volatile elements is observed in both the interstellar medium (ISM) and Solar system material. While exothermic exchange reactions enrich molecules with heavier isotopes such as Deuterium, the isotope selective photodissociation can be coupled with ice formation to enrich the ice mantle with rare isotopes. The efficiency of this fractionation depends on the photodesorption yields, which has been studied in laboratory experiments.

Dwarf irregular galaxies are places of ongoing star-formation in the low-redshift Universe. Low metallicity dwarfs were originally thought to be the youngest galaxies in the local Universe, however, there is now evidence that they consist of matter which has previously undergone evolution and is enriched by star-formation. Here we present a sample of seven nearby metal-poor dwarf galaxies with a young stellar populations selected from the SDSS which we study using integral field unit (IFU) data from the VIMOS instrument, covering the spectral range between the He II 4686 line and the [SII] 6718/6733 Å doublet. We present property maps across the galaxies and compare different galaxies and different HII regions within the same galaxy. We find that the properties within one galaxy are not uniform and they also differ between different galaxies concerning star-formation, kinematics and metallicity and morphology. The observed differences across individual galaxies together with disturbed kinematics and morphologies can be interpreted as possible signs of recent interactions and/or mergers. Additionally, we present a comparison of different metallicity calibrations and search for systematic differences obtained using different methods.

MERLIN observations of 6.668-GHz Methanol and 6.035-GHz OH emission from the known massive star-formation region ON1 are presented. Maser components are found to lie at the southern edge of the UCHII with consistent polarization angles across the strongest features. Zeeman splitting of OH shows magnetic field strengths between +0.4 to −5.3 mG and from cross-correlation a tentative methanol magnetic field of −18mG is detected.

OH masers are sensitive probes of the kinematics and physical conditions, and give unique information on the magnetic field through their polarization. Zeeman splitting of the OH lines can give the magnetic field strength and direction. Observing OH masers with MERLIN we studied the bipolar outflow in the star-forming region ON1, which hosts one of the earliest known ultra-compact (UC) HII regions. The strongest masers lie near the southern edge of the UCHII region in an elongated distribution. The maser distribution is orthogonal to the bipolar outflow seen in HCO+, suggesting that the OH masers may be embedded in a molecular disk or torus around a young B0.3 star, most likely tracing a shock front. An isolated group of 1720-MHz masers is also seen to the East. The magnetic field deduced from Zeeman splitting of the OH maser lines shows a large-scale order, with field values ranging from -0.4 to -4.6 mG. These results add to the growing body of evidence for OH masers associated with molecular disks or tori at the centre of bipolar outflow from massive young stars, and for a significant role played by the magnetic field in generating or channeling the bipolar outflow. Further details are presented by Nammahachak et al. 2006.