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The MeerKAT (64 x 13.5m dish radio interferometer) is South Africa's precursor instrument for the Square Kilometre Array (SKA), exploring dish design, instrumentation, and the characteristics of a Karoo desert site and is projected to be on sky in 2016. One of two top-priority, Key Projects is a single deep field, integrating for 5000 hours total with the aim to detect neutral atomic hydrogen through its 21 cm line emission out to redshift unity and beyond. This first truly deep HI survey will help constrain fueling models for galaxy assembly and evolution. It will measure the evolution of the cosmic neutral gas density and its distribution over galaxies over cosmic time, explore evolution of the gas in galaxies, measure the Tully-Fisher relation, measure OH maser counts, and address many more topics. Here we present the observing strategy and envisaged science case for this unique deep field, which encompasses the Chandra Deep Field-South (and the footprints of GOODS, GEMS and several other surveys) to produce a singular legacy multi-wavelength data-set. [ABSTRACT FROM PUBLISHER]

Edge-on spiral galaxies offer a unique perspective on the vertical structure of spiral disks, both stars and the iconic dark dustlanes. The thickness of these dustlanes can now be resolved for the first time with Herschel in far-infrared and sub-mm emission. We present NHEMESES, an ongoing project that targets 12 edge-on spiral galaxies with the PACS and SPIRE instruments on Herschel. These vertically resolved observations of edge-on spirals will impact on several current topics.First and foremost, these Herschel observations will settle whether or not there is a phase change in the vertical structure of the ISM with disk mass. Previously, a dramatic change in dustlane morphology was observed as in massive disks the dust collapses into a thin lane. If this is the case, the vertical balance between turbulence and gravity dictates the ISM structure and consequently star-formation and related phenomena (spiral arms, bars etc.). We specifically target lower mass nearby edge-ons to complement existing Herschel observations of high-mass edge-on spirals (the HEROES project).Secondly, the combined data-set, together with existing Spitzer observations, will drive a new generation of spiral disk Spectral Energy Distribution models. These model how dust reprocesses starlight to thermal emission but the dust geometry remains the critical unknown.And thirdly, the observations will provide an accurate and unbiased census of the cold dusty structures occasionally seen extending out of the plane of the disk, when backlit by the stellar disk. To illustrate the NHEMESES project, we present early results on NGC 4244 and NGC 891, two well studies examples of a low and high-mass edge-on spiral. [ABSTRACT FROM PUBLISHER]

Interstellar dust is still a dominant uncertainty in Astronomy, limiting precision in e.g., cosmological distance estimates and models of how light is re-processed within a galaxy. When a foreground galaxy serendipitously overlaps a more distant one, the latter backlights the dusty structures in the nearer foreground galaxy.Such an overlapping or occulting galaxy pair can be used to measure the distribution of dust in the closest galaxy with great accuracy. The STARSMOG program uses Hubble to map the distribution of dust in foreground galaxies in fine (<100 pc) detail. Integral Field Unit (IFU) observations will map the effective extinction curve, disentangling the role of fine-scale geometry and grain composition on the path of light through a galaxy.The overlapping galaxy technique promises to deliver a clear understanding of the dust in galaxies: geometry, a probability function of dimming as a function of galaxy mass and radius, and its dependence on wavelength. [ABSTRACT FROM PUBLISHER]

Interstellar dust is still the dominant uncertainty in Astronomy, limiting precision in e.g., cosmological distance estimates and models of how light is re-processed within a galaxy. When a foreground galaxy serendipitously overlaps a more distant one, the latter backlights the dusty structures in the nearer foreground galaxy. Such an overlapping or occulting galaxy pair can be used to measure the distribution of dust in the closest galaxy with great accuracy. The STARSMOG program uses HST observation of occulting galaxy pairs to accurately map the distribution of dust in foreground galaxies in fine (<100 pc) detail. Furthermore, Integral Field Unit observations of such pairs will map the effective extinction curve in these occulting galaxies, disentangling the role of fine-scale geometry and grain composition on the path of light through a galaxy.The overlapping galaxy technique promises to deliver a clear understanding of the dust in galaxies: the dust geometry, a probability function of the amount of dimming as a function of galaxy type, its dependence on wavelength, and evolution of all these properties with cosmic time using distant, high-redshift pairs. [ABSTRACT FROM PUBLISHER]

Models of galaxy formation in a hierarchical universe predict substantial scatter in the halo-to-halo stellar properties, owing to stochasticity in galaxies’ merger histories. Currently, only few detailed observations of galaxy’s halos are available, mainly for the Milky Way and M31. The Galaxy Halos, Outer disks, Substructure, Thick disks and Star clusters (GHOSTS) HST survey is the largest study to date of the resolved stellar populations in the outskirts of disk galaxies and its observations offer a direct test of model predictions. Here we present the results we obtain for six highly inclined nearby Milky Way-mass spiral galaxies. We find a great diversity in the properties of their stellar halos. [ABSTRACT FROM PUBLISHER]