Letters of Intent for 2015

LoI 2015-212
Focus Meeting: Meeting the Neighbours: The Magellanic System

Date: 4 August 2015 to 5 August 2015
Location: Honolulu, United States
Contact: Annie Hughes (hughes@mpia.de)
Coordinating division: Division H Interstellar Matter and Local Universe
Co-Chairs of SOC: Jean-Philippe Bernard (IRAP)
Erik Muller (NAOJ)
David Nidever (Uni. of Michigan)
Co-Chairs of LOC: Annie Hughes (MPIA)
Juergen Ott (NRAO)



* Dust: insights from SAGE/HERITAGE/Planck; sources of dust production in the Magellanic Clouds; composition and optical properties of dust in the Magellanic Clouds versus the Galaxy; polarisation and magnetic field results

* Interstellar gas, hot and cold: new views from ALMA and single-dish CO surveys; Chandra/XMM-Newton X-ray surveys; GALEX/SWIFT UV surveys, WHAM; Herschel spectroscopy of Magellanic HII regions; thermal phase balance in the atomic medium; progress and possibilities for astrochemistry in the low-metallicity Magellanic Clouds

* The interaction: proper motion measurement results; formation, ISM phases and enrichment of the Stream; the 3D structure of the interacting system; formation of the LMC bar; relationship to chemo-dynamical evolution of the Clouds

* Stars and clusters: stars in the halo and tidal tails; cluster evolution in the Clouds; the age-metallicity relationship of clusters and field stars; the stellar population of the Magellanic Bridge; the onset and progress of star formation at the different (low) metallicity regimes within the Clouds; resolved star formation histories of the LMC and SMC; IMF studies; the 3D structure of the Clouds; stellar remnants and compact objects; SN1987A

* The Magellanic System and cosmology: comparison to other Magellanic type dwarf galaxies and interaction systems; gas-phase metal abundances and BBN; new distance estimates to the Clouds; new insights into the properties of standard candles



Due to their proximity, the Magellanic Clouds provide an important extragalactic laboratory to study a diversity of astrophysical phenomena including star formation at low metallicity, the final stages of stellar evolution, the baryon fraction of galactic haloes, and the role of interactions in galaxy evolution. With a rich archive of multi-wavelength legacy datasets that can resolve individual stars and gas clouds, the Magellanic Clouds serve as a bridge between the Galactic and extragalactic regime for understanding problems such as the origin of Larson’s Laws, the stellar age-metallicity relationship, the Kennicutt-Schmidt relation and the radio-FIR correlation. For studies at higher redshift, the combination of the proximity and low metallicity of the Magellanic System makes it a unique nearby template for how galaxies assemble their mass and form stars in the early Universe.

The last IAU Symposium dedicated to the Magellanic Clouds occurred in 2007. Since then, a wealth of new observational data on the Clouds has been assembled, and the analysis of earlier observational efforts has continued apace. Examples include the SAGE and HERITAGE infrared surveys, UV surveys by GALEX and SWIFT, the VMC near-infrared photometric survey, wide-field X-ray surveys by XMM-Newton, proper motion and deep-imaging campaigns with the HST, submillimetre observations of dust emission and polarisation by Planck, a host of single-dish CO surveys that have been conducted in preparation for ALMA, as well as the first observational results from ALMA itself. Recent studies in the Magellanic System have continued to make major contributions to the wider discipline, with results that have fine-tuned the cosmological distance scale, tested the predictions of Big Bang Nucleosynthesis, and identified new agents of dust production in galaxies.

Nevertheless, the latest data have already raised new questions such as: What fraction of the cool interstellar gas is undetectable in traditional tracers like CO and HI? What causes the variations in dust emissivity between the Clouds and the Milky Way? What is the history and future of the interaction between the Clouds and the Milky Way? What is the age and origin of the stellar population in the Magellanic Bridge? What is responsible for the extended main-sequence turn-off in Magellanic star clusters? Does the IMF differ for field and cluster populations?

In light of these emerging puzzles and the wealth of new data at our disposal, it is timely to organize another meeting on the Magellanic System. The proposed meeting at the IAU GA will bring together the large international community that studies diverse aspects of the Magellanic System in a forum that aims to promote our understanding of the System as a whole.