Letters of Intent received in 2016

LoI 2018-1893
Dwarf Galaxies: From the Deep Universe to the Present

Topics

Local Group Dwarf Galaxies
• Differences/Insights: satellite galaxies, ultra-faint dwarfs, gas-rich systems
• Near-field cosmology
• Proper motion studies and the dynamical evolution of dwarfs

The Interstellar Medium (ISM) and Star Formation in Dwarfs
• Kinematics: random gas motions, pressure support, coherent circular velocity?
• Star formation feedback and the ISM
• Star formation at extremely low masses and/or low metallicities

Metallicity and Chemical Evolution
• Star-formation feedback, galactic winds, mass loading
• Luminosity-Metallicity relation for low-mass galaxies
• Changes in ISM, CO, dust, and star formation as a function metallicity

The Dwarf Galaxy – Environment Connection
• Variations in the faint end of the luminosity function in different environments
• Stellar/tidal streams, interacting and merging dwarfs
• AGN and the starburst mode of star formation in dwarfs

Low-Mass Galaxies at High Redshift
• Discovery and classification via imaging, spectroscopy, and gravitational lensing models
• Physical properties (stellar and gas masses, metallicity, SFRs) and their evolution as a function of time
• The luminosity function of dwarfs at high z.

Dwarfs as Cosmological Probes
• Dark matter content and profiles
• Epoch of reionization: dwarfs as contributors and tracers
• Constraints on LCDM: comparison between theoretical predictions and observations (e.g., too big to fail, missing satellite problem)

Future Prospects
• New telescope missions including: JWST, SKA precursor HI Surveys, IFU Surveys, E-ELT, GMT, TMT, LSST, ALMA, GAIA
• New cosmological and hydrodynamic simulation efforts

Potential Session Headings:
• Local Group Dwarf Galaxies
• Stellar, ISM, and Chemical Evolution of Dwarfs
• The Role of Environment
• Dwarfs at High Redshift
• Dwarfs a Cosmological Probes

Rationale

Dwarf galaxies have long served as excellent, individual laboratories for studying star formation, feedback processes, gas kinematics, and chemical enrichment in the local universe. As community interest in dwarfs has gained momentum, the study of dwarf galaxies has broadened to encompass larger questions themed around structure formation, stellar mass assembly, and the role environment plays in galaxy evolution. Now that cosmological simulations of structure formation are finally capable of resolving dwarf galaxies in increasingly larger cosmological volumes, the worlds of dwarf galaxy theory and observations are at a crossroads.

Our growing body of knowledge on dwarfs is diverse and stretches back to early cosmic times. For example, satellites at increasingly lower masses in the Local Group have placed limits on the effects of reionization. These dwarf galaxies are now not only seen as analogs to galaxies in the early universe, but they have become direct probes of the earliest epochs of star formation. Nearby galaxy studies have begun to statistically populate the faint-end of the luminosity function, bridging the gap in the baryonic Tully-Fisher relation between dwarf spheroidals and irregulars but also revealing environmental variations. The burgeoning samples of extremely metal-poor star-forming dwarfs have opened new avenues of research on star formation in pristine environments, creating tension with our current understanding of stellar feedback and the retention of baryons at low masses. The expanding physical volume probed by current telescopes means the properties and histories of isolated dwarfs can be compared in environments ranging from dwarf galaxy associations, dwarfs in groups, stellar streams, and directly interacting systems. The numbers of observed dwarfs can further be compared to cosmological simulations as direct tests of the Lambda Cold Dark Matter paradigm.

At the same time, advancements in observational techniques have moved us into the era of direct observations of dwarfs at high redshift, including studies of dwarf galaxies directly contributing to the reionization the universe. For example, dwarf galaxies in the mass range of 107-108 Msun are now being studied out to redshift 6; this is an area poised for significant potential growth. Such observational advances have been paralleled by large chemo- and hydro-dynamical simulations that are now resolving structures on dwarf galaxy mass-scales over critical cosmic timescales for galaxy evolution.

In this symposium, our goal is to integrate the current knowledge of dwarf galaxies across multiple distance scales and multiple communities, to build not only a consistent picture of low-mass systems across cosmic time but to also synthesize cosmological constraints from dwarf galaxy populations. The meeting will incorporate (i) detailed studies of Local Group satellites, (ii) star formation, feedback, gas kinematics, and chemical enrichment (or lack thereof) in nearby dwarfs, (iii) the properties of dwarfs at high-redshift, (iv) hydrodynamical simulations and cosmological models of low-mass structures. The symposium coincides with the commencement of a number of key telescope missions including JWST, SKA precursor HI Surveys, IFU surveys, E-ELT, GMT, LSST, ALMA, and GAIA and the recent advent of big simulations such as Illustris and Eagle capable of resolving the history and structure of dwarf galaxies within a cosmologically representative setting. Thus, discussion on the pivotal challenges and opportunities for dwarf galaxy research in the changing observational landscape will be highly encouraged. The format of the symposium aims to balance oral contributions from junior and senior astronomers, favor longer talks with sufficient time allocated for discussion, and include thematic, dedicated poster sessions.

There is a broad base of interest for a dwarf galaxy symposium. Below, we provide a list of leading astronomers from across the globe who support this symposium, many of whom will comprise the SOC or be invited speakers.

Elias Brinks (University of Hertfordshire), Jay Gallagher (University of Wisconsin), Francois Hammer (Observatoire Paris), Gerhard Hensler (University of Vienna), Helmut Jerjen (Australian National University), Janice Lee (STScI), Thorsten Lisker (Heidelberg University), Polis Papaderos (University of Porto), Reynier Peletier (Kapteyn Astronomical Institute), Simone Recchi (University of Vienna), Fabian Walter (MPIA)