Splinter Meeting ISM

Confronting simulations of the interstellar medium with observations and measurements

Convenor(s): Michael Schulreich, Dieter Breitschwerdt
TU Berlin

The interstellar medium (ISM) is highly turbulent, consists of multiple phases, and is characterized by complicated, mutually interacting structures on all resolvable spatial and temporal scales. As such, it can only be treated in its full non-linear complexity by means of numerical simulations, whose resolution, domain size, and number of included dimensions and physical processes goes hand in hand with the progress in computational capabilities. Depending on the volume range considered (and hence on the smallest region resolved), current works can be roughly divided into three classes: small-scale, meso-scale, and large scale. A physically realistic three-dimensional model that covers all dynamical ranges of an entire star-forming galaxy is still out of reach, though there are efforts to achieve this to some degree by coupling the adaptive mesh refinement technique with zoom-ins to specific regions.
As technology advances, also observations have improved dramatically in both depth and resolution, enriching our knowledge about the ISM as a whole and putting constraints on theoretical models and simulations. In the last few years these have been specifically X-ray observations to cover the hot ISM, (far-)infrared, submillimeter and radio facilities such as Spitzer, Herschel, ALMA, IRAM, SOFIA, LOFAR and many others to map star formation regions. In addition, a new branch of research, deep-sea astronomy, has been established during the past two decades, which is dedicated to the search and analysis of radioisotopic signatures of cosmic events, such as recent nearby supernova explosions, in the ocean floor, thus posing additional constraints for models of the ISM, at least in our Galactic neighbourhood.
The aim of this splinter meeting is to bring together the large ISM community, draw on its wealth of experience in all those fields by sharing experiences and ideas, and summarize our current observational and theoretical understanding of the ISM. Key topics include (but are not limited to):

  • strategies of comparing observations, measurements, and simulations; translation of observables into diagnostic parameters of the ISM, such as gas density, gas temperature, strength of the magnetic and radiation field, etc.
  • cosmic rays as the high energy component of the ISM
  • magnetic fields, interaction with plasma and particles, magnetic reconnection
  • interaction of runaway stars and high-velocity clouds with the ISM
  • energy sources and sinks, e.g. supernovae, stellar winds, radiative cooling etc.
  • structure and evolution of the local ISM as derived from dust measurements (interstellar extinction; radioisotopic anomalies on Earth and Moon) and from tracing star clusters back in time ("Galactic archeologyā€¯)
  • ISM in different Hubble type galaxies, nearby and at high redshift
  • new numerical schemes applied in state-of-the-art ISM simulations; numerical challenges encountered during code development and how these can be addressed

Related contributions *)

*) submitted abstracts, acceptance pending.