Abstract Details

Name: Aditi Vijayan
Affiliation: RRI
Conference ID: ASI2020_119
Title : Kinematic & Mutliwavelength Signature of Interacting Outflows
Authors and Co-Authors : Aditi Vijayan, L. Armillotta, C. G. Kim, M. Li, B. B. Nath, E. Ostriker, P. Sharma, Y. Shchekinov,
Abstract Type : Oral
Abstract Category : Extragalactic Astronomy
Abstract : Gas outflows generated due to stellar activity in a star forming galaxy are critical in understanding galaxy evolution. These outflows are multi-phase in nature, that is they are characterised by a wide temperature range. The fate of the gas once ejected- whether it turns back and falls back on the disk or escapes into the circumgalatic medium(CGM) - depends on its temperature (as well as density) and its interaction with other phases. To quantify the interactions between the phases, we analyse simulations of the local interstellar medium (ISM). We use ballistic approximation to study mass distribution of phases of the outflowing gas at different heights in the galaxy. According to the ballistic model, gas trajectories in outflows can be determined by conversion of kinetic energy into potential and vice versa. This approximation can be used to understand cloud trajectories upto ~100 km/s. For higher velocities, the approximation fails and we need to include the effect of mass and momentum exchange between phases. The effect of such an exchange is reflected in X-ray observations. We discuss results from large box 3-D hydrodynamic simulations of star formation in a galaxy. The region of interaction between the clumps of cold and hot gas are strong sources of soft X-rays. Hardening of X-rays near the disk indicates higher momentum exchange between the two phases. Finally, a holistic picture of feedback is incomplete without a discussion about non-thermal components of outflows. We also present results from simulations with magnetic field and its effect on cosmic ray electrons as well as a comparison with observed synchrotron halos of edge-on galaxies.