GBT14B-076

A GBT Survey of Neutral Atomic Hydrogen in the Galactic Centre Wind

Abstract

Using the Australia Telescope Compact Array (ATCA) we have discovered a population of neutral clouds entrained in the "Fermi Bubbles": the gamma-ray emitting regions produced by the wind flowing out from the Galactic Centre. The kinematics of the HI clouds as determined from their 21cm emission velocities suggests that they are accelerated in two cones away from the nucleus. We propose a GBT survey to measure this population over a large area more distant from the Galactic Centre than covered by the ATCA, and with greater sensitivity. The data will allow us to specify the geometry and velocity of the flow more precisely, place limits on neutral cloud lifetimes in a hot wind, and clarify the emission mechanism for the high energy radiation of the Fermi bubbles. As galactic winds are an essential feature of galaxy evolution, results from this study will have wide applicability to other environments.

Investigators

Name	Institution
Jay Lockman	Green Bank Observatory
Alyson Ford	Arizona, University of
Naomi McClure-Griffiths *	Australian National University
Roland Crocker	Australian National University; Max-Planck-Institut für Kernphysik
Vanessa Moss	Netherlands Institute for Radio Astronomy; Sydney, University of

* indicates the PI