Weighing the Local Interstellar Medium using Gamma Rays and Dust
The ratio between the gas and dust densities in galactic environments is among the most important parameters in understanding star formation and galaxy evolution. Typical constraints on this ratio stem from radio observations of dust emission and absorption, as well as radio line emission from standard gas tracers. We develop an entirely new method based on gamma-ray observations, which trace the convolution of the well-measured local cosmic-ray density and the well-measured high-latitude gamma-ray emission intensity. We obtain results that are consistent with many previous studies, but depend on an entirely independent set of systematic uncertainties. Moreover, our results have the precision to untangle the tension in previous world leading measurements, quantitatively improving our models of local gas and dust.
Read MoreResearch Topics
- Highlights and Overview
- Dark Matter(66)
- Galactic Center Excess(19)
- Gamma-Ray Searches(16)
- Multiwavelength(8)
- Cosmic-Rays Searches(12)
- Dark Matter Models(20)
- Axion Dark Matter(2)
- Astrophysics(65)
- TeV Halos(18)
- Gamma-Ray Astronomy(26)
- Cosmic-Ray Astronomy(12)
- Radio Astronomy(5)
- Neutrino Astronomy(4)
- Solar Physics(6)
- X-Ray Binaries(7)