X-ray Shadowing Experiments Toward Infrared Dark Clouds
arXiv:1008.0416 · doi:10.1088/0004-637X/721/2/1319
Abstract
We searched for X-ray shadowing toward two infrared dark clouds (IRDCs) using the MOS detectors on XMM-Newton to learn about the Galactic distribution of X-ray emitting plasma. IRDCs make ideal X-ray shadowing targets of 3/4 kev photons due to their high column densities, relatively large angular sizes, and known kinematic distances. Here we focus on two clouds near 30 deg. Galactic longitude at distances of 2 and 5 kpc from the Sun. We derive the foreground and background column densities of molecular and atomic gas in the direction of the clouds. We find that the 3/4 kev emission must be distributed throughout the Galactic disk. It is therefore linked to the structure of the cooler material of the ISM, and to the birth of stars.
Accepted to ApJ
References in corpus (9)
- The Boston University-Five College Radio Astronomy Observatory Galactic Ring Survey
- The VLA Galactic Plane Survey
- A Catalog of Galaxy Clusters Observed by XMM-Newton
- Kinematic Distances to Molecular Clouds identified in the Galactic Ring Survey
- Resolution of the Distance Ambiguity for Galactic HII Regions
- Suzaku Observations of the Local and Distant Hot ISM
- Xmm-Newton Observations of the Diffuse X-ray Background
- Comparing Suzaku and XMM-Newton Observations of the Soft X-ray Background: Evidence for Solar Wind Charge Exchange Emission
- An XMM-Newton Observation of the Local Bubble Using a Shadowing Filament in the Southern Galactic Hemisphere