A High Spectral Resolution Observation of the Soft X-ray Diffuse Background with Thermal Detectors
Abstract
A high spectral resolution observation of the diffuse X-ray background in the 60 - 1000 eV energy range has been made using an array of thirty-six 1 mm^2 micro-calorimeters flown on a sounding rocket. Detector energy resolution ranged from 5-12 eV FWHM, and a composite spectrum of ~ 1 steradian of the background centered at l = 90, b = +60 was obtained with a net resolution of ~ 9 eV. The target area includes bright 1/4 keV regions, but avoids Loop I and the North Polar Spur. Lines of C VI, O VII, and O VIII are clearly detected with intensities of 5.4 +/- 2.3, 4.8 +/- 0.8, and 1.6 +/- 0.4 photons cm^-2 s^-1 sr^-1, respectively. The oxygen lines alone account for a majority of the diffuse background observed in the ROSAT R4 band that is not due to resolved extragalactic discrete sources. We also have a positive detection of the Fe-M line complex near 70 eV at an intensity consistent with previous upper limits that indicate substantial gas phase depletion of iron. We include a detailed description of the instrument and its detectors.
Cite
@article{arxiv.astro-ph/0205012,
title = {A High Spectral Resolution Observation of the Soft X-ray Diffuse Background with Thermal Detectors},
author = {D. McCammon and R. Almy and E. Apodaca and W. Bergmann Tiest and W. Cui and S. Deiker and M. Galeazzi and M. Juda and A. Lesser and T. Mihara and J. P. Morgenthaler and W. T. Sanders and J. Zhang and E. Figueroa-Feliciano and R. L. Kelley and S. H. Moseley and R. F. Mushotzky and F. S. Porter and C. K. Stahle and A. E. Szymkowiak},
journal= {arXiv preprint arXiv:astro-ph/0205012},
year = {2008}
}
Comments
To appear in The Astrophysical Journal