We present a detailed spectroscopic study of the hot gas in the Galactic halo toward the direction of a blazer PKS 2155-304 ( z = 0.117 ) .
The O \emissiontype VII and O \emissiontype VIII absorption lines are measured with the Low and High Energy Transmission Grating Spectrographs aboard Chandra , and the O \emissiontype VII , O \emissiontype VIII , and Ne \emissiontype IX emission lines produced in the adjacent field of the PKS 2155-304 direction are observed with the X-ray Imaging Spectrometer aboard Suzaku .
Assuming vertically exponential distributions of the gas temperature and the density , we perform a combined analysis of the absorption and emission data .
The gas temperature and density at the Galactic plane are determined to be 2.5 ( +0.6 , -0.3 ) \times 10 ^ { 6 } K and 1.4 ( +0.5 , -0.4 ) \times 10 ^ { -3 } cm ^ { -3 } and the scale heights of the gas temperature and density are 5.6 ( +7.4 , -4.2 ) kpc and 2.3 ( +0.9 , -0.8 ) kpc , respectively .
These values are consistent with those obtained in the LMC X-3 direction .