X-ray Hardness and Quantiles

Hardness ratios calculated from the predicted ACIS-S Aimpoint spectra of selected X-Atlas targets (× = hot star; ◊ = cool star). S, M, and H are the total predicted counts in the passbands listed on the plot. Theta-1 Ori E in Obsid 4 is circled in red on the plot.

Hardness ratios calculated from the predicted ACIS-I Aimpoint spectra of selected X-Atlas targets (× = hot star; ◊ = cool star). S, M, and H are the total predicted counts in the passbands listed on the plot. Theta-1 Ori E in Obsid 4 is circled in red on the plot.

Hardness Ratios for Theta-1 Ori E, Obsid 4
Aimpoint	HR₁ = (H-M)/(H+M)	HR₂ = (M-S)/(M+S)	HR₃ = (H-S)/(H+S)
ACIS-S	-0.076	0.647	0.601
ACIS-I	-0.035	0.749	0.733

X-ray Quantiles

Quantile-based color-color diagram: (m = Q₅₀ = (E₅₀ - E_lo)/(E_hi - E_lo)). E_lo = 0.3 keV; E_hi = 8.0 keV

View complete listing of X-Atlas Spectral Metrics (Hardness, Quantiles).

Quantiles for Theta-1 Ori E, Obsid 4

Aimpoint Quantiles 25 % 25 % Error 50 % 50 % Error 75 % 75 % Error
ACIS-S keV 1.059 0.007 1.365 0.009 1.862 0.011

Q-norm 0.099 0.001 0.138 0.001 0.203 0.001
ACIS-I keV 1.117 0.007 1.424 0.009 1.876 0.013

Q-norm 0.106 0.001 0.146 0.001 0.205 0.002

Observation Preview

Chandra Configuration for the Observation

Return to Search Page

X-Atlas Home

ACIS-S hot stars JPG Postscript	ACIS-S cool stars JPG Postscript
ACIS-I hot stars JPG Postscript	ACIS-I cool stars JPG Postscript

Quantiles for Theta-1 Ori E, Obsid 4
Aimpoint	Quantiles	25 %	25 % Error	50 %	50 % Error	75 %	75 % Error
ACIS-S	keV	1.059	0.007	1.365	0.009	1.862	0.011
ACIS-S	Q-norm	0.099	0.001	0.138	0.001	0.203	0.001
ACIS-I	keV	1.117	0.007	1.424	0.009	1.876	0.013
ACIS-I	Q-norm	0.106	0.001	0.146	0.001	0.205	0.002