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. PI-1 UMA in Obsid 23 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. PI-1 UMA in Obsid 23 is circled in red on the plot.

Hardness Ratios for PI-1 UMA, Obsid 23
Aimpoint	HR₁ = (H-M)/(H+M)	HR₂ = (M-S)/(M+S)	HR₃ = (H-S)/(H+S)
ACIS-S	-0.361	-0.349	-0.630
ACIS-I	-0.259	-0.137	-0.382

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 PI-1 UMA, Obsid 23

Aimpoint Quantiles 25 % 25 % Error 50 % 50 % Error 75 % 75 % Error
ACIS-S keV 0.737 0.004 0.854 0.001 1.073 0.007

Q-norm 0.057 0.001 0.072 0.000 0.100 0.001
ACIS-I keV 0.796 0.000 0.942 0.004 1.307 0.011

Q-norm 0.064 0.000 0.083 0.001 0.131 0.001

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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 PI-1 UMA, Obsid 23
Aimpoint	Quantiles	25 %	25 % Error	50 %	50 % Error	75 %	75 % Error
ACIS-S	keV	0.737	0.004	0.854	0.001	1.073	0.007
ACIS-S	Q-norm	0.057	0.001	0.072	0.000	0.100	0.001
ACIS-I	keV	0.796	0.000	0.942	0.004	1.307	0.011
ACIS-I	Q-norm	0.064	0.000	0.083	0.001	0.131	0.001