Target Preview

Observation ID Observation Date Target Star Name Object Class Spectral Type B-V Magnitude RA (deg) DEC (deg) Exposure (s)
3738 2003-08-12 20:59:02 Sigma Ori HD 37468 Double or multiple star O9.5V+B0.5V -0.2400 84.686500 -2.600060 90967.74

Chandra Configuration for the Observation

Zeroth-Order Image

Image File Missing: Snapshot of the Zeroth-Order Image
Zeroth-Order Events Zeroth-Order Count Rate (cts/s) Pileup
2894 0.0318 mild
The zeroth-order image for Sigma Ori

Hardness Ratios and Quantiles

Hardness ratios and quantiles are calculated from the predicted ACIS-S or ACIS-I aimpoint spectra, as indicated.
Hardness Ratios
Aimpoint HR1 = (H-M)/(H+M) HR2 = (M-S)/(M+S) HR3 = (H-S)/(H+S)
ACIS-S -0.838 -0.535 -0.948
ACIS-I -0.808 -0.329 -0.898
S, M, and H represent the predicted total counts in the following passbands:
S: 0.3-0.9 keV
M: 0.9-1.5 keV
H: 1.5-8.0 keV
Quantiles
Aimpoint Quantiles 25 % 25 % Error 50 % 50 % Error 75 % 75 % Error
ACIS-S keV 0.635 0.000 0.767 0.000 0.898 0.006
Q-norm 0.044 0.000 0.061 0.000 0.078 0.001
ACIS-I keV 0.708 0.000 0.840 0.007 0.971 0.007
Q-norm 0.053 0.000 0.070 0.001 0.087 0.001
Normalized quantiles (Q-norm) are defined as:
Qx = (Ex - Elo)/(Ehi - Elo)
Where Elo = 0.3 keV and Ehi = 8.0 keV.
Hardness Ratio plots and Quantile-based Color-Color DiagramsX-Atlas Hardness Ratios and Quantiles Listing

Spectral Metrics

A series of line-line, line-continuum, and continuum-continuum ratios calculated from the high-resolution 1st order MEG or LEG spectrum.
Line-Line Ratios
Ne X / O VIII Ne2O Error O VII(i) / O VII(f) Oif Error O VII(r) / O VIII O78 Error O VIII / Fe XVII O8Fe Error Mg XII / Fe XVII Mg2Fe Error Si XIV / Fe XVII Si2Fe Error S XV / Fe XVII S2Fe Error
1.1473 0.9436 0.0000 0.0000 0.2890 0.2368 0.1026 0.0420 0.0085 0.0541 0.0000 0.0000 0.0133 0.0154

short line / cont
Line-Continuum & Continuum-Continuum Ratios
sl2c Error long line / cont ll2c Error line / cont l2c Error cont long / cont short cl2cs Error cont long / cont med cl2cm Error cont med / cont short cm2cs Error
0.1786 0.0665 0.2557 0.0811 0.4516 0.1057 3.8423 0.2086 4.1094 0.2383 14.3839 0.9598
X-Atlas Spectral Metrics Listing

Spectral Fits

Image File Missing: 2T xsmekal zeroth-order fit
Mewe-Kaastra-Liedahl 2-temperature fit of the low-resolution zeroth-order spectrum of Sigma Ori.
Warning: The zeroth-order spectrum may be subject to distortions from pileup.

Image File Missing: 2T xsmekal ACIS-S fit
Mewe-Kaastra-Liedahl 2-temperature fit of the predicted low-resolution ACIS-S Aimpoint spectrum of Sigma Ori. The predicted spectrum was scaled to 1500 counts.

Image File Missing: 2T xsmekal ACIS-I fit
Mewe-Kaastra-Liedahl 2-temperature fit of the predicted low-resolution ACIS-I Aimpoint spectrum of Sigma Ori. The predicted spectrum was scaled to 1500 counts.

Aimpoint Model nH (1022/cm3) nH error kT (keV) kT error kT2 (keV) kT2 error Abundance (solar) Abundance error Flux (ergs/cm2/s) Flux Emission Ratio (kT2/kT1) Reduced Chi2 DoF
zeroth-order xswabs*(xsmekal1+xsmekal2) 1.258 0.043 0.010 925.27 0 0 12.29 64
ACIS-S xswabs*(xsmekal1+xsmekal2) 0.053 0.561 0.229 0.75 7.36675e-14 2.93205 1.51 46
ACIS-I xswabs*(xsmekal1+xsmekal2) 0.053 0.687 0.253 0.18 1.57217e-13 8.08288 1.24 47
X-Atlas Spectral Fits Listing

HETG Light Curve

Image File Missing: HETG Light Curve
GLvary
Odds-0.771
Prob.0.145
Var. Index0
HETG light curve for Sigma Ori, constructed from all ±1st, ±2nd, and ±3rd order HETG events.

HETG HEG Spectrum

Image File Missing: High-Resolution 1st Order HEG spectrum of obsid 3738
High-Resolution 1st Order HEG Spectrum for Sigma Ori

HETG MEG Spectrum

Image File Missing: High-Resolution 1st Order MEG Spectrum of obsid 3738
High-Resolution 1st Order MEG Spectrum for Sigma Ori

X-Atlas Data Products

Spectral Data
PHA II HEG ±1st Order PHA HEG ±1st Order gARF MEG ±1st Order PHA MEG ±1st Order gARF [Counts/s/Å] FITS [Counts/s/Å] text [ph/s/Å/cm2] FITS [ph/s/Å/cm2] text
Standard Data Products (Cycle 06)
Aimpoint ARFAimpoint RMF
ACIS-SACIS-IACIS-SACIS-I
Retrieve observation data from the Chandra Data Archive: WebChaSeR
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