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Observation ID Observation Date Target Star Name Object Class Spectral Type B-V Magnitude RA (deg) DEC (deg) Exposure (s)
3 1999-10-31 05:58:56 Theta-1 Ori A HD 37020 Triple System -- Variable Star B0.5V 0.0200 83.815950 -5.387250 49483.69

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
1853 0.0374 mild
The zeroth-order image for Theta-1 Ori A

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 -0.509 0.214 -0.331
ACIS-I -0.458 0.440 -0.021
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 0.810 0.013 1.015 0.005 1.263 0.011
Q-norm 0.066 0.002 0.093 0.001 0.125 0.001
ACIS-I keV 0.927 0.006 1.073 0.009 1.394 0.023
Q-norm 0.081 0.001 0.100 0.001 0.142 0.003
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

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
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 Theta-1 Ori A.
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 Theta-1 Ori A. 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 Theta-1 Ori A. 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) 0.237 2.622 1.020 0.30 1.34473e-12 0.749837 1.26 91
ACIS-S xswabs*(xsmekal1+xsmekal2) 0.000 30.000 1.076 0.27 1.4067e-13 7.15183 2.67 66
ACIS-I xswabs*(xsmekal1+xsmekal2) 0.000 7.357 1.021 0.26 1.97313e-13 6.99734 2.44 65
X-Atlas Spectral Fits Listing

HETG Light Curve

Image File Missing: HETG Light Curve
GLvary
Odds-0.225
Prob.0.373
Var. Index0
HETG light curve for Theta-1 Ori A, constructed from all ±1st, ±2nd, and ±3rd order HETG events.

HETG HEG Spectrum

Image File Missing: High-Resolution 1st Order HEG spectrum of obsid 3
High-Resolution 1st Order HEG Spectrum for Theta-1 Ori A

HETG MEG Spectrum

Image File Missing: High-Resolution 1st Order MEG Spectrum of obsid 3
High-Resolution 1st Order MEG Spectrum for Theta-1 Ori A

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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