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Observation ID Observation Date Target Star Name Object Class Spectral Type B-V Magnitude RA (deg) DEC (deg) Exposure (s)
2746 2002-08-16 22:04:32 4U 1850-087 1A 1850-087 Ultracompact X-ray Binary undef 0.2000 283.270240 -8.705680 49749.76

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
51931 1.0438 severe
The zeroth-order image for 4U 1850-087

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 0.120 0.486 0.573
ACIS-I 0.154 0.662 0.740
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 1.117 0.007 1.482 0.000 2.081 0.001
Q-norm 0.106 0.001 0.153 0.000 0.231 0.000
ACIS-I keV 1.205 0.000 1.555 0.000 2.241 0.007
Q-norm 0.117 0.000 0.163 0.000 0.252 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
0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000

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
0.0000 0.0000 0.0000 0.0000 0.0004 1814.4606 0.0072 0.0000 0.0072 0.0000 220.1880 0.0528
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 4U 1850-087.
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 4U 1850-087. 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 4U 1850-087. 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) 0.060 50.000 1.531 0.14 4.57345e-11 1.29479 10.52 500
ACIS-S xswabs*(xsmekal1+xsmekal2) 0.258 2.815 1.000 0.25 1.90973e-13 0 1.30 76
ACIS-I xswabs*(xsmekal1+xsmekal2) 0.280 3.026 1.000 0.21 2.63152e-13 0 1.12 77
X-Atlas Spectral Fits Listing

LETG Light Curve

Image File Missing: LETG Light Curve
GLvary
Odds2.266
Prob.0.995
Var. Index7
LETG light curve for 4U 1850-087, constructed from all ±1st, ±2nd, and ±3rd order LETG events.

LETG LEG Spectrum

Image File Missing: High-Resolution 1st Order LEG spectrum of obsid 2746
High-Resolution 1st Order LEG Spectrum for 4U 1850-087

X-Atlas Data Products

Spectral Data
PHA II LEG ±1st Order PHA LEG ±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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