Target Preview

Observation ID Observation Date Target Star Name Object Class Spectral Type B-V Magnitude RA (deg) DEC (deg) Exposure (s)
2538 2002-07-10 11:27:42 V824 ARA HD 155555 Variable of RS CVn type K1Vp 0.7800 259.356240 -66.951120 94218.76

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
22896 0.2430 severe
The zeroth-order image for V824 ARA

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 -0.556 0.062 -0.512
ACIS-I -0.506 0.257 -0.286
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 0.796 7.204 0.971 0.000 1.205 0.001
Q-norm 0.064 0.936 0.087 0.000 0.117 0.000
ACIS-I keV 0.869 7.131 1.029 6.971 1.336 0.000
Q-norm 0.074 0.926 0.095 0.905 0.135 0.000
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
2.9465 1.8114 0.7816 1.1879 0.0802 0.0691 0.2407 0.1075 0.2447 0.0846 0.0973 0.0308 0.1023 0.0248

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
0.0044 0.0001 0.0025 0.0002 0.0076 0.0004 0.0184 0.0000 0.0185 0.0000 210.0090 0.4519
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 V824 ARA.
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 V824 ARA. 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 V824 ARA. 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) 0.000 3.530 0.802 0.26 1.14173e-11 0.363612 2.15 372
ACIS-S xswabs*(xsmekal1+xsmekal2) 0.054 1.804 0.668 0.28 7.00749e-14 1.32133 0.82 61
ACIS-I xswabs*(xsmekal1+xsmekal2) 0.005 1.483 0.653 0.27 1.14814e-13 1.16365 0.67 60
X-Atlas Spectral Fits Listing

HETG Light Curve

Image File Missing: HETG Light Curve
GLvary
Odds323.321
Prob.1.000
Var. Index10
HETG light curve for V824 ARA, constructed from all ±1st, ±2nd, and ±3rd order HETG events.

HETG HEG Spectrum

Image File Missing: High-Resolution 1st Order HEG spectrum of obsid 2538
High-Resolution 1st Order HEG Spectrum for V824 ARA

HETG MEG Spectrum

Image File Missing: High-Resolution 1st Order MEG Spectrum of obsid 2538
High-Resolution 1st Order MEG Spectrum for V824 ARA


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

Return to Search Page