View X-Atlas Observation

Observation ID	Observation Date	Target	Star Name	Object Class	Spectral Type	B-V Magnitude	RA (deg)	DEC (deg)	Exposure (s)
2571	2002-09-04 14:54:52	ZETA OPH	HD 149757	Be Star	O9.5Vnn	0.0190	249.289750	-10.567090	35414.61

Chandra Configuration for the Observation

Zeroth-Order Image

Zeroth-Order Events	Zeroth-Order Count Rate (cts/s)	Pileup
3156	0.0891	severe

The zeroth-order image for ZETA OPH

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	-0.746	-0.269	-0.846
ACIS-I	-0.706	-0.067	-0.737

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	0.723	0.005	0.854	0.000	1.000	0.007
ACIS-S	Q-norm	0.055	0.001	0.072	0.000	0.091	0.001
ACIS-I	keV	0.781	0.004	0.913	0.002	1.088	0.007
ACIS-I	Q-norm	0.062	0.001	0.080	0.000	0.102	0.001

Normalized quantiles (Q-norm) are defined as:

Q_x = (E_x - E_lo)/(E_hi - E_lo)

Where E_lo = 0.3 keV and E_hi = 8.0 keV.

Hardness Ratio plots and Quantile-based Color-Color Diagrams

X-Atlas Hardness Ratios and Quantiles Listing

Spectral Metrics

A series of line-line, line-continuum, and continuum-continuum ratios calculated from the high-resolution 1^st 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
4.0851	2.8871	0.0000	0.0000	0.6327	0.8961	0.0561	0.0330	0.0523	0.0567	0.0684	0.0907	0.0105	0.0355

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
0.0937	0.0164	0.0557	0.0180	0.1595	0.0248	0.9688	0.0122	1.0275	0.0136	16.4929	0.2984

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 ZETA OPH.
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 ZETA OPH. 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 ZETA OPH. 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)	0.018		0.618		0.010		0.11		0	0	1.02	79
ACIS-S	xswabs*(xsmekal1+xsmekal2)	0.207		0.618		0.176		1.50		1.61425e-13	1.42269	1.06	52
ACIS-I	xswabs*(xsmekal1+xsmekal2)	0.207		0.595		0.099		1.50		3.15108e-13	3.46928	1.45	51

X-Atlas Spectral Fits Listing

HETG Light Curve

GLvary
Odds	-1.529
Prob.	0.029
Var. Index	0

HETG light curve for ZETA OPH, constructed from all ±1^st, ±2^nd, and ±3^rd order HETG events.

HETG HEG Spectrum

Image File Missing: High-Resolution 1st Order HEG spectrum of obsid 2571

High-Resolution 1st Order HEG Spectrum for ZETA OPH

HETG MEG Spectrum

Image File Missing: High-Resolution 1st Order MEG Spectrum of obsid 2571

High-Resolution 1st Order MEG Spectrum for ZETA OPH

X-Atlas Data Products

Spectral Data
PHA II	HEG ±1^st Order PHA	HEG ±1^st Order gARF	MEG ±1^st Order PHA	MEG ±1^st 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 ARF		Aimpoint RMF
ACIS-S	ACIS-I	ACIS-S	ACIS-I

Retrieve observation data from the Chandra Data Archive: WebChaSeR

Target Preview