View X-Atlas Observation

Observation ID	Observation Date	Target	Star Name	Object Class	Spectral Type	B-V Magnitude	RA (deg)	DEC (deg)	Exposure (s)
2971	2002-03-21 04:19:07	3C 279	QSO B1253-05	Quasar	undef	0.0000	194.046520	-5.789350	106501.67

Chandra Configuration for the Observation

Zeroth-Order Image

Zeroth-Order Events	Zeroth-Order Count Rate (cts/s)	Pileup
24327	0.2284	severe

The zeroth-order image for 3C 279

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	0.100	0.132	0.229
ACIS-I	0.154	0.400	0.522

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	0.898	0.000	1.321	0.007	2.008	0.005
ACIS-S	Q-norm	0.078	0.000	0.133	0.001	0.222	0.001
ACIS-I	keV	1.073	0.003	1.482	0.000	2.387	0.009
ACIS-I	Q-norm	0.100	0.000	0.153	0.000	0.271	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
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
0.0030	0.0001	0.0002	0.0000	0.0032	0.0001	0.0106	0.0000	0.0108	0.0000	53.1078	0.0549

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 3C 279.
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 3C 279. 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 3C 279. 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		50.000		0.826		0.02		1.16668e-11	0.121198	1.65	485
ACIS-S	xswabs*(xsmekal1+xsmekal2)	0.040		16.332		0.352		0.07		1.11531e-13	0.052495	0.79	74
ACIS-I	xswabs*(xsmekal1+xsmekal2)	0.010		6.964		0.766		0.49		1.45536e-13	0.0291907	1.02	76

X-Atlas Spectral Fits Listing

HETG Light Curve

GLvary
Odds	8.820
Prob.	1.000
Var. Index	8

HETG light curve for 3C 279, 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 2971

High-Resolution 1st Order HEG Spectrum for 3C 279

HETG MEG Spectrum

Image File Missing: High-Resolution 1st Order MEG Spectrum of obsid 2971

High-Resolution 1st Order MEG Spectrum for 3C 279

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

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