View X-Atlas Observation

Observation ID	Observation Date	Target	Star Name	Object Class	Spectral Type	B-V Magnitude	RA (deg)	DEC (deg)	Exposure (s)
1387	1999-10-06 17:38:28	SN 1987A	LMC SN	Supernova	Sm...	0.1800	83.866670	-69.270030	68791.35

Chandra Configuration for the Observation

Zeroth-Order Image

Zeroth-Order Events	Zeroth-Order Count Rate (cts/s)	Pileup
577	0.0084	none

The zeroth-order image for SN 1987A

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	-0.197	-0.153	-0.339
ACIS-I	-0.137	0.188	0.054

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	0.664	0.010	0.956	0.009	1.424	0.016
ACIS-S	Q-norm	0.047	0.001	0.085	0.001	0.146	0.002
ACIS-I	keV	0.869	0.011	1.190	0.025	1.686	0.030
ACIS-I	Q-norm	0.074	0.001	0.116	0.003	0.180	0.004

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
13.0944	64.0518	0.0000	0.0000	0.0000	0.0000	0.6317	3.8559	2.1269	9.4992	1.0300	4.3301	0.6400	3.8322

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
0.4947	0.2244	0.3062	1.4697	0.8338	1.4869	1.8039	0.1498	3.7340	0.6350	0.9346	0.1595

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 SN 1987A.
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 SN 1987A. 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 SN 1987A. 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		4.391		0.010		80.12		3.03452e-13	0	2.18	20
ACIS-S	xswabs*(xsmekal1+xsmekal2)	0.010		2.860		0.227		0.00		1.46804e-13	0.598809	1.54	67
ACIS-I	xswabs*(xsmekal1+xsmekal2)	0.010		2.908		0.651		0.02		1.83772e-13	0.952853	1.98	68

X-Atlas Spectral Fits Listing

HETG Light Curve

GLvary
Odds	245.863
Prob.	1.000
Var. Index	10

HETG light curve for SN 1987A, 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 1387

High-Resolution 1st Order HEG Spectrum for SN 1987A

HETG MEG Spectrum

Image File Missing: High-Resolution 1st Order MEG Spectrum of obsid 1387

High-Resolution 1st Order MEG Spectrum for SN 1987A

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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