SUPERNOVA REMNANTS
IN THE
MAGELLANIC CLOUDS
JOHN R. DICKEL
UNIVERSITY OF NEW MEXICO
AND
ROSA MURPHY WILLIAMS
COLUMBUS STATE UNIVERSITY
Preliminary SNR tables at:
http://hoth.ccssc.org/mcsnr/test.php
SNR IDENTIFICATION
• EXTENDED GENERALLY SHELL -LIKE OBJECT 0.2 PC FOR 1987A TO 158 PC FOR DEM L203
(1 PC IS 4 ARCSEC AT THE LMC AND 3.4 ARCSEC
AT THE SMC)
• NON THERMAL RADIO SPECTRA - TYPICAL
SPECTRAL INDICES,  = -0.5,
WHERE Sf = const f
• THERMAL X-RAYS - TYPICAL TEMP ~ 1 keV
WITH A LARGE SPREAD
• CAVEAT - PULSAR WIND NEBULAE HAVE
FLATTER RADIO SPECTRA AND NON-THERMAL
HIGH ENERGY X-RAY TAILS
• [S II]/ Ha > 0.4
= -0.48
DEM L81
= 0.0
X-RAY SPECTRUM OF N103 SNR
(usually incorrectly called N103B)
THIS SHOWS THE THERMAL NATURE OF THE EMISSION
LEWIS, K. ET AL. 2003 ApJ, 582, 770
SNR MCELS J0521-6542
3 COLOR
[S II]
H
RATIO
[S II]/H
TYPE CLASSIFICATION OF
MAGELLANIC CLOUD SNRS
CORE COLLAPSE:
PRESENCE OF A PULSAR OR OTHER COMPACT REMAINS
IN A REGION OF YOUNG STARS
OXYGEN RICH
TYPE Ia:
XRAY SPECTRA SHOW LINES OF HIGHLY IONIZED
INTERMEDIATE MASS ELEMENTS
BALMER DOMINATED IN OPTICAL
0540-693 - A PROTOTYPE COMPOSITE SNR
50-MSEC PULSAR, PWN, O-RICH SHELL,
ORGANIZED POLARIZATION IN THE PWN
6-CM RADIO IMAGE
N157B ANOTHER COMPOSITE
Radio - contours are
2,3,4,6,7 nJy/beam
X-ray - contours are
5,10,20,30,40,100,300,600
counts from 0.1-10 keV
The shell can be seen faintly on the southern part of the radio image.
The 16-msec X-Ray pulsar is at the center of the bright X-Ray
contours and at the position of the cross in the radio image.
SPECTRUM OF N157B
IT WILL BE VERY DIFFICULT TO MAKE ONE CONTINUOUS
SPECTRUM FOR THIS OBJECT
X-RAY SPECTRUM OF N103 SNR
NOTE THE MANY LINES OF HIGHLY
IONIZED INTERMEDIATE-MASS ELEMENTS
LEWIS, K. ET AL. 2003 ApJ, 582, 770
H LINE PROFILE TOWARD THE
TYPE Ia BALMER-DOMINATED SNR 0519-675
UNEQUILIBRATED VELOCITY 1180 KM/S
EQUILIBRATED 1580 KM/S
SMITH, R. C. ET AL. 1991, ApJ, 375, 652
JY/BEAM
N19 AREA IN THE SMC
RED: X-RAY CONTOURS GREYSCALE: 13-CM RADIO
N19 AREA IN THREE WAVELENGTHS
H22 cm Radio
1.5 - 8 keV X-ray
SOME STATISTICS
LMC
SMC
49
19
CORE COLLAPSE
12
4
TYPE Ia
6
1
UNKNOWN
31
14
TOTAL NUMBER OF SNRS
STANDARD STATISTICS EXPECTED IN IRREGULAR
GALAXIES PREDICT ABOUT 10% TYPE Ia SNe.
RADIO LUMINOSITY vs DIAMETER FOR LMC SNRs
slope -1.13
corr coef 0.08
1987A
DEM L71
CONCLUSION: THERE IS NO CORRELATION OF
LUMINOSITY WITH DIAMETER
(IN AGREEMENT WITH PREVIOUS STUDIES)
X-RAY - RADIO LUMINOSITIES OF LMC SNRs
DEM
DEM L71
L71
slope 0.77
corr. coeff 0.41
CONCLUSION: BRIGHTER X-RAY EMISSION MAY, IN
GENERAL, CORRESPOND TO BRIGHTER RADIO BUT
THERE IS NO CLEAR CORRELATION
CHANDRA IMAGE OF CAS A
1.1 keV
2keV
5 keV
X-RAY IMAGE AND RADIO CONTOURS OF
THE OXYGEN RICH SNR N132D,
THE BRIGHTEST LMC RADIO SOURCE
SNR 1E0102-72.3 in the Small Magellanic Cloud
radio X-ray
optical in the light of [O III] characteristic of oxygen rich SNRs
Note that the radio shell lies outside the X-ray one – an unusual
condition in shell SNRs.
THE MAGELLANIC CLOUD CANDIDATES ARE
ABOUT 20 TIMES FURTHER AWAY THAN CAS A SO
THE REQUIRED SENSITIVITY NEEDS TO BE
INCREASED BY A FACTOR OF 400.
THE INTERNATIONAL X-RAY OBSERVATORY (IXO)
WILL BE ABOUT 100 TIMES MORE SENSITIVE
THAN CHANDRA THEREFORE WITH MODESTLY
LONGER EXPOSURES THE FIRST TASK FOR IXO
SHOULD BE TO FIND THE COOLING NEUTRON
STARS IN N132D AND 1E0102-723.
THE REWARD FOR DOING SO: A BOTTLE OF
EITHER DICKEL TENNESSEE WHISKEY OR
GRUET NEW MEXICO CHAMPAGNE
Preliminary SNR tables at:
http://hoth.ccssc.org/mcsnr/test.php
Please send us references, new data, etc.
We will eventually get proper pages for
each SNR.