sleuthing the ejecta/csm geometry of a 30 mo · sleuthing the ejecta/csm geometry of a 30 mo sn dan...
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SN 1996cr light-curve on "Immler&Kuntz ('05)" plot
Modeling SN 1996cr's X-ray lines at high-resolution:Sleuthing the Ejecta/CSM Geometry of a 30 MO SN
Dan Dewey (MIT Kavli Inst.), F.E. Bauer (PUC-Chile), V.V. Dwarkadas (U Chicago)
DD was supported by NASA through SAO contract SV3-73016 to MIT for Support of the Chandra X-Ray Center (CXC) and Science Instruments. Support for FEB's work was provided by NASA through the Chandra Guest Observing program from the CXC. Support for VVD's work was provided by NASA through Chandra Award Number GO9-0086B issued by the CXC. The CXC is operated by the Smithsonian Astrophysical Observatory for and on behalf of NASA under contract NAS8-03060.
SN 1996cr, located in the Circinus Galaxy,was non-detected in X-rays at ~ 2 years,yet brightened to Lx ~ 4x1039 erg/s (0.5-8 keV) after 10 years.
Bauer et al. (2008)Circinus Galaxy(2MASS JHK)
24"0.43 kpc
vHI ~ 434 +/-3 km/szvel = 0.001448
3.7 MpczHubble ~ 0.001
SN 1996cr
4
SN 1996cr
0.5-2 keV87A
?
?
= O-rich
dia ~ 0.01"
A 1-D hydro model of theejecta-CSM interation producesgood agreement with the measured X-ray light curves and spectra at multiple epochs.
We conclude that SN 1996cr was most likelya massive star, M > 30 solar masses, which wentfrom an RSG to a brief W-R phase before explodingwithin its r ~ 0.04 pc wind-blown shell.
small densityvariation
1051 erg4.5 MO
CSM:wind-blown bubble
~ 0.6 MO in shell. .
10-20, 10-6 to 10-4
(Fransson+ 1996)
1k-2.5k, 10-5 to 10-4
(Chiosi&M '86)
Hydro- Allowed Region for
'96cr Wind 2 --suggests W-R phase
Dwarkadas et al. (2010) "DDB10"
Further analysis of deep Chandra HETG observations (PI Bauer, 485 ks) allows line-shape fitting of a handful of bright lines in the spectrum.
opaquecore
high kT
lower kT
DDB'10: 1-D Ejecta - CSM Configuration
t0 = 1995.4
shoc
ked e
jecta
blastwave
-CSM
effect ofsmall density
variation
Data and Hydro-X-Ray lightcurves
Energy (keV)
Si lines (l) and Fe lines (r) are best-fit with different Polar models
Si Fe
Fe XXIV low-E line has similar values as the Si:
this suggests a kTvariation, instead of an abundance
variation.
The higher kT Fe-K emission is mostly at high lattitudes; this may be the result of either lower CSM densities or higher ejecta velocities near the poles. Similar CSM characterization may be possible around other SNe and, with higher-throughput X-ray observations, GRBs as well.
The detailed line shapesare well fit by "Polar" emissionmodels with opening angles of~60 (Si) and ~20 (Fe) degrees,viewed off-axis at ~55 degrees.
Bauer et al. (in prep.)
.
High-velocity oxygenlines at ~ 10 years
He-like
H-like
LRF LRF
FeXXIV
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