J/MNRAS/431/2453 SN1996cr radio observations (Meunier+, 2013)
Performing a stellar autopsy using the radio-bright remnant of SN 1996cr.
Meunier C., Bauer F.E., Dwarkadas V.V., Koribalski B., Emonts B.,
Hunstead R.W., Campbell-Wilson D., Stockdale C., Tingay S.J.
<Mon. Not. R. Astron. Soc., 431, 2453-2463 (2013)>
=2013MNRAS.431.2453M 2013MNRAS.431.2453M
ADC_Keywords: Supernova remnants ; Radio sources
Keywords: methods: numerical- circumstellar matter- supernovae: general -
supernovae: individual: SN 1996cr - stars: winds, outflows
Abstract:
We present newly reduced archival radio observations of SN 1996cr in
the Circinus Galaxy from the Australia Telescope Compact Array and the
Molonglo Observatory Synthesis Telescope, and attempt to model its
radio light curves using recent hydrodynamical simulations of the
interaction between the supernova (SN) ejecta and the circumstellar
material (CSM) at X-ray wavelengths. The radio data within the first
1000d show clear signs of free-free absorption (FFA), which decreases
gradually and is minimal above 1.4GHz after day ∼3000. Constraints
on the FFA optical depth provide estimates of the CSM free electron
density, which allows insight into the ionization of SN 1996cr's CSM
and offers a test on the density distribution adopted by the
hydrodynamical simulation. The intrinsic spectral index of the
radiation shows evidence for spectral flattening, which is
characterized by α=0.852±0.002 at day 3000 and a decay rate
of Δα=-0.014±0.001yr-1. The striking similarity in
the spectral flattening of SN 1987A, SN 1993J and SN 1996cr suggests
this may be a relatively common feature of SNe/CSM shocks. We adopt
this spectral index variation to model the synchrotron radio emission
of the shock, and consider several scalings that relate the parameters
of the hydrodynamical simulation to the magnetic field and electron
distribution. The simulated light curves match the large-scale
features of the observed light curves, but fail to match certain
tightly constraining sections. This suggests that simple energy
density scalings may not be able to account for the complexities of
the true physical processes at work, or alternatively, that the
parameters of the simulation require modification in order to
accurately represent the surroundings of SN 1996cr.
Description:
Bauer et al. (2008ApJ...688.1210B 2008ApJ...688.1210B) provide radio data up to 2007.
However, since more data exist for comparison, and some of the data
presented in Bauer et al. (2008ApJ...688.1210B 2008ApJ...688.1210B) were rereduced to
clean up artefacts and incorporate a larger array of calibration data,
we detail the data reduction procedures here. The data presented here
supersede those of Bauer et al. (2008ApJ...688.1210B 2008ApJ...688.1210B)
Numerous observations of the Circinus Galaxy exist from studies at
radio wavelengths spanning 1995 to 2011 (e.g., Elmouttie et al.
1995MNRAS.275L..53E 1995MNRAS.275L..53E; Greenhill et al. 1997ApJ...474L.103G 1997ApJ...474L.103G; Phillips et
al. 1998MNRAS.300.1131P 1998MNRAS.300.1131P; Jones et al. 1999MNRAS.302..649J 1999MNRAS.302..649J; McCallum et
al. 2005AJ....129.1231M 2005AJ....129.1231M, 2009MNRAS.392.1339M 2009MNRAS.392.1339M; Wilson et al.
2011MNRAS.416..832W 2011MNRAS.416..832W). These were retrieved from the Australia
Telescope Compact Array (ATCA) archive1 and were reduced with miriad
(v4.0.5 and v20110616) following the procedures outlined in the ATNF
Miriad User Manual.
Objects:
-------------------------------------------------------------
RA (ICRS) DE Designation(s)
-------------------------------------------------------------
14 13 10.05 -65 20 44.8 SN1996cr = CXOU J141310.0-652044
-------------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 175 71 ATCA Radio observations (Australia Telescope
Compact Array)
tablea1.dat 141 71 Flux densities of Calibrators
tablea2.dat 140 73 Flux densities of the nucleus
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Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "date" Obs.Date Starting date of observation
12- 13 I2 --- Ep [1/14]? Epoch number whose data were combined,
as described in Sec. 3.2.
16- 19 I4 d Time [-120/5791] Days from explosion date
21- 26 A6 --- ObsID Observing program ID
28- 33 A6 --- Array Array configuration
35- 39 I5 MHz Freq1 [88632]?=0 Observed W band mean frequency (3)
41- 45 F5.2 mJy Sint1 ?=0 Integrated flux density in band W (1)
47- 50 F4.2 mJy e_Sint1 ?=0 rms uncertainty on Sint1 (2)
52- 56 I5 MHz Freq2 [34496]?=0 Observed Ka band mean frequency Ka
58- 62 F5.2 mJy Sint2 ?=0 Integrated flux density in band Ka (1)
64- 67 F4.2 mJy e_Sint2 ?=0 rms uncertainty on Sint2 (2)
69- 73 I5 MHz Freq3 [16960/23659]?=0 Observed K band mean frequency
75- 79 F5.2 mJy Sint3 ?=0 Integrated flux density in band K (1)
81- 85 F5.2 mJy e_Sint3 ?=0 rms uncertainty on Sint3 (2)
87- 90 I4 MHz Freq4 [6024/9000]?=0 Observed X band mean frequency
91 A1 --- l_Sint4 Limit flag on Sint4
92- 97 F6.2 mJy Sint4 ?=0 Integrated flux density in band X (1)
99-103 F5.2 mJy e_Sint4 ?=0 rms uncertainty on Sint4 (2)
105-108 I4 MHz Freq5 [4786/5500]?=0 Observed C band mean frequency
109 A1 --- l_Sint5 Limit flag on Sint5
110-115 F6.2 mJy Sint5 ?=0 Integrated flux density in band C (1)
117-121 F5.2 mJy e_Sint5 ?=0 rms uncertainty on Sint5 (2)
123-126 I4 MHz Freq6 [2100/2768]?=0 Observed S band mean frequency
127 A1 --- l_Sint6 Limit flag on Sint6
128-133 F6.2 mJy Sint6 ?=0 Integrated flux density in band S (1)
135-139 F5.2 mJy e_Sint6 ?=0 rms uncertainty on Sint6 (2)
141-144 I4 MHz Freq7 [1376/1664]?=0 Observed L band mean frequency
145 A1 --- l_Sint7 Limit flag on Sint7
146-151 F6.2 mJy Sint7 ?=0 Integrated flux density in band L (1)
153-157 F5.2 mJy e_Sint7 ?=0 rms uncertainty on Sint7 (2)
159-162 I4 MHz Freq8 [843]?=0 Observed UHF band mean frequency (4)
164-169 F6.2 mJy Sint8 ?=0 Integrated flux density in band UHF (1)
171-175 F5.2 mJy e_Sint8 ?=0 rms uncertainty on Sint8 (2)
--------------------------------------------------------------------------------
Note (1): Integrated flux densities, as determined from UVFIT or IMFIT in
Miriad, or 3σ upper limits, as determined from IMSTAT in Miriad.
Note (2): Uncertainties include both statistical and systematic error terms.
The systematic error is estimated from the ratio of the measured calibrator
fluxes over its estimated historical value based on monitored light curves
(typical variance was 5-20%).
Note (3): 89GHz data provided by Ott (Private communication).
Note (4): 843MHz data provided by Campbell-Wilson/Hunstead.
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Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "date" Obs.Date Starting date of observation
12- 17 A6 --- ObsID Observing program ID
19- 26 A8 --- Cal Calibrator
28- 32 I5 MHz Freq2 [34496]?=0 Observed K band mean frequency
34- 39 F6.2 mJy Sint2 ?=0 Integrated flux density in band Ka (1)
41- 45 F5.2 mJy e_Sint2 ? rms uncertainty on Sint2
47- 51 I5 MHz Freq3 [16960/23659]?=0 Observed K band mean frequency
53- 59 F7.2 mJy Sint3 ?=0 Integrated flux density in band K (1)
61- 65 F5.2 mJy e_Sint3 ? rms uncertainty on Sint3
67- 70 I4 MHz Freq4 [6024/9000]?=0 Observed X band mean frequency
72- 78 F7.2 mJy Sint4 ?=0 Integrated flux density in band X (1)
80- 84 F5.2 mJy e_Sint4 ? rms uncertainty on Sint4
86- 89 I4 MHz Freq5 [4786/5500]?=0 Observed C band mean frequency
91- 97 F7.2 mJy Sint5 ?=0 Integrated flux density in band C (1)
99-103 F5.2 mJy e_Sint5 ? rms uncertainty on Sint5
105-108 I4 MHz Freq6 [2100/2496]?=0 Observed S band mean frequency
110-116 F7.2 mJy Sint6 ?=0 Integrated flux density in band S (1)
118-122 F5.2 mJy e_Sint6 ? rms uncertainty on Sint6
124-127 I4 MHz Freq7 [1376/1664]?=0 Observed L band mean frequency
129-135 F7.2 mJy Sint7 ?=0 Integrated flux density in band L (1)
137-141 F5.2 mJy e_Sint7 ? rms uncertainty on Sint7
--------------------------------------------------------------------------------
Note (1): Integrated flux densities in units of mJy as measured by UVFIT in
MIRIAD.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "date" Obs.Date Starting date of observation
12- 17 A6 --- ObsID Observing program ID
19- 23 I5 MHz Freq1 [88632]?=0 Observed Wa band mean frequency
25- 29 F5.2 mJy Sint1 ?=0 Integrated flux density in band Wa (1)
31- 34 F4.2 mJy e_Sint1 ?=0 rms uncertainty on Sint1
36- 40 I5 MHz Freq2 [34496]?=0 Observed Ka band mean frequency
42- 46 F5.2 mJy Sint2 ?=0 Integrated flux density in band Ka (1)
48- 51 F4.2 mJy e_Sint2 ?=0 rms uncertainty on Sint2
53- 57 I5 MHz Freq3 [16960/23659]?=0 Observed K band mean frequency
59- 64 F6.2 mJy Sint3 ?=0 Integrated flux density in band K (1)
66- 70 F5.2 mJy e_Sint3 ?=0 rms uncertainty on Sint3
72- 75 I4 MHz Freq4 [6024/9000]?=0 Observed X band mean frequency
77- 82 F6.2 mJy Sint4 ?=0 Integrated flux density in band X (1)
84- 88 F5.2 mJy e_Sint4 ?=0 rms uncertainty on Sint4
90- 93 I4 MHz Freq5 [4786/5500]?=0 Observed C band mean frequency
95- 99 F5.2 mJy Sint5 ?=0 Integrated flux density in band C (1)
101-104 F4.2 mJy e_Sint5 ?=0 rms uncertainty on Sint5
106-109 I4 MHz Freq6 [2100/2768]?=0 Observed S band mean frequency
111-116 F6.2 mJy Sint6 ?=0 Integrated flux density in band S (1)
118-122 F5.2 mJy e_Sint6 ?=0 rms uncertainty on Sint6
124-127 I4 MHz Freq7 [1376/1664]?=0 Observed L band mean frequency
129-134 F6.2 mJy Sint7 ?=0 Integrated flux density in band L (1)
136-140 F5.2 mJy e_Sint7 ?=0 rms uncertainty on Sint7
--------------------------------------------------------------------------------
Note (1): Integrated flux densities as measured by UVFIT or IMFIT in Miriad.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 16-Jun-2014