ATCA Observations of SN2001ig

Stuart Ryder & Kelly Kranz (AAO)
Elaine Sadler (University of Sydney)
Ravi Subrahmanyan (ATNF Narrabri)




This page contains an up-to-date record of multi-frequency observations of Supernova 2001ig obtained with the Australia Telescope Compact Array. The supernova was discovered by the Rev. Bob Evans on Dec 10.43 UT (IAUC 7772). Initial spectroscopy from LCO suggested it may be a Type IIb, similar to SN 1987K (IAUC 7772), while a NTT spectrum indicated it may be more akin to SN 1993J (IAUC 7781). At the request of Kurt Weiler (NRL), observations were first carried out at radio wavelengths on Dec 15 with the ATCA by S. Ryder and K. Kranz. A positive detection was recorded at 3cm, but only an upper limit could be determined at 6cm (IAUC 7777; click here to see the images). Initial monitoring took place at roughly 5 day intervals, using unallocated blocks of ATCA time, but later observations used blocks formally allocated to this project (C1066). The table below summarises results from all observations to date. An analysis of the data up to July 2003 has been published in Ryder et al. 2004, MNRAS, 349, 1093.

Due to poor phase stability at the higher frequencies, observations are scaled to reference values from Dec 15 2001 for the nearby source at RA=22h 57m 29.6s, Dec=-41o 02'40": S(8640 MHz) = 5.8 mJy, S(4790 MHz) = 12.9 mJy, S(2496 MHz) = 26.4 mJy, S(1376 MHz) = 47.0 mJy. Fluxes in mJy for the SN have been determined using the Miriad task uvfit to minimise uncertainties introduced by cleaning, phase stability, etc. Fields marked "..." indicate observations were taken, but data not yet reduced, or poor phase stability/limited observing time precludes a flux measurement. 

Beginning with the 11 July 2002 observation, the S-band observing frequency was changed from 2496 MHz, to 2368 MHz to reduce in-band interference. For a spectral index of -0.97 for the nearby source between L-band and S-band, the interpolated S(2368 MHz) = 27.8 mJy.
 
 

UT Date
Observer(s)
S(18.8 GHz)
S(8.6 GHz)
S(4.8 GHz)
S(2.4 GHz)
S(1.4 GHz)
2001-12-15
08h-14h
SR, KK
2.1 +/- 0.3
0.6 +/- 0.3
 ...
<0.8
2001-12-18
02h - 04h
SR, KK
3.9 +/- 1.6
1.6 +/- 0.2


2001-12-22
02.5h - 08h
RS
8.7 +/- 0.8
2.7 +/-0.3 


2001-12-26
02h - 08h
RS
15.0 +/- 3.0
4.8 +/- 0.3


2001-12-31
01h - 06h
SR, RS
43 +/- 4
...
6.3 +/- 0.3
<4.6
<1.8
2002-01-07
06h - 10.5h
SR, KK
...
10.6 +/- 0.3
...
...
2002-01-10
06.5h - 10.5h
RS
22 +/- 3
23.6 +/- 4.1
14.2 +/- 0.9


2002-01-15
06h - 11h
RS, SR, KK
11 +/- 4
18.9 +/- 5.6
15.1 +/- 0.7


2002-01-20
03h - 06h
RS


5.3 +/- 0.3
...
2002-02-02
03.5h - 07.5h
SR
9.9 +/- 2.2
18.4 +/- 4.4


2002-02-17
03.5h - 10h
RS
7.0 +/- 1.1
11.0 +/- 0.5


2002-02-26
0h - 06h
RS


11.5 +/- 0.3
7.0 +/- 0.5
2002-03-16
21.5h - 04.5h
RS
10.7 +/- 2.0
18.1 +/- 1.3


2002-03-18
22h - 05h
RS


25.1 +/- 1.3
13.8 +/- 1.5
2002-03-28
18h - 05.5h
RS
11.1 +/- 2.0
21.9 +/- 1.0
23.5 +/- 0.3
14.2 +/- 0.6
2002-04-09
19.5h - 22.5h
SR
12.6 +/- 0.7
21.2 +/- 0.6


2002-04-22
17h - 22h
SR
12.7 +/- 0.9
21.6 +/- 0.7


2002-05-12
16h - 04h
RS
12.4 +/- 0.5
21.7 +/- 0.4
30.3 +/- 1.6
21.8 +/- 1.0
2002-05-27
20h - 02h
ES
8.0 +/- 1.7
15.6 +/- 1.3
24.4 +/- 0.3
21.5 +/- 0.7
2002-06-09
20.5h - 01.5h
SR
6.2 +/- 1.7
11.9 +/- 1.2
19.7 +/- 1.0
19.5 +/- 0.6
2002-06-30
18h - 23.5h
SR
4.6 +/- 1.4
8.9 +/- 1.0
14.4 +/- 0.6
19.5 +/- 0.8
2002-07-11
16h - 22.5h
RS
4.0 +/- 1.2
7.6 +/- 0.9
14.9 +/- 0.4
19.8 +/- 1.2
2002-07-28
14h - 22h
RS
3.6 +/- 0.9
7.1 +/- 0.7
13.0 +/- 0.3
18.2 +/- 0.5
2002-08-11
14.5h - 18.5h
ES
3.3 +/- 1.0
6.4 +/- 0.8
12.7 +/- 0.3
18.1 +/- 1.0
2002-08-23
09h - 14.5h
ES
3.8 +/- 0.5
6.7 +/- 0.3
 12.5 +/- 0.2
17.8 +/- 0.9
2002-08-31
7.5h - 19.5h
SR
3.7 +/- 0.3
6.7 +/- 0.2
12.5 +/- 0.2
17.4 +/- 0.9
2002-09-17
11h - 17h
SR
3.2 +/- 1.0
6.6 +/- 0.7
12.3 +/- 0.3
16.4 +/- 0.6
2002-10-12
11h - 18h
RS
2.7 +/- 0.9
6.7 +/- 0.4
10.2 +/- 0.6
15.4 +/- 0.8
2002-11-22
06h - 15h
ES
2.5 +/- 0.3
4.5 +/- 0.3
8.0 +/- 0.3
11.7 +/- 0.5
2002-12-17
05h - 14h
SR
1.3 +/- 0.3
3.6 +/- 0.3
6.5 +/- 0.5
11.5 +/- 1.1
2003-01-08
03.5h - 07h
SR Unsuccessful search for SN 2003B in NGC 1097.



2003-02-05
23.5h - 4.5h
SR
1.8 +/- 0.4
2.2 +/- 0.2
6.1 +/- 0.5
10.0 +/- 1.3
2003-03-16
01h - 5.5h
RS
1.5 +/- 0.4
2.6 +/- 0.3
5.5 +/- 0.4
8.8 +/- 0.4
2003-05-20
15h - 21h
RS

1.2 +/- 0.5
2.4 +/- 0.2
4.5 +/- 0.2
7.7 +/- 0.7
2003-08-03
13h - 19h
RS

0.9 +/- 0.4
2.0 +/- 0.2
3.8 +/- 0.3
6.3  +/- 0.4
2003-11-07
05h - 10.5h
SR

0.8 +/- 0.3
1.6 +/- 0.2
3.1 +/- 0.3
5.1 +/- 0.5
2004-02-14
22h - 10h
SR

0.8 +/- 0.3
1.3 +/- 0.2
2.3 +/- 0.3
4.5 +/- 0.4
2004-04-01
19h - 07h
RS

0.6 +/- 0.3
1.6 +/- 0.2
2.0 +/- 0.2
2.5 +/- 0.4


Last modified 28 June 2005 by Stuart Ryder (sdr@aaoepp.aao.gov.au)