Radio Supernovae

1
A Radio Perspective on the GRB-SN Connection
Alicia Soderberg May 25, 2005 Zwicky Conference
2
Gamma-Ray Bursts

• highly relativistic (?100) jets (? few
  degrees) ?-ray emission
• mildly relativistic (?lt10) ejecta produce
  afterglow emission
• imply central engine
• spherical explosion produces non-relativistic
  (??lt1) optical SN emission (Type Ibc)
• Rate 2.5 x 102 Gpc-3 yr-1

3
Type Ibc Supernovae

• NO H in optical spectra (10)
• NO ?-ray emission
• NON-relativistic, ??lt1, synchrotron emission
  from mildly asymmetric ejecta
• NO evidence for central engines
• spherical explosion drives non-relativistic
  optical SN
• Rate 4.8 x 104 Gpc-3 yr-1

?
Type Ibc Supernovae
0.5 of SNe Ibc associated with GRBs
4
Spherical Jet Framework
?
connection
GRBs
SNe Ibc
5
GRB980425 and Type Ic SN1998bwA GRB/SN
Connection

• z0.0085 (36 Mpc)
• SN1998bw discovered within BeppoSAX error box for
  GRB 980425
• Two key probes
• Optical Radio

(Galama et al., 1998 Pian et al. 2000)
6
GRB980425 and Type Ic SN1998bwA luminous local
SN
Optical emission requires 0.5 M? Nickel v
60,000 km/s (Iwamoto et al.1998 Woosley et al.
1999)
7
GRB980425 and Type Ic SN1998bwThe most luminous
radio SN
E 5 x 1049 erg ?3 ejecta (Kulkarni et
al.1998 Li Chevalier 1999)
What fraction of SNe Ibc are like SN1998bw?
8
Caltech/NRAO/ATCA Radio Type Ibc SN Survey

• RADIO is most sensitive to relativistic ejecta
• 1. Synchrotron emission traces the fastest ejecta
  
• 2. The synchrotron peak is near/below the radio
  band.
• 3. Higher frequencies dominated by other
  processes.
• Observe EVERY (optically selected) SN Ibc within
  100 Mpc

9
VLA Survey of Type Ibc Supernovae Results 11
detections 82 upper limits
Radio bright SN Ibc are rare and diverse.
(Soderberg et al. 2005 Berger et al. 2002,03
Kulkarni et al. 1998)
10
Equipartition Energy and Velocity
Out of 93 SNe, none like SN1998bw and/or GRBs lt
1 GRB/SN
11
Radio Analysis of SN 2003L

• Detailed Modeling
• E 1049 erg
• v 0.2c
• r t
• B r -1
• n r -2
• Mdot 10-5 M?/yr

(Soderberg et al., 2005a)
12
Hidden GRB Jets in Local SNe Ibc
log (F?)
log (time)
No ?-rays seen
13
Hidden GRB Jets in Local SNe Ibc
Afterglow begins
log (F?)
log (time)
14
Hidden GRB Jets in Local SNe Ibc
log (F?)
log (time)
15
Hidden GRB Jets in Local SNe Ibc
log (F?)
log (time)
Type Ibc SN!
16
Hidden GRB Jets in Local SNe Ibc
log (F?)
log (time)
17
Hidden GRB Jets in Local SNe Ibc
log (F?)
log (time)
18
Hidden GRB Jets in Local SNe Ibc
log (F?)
log (time)
19
Hidden GRB Jets in Local SNe Ibc
log (F?)
log (time)
20
Hidden GRB Jets in Local SNe Ibc
log (F?)
log (time)
21
Hidden GRB Jets in Local SNe Ibc
t 1 week to few yrs
log (F?)
log (time)
22
Constraints on Off-Axis GRBs
Out of 53 SNe Ibc, None house GRBs lt 2
GRB/SN Broad-lined events are NO exception lt
20 GRB/BL
(Soderberg et al. in prep)
23
OPTICAL Peak SN magnitudes

• GRB-SNe do NOT necessarily synthesize more 56Ni
  than local SNe Ibc.

(Soderberg et al., 2005c)
24
Conclusions Future Progress
Radio SNe Ibc are rare and diverse. Their
optical properties are similarly diverse and
overlap with GRBs 10 are radio bright lt 1
with relativistic ejecta lt 2 with off-axis GRB
jets ATA will enable further progress, but SN
studies will still be limited by optical
discoveries. We need MORE small telescope
campaigns.
25
Broad-lined SNe Ibc
Radio limits imply unusual shock parameters
and/or low densities.