1Michael Bietenholz, Hartebeesthoek Radio Observatory, South Africa

VLBI of Supernovae and VLBI of Supernovae and Gamma Ray BurstsGamma Ray Bursts

2Dr. Michael Gaylard

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• Resolution: we can resolve the explosive outflows. • Normal supernova: 20000 km/s = 0.4 mas/yr at 10 Mpc,

relativistic supernova or GRB, c = 0.6 mas/yr at 100 Mpc• Determine ejecta speed• Nature and geometry of the ejecta – jets? Clumpiness?

Bipolar ejections?• Radio emission is usually due to the interaction of the ejecta

with the surrounding material: from interaction we can learn about both ejecta and the surrounding material

• Evolution of SN shells, shock acceleration, eventual merging with ISM

• Compact remnant of a core-collapse SN?• Supernova rates, especially in dusty environments• Direct distances with the expanding shock front method – out

to Virgo cluster

Introduction: Why Image Supernovae and GRBs with VLBI?

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Supernovae: Radio Detection of SNe

• Optical: several hundred SNe are detected each year

• Radio: Only core collapse (Type II, Type I b/c) detected to date (limits in Ia next talk). Only a few SNe detected each year in radio; total radio detections to date ~60

• Even fewer have been resolved by radio observations - so every VLBI observation is of great value

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RSNe Detected with VLBI Name Type Host

galaxyDistance

(Mpc)Peak

(mJy at 8 GHz)

References

SN 1978K II NGC 1313 4 >100? Smith et al 2007.

SN 1979C II M100 16 6 Bartel & Bietenholz, Marcaide et al

SN 1980K II NGC6946 6 2 Bartel 1985

SN 1986J II NGC891 10 100 Bietenholz et al 2004

SN 1987A II LMC 0.05 80 Jauncey, Ng, Manchester

SN 1993J II M81 4 100 Bietenholz, Bartel, Marcaide

SN 1994I Ic M51 8 20 Bietenholz & Bartel, unpublished

SN 1996cr II Circinus 3.6 ~100 Bauer et al, Bartel et al in prep

SN 2001em Ib/c NGC 7112 80 4 Bietenholz, Paragi, Schinzel

SN 2001gd II NGC 5033 13 4 Pérez-Torres et al 2008

SN 2003gk Ib NGC 7460 45 2 Bietenholz et al 2013

SN 2003L Ib/c NGC 3506 92 3 Soderberg et al 2005

SN 2004et II NGC 6946 6 2 Martí-Vidal et al

SN 2007gr Ib/c NGC 1058 10 <~ 1 Paragi et al 2007

SN 2007uy Ib NGC 2770 27 1 van der Horst 2011

SN 2008D BL Ib/c NGC 2770 27 3 Soderberg, Bietenholz Paragi

SN 2008iz II? M82 3.6 150 Brunthaler et al 2010

SN 2009bb BL Ib/c NGC 3278 40 18 Bietenholz et al 2010

SN 2011dh IIb M51 8.4 7 Bietenholz et al, Martí-Vidal et al

Approximately 30 RSNe with flux densities > 1 mJy have been detected in radio, and >100 have upper limits.

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RSNe Detected with VLBI Name Type Host

galaxyDistance

(Mpc)Peak

(mJy at 8 GHz)

References

SN 1978K II NGC 1313 4 >100? Smith et al 2007.

SN 1979C II M100 16 6 Bartel & Bietenholz, Marcaide et al

SN 1980K II NGC6946 6 2 Bartel 1985

SN 1986J II NGC891 10 100 Bietenholz et al 2004

SN 1987A II LMC 0.05 80 Jauncey, Ng, Manchester

SN 1993J II M81 4 100 Bietenholz, Bartel, Marcaide

SN 1994I Ic M51 8 20 Bietenholz & Bartel, unpublished

SN 1996cr II Circinus 3.6 ~100 Bauer et al, Bartel et al in prep

SN 2001em Ib/c NGC 7112 80 4 Bietenholz, Paragi, Schinzel

SN 2001gd II NGC 5033 13 4 Pérez-Torres et al 2008

SN 2003gk Ib NGC 7460 45 2 Bietenholz et al 2013

SN 2003L Ib/c NGC 3506 92 3 Soderberg et al 2005

SN 2004et II NGC 6946 6 2 Martí-Vidal et al

SN 2007gr Ib/c NGC 1058 10 <~ 1 Paragi et al 2007

SN 2007uy Ib NGC 2770 27 1 van der Horst 2011

SN 2008D BL Ib/c NGC 2770 27 3 Soderberg, Bietenholz Paragi

SN 2008iz II? M82 3.6 150 Brunthaler et al 2010

SN 2009bb BL Ib/c NGC 3278 40 18 Bietenholz et al 2010

SN 2011dh IIb M51 8.4 7 Bietenholz et al, Martí-Vidal et al

Approximately 30 RSNe with flux densities > 1 mJy have been detected in radio, and >100 have upper limits.

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Radio Lightcurves (SN 1993J)• Typical

pattern seen in SNe with frequency-dependent rise and then a power-law decay after the supernova has become optically thin

• Increase in the steepness of the decay at t ≈ 2500 days (Bartel et al 2002)

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VLBI Movie of SN 1993J• Global Array

VLBI at 8.4 GHz, then 5 GHz and 1.6 GHz for last epochs

• 35 Epochs of VLBI

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DecelerationRadius scaled by t0.8 to show deviations from powerlaw expansion

Bietenholz et al 2010

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1.7 GHz

6 Mar 2010, day 6187 ~ 16 years after the explosion

Explosion Center

μJy/beam

• Global array: 18 antennas (EVN + VLBA + GBT). Used in-beam calibrator technique

• Image background rms: 3.7 μJy/beam

• Radius: 5.1 × 1017 cm (34,000 AU; 0.16 pc)

• Expanding at ~7,500 km/sec

• Limit on a PWN at centre? – 50 μJy at 1.6 GHz

= 25% of Crab Nebula– Bietenholz et al 2003: 50 μJy

at 8.4 GHz (stacked 3 epochs,1998-2000)

– Marti-Vidal & Marcaide 2014: 102 μJy at 5.0 GHz (stacked images)

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Central Component in SN1986J

• Central component turned on at age ~15 yr

0.8 milli-arcsec (1017 cm)

• 200 × the current radio luminosity of the Crab Nebula at 15 GHz

Bietenholz, Bartel & Rupen 2004

Multi-frequency VLBI Image:

Contours, red: 5 GHz

Blue white: 15 GHz

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Central Component in SN1986J

Bietenholz, Bartel & Rupen 2004

Multi-frequency VLBI Image:

Contours, red: 5 GHz

Blue white: 15 GHz

Youngest Neutron Star

or Black Hole?

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SN 1987A

Comparison of VLBI image to optical and X-ray images. Contours: VLBI at 1.7 GHz, 0.5, 1.5, 3, and 5 mJy/beam. Ng et al 2011

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SN 1987A

Comparison of VLBI image to optical and X-ray images. Contours: VLBI at 1.7 GHz, 0.5, 1.5, 3, and 5 mJy/beam. Ng et al 2011

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ULIRGs: Supernova Factories

• Arp 220 (Conway et al), Arp 299 (Bondi, Neff, Ulvestad et al.), IRAS 23365+3604 (Romero-Cañizales, Pérez-Torres et al.)

• High Sensitivity Array observations at 14 and Global VLBI at 8.4 GHz

• 17 sources detected, mostly resolved at 14 GHz

• VLBI crucial to distinguishing starburst and AGN

Conway et al 2010

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Relativistic Expansion: SNe and GRBs

Image: Saxton

• Long Duration GRB’s associated with Type Ibc supernovae

• Collapse of massive star into a black hole powers highly relativistic jet

• GRB’s are jets oriented near the line of sight

• The jets not near the line of sight may be visible in radio

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Relativistic Expansion: SNe and GRBs

Image: Saxton

• Long Duration GRB’s associated with Type Ibc supernovae

• Collapse of massive star into a black hole powers highly relativistic jet

• GRB’s are jets oriented near the line of sight

• The jets not near the line of sight may be visible in radio

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SN 2009bb VLBI observations

Peak brightness 613 μJy/bm,

rms = 128 μJy/bm,

VLBA, VLA, Hobart, Tidbinbilla2009 Jun 12 (age = 85 days)

40 Mpc

Upper limit on angular size = 0.64 mas = 1.74c

SN2009bb

Bietenholz et al 2010

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Limits on Off-Axis JetsOff-axis jets could be detectable in the radio

However, lower efficiency in par-ticle acceleration or lower magnetic field could dras-tically lower model curves

Luminosity limits: Bietenholz et al 2014, and Soderberg et al 2006 (S2006)

Bietenholz et al 2014

SN 2003gk

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SN 2003gk VLBI Observations

8.4 GHz

VLBA + Ef + Arecibo

Age=~7.5 yrs (2011 Apr 11)

Contours: 20, 30, 50, 70, 90% of peak of 86 μJy/ beam

r = 1 light-year

Bietenholz et al 2014

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Limits on Off-Axis JetsOff-axis jets could be detectable in the radio

However, lower efficiency in par-ticle acceleration or lower magnetic field could dras-tically lower model curves

Luminosity limits: Bietenholz et al 2014, and Soderberg et al 2006 (S2006)

Bietenholz et al 2014

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VLBI Expansion Measurements: by Taylor et al. & Pihlstrom et al. show clear deceleration, with transition to non-relativistic regime at t ~ 1yr

Relativistic Expansion: GRB 030329 (SN 2003dh)

22 Apr 2003

Size ~1 pc = 3 light years

Taylor et al, 2004, 2005; Pihlstrom et al. 2007, Mesler et al 2012

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VLBI Expansion Measurements: by Taylor et al. & Pihlstrom et al. show clear deceleration, with transition to non-relativistic regime at t ~ 1yr

Relativistic Expansion: GRB 030329 (SN 2003dh)

22 Apr 2003

Size ~1 pc = 3 light years

Speed of light

Taylor et al, 2004, 2005; Pihlstrom et al. 2007, Mesler et al 2012

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The Future of Supernova VLBI

• More sensitivity – follow supernova for longer• Resolve older, more distant supernovae:

Cas A is 1 μJy and 6 mas at 170 Mpc - fill in the gap between supernovae and supernova remnants

• Supernova rates → star formation rates• Pop III Hypernova• GRBs and orphan afterglows

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VLBI Supernova Gallery

SN 1987A SN 1993J

SN 1996cr SN 2008iz M82SN 2011dh

SN 1996cr, 1993J, SN1986J, SN1979C: Bietenholz, Bartel et al; SN 2008iz Brunthaler et al 2010; M82 supernova/SNR: McDonald, Beswick, Argo et al

SN 1979C SN 1986J

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Comparison of RSNe & SNRs

McDonald et al., 2001