michael bietenholz, hartebeesthoek radio observatory, south africa
DESCRIPTION
VLBI of Supernovae and Gamma Ray Bursts. Michael Bietenholz, Hartebeesthoek Radio Observatory, South Africa. Dr. Michael Gaylard. Introduction: Why Image Supernovae and GRBs with VLBI?. Resolution: we can resolve the explosive outflows. - PowerPoint PPT PresentationTRANSCRIPT
1Michael Bietenholz, Hartebeesthoek Radio Observatory, South Africa
VLBI of Supernovae and VLBI of Supernovae and Gamma Ray BurstsGamma Ray Bursts
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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SN 1994I Ic M51 8 20 Bietenholz & Bartel, unpublished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