PILOT Survey for Supernovae in Starbursts

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PILOT Survey forSupernovae in Starbursts

• Stuart D. Ryder
• Anglo-Australian Observatory
• Seppo Mattila
• Stockholm Observatory

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Why Supernovae?

• Core-collapse SNe (CCSNe) generate/liberate the
  bulk of the light metals.
• CCSNe directly trace recent massive SFR (cf. UV,
  Ha, FIR, radio, Fe II, )
• Can serve as probes of extinction and ISM.
• CCSNe blast wave probes progenitor mass-loss
  history.

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Why Starbursts?

• Supernova Factories ULIRGs (LIR gt 1012 L?)
  have SFRs gt 100 M? yr -1, so gt 1 CCSN yr -1.
• High Z ? high MLR, may influence SN evolution.
• ULIRGs/starburst galaxy nuclei are crowded,
  heavily-extincted (AV gt 10) regions ? NIR, radio.
• NIR allows follow-up at much earlier epochs not
  all CCSNe are radio-loud.
• WHTINGRID/LIRIS K-band monitoring of 40 nearby
  (D lt 45 Mpc) non-AGN starbursts.
• VLTNACO monitoring of 14 ULIRGs out to
  D 300 Mpc.

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Historical SN in NGC 7714

• Found in archival UKIRT K image from Sep 1998.
• Optimal Image Subtraction (Allard Lupton 1998).
• lt 1 kpc from nucleus.
• Not seen in U, J, H ? AV gt 6.

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AO on ULIRGs

• Require Strehl ratios 0.2 0.3 to yield 0.06"
  (100 pc) resolution _at_ 300 Mpc.
• NACO currently delivers (time variable) SR 0.1
  when guiding on ULIRG nucleus.

NICMOS 1"
IRAS 23128-5919 IRAS 17208-0014
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Discovery rate

• Assume
• Stable, near diffraction-limited (0.3") PSF over
  FOV of InSb array (0.23" pix-1).
• 10 min exposures ? 10s for K22.5.
• Monitor 15 ULIRGs out to 150 Mpc.
• Detectable fraction increases with nuclear
  distance out to 500 pc.
• M82 SNR extinction distribution (AV 24, s 9).
• Template light curves for ordinary (MK 18.6)
  and slowly declining (MK 20.0) CCSNe.

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Summary

• Expect
• 46 CCSNe (for 530 slow-decliners) by observing
  sample annually
• 9 CCSNe per year by observing each galaxy 3
  times
• More frequent monitoring ? light curves.
• PILOT would deliver comparable CCSNe discovery
  rates to AO ULIRG survey on 8m, or nearby
  starburst survey with 4m telescopes.