70 likes | 224 Views
PILOT Survey for Supernovae in Starbursts. Stuart D. Ryder Anglo-Australian Observatory Seppo Mattila Stockholm Observatory. SN 2001ig (Ryder et al. 2004, MNRAS, in press). Why Supernovae?. Core-collapse SNe (CCSNe) generate/liberate the bulk of the light metals.
E N D
PILOT Survey forSupernovae in Starbursts Stuart D. Ryder Anglo-Australian Observatory Seppo Mattila Stockholm Observatory
SN 2001ig (Ryder et al. 2004, MNRAS, in press) 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.
Why Starbursts? • “Supernova Factories” – ULIRGs (LIR > 1012 L) have SFRs > 100 M yr -1, so > 1 CCSN yr -1. • High Z high MLR, may influence SN evolution. • ULIRGs/starburst galaxy nuclei are crowded, heavily-extincted (AV > 10) regions NIR, radio. • NIR allows follow-up at much earlier epochs; not all CCSNe are “radio-loud”. • WHT+INGRID/LIRIS K-band monitoring of 40 nearby (D < 45 Mpc) non-AGN starbursts. • VLT+NACO monitoring of 14 ULIRGs out to D ~ 300 Mpc.
Historical SN in NGC 7714 • Found in archival UKIRT K image from Sep 1998. • Optimal Image Subtraction (Allard & Lupton 1998). • < 1 kpc from nucleus. • Not seen in U, J, H AV > 6.
AO on ULIRGs • Require Strehl ratios ~0.2 – 0.3 to yield 0.06" (100 pc) resolution @ 300 Mpc. • NACO currently delivers (time variable) SR ~ 0.1 when guiding on ULIRG nucleus. NICMOS 1" IRAS 23128-5919 IRAS 17208-0014
Discovery rate • Assume: • Stable, near diffraction-limited (0.3") PSF over FOV of InSb array (0.23" pix-1). • 10 min exposures 10s for K=22.5. • 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.
Summary • Expect: • 4–6 CCSNe (for 5–30% 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.