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The progenitor stars of core-collapse supernovae. Stephen J. Smartt Astrophysics Research Centre Queen’s University Belfast. Queen’s SNe & Massive star group: J. Eldridge, S. Mattila, A. Pastorello, M. Crockett, D. Young, M. Hendry, P. Dufton, C. Trundle, I. Hunter
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The progenitor stars of core-collapse supernovae Stephen J. Smartt Astrophysics Research Centre Queen’s University Belfast Queen’s SNe & Massive star group: J. Eldridge, S. Mattila, A. Pastorello, M. Crockett, D. Young, M. Hendry, P. Dufton, C. Trundle, I. Hunter Others: J. Maund (Texas), J. Danziger (Trieste), P. Meikle (Imperial),
Overview • Core-collapse SNe drive the chemical evolution of galaxies, and formation through feedback • Test stellar evolution theory and NS/BH formation scenarios • Linked to the formation of long duration GRBs • Are the ideas of SNe progenitor stars correct ? • Are SNe explosion and lightcurve models consistent ?
Summary of SNe types Supernovae are classified by their optical spectra • No hydrogen • • Type I • Si He He or Si Ia Ib Ic Hydrogen lines Type II Photometry/spectra properties II-P, II-L, IIn, IIb, II-p ———
M101 NGC3621 Example: • HST Key project – H0withCepheids • Blue supergiants at 2-7Mpc from 8m telescopes - Bresolin et al. (2001) NGC3949
First red supergiant progenitor • SN2003gd discovered 2003 June 12 • Normal type II-P • M74 - distance 9.3 1.8 Mpc • 3100s WFPC2 pre-explosion image F606W • Gemini gri (480-960s), 0.56” images
Detection of progenitor • HST ACS - ToO (Cycles 10-15) • Smartt et al. (2003), Van Dyk et al. (2003): possible progenitors from ground based astrometry calibration • Star A: Differential astrometry: r = 13 ± 33 mas
V=25.8 ± 0.15 V–I=2.5 ± 0.2 d=9.1 ± 1.9 kpc ; E(B–V)=0.14 ± 0.13 K5-M3Ib supergiant (Elias et al. 1985) STARS stellar evolutionary tracks: M = 8 -2M +4 Magnitudes and colours of progenitor Smartt et al. 2004, Science
SN2005cs in M51 • SN2005cs – discovered 20050628 • Hubble Heritage Team - deep mosaic BVI+H with ACS (Jan. 2005) • F814W/F555W 1360s • WFPC2 U+R band (Jul. 1999) Also deep NIR images: NICMOS (F110W+F160W; see Li et al. 2006) Gemini NIRI (JHK) 500-600s deep UBVRIJHK images
Maund et al. (2005), Li et al. (2006) Detection of progenitor • HST ToO : ACS post-explosion (F555W) • Star detected in I-band only (J. Maund PhD thesis) • I=23.3±0.05, and limiting V-band mag is V5 > 25 • Not detected in any of the NIR bands; K>20.7
Other examples: no detection • SN1999gi in NGC3184, • HST U+V pre-explosion • D=11Mpc (Leonard et al. 2002) • M 12 M Smartt et al. 2001 • SN2001du in NGC1365 • HST UVI pre-explosion • D=17Mpc (Cepheid Key P.) • M 15 M Smartt et al. 2002
Summary of II-P progenitors Rest from Crockett et al. 2006, Maund & Smartt 2005, Maund et al. 2005, Hendry et al. 2006, Smartt et al. 2004, 2003, 2002, 2001
93J Observed Ib/c Observed II-P 80K 87A Heger et al. (2000) - now can place observational constraints
STARS stellar evolutionary tracks (Eldridge & Tout 2004) • Eldridge, Smartt (in prep) - probability without mass cut ~5%
Late time tail powered by radioactive 56Ni • 56Ni explosively created from Si burning after core-collapse • Direct probe of the explosion • How Is it related to progenitor mass ? UVOIR Light Curves and 56Ni Mass
Black-hole forming SNe ? • Zampieri et al., Nomoto et al - low luminosity SNe form black-holes • No evidence so far of the branching at high luminosity • Detailed comparison with models now possible
Constraints on a Type Ic • SN2004gt - type Ic • Gamma-ray bursts coincident with Ic supernovae
Restricted region in the HRD • We would have detected massive evolved stars • Either a star of 120-150M or • More likely a lower mass object in a binary • Four other Ib/c SNe, all with similar luminosity limits • Type Ia SNe - 7 events, no object/cluster. Maund, Smartt, Schwiezer (2005) Gal-Yam et al. (2005)
Conclusions • SN II-P: most common type, red supergiant progenitors (~M0Ib 8-12M) • Detections and limits on 15 II-P SNe imply they only come from RSG stars with MZAMS<15M • No evidence for BH forming Sne • Within 3 years project ~30 progenitors (HST SNAP + VLT/Gemini NIR purpose built archive) • Optical/NIR monitoring of SNe gives 56Ni - probe of explosion • Direct constraints on all core-collapse SNe types
Nsn (Vrad <1500) = 8.7 yr-1 Nearby core-collapse SNe: discovery rates H0= 75 kms-1Mpc-1 No. of SN per year in galaxies less than Vrad km/s
Radio and X-ray luminosity of II-P Chevalier et al. (2005) Radio and X-ray LPconsistent with direct mass estimates
M31 RSG variable • Young, Smartt et al. in prep. • 4 years monitoring of M31 (microlensing) • Largest variation ±0.5m • ±0.2 dex in logL/L • M-type supergiant, M~20M, logL~5.2 dex
d=8.4 ± 1 kpc; E(B – V)=0.14 ± 0.02 Colours of K5-M4Ib supergiant scaled to I=23.3 Bluer than early K-type and it would be detected in V and R. Magnitudes and colours of progenitor Magnitude Wavelength
Dust enshrouded red supergiants ? • Could progenitors be dusty red supergiants, some of higher luminosity ? • SNe are clearly not reddened • But could be destroyed in explosion (e.g. Meikle & Graham 1986)? • Our deep K-band image rules this out (K>20.7) • If visual extinction AV~5 • K-band limit implies MK>-9.5 or log L/L < 4.6 • Hence M < 12M Gemini NIRI K-band 0.5” 50 Galaxies (<10Mpc) surveyed with VLT/Gemini/UKIRT. Deep JHK images for future SNe
ACS images • SN1993J: U330=20.8 • 3 Faint companions within 0.35” • Contribution to SN of <20% • Why is SN1993J so bright in UV ? • Deep, near-UV Keck spectrum with LRIS-B
Evolutionary model • ZAMS = 15 and 14Mstars • 5.8 year period • High mass loss from progenitor to companion ~1000 yrs pre-explosion (4x10-2 M/yr) • SN1987A like event (in 10 000 years time) ? Maund, Smartt, Kudritzki, Podsiadlowski, Gilmore 2004, Nat.