Core-Collape SN Progenitors: Light-Curves and Stellar Evolution

Melina Cecilia Bersten

2016, August 11th

O. Benvenuto, K. Nomoto, G. Folatelli, M. Orellana

CCSNe – p.1/22 Core-Collapse Supernovae

End of massive stars (M0 & 8M⊙) – Stellar evolution test Which type of progenitor corresponds to each type of SN? Isolated stars or interacting binary systems?

Credit: M. Modjaz Smartt+09

CCSNe – p.2/22 Core-Collapse Supernovae

End of massive stars (M0 & 8M⊙) – Stellar evolution test Which type of progenitor corresponds to each type of SN? Isolated stars or interacting binary systems? Single stars Binaries

Eldridge+13

CCSNe – p.2/22 Progenitor Stars Archival pre-explosion imaging

Environmental and metallicity studies

SN rates

Mass-loss rates from radio & X-rays

Spectropolarimetry

Flash spectroscopy

Light-curve and spectrum modeling

CCSNe – p.3/22 Progenitor Stars Archival pre-explosion imaging (. 30 Mpc) ≈ 20 detections + 30 upper limits (Van Dyk, Smartt, etc.)

Most are RSG – SNe II

A few YSG – SNe IIb

No detections for SN Ib or Ic until iPTF13bvn

LBV – SNe IIn

BSG – SN 1987A

Deﬁciency of progenitors with

log L/L⊙ & 5.1 =⇒

MZAMS . 16-18 M⊙

Smartt+15

CCSNe – p.4/22 Progenitor Stars

Spectral modeling: photosperic and nebular (homologous expansion) Nucleosynthesis, chemical abundances, progenitor mass, explosion mechanism (CMFGEN, SEDONA, Phoenix, Mazzali, Tardis...)

Dessart & Hillier 11, Jerkstrand+12 CCSNe – p.4/22 Progenitor Stars Hydrodynamic modeling: LC + expansion velocities Progenitor mass, radius, explosion energy, 56Ni mass (Kepler, Stella, Utrobin, Bersten+, SNEC,...)

11dh 10as 09fj 99ex 05bf 08D 87a 99em

CCSNe – p.4/22 Hydrodynamical Models

One-dimensional Lagrangian code with ﬂux-limited radiation diffusion and gray transfer for gamma-rays (Bersten et al. 2011) Pre-SN structures: stellar evolution and parametric models

Type IIb-Ib-Ic Type II-Plateau

CCSNe – p.5/22 H-rich progenitors

CCSNe – p.6/22 Type II-P Supernovae

Most common type of stellar explosion (≈ 50% of CCSNe) Good distance indicators: EPM, SEAM, and SCM RSG structure with H-rich envelope (predicted by theory and conﬁrmed by obsevations: SN 2008bk, SN 2005cs, SN 2012aw) Pre-supernova imaging + stellar evolution models =⇒ MZAMS: 8–16 M⊙ (Smartt+09, 15) Hydrodynamical modeling favors high mass range

CCSNe – p.7/22 Pre-SN Density Structure

LC sensitive to H envelope but not to He core (Dessart+11)

He core (not H envelope) connected with MZAMS

⇓

Same MZAMS, different H envelope =⇒ different mass loss?

CCSNe – p.8/22 Type II-P Supernovae

Most common type of explosion (≈ 50% of CCSNe) Good distance indicators: EPM, SEAM, and SCM RSG structure with H-rich envelope (predicted by theory and conﬁrmed by obsevations: SN 2008bk, SN 2005cs, SN 2012aw) Pre-supernova imaging + stellar evolution models =⇒ MZAMS: 8–16 M⊙ (Smartt+09, 15) Light curves of SNe II-P Very dependent on the initial density structure assumed

Sensitive to the H env. mass, but not easy to connect with MZAMS

Rise time study suggests radii of ≈ 500 R⊙ or some CSM around (González-Gaitán+15). Smaller than typical observed RSG radii (Levesque+06)

CCSNe – p.9/22 H-poor progenitors

CCSNe – p.10/22 Stripped-envelope SNe

Cooling phase with strong dependence on progenitor radius

Models for compact progenitors show initial plateau (see also Dessart+11) Second peak powered by radioactive decay 56 Depends on Eexp, Mej, MNi and Ni distribution

CCSNe – p.11/22 Mass-loss Mechanisms

Single, massive (& 25 M⊙) Wolf-Rayet stars with strong winds

=⇒ He core mass & 8 M⊙ Interacting binaries can make lower-mass stars lose their envelopes

Single-star mass-loss Binary-star mass-transfer

CCSNe – p.12/22 Stripped-envelope SNe

SN Ibc progenitors come from younger populations than the bulk of the type II progenitors (Anderson+12)=⇒ higher mass progenitors? YSG connected to SNe IIb. Three conﬁrmed (SN 1993J, SN 2008ax, SN 2011dh). One candidate (SN 2013df). One (and possibly two) binary companion detection

CCSNe – p.13/22 The Type IIb SN 2011dh Best observed SE-SN since 1993J Conﬁrmed YSG progenitor (Maund+11, Van Dyk+11, 13, Ergon+14) Explosion and binary evolution models (Bersten+12, Benvenuto+13)

A blue source in UV: hot companion? (Folatelli+14) But optical data did not conﬁrm (Maund+15)

4.1187

15 14

12 13

12 5 11 11 10 9 8 7 6

12.844

Bersten+12, Benvenuto+13 CCSNe – p.14/22 The Type IIb SN 2008ax Bright and blue source in HST pre-SN images: WR or stellar cluster (Crockett+08) HST post-explosion images: 2011: source contamination 2013: disappearance of the progenitor. Third conﬁrmation for SNe IIb New photometry + LC analysis: Low-mass star stripped by binary interaction

Folatelli, Bersten+15 CCSNe – p.15/22 Stripped-envelope SNe

No SN Ibc progenitors =⇒ binaries (Eldridge+13) But pre-SN Ibc are different from observed WR stars (hotter and optically faint WO; Yoon+12 and Groh+13). iPTF13bvn: the exception

Eldridge+13 Yoon+12

CCSNe – p.16/22 iPTF13bvn: First SN Ib progenitor?

A bright source identiﬁed in HST pre-SN images (Cao+13)

Massive WN star ﬁts the photometry (Groh+13)

Low-mass star stripped by binary interaction (Bersten+14, Fremling+14)

Revised pre-SN photometry favors binary (Eldrige+15, Kim+15) Post-explosion photometry: progenitor disappearance (Folatelli’s talk)

48 44

32 He-Burning

28 He-Burning

SN 24

C-Burning 20

H-free 16 ZAMS H-Burning

Bersten+14

CCSNe – p.17/22 Progenitor Radius

No evidence of shock cooling =⇒ R ≈ a few R⊙ ?

Cao+13

Bersten+14

CCSNe – p.18/22 Progenitor Radius

We tested envelopes of different radii attached to the He4 model

Progenitors with R< 150R⊙ are possible

Even with texp known to ≈1 day, R⊙ is not well constrained =⇒ several observations per night are necessary

150 100 50

Cao+13

Bersten+14 CCSNe – p.18/22 Stripped-envelope SNe

No SN Ibc progenitors =⇒ binaries (Eldridge+13) But pre-SN Ibc are different from observed WR stars (hotter and optically faint WO; Yoon+12 and Groh+13). iPTF13bvn: the exception More evidence for binarity: Too high observed SN-Ibc rate for single WR stars (Smith+11, Li+11, ...)

At least 70% of massive stars are CBS (Sana+12)

Low ejecta masses ≈1-4 M⊙ from LC of SE-SN sample (Drout+11, Lyman+16, ...)

CCSNe – p.19/22 CSP Stripped-envelope SN Sample

≈ 34 SE SNe with highly precise optical and NIR photometry from the Carnegie Supernova Project (CSP) (Stritzinger+ in prep.) Homogeneous & densely covered data set

Hydro models grid: MNi= 0.03–0.28 M⊙, E= 0.3–4 foe, Mej= 1–6.2 M⊙ =⇒ low-mass progenitors (same as Drout+11, Lyman+16, ...)

Taddia+ in prep.

CCSNe – p.20/22 Numerical Magnetar Model

ASASSN-15lh: physically plausible magnetar parameters that reproduce the shape of the LC but only for a massive progenitor (& 8M⊙) The homologous expansion, usually assumed in SN studies, can be broken because of the additional energy source. See Poster by M. Orellana

67.5 d 153.2 d 53.2 d 40 40.5 d 126.6 d

28.0 d 103.8 d 25.4 d 84.2 d 30 22.0 d 18.2 d km/s)

3 12.7 d 10.5 d

v (10 20 6.1 d

1.1 m - 6.0 d 10

5.3 s 20.9 s 49.5 s

3 4 5 6 7 8

M r / M O• Bersten+16 CCSNe – p.21/22 Summary

Stripped-envelope SNe seem to come predominantly from binaries

Consistent results from pre-explosion data, light-curve and spectral modeling

Where are the binary companions?

Type II SNe: Larger progenitor masses from Hydro modeling than from pre-explosion imaging and spectral modeling

CCSNe – p.22/22