Insights from Radio Wavelengths into Supernova Progenitors

Laura ChomiukJansky Fellow, Michigan State University

Supernova Types: I vs. II

Type I:No Hydrogen

Thermonuclear WD explosions (Ia)

and Core collapse of massive stars stripped of H envelopes (Ib/c)

Type II:Show Hydrogen

Core collapse of massive stars with H envelope

Supernova Types: A Continuum of H-richness

(Smartt 2009)

A diverse, complicated zoo of massive stars and core-collapse SNe

+ SNe Ia

Searching for SN progenitors directly with optical imaging

SN 2005gl

Before During After

Or, constraining SN progenitors indirectly-- in the radio

Soderberg et al (2008)

SN 1970G: The first SN detected in the radio

(Gottesman et al. 1972, Goss et al. 1973)

shell

SN 1994I @ 20 cm Weiler et al. (2011)

absorbed (either free-free or synchrotron)

synchrotron τ ≈ 1

fading because

blast decelerates

and CSM decreases in

density

vw ≈ 30 km/svsn ≈ 10,000 km/s

SN blast probes ~1 year of mass loss in one day!

What makes a SN bright at radio wavelengths?

A fast blastwave Expansion into dense surroundings

Radio bolsters a division in Type I SNe:

Type Ib/c: Show radio emission, core collapse

Type Ia: No radio emission, thermonuclear

(Panagia et al. 1986)

Relativistic SN 1998bw associated with GRB 980425

(Kulkarni et al. 1998, Wieringa et al. 1999)(Galama et al. 1998)

A diversity of mass loss histories

SN 2003bg (Soderberg et al. 2006)

Shells, Spirals, and Shelves

SN 1993J (Weiler et al. 2007)

SN 2007bg (Salas et al. 2012)(Ryder et al. 2004)

SN 2001ig

SNe Ib/c: WR stars or interacting binaries?

Mdot/vwind = 10-10 10-9 10-8 10-7 10-6

M yr-1 / km s-1

SNe Ib/c show mass loss rates consistent with WR stars.

Still no radio emission from SNe Ia

(Panagia et al. 2006)

Time Since Explosion (Days)

Radio Luminosity (erg/s/Hz)

WD + Giant

WD + Sub-giant or Main Sequence WD + WD

(NASA/Swift/ Aurore Simonnet, Sonoma State Univ.)

Different progenitor models predict different circumbinary environments.

...And still no radio emission from SNe Ia!

Assumes vw = 50 km/s

VLA

JVLA

nISM = 1 cm

-3

M = 10

-8 M yr-1

.

Strong limits on the environment of SN 2011fe from EVLA

(Chomiuk et al. 2012, Horesh et al. 2011)

SN 2011fe

assumes vw = 50 km/s

nISM = 1 cm

-3

M = 10

-8 M yr-1

.

Chomiuk et al. (2012), Margutti et al. (2012)

Strong limits on the environment of SN 2011fe from EVLA

SN 2009ip: Watching an LBV explode

(Mauerhan et al. 2012)

(Mauerhan et al. 2012)

SN 2009ip: No longer an impostor since ~Sept 15

No radio detection yet; VLA monitoring ongoing

SN 1970G revisited

33.7 ± 4.3 μJy @ 5 GHz (Dittman et al. in prep)

SN 1970G consistently challenges our radio facilities

(Stockdale et al. 2001, Dittman et al. in prep)

SN 1970G: Decline in Radio + Rise in X-rays = Compact Object?

(Dittman et al. in prep)

Radio light curves of SNe trace mass loss histories of progenitors.

Discovery of first radio SN

Theory of radio SN

Type I SNe split into Ia and Ib/c

Long GRB associated with a relat-ivistic SN

Diversity of mass loss histories• Ib/c mass loss consistent with WR• No Ia radio detections

Jansky VLA Era:• Sensitivity Bonanza!• Relativistic SNe w/o GRBs• Still no Ia radio detections

end

A continuum in blast wave velocities between normal SNe Ib/c and GRBs

(Soderberg et al. 2010, more in prep)