SUPERNOVA!

SN 1994D in NGC 4526, NASA / ESA / Hubble Key Project Team / High-Z Supernova Search Teamhttp://www.spacetelescope.org/images/html/opo9919i.html

David CorlissToledo Astronomical Association

February 6, 2009

OUTLINE

BASIC FACTS

TYPES OF SUPERNOVAE

1a SN - HOW THEY HAPPEN

RESEARCH

SUPERNOVA SURVEYS

REFERENCES

A SUPERNOVA IS …..

BRIGHTThey can briefly outshine their entire galaxyENERGETICIn just a few weeks, a supernova can give off as much energy as the sun in it’s entire lifetimeRAREOn average, only one every 50 years in the entire Milky Way

FASTUp to 3% of the speed of light

TWO TYPESType Ia

Violent explosion of a White Dwarf star caused by a runaway nuclear reaction

Ib , Ic and Type II

Complex core collapse of a giant star releases energy, blowing off the outer layers into space and leaving behind a Pulsar or Black Hole

Tycho’s Supernova

X-ray image of the SN 1572

remnant as seen by Calar Alto Observatory

www.nasa.gov/multimedia/imagegallery

SN 185

CHANDRA X-ray image of the SN 185 remnant

Observed by Chinese astronomers in 185 - the earliest known record of

a supernova

Type Ia

NASA/CXC/Univ. of Utrecht/J.Vink et al. XMM-Newton: ESA/Univ. of Utrecht/J.Vink et al

http://chandra.harvard.edu/photo/2006/rcw86

SN 1006

CHANDRA X-ray image of the SN 1006 remnant

Brightest Apparent

Magnitude event ever recorded –

brighter than Venus

Type Ia

NASA/CXC/Rutgers/J.Hughes et al.

http://chandra.harvard.edu/photo/2005/sn1006/

Cassiopeia A

CHANDRAX-ray image

Type IIbThe Pulsar is very bright at

Radio wavelengths but the SN remnant

is very faint optically

NASA/CXC/SAO/Rutgers/J.Hughes

http://chandra.harvard.edu/photo/1999/casajph/

SN 1987AType II

Exploded 168,000 years ago in the LMC but the light only got to us in 1987

NASA / ESA http://www.spacetelescope.org/index.html

ENERGY RELEASED BYCORE COLLAPSE PUSHESOUTER LAYER AWAY TOBECOME A PLANETARY

NEBULA

CARBON & OXYGENCORE COLLAPSES,BECOMES PULSAROR BLACK HOLE

TYPE Ib, Ic & TYPE II

SUPERNOVA: Core Collapse

SNR 1054CRAB

NEBULATYPE 2: CORE

COLLAPSEWITH A CENTRALPULSAR

M1, the Crab Nebula. Courtesy of NASA/ESA

TYPE 1a SUPERNOVA: STEP 1White Dwarf star accumulates mass

from a binary companionhttp://hubblesite.org/newscenter/newsdesk/archive/releases/1995/23/image/a

THIN OUTER LAYER OF

HYDROGEN AND HELIUM

CARBON / OXYGEN CORE

WHEN THE MASS OFTHE STAR REACHES

1.38 SOLAR MASSES, THE TEMPERATURE IN THE COREBECOMES HIGH ENOUGH TO

MAKE THE CARBON FUSE

TYPE 1a SUPERNOVA: STEP 2Carbon Detonation

LIGHTMv = -19.35 BILLIONTIMES AS

BRIGHT ASTHE SUN

TYPE 1a SUPERNOVA: STEP 3Explosion

LOTS ANDLOTS ANDLOTS OF

NEUTRINOS

THIN SHELL OF GASEXPANDS AT UP TO

3% THE SPEED OF LIGHTCARBON / OXYGEN

CORE VANISHES

SUPERNOVA SURVEYS

SLOAN DIGITAL SKY SURVEY

PURPOSEMap 25% of the Sky and Everything in it

INSTRUMENTAutomated 2.5m APO Telescope

CRITERIAAnything and Everything in the Survey Area

HOW MANY100 M Objects; 580 Supernovae

SUPERNOVA SURVEYS

ESSENCE

PURPOSEMeasure the Amount of Dark Energy

INSTRUMENTCTIO 4m and others

CRITERIAType IaEarly Universe: z = 0.2 to 0.8

HOW MANYSeeking 200 Type Ia; 90 so far

SUPERNOVA SURVEYS

SUPERNOVA LEGACY SURVEY

PURPOSEDetect and Monitor, Measure Characteristics

HOW MANYSeeking 2,000 Supernovae

INSTRUMENTCFHT 3.58m / 340 MP

CRITERIAHigh Redshift Early Universe

SUPERNOVA SURVEYS

VIMOSPURPOSEFind the rate at which supernovae happen

CRITERIARedshift from ~0.1 to ~1.2

HOW MANY14 Confirmed, another 23 possibles

INSTRUMENTVIMOS Wide-Field Multiple-Object Spectrograph

What We Can Learn From Supernovae

Systematic Control

Host-galaxy dust extinction

Wavelength-dependent absorption identified with high S/N multi-band photometry.

Supernova evolution Supernova subclassified with high S/N light curves and peak-brightness spectrum.

Malmquist bias Supernova discovered early with high S/N multi-band photometry.

K-correction Construction of a library of supernova spectra.

Gravitational lensing Measure the average flux for a large number of supernovae in each redshift bin.

Non-Type Ia contamination

Classification of each event with a peak-brightness spectrum.

For accurate and precision cosmology,need to identify and control systematic uncertainties.

Eric Linder University of California, BerkeleyLawrence Berkeley National Lab

REFERENCES

• SN 1994D in NGC 4526, NASA / ESA / Hubble Key Project Team / High-Z Supernova Search Team• X-ray image of the SN 1572 remnant / Calar Alto Observatory / NASA• NASA/CXC/Univ. of Utrecht/J.Vink et al. XMM-Newton: ESA/Univ. of Utrecht/J.Vink et al• NASA/CXC/Rutgers/J.Hughes et al.• SN 1987A - NASA / ESA• NASA /HST hubblesite.org/newscenter/newsdesk/archive/releases/1995/23/image/a• Sloan Digital Sky Survay / Sloan Foundation• Eric Linder / University of California, Berkeley Lawrence Berkeley National Lab