supernova! sn 1994d in ngc 4526, nasa / esa / hubble key project team / high-z supernova search team
TRANSCRIPT
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