SNP2008, Ohio University, July 8-11

Impact of Nuclear Input onX-ray bursts

Richard H. CyburtRyan FergusonZach MeiselScott WarrenMatthew AmthorKarl SmithHendrik Schatz

SNP2008, Ohio University, July 8-11

Outline

Motivation nuclear physics in astrophysics X-ray bursts Astrophysics in nuclear physics Conclusions

SNP2008, Ohio University, July 8-11

Motivation

Big Bang Nucleosynthesis

CR Nucleosynthesis

s-process

r-process

p-process

nova

supernova

x-ray bursts

stars

Origin of Elements!Explosion Light Curves!

SNP2008, Ohio University, July 8-11

A Closer Look

Nuclear Structure impacts nuclear astrophysics!

SNP2008, Ohio University, July 8-11

Let’s consider X-ray bursts

They’re explosions! They’re on neutron stars! They go off regularly! We can see ~1000s of them!

Sounds pretty cool, but… How easy are they to understand?

SNP2008, Ohio University, July 8-11

Type I X-ray bursts

Accreting H/He but not too fast

n.s. fairly old low B-field slow rotation

Thermonuclear runaway

SNP2008, Ohio University, July 8-11

rp-process

Helium burns to Carbon

rapid (p,)/(,p)/+ decays Up the N=Z line on nuclide chart

Peak brightness <A>~56

SNP2008, Ohio University, July 8-11

Movie

SNP2008, Ohio University, July 8-11

Nuclear input

Thermonuclear reaction rates Not well covered by expt. Relies heavily on theory Which relies on nuclide masses

weak decay rates Need & T dependent rates Good expt. g.s. coverage

Time lag incorporating new input

SNP2008, Ohio University, July 8-11

rp-process db summary

•expt based rates•thry based rates

SNP2008, Ohio University, July 8-11

New Theory Rates (p,)

Within a factor of 2

SNP2008, Ohio University, July 8-11

New Theory Rates (,p)

SNP2008, Ohio University, July 8-11

Impact of New Rates

SNP2008, Ohio University, July 8-11

Theory Rates

Rates are all Rauscher rates Small impact w/ Rauscher rates What about other models?

They need to be publically available!

SNP2008, Ohio University, July 8-11

JINA Reaclib Database

stores rxn rates in standard form

remembers old versions

Online interface easily accessible

Provides link of communication

SNP2008, Ohio University, July 8-11

www.nscl.msu.edu/~nero/db

SNP2008, Ohio University, July 8-11

Conclusions

Goal: nuke input not dom. uncertainty Use x-ray bursts to understand n.s. constrain exotic physics

Nuclear astro. gaining much ground new expt. facilities/techniques large computational efforts Theories ever-scrutinized