(ESAC)

European Space Astronomy Centre

Jan-Uwe NessJan-Uwe NessXMM-Newton Science Operations CentreXMM-Newton Science Operations Centre

Application of X-ray PlasmaDiagnostics to Nova Winds

ChandraXMM-Newton

Swift

The RS Oph system Recurrent Nova with 6 recorded outbursts since 1898

Accreted

material:H-rich!

Nuclear burning ignites

outburst

WD

Accreted

material:H-rich!

Nuclear burning ignites

outburst

enough radiativeenergy is producedto drive a wind with

v ≈ 1500 km s-1

WD

Pseudo Stellar

AtmosphereNuclear burning

Photosphere

Radiatively driven expansion

brightest in optical -> discovery

equivalent toa stellarradiation zone

R=100x106km

after 1 day

WD

WD

Nuclear burning

Photosphere

Density drops, outer layers go optically thin

=> Radius of Photosphere recedes to inner, hotter, layers

Pseudo Stellar

Atmosphere

Pseudo Stellar

AtmosphereNuclear burning

Photosphere

=> fades in optical but Lbol constant

=> spectrum shifts to higher energies ...

WD

Pseudo Stellar

AtmosphereNuclear burning

Photosphere

.... until the peak of the spectrum reaches soft X-rays

--> direct observations of nuclear burning

Super-Soft-SourceX-ray spectrum

⇒ SSS phaseWD

Lbol=1038 erg/s

WD WD WD

Constant Bolometric Luminosity phaseConstant Bolometric Luminosity phase

optical UV X-ray

Novae are powered by nuclear burning

The pressure is not high enough on a WD

surface to produce any elements heavier

than Helium

The CNO cycle changes the relative

abundances of C, N, and O

If the nova ejecta show any other

anomalies in composition, then either

- WD material has been dredged up

- The companion is anomalous

SSS Emission from hot white dwarf

Shock withstellar wind

+ giant in Symbiotic Novae

+ MS star in Classical Novae

Osborne et al. (2011)

shock phase SSS phase nebular phase

Swift observations of RS Oph

optical

Osborne et al. (2008)

shock phase SSS phase nebular phase

Swift observations of RS Oph

Ch

an

dra

/XM

M

XM

M-N

ew

ton

Ch

an

dra

XM

M-N

ew

ton

----

--- -

----

Ch

an

dra

Ch

an

dra

Swift spectra

grating spectra

RS Oph: 13.8 days after outburst H-like ionsHe-like ionsother lines(FeXVII - FeXXV)

simultaneousChandra and XMMspectra

Ness & Jordan (2008) MNRAS 385, 1691

3-T APEC model reproducesthe observations

==>Assumption of collisional

equilibrium may not be too bad

proper EMD analysis

f G T

N

O NeSi

MgS

Fe

f G T

f G T

N

O

Ne

Mg Si

S

Fe

solarabundance

0.46 x solar

N high=>CNO-cycledmaterial

RS Oph secondary has [N/Fe]=0.9:(Pavlenko et al. 2008)

=> 20-40% of N fromoutburst or companion

Sample of M giants bySmith & Lambert (1985/86)

RS Oph secondary has [N/Fe]=0.9:(Pavlenko et al. 2008)

=> 20-40% of N fromoutburst or companion

Sample of M giants by Rich et al. (2007)

Mg, Si not produced in outburst=> must come from WD or companion

The companion in Symbiotic Novae is a giant star that has similar abundance ano- malies as those expected in nova ejecta The abundances for RS Oph appear more anomalous than for typical stars of the same spectral type as the companion We might be seeing WD material

=> too many heavy elements for SN Ia But: The companion in symbiotics is stripped off the outer layers, exposing layers with different abundances.

Summary