Miller sapporo draft

New perspectives on B star X-ray emission: The high-resolution X-ray spectra of Spica and β Cen : 

New perspectives on B star X-ray emission: The high-resolution X-ray spectra of Spica and β Cen

Slide2: 

Collaborators on both projects: Nathan Miller Joe Cassinelli β Cen Ton Raassen Emre Tepedelenlioglu Rolf Mewe Spica Ron Reynolds Joe MacFarlane Nate Hall

Main Question: Where and how do B stars produce their X-rays? Three approaches:: 

Main Question: Where and how do B stars produce their X-rays? Three approaches: Line profiles – broadened or not? Line ratios from He-like ions Is X-ray flux affected by β Cep-type pulsations

Stars’ Biographical Details: 

Stars’ Biographical Details

β Cen XMM spectra: 

β Cen XMM spectra

Spica LETG-ACIS-S spectrum: 

Spica LETG-ACIS-S spectrum

1. Emission Line Profiles: 

1. Emission Line Profiles

Profiles of CVI lineof β Cen : 

Profiles of CVI line of β Cen

Spica Line Profiles(vs. scaled Capella in red): 

Spica Line Profiles (vs. scaled Capella in red) (Capella Aa (the main X-ray source) had v ≈ +25 km/s during the observation shown here (Ishibashi & Dewey 2005)

2. f/i Ratios from He-like Ions: 

2. f/i Ratios from He-like Ions

f/i ratios for β Cen (Kurucz model): 

f/i ratios for β Cen (Kurucz model)

Spica’s Ne IX fir region: 

Spica’s Ne IX fir region

Spica’s O VII fir region: 

Spica’s O VII fir region

Density falloff in Spica’s windCritical Densities Marked:Radiation will control f/i ratio: 

Density falloff in Spica’s wind Critical Densities Marked: Radiation will control f/i ratio

Interpreting Spica’s f/i ratios(Hubeny model) : 

Interpreting Spica’s f/i ratios (Hubeny model)

Interpreting Spica’s f/i ratios(Kurucz model – calc by MacFarlane) : 

Interpreting Spica’s f/i ratios (Kurucz model – calc by MacFarlane)

-H II region is relatively isolated-Will use to measure ionizing flux and calibrate photospheric FUV/EUV flux which effects f/i ratios: 

-H II region is relatively isolated -Will use to measure ionizing flux and calibrate photospheric FUV/EUV flux which effects f/i ratios Spica’s H II region (Wisconsin H-Alpha Mapper (WHAM) image)

3. X-ray Lightcurves: 

3. X-ray Lightcurves

β Cen Lightcurves: 3 XMM instruments: 

β Cen Lightcurves: 3 XMM instruments

β Cen – folded on β Cep period: 

β Cen – folded on β Cep period

Spica β-Cep-Type History: 

Spica β-Cep-Type History Seen as β Cep variable by Shobbrook et al. (1969) with p=0.1738 d (pulsations evident in archived observations) Photometric variations died out by 1972 (Lomb 1978) May still be pulsing, but axis of NRP may have processed so that we are observing pole-on (Balona 1985) (precession period 130-140 yrs) (Dukes 1974)

Spica’s X-ray Lightcurve: 

Spica’s X-ray Lightcurve

Spica data folded on β Cep period: 

Spica data folded on β Cep period

Conclusions:: 

Conclusions: X-ray emission lines are not strongly Doppler-broadened in either case He-like ions indicate X-rays formed at a range of radii (at least for Spica) No evidence is found for either star to be variable in X-rays on their β Cep periods