CII and OII Recombination Lines in Extragalactic HII Regions

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CII and OII Recombination Lines in Extragalactic
HII Regions
A????a, June 23rd 2008
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In collaboration with
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The aims

• Measure CII and OII recombination lines (RLs)
• in extragalactic HII regions and HII
  galaxies,
• I(?) ?10-4 I(H?)?
• Fainter than the optical OIII and UV CIII
  lines
• Derive C/H and O/H ratios from RLs
• almost independent on Te and Ne
• independent on the reddening law (in the case of
  C )?

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The aims

• Estimate the Abundance Discrepancy Factor (ADF)
  
• ADF(Xi) log (Xi/H)RLs log(Xi/H)CELs
• Explore the behavior of the ADF with respect to
  HII region
• and host galaxy properties
• Derive C and C/O gradients in galaxies and model
  them

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The observational requirements
We need

• Deep
• (large aperture telescopes)?
• High Spectral Resolution
• (R?10,000)?

Spectrophotometry
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The data

• HIRES _at_ 10m Keck I (echelle)?
• 9 GEHRs in
  spiral and dwarf galaxies
• UVES _at_ 8m VLT (echelle)?
• (8 HII galaxies) and 1 GEHRs in a
  dwarf galaxy
• ISIS _at_ 4.2m WHT (intermediate resol.)?
• 
  Additional data for 2 GEHRs

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The HIRES_at_Keck objects
HII regions in M101
Keck obs
WHT obs
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The HIRES_at_Keck objects
HII regions in M33
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The HIRES_at_Keck objects
HII regions in NGC 2403
VS 24
VS 38
VS 44
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The HIRES_at_Keck data
NGC 2363
Low metallicity object 12log(O/H) (CELs) 7.76
1.5 hours integration time , 99 lines
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The HIRES_at_Keck data
NGC 604 (M 33)?
1 hour integration time, 135 lines
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The HIRES_at_Keck data
K932 (M 31)?
1.5 hours integration time, 100 lines
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The preliminary results
The ADF(O)?
ADF(O) log (O/H)RLs log(O/H)CELs

• Average ADF(O) of the Galactic sample
  0.30 ? 0.08
• (García-Rojas 2006, García-Rojas Esteban 2007)?

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The preliminary results
The ADF(C)?
a Garnett et al. (1999), assuming RV 3.1 /
5.0 b Garnett et al. (1995)?
C/H (CELs) determined from UV lines (Garnett
et al. 95, 99)?
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The preliminary results
Future analysis
Explore correlations between the ADF and

• Metallicity
• FWHM of the lines and gas kinematics
• Properties of the host galaxy (morphological
  type, size...)

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The preliminary results
The associated t2

• Average t2(O) of the Galactic sample
  0.035 ? 0.006
• (García-Rojas 2006, García-Rojas Esteban 2007)?

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The preliminary results
The O gradients
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The preliminary results
The C and C/O gradients
a Esteban et al. (2005)?
C abundance gradient steeper than O gradient
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The preliminary results
C/O vs. O/H in HII regions
GEHRs in spirals
GEHRs in dwarf galaxies
Models for the Solar vicinity (RG8 kpc)
high wind yields Mup 80 M?
(Carigi et al. 2005)?
low wind yields Mup 60 M?
(Carigi Peimbert 08)?
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The preliminary results
C/O vs. O/H in HII regions
GEHRs in spirals
GEHRs in dwarf galaxies
GEHRs in dwarf galaxies (literature)?
Models for the Solar vicinity (RG8 kpc)
high wind yields Mup 80 M?
(Carigi et al. 2005)?
low wind yields Mup 60 M?
(Carigi Peimbert 08)?
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The preliminary results
C/O vs. O/H in HII regions
GEHRs in spirals
GEHRs in dwarf galaxies
GEHRs in dwarf galaxies (literature)?
Galactic HII regions
Models for the Solar vicinity (RG8 kpc)
high wind yields Mup 80 M?
(Carigi et al. 2005)?
low wind yields Mup 60 M?
(Carigi Peimbert 08)?
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The preliminary results
C/O vs. O/H in HII regions
GEHRs in spirals
GEHRs in dwarf galaxies
GEHRs in dwarf galaxies (literature)?
Galactic HII regions
Models for the Galactic Disk at RG4 kpc
high wind yields Mup 80 M?
(Carigi et al. 2005)?
low wind yields Mup 60 M?
(Carigi Peimbert 08)?