Karen Kwitter
Williams College
IAU 283
July 26, 2011 NGC 2818
NASA, ESA, Hubble Heritage Team
PN postage stamp images from HST
1936 T. Page letter in Nature NGC 7027 & NGC 7662: Ar, Ne >> Earth
1939 Bowen & Wyse, Lick Obs. Bulletin
NGC 6572, NGC 7027, NGC 7662: ~solar composition
2006-2011 >300 refereed papers in ADS on PN
abundances: familiar elements,
heavier elements, s-process,
molecules, dust
bpc.edu
Péquignot & Baluteau (1994); Baluteau et al. (1995); Zhang, Dinerstein, Sterling et al. (2001, 2008); Liu et al. (2005, 2007); Sharpee et al. (2007)
* *
reflect progenitor’s ISM
*There is some evidence that nuclear processes can affect
these (Pequignot et al. 2000, Dinerstein et al. 2003; Herwig
2005, Wang & Liu 2008, Milingo et al. 2010 – more later)
bpc.edu
bpc.edu
http://en.wikipedia.org/wiki/en:Creative_Commons
s-process
affected by star’s nucleosynthesis
• get 1-D information @ medium resolution; typically ≲150 lines
down to ~1% x Hb
for brighter objects can get deep
spectra w/high S/N; at right, in NGC 7009 Fang & Liu (2011; poster
here) have identified 1170 features
down to ~0.01% x Hb
but, LSS fails to fully utilize the potential of 2D detectors…
WIYN,NOAO,NSF
Milky Way: Kingsburgh & Barlow
Liu & colleagues
Maciel, Costa & colleagues
Milanova & Koltygin
Perinotto & colleagues
Stasińska & colleagues
Henry, Kwitter & colleagues
Magellanic Clouds:
Boroson & Liebert
Leisy & Dennefeld
Maciel, Costa & colleagues
Dopita & colleagues
Stanghellini, Shaw et al.
Vasiliadis & colleagues.
Juan Carlos Casado (TWAN)
Fred Espenak
exploits 2D detectors with serious multiplexing
Tsamis & collaborators; Sandin & collaborators
NGC 5882 Tsamis et al. 2008
Hb
He II 4686 [O III]
4959
IC 3568
NGC 7662, center
Sandin et al. 2008
c
Te
PMAS, Calar Alto FLAMES/Giraffe Argus, VLT
M1-42 (Pottasch et al. 2007) Spitzer/JPL
• Spitzer IRS provided high-
quality spectra covering
important ions of e.g., Ne,
O, S, Ar (& Fe, Si, Mg)
• Need for ICFs is reduced
• Fine-structure lines have
small T-dependence
Pottasch, Bernard-Salas & collaborators
Stanghellini, Shaw & collaborators
Guzman-Ramirez & collaborators
• prominent ions of He, C, N, O
• avoids usually large ICF(N)
• at right, TS01, the most O-poor PN
known (O/H~1/70 x solar)
• IUE quality superseded by HST COS
& STIS; as yet, small database
HST/STIS Cy19 : Dufour et al. – 10 MW PNe
Guerrero et al. – NGC 6543
STIS [N V]
[C IV] He II
[N IV]
TS-01 Stasińska et al. 2010
HST/STIS
• correct reduced slit fluxes for reddening
• calculate Te, Ne, X+i/H+
N-level atom codes
• calculate ICF’s per some recipe or model*
to derive X/H:
*unless you have all relevant ionization stages
ICF(X) = total X abundance
sum of observable X ions
- Whitford 1958
- Miller & Mathews 1972
- Savage & Mathis 1979
- Seaton 1979
- Howarth 1983
- Fitzpatrick 1999
- Clayton, Cardelli & Mathis 1989
• correct reduced slit fluxes for reddening
fl
An example:
For c=1, the corrected ratio of [O II] I3727/I7323 obtained using CCM vs. SM differs by ~15%, leading to ~1000K difference in the
derived T[O II]…
Il (Xi)
I(Hb) f (Te,Ne ) C
N(X i)
N(H)
Abundance Software Te , Ne ,
N(X+i)/N(H+) Il(X+i)/I(Hb)
• calculate: Te , Ne , X+i/H+
…in NGC 6543, the
systematic uncertainty
introduced by the choice
of atomic data is
comparable to or larger
than the statistical
uncertainties for some
temperatures, densities
and abundances.
R. Wesson (private communication)
on the ground… poster by
Wesson;
talk by
Luridiana
N/H
…not a stationary target
T[S II]
•calculate ionization correction factors (ICFs) per a recipe or model* to derive X/H
*unless you have observed all relevant ionization stages
talk by
Gonçalves
ICFs best determined using photoionization
models; otherwise, exploit IP coincidences
• Kingsburgh & Barlow (1994): developed a good set
still used by many
• Henry & Ferland are currently running sets of
CLOUDY models to evaluate ICFs under a wide
range of stellar T*, Ne, and Z.
… so at each step we have an opportunity for
divergence, independent of measured fluxes!
• Georgiev et al. (2008): NGC 6543
NLTE star and wind model agrees
with ORL values for He, C, O (but
not N)
• García-Rojas et al. (2009): observed
several PNe with WC central stars;
t2 ~0.04; no evidence of cool, C-rich
inclusions, even when the central
stars are H-deficient
recent summary by Peña (2011); Bob Rubin’s talk yesterday
• Yuan et al. (2011): NGC 6153 - 3D bi-
abundance model with 800K
inclusions best reproduces observed
spectrum
• Zhang (2008): NGC 7009 - high
resolution line profiles suggest ORLs,
CELs may originate in kinematically
different regions
• Williams et al. (2008): UV absorption
abundances in 3 PNe agree better
with CEL than ORL abundances
(Liu & colleagues) (Peimbert, Torres-Peimbert & colleagues)
This is becoming testable, and will eventually be sorted out…
ADF=(X/H)ORL/(X/H)CEL
posters by
Peimberts; Fierro et al.;
McNabb et al.; R.-Garcia & Peña
: 1D photoionization code (Stasińska 2005)
: 1D photoionization code (Ferland et al. 1998)
: 1D photoionization/shock code (Kewley 2001)
: 1D photoionization code (Rubin et al. 1994)
: Pseudo-3D photoionization code (Morriset 2005)
: fully 3D Monte Carlo photoionization code
(Ercolano et al. 2003)
: 1-D RHD code (Perinotto et al. 1998) – poster by Jacob
X
X
all abundances are
medians; error bars
show characteristic
uncertainties
different He+
recomb coeff
• good agreement
within uncertainties
• O, Ne, Ar ≈ solar N,C > solar
S < solar
DISK BULGE & HALO
MW Disk Magellanic Clouds
Maciel et al. 2010
+: SMC •: LMC •: MW
models: Karakas & Lattanzio 2007, 1-6
M
similar behavior in all 3 galaxies implies similar origin of N, He
log(N/O) vs. He/H
Karakas (2009): 1-6 M
Marigo (2001): 0.8-5 M
log(N/H) vs. log(He/H)
HKB04 all recalculated,
good T & N determinations
• LMC PNe show
negative trend, HBB
• Type I MWPNe
may also
• SMC PNe do not no HBB
Ne vs. O
• Wang & Liu (2008): Ne, O production only at 12+log(O/H) < 8 (<ZSMC)
• Milingo et al. (2010): some evidence for Ne production, based on on comparison with H II regions; no difference between Type I and Type II PNe
• Peimbert et al. (1992); Peña et al. (this meeting): argue that the ICF for Ne (Ne/O=Ne++/O++) is inadequate at low ionization typically found in H II regions
lower limits, offering an explanation for Milingo et al.’s finding
Maciel et al. 2010
+ SMC LMC MW
Maciel et al.: no correlation between
Ne/O and O over >2 dex in O/H
Ne vs. O
Ar follows H II region
trend, but with larger
scatter than Ne…
Sulfur stinks!
posters by
Henry et al.
Jacob et al.
Karakas: 1-6 M
MW disk PNe – Maciel & Costa (2011) LMC/SMC – Stanghellini et al. (2009)
filled: SMC open: LMC
• Average He and N are higher for asymmetric PNe than for
symmetric PNe
• The opposite is true for C.
• Higher O, Ne, S, Ar in asymmetric PNe younger progenitors
Aasymm,symm - Aall
• SMC PNe tend to be C-rich, implying no HBB
talk by
Karakas;
poster by
Sterling et al.
• Sharpee et al. (2007) detected lines of Br, Kr,
Xe, Rb, Ba, and Pb; Te & I (?); Kr, Xe
enhanced
• Sterling & Dinerstein (2008), detected Kr &/or
Se in 81 of 120 PNe:
- Non-Type I: [Se/(O)]ave= +0.36
[Kr/(O)]ave = +1.02 Kr significantly enhanced
- Type I PNe show little s-process enrichment
- Positive correlation between s-process
enrichments and C/O, as expected in TDU
- No significant difference with central star type
• Future progress relies heavily on knowing
transition rates and collision strengths
Se
Kr
• Delgado Inglada et al. (2009): 33 low-ionization PNe
• median 12+log(Fe/H) = 5.85 (4.27 – 6.49)
• depletion range [Fe/H]: -1.01 to -3.2 (=7.50; Asplund et al. 2009)
- Fe > 90% depleted
- Mdust/Mgas ≥ 1.3 x 10-3
- depletion scales with C/O ratio (poster)
poster by
Delgado
Inglada et al.
See also: Rodriguez & Rubin (2005); Stasińska & Szczerba (1999)
• He, C, N, O, Ne, S, Ar, Fe, s-process abundances have been
determined in 10’s -100’s of PNe in the MW and MC’s.
• IR & UV observations have provided some improved results.
• Significant disparities result from different analysis choices.
• O, Ne, and Ar are positively correlated with each other, as
expected. S is problematic. In general, scatterPNe > scatterH2BCG.
• C, N generally exceed solar, consistent with current LIMS model
predictions including TDU; low-C PNe in the Milky Way & LMC
show evidence of HBB.
• Models cover the parameter space of observed abundances
• s-process elements can be significantly enhanced above solar in
non-Type I PNe.
• Fe is significantly depleted in PNe
.
• atomic data for more atoms, wider regimes
- “normal data” for heavy atoms (Sterling poster)
- low-T parameters for light atoms (Fang poster)
• improved ICFs (metallicity; ionization; geometry)
• more 2D abundance studies/3D modeling
• abundance discrepancy resolution
• coordination/testing among 5-LA programs
• understanding the effect of binarity on observed
abundances in CE scenario
• development of a “strong-line method” when direct
Te measurement not possible
(aside from big ground & space telescopes & good spectrographs)
Students: Funding Sources: Jesse Levitt ’08 NSF
Matt Johnson ’07 NASA
Peter O’Malley ’07 U. Oklahoma
Julie Skinner ’07 Williams College
Anne Jaskot ’08 Emma Lehman ’10
Tim Miller (‘G OU)
Collaborators: Dick Henry
Bruce Balick
Reggie Dufour
Gary Ferland
Jacquelynne Milingo Dick Shaw
THE END EL FINAL