The PHOENIX Model Atmosphere Package - FTP Directory Listing

The PHOENIX Model
Atmosphere Package
Peter H. Hauschildt
yeti@hs.uni-hamburg.de
Hamburger Sternwarte
Gojenbergsweg 112
21029 Hamburg
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.1

PHOENIX version 16
integrated /1D and /3D versions
same micro-physics from 1D to 3D
new EOS (ACES)
dust formation/destruction →
DRIFT (Helling & Woitke)
massively parallel:
multi-stage domain decomposition
MPI
weak & strong scaling verified to 4k+ processes
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.2

Applications
PHOENIX v16 is being used to model
“all” types of normal stars
nova and supernova atmospheres
very low mass stars, brown dwarfs & Exoplanet
atmospheres
irradiated planets/stars
terrestrial planets
disks (proto-planetary, AGN)
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.3

Model Construction
Basic Physical Model
spherical shell
static (stars) or expanding (novae, winds, SNe)
hydrostatic or hydrodynamical equilibrium
central source provides energy
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.4

Model Construction
Constraint equations:
energy conservation
→ temperature structure
momentum conservation
→ pressure & velocity structure
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.5

Model Construction
“Auxiliary” equations:
Radiative transfer equation
solved via (non-local) operator splitting
full characteristics based method
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.6

Model Construction
Radiative transfer equation
1 or 3D
time independence
problem: scattering (dust, lines)
∂
∂t I(ν,⃗x, ˆ⃗n) + ˆ⃗n · ∇I(ν,⃗x, ˆ⃗n)
(
= χ(ν,⃗x) S(ν,⃗x) − I(ν,⃗x, ˆ⃗n)
)
solve for large optical depths & strong scattering
allow for irradiation, velocity fields
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.7

3DRT Framework
Cartesian (spherical, cylindrical) coordinates
voxel grid (“cells”)
physical data constant within a voxel
solve RT inside the voxels
grid coordinates, e.g., [−n x , +n x ]
→ voxel coordinates from (−n x , −n y , −n z ) to
(+n x , +n y , +n z )
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.8

Data size
small grid:
n x = n y = n z = 32
→ (2 ∗ 32 + 1) 3 = 274 625 voxels
compare to typically 64 to 128 grid points in 1D!
large grid:
n x = n y = n z = 128
→ (2 ∗ 128 + 1) 3 = 16 974 593 voxels
→ one scalar physical variable (e.g., T) → 129 MB
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.9

3DRT Framework
solution through operator splitting
[1 − Λ ∗ (1 − ǫ)] ¯J new = ¯J fs − Λ ∗ (1 − ǫ) ¯J old ,
where ¯J fs = ΛS old .
need method to perform FS
need method to construct Λ ∗
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.10

Computation of Λ ∗
tri-diagonal operator in the 1D case
→ nearest neighbor Λ ∗ in 3D
1D: considers interaction of point with two direct
neighbors
3D: interaction of a voxel with the 3 3 − 1 = 26
surrounding voxels
(or 6 neighbors in strictly face-centered view)
3D: storage requirements large but worth it!
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.11

convergence: ǫ l = 10 −8
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.12

Model Construction
“Auxiliary” equations:
equation of state → (T,P gas ,ρ) relation
high temperatures:
(hot stars, Supernovae, novae)
→ need to include many ions
low temperatures:
(Brown dwarfs, Jupiter-like planets, cool
novae)
→ need to include 100’s of molecules & dust
species
ACES EOS (Travis Barman), valid above 100 K
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.13

Molecules
Selected molecules considered in the EOS
NH C 2 CN CO MgH CaH SiH TiO H 2 O H 2
N 2 NO CO 2 O 2 ZrO VO MgS SiO AlH HCl
HF HS TiH AlO BO CrO LaO MgO ScO YO
SiF NaCl CaOH HCN C 2 H 2 CH 4 CH 2 C 2 H HCO NH 2
LiOH C 2 O AlOF NaOH MgOH AlO 2 Al 2 O AlOH SiH 2 SiO 2
H 2 S OCS KOH TiO 2 TiOCl VO 2 FeF 2 YO 2 ZrO 2 BaOH
LaO 2 C 2 H 4 C 3 SiC 2 CH 3 C 3 H NH 3 C 2 N 2 C 2 N CaF 2
AlOCl Si 2 C CS 2 CaCl 2 AlF CaF Si 2 SiS CS AlCl
KCl CaCl TiS TiCl SiN AlS AL 2 FeO SiC TiF 2
FeH LiCl NS NaH SO S 2 AlBO 2 AlClF AlCl 2 AlF 2
AlOF 2 AlO 2 H Al 2 O 2 BeBO 2 OBF HBO HBO 2 HBS BH 2 BO 2 H 2
BH 3 H 3 BO 3 KBO 2 LiBO 2 NaBO 2 BO 2 BaCl 2 BaF 2 BaO 2 H 2 BaClF
BeCl 2 BeF 2 BeOH BeH 2 BeH 2 O 2 Be 2 O Be 3 O 3 ClCN CHCl CHF
CHP CH 3 Cl KCN NaCN BeC 2 C 2 HCl C 2 HF (NaCN) 2 C 4 C 5
CaO 2 H 2 MgClF SiH 3 Cl FeCl 2 K 2 Cl 2 MgCl 2 Na 2 Cl 2 TiOCl 2 SrCl 2 TiCl 2
ZrCl 2 TiCl 3 ZrCl 3 ZrCl 4 CrO 2 SiH 3 F OTiF SiH 2 F 2 MgF 2 SrF 2
ZrF 2 TiF 3 ZrF 4 FeO 2 H 2 SrOH (KOH) 2 (LiOH) 2 MgO 2 H 2 (NaOH) 2 SrO 2 H 2
PH 2 PH 3 SiH 4 Si 2 N PO 2 SO 2 P 4 Si 3 NO 2 NO 3
C 3 N C 2 H 3 C 4 H HC 3 N C 4 H 2 CH 3 CN HC 5 N C 6 H C 4 H 4 C 6 H 2
HC 7 N C 4 H 4 S C 4 H 4 O C 4 H 6 C 6 H 4 HC 9 N C 5 H 5 N C 6 H 5 O C 6 H 6 C 6 H 6 O
HC 11 N OH − CH − C − 2 OH CH CN − SiH − H − 2 HS −
CS − FeO − BO − AlCl
− 2 AlF
− 2 AlOF − 2 AlOH − CO
− 2 NO + H
+ 2
TiO + ZrO + AlOH + BaOH + HCO + CaOH + SrOH + H 3 O + H + 3
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.14

Liquids & Solids
Selected liquid/dust species considered in the EOS
Al/l B/l Ba/l Be/l Ca/l Cr/l Cu/l Fe/l K/l
Li/l Mg/l Mn/l Na/l Nb/l Ni/l P/l S/l Si/l
Sr/l Ti/l V/l Zn/l Zr/l BeO/l ClK/l NbO/l OSr/l
ClNa/l VO/l B 2 Ti/l BaCl 2 /l CaCl 2 /l Cl 2 Fe/l Cl 2 Sr/l O 2 Si/l Li 2 O/l
Mg 2 Si/l Cu 2 O/l Cl 3 Fe/l Cr 2 O 3 /l NiS 2 /l BLiO 2 /l Cl 2 S 2 /l Ni 3 S 2 /l Al 2 O 3 /l
O 3 V 2 /l Cl 5 Nb/l Nb 2 O 5 /l B 4 K 2 O 7 B 4 Na 2 O 7 Li 2 O 3 Si B 4 Li 2 O 7 Mg 3 O 8 P 2 Al 3 F 14 N
B 5 H 9 /l H 10 O 8 S B 8 K 2 O 13 B 10 H 14 Al B Ba Be C
Ca Co Cr Cu Fe Li Mg Mn Na
Nb Ni P S Si Sr Ti V Zn
Zr MgO FeS CaO CaS MgS TiN AlN NiS
MnS TiO VO CuO FeO TiC SiC ZrC H 2 O
TiO 2 ZrO 2 SiO 2 FeS 2 NiS 2 Mg 3 N 2 Ni 3 S 2 Ti 2 O 3 Ti 3 O 5
Ti 4 O 7 V 2 O 3 Al 2 O 3 Al 2 O 3 Al 2 O 3 Al 2 O 3 Al 2 S 3 Cr 2 O 3 CaTiO 3
MgTiO 3 MgSiO 3 CaSiO 3 MnSiO 3 Na 2 SiO 3 K 2 SiO 3 Fe 2 SiO 4 Ca 2 SiO 4 Mg 2 SiO 4
ZrSiO 4 Fe 2 O 3 Fe 3 O 4 MgAl 2 O 4 MgTi 2 O 5 Al 2 SiO 5 CaMgSi 2 Ca 2 MgSi Ca 2 Al 2 S
CaAl 2 Si KAlSi 3 O NaAlSi 3 Al 6 Si 2 O MgC 2 Cr 3 C 2 Mg 2 C 3 Al 4 C 3 Cr 7 C 3
Cr 23 C 6
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.15

Model Construction
statistical equilibrium equations
→ relate the population of each energy level to
non-local radiation field and to collisional
processes
radiative transfer & statistical equilibrium
equations are intricately coupled
→ must be solved together
→ statistical equations are inherently non-local ⇒
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.16

Fe NLTE model atoms
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.17

Model Construction
atomic line blanketing: ≈ 5 − 30 × 10 6 lines
dynamically selected from a list of 83 × 10 6 lines
molecular line blanketing: ≈ 15 − 600 × 10 6 lines
dynamically selected from a list of 1.2 × 10 9 lines
direct opacity sampling of line blanketing
depth dependent line profiles
→ no ODF or opacity sampling tables (NLTE!).
special profiles for important lines
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.18

Computational Problem
1D (serial) CPU time: 1–6 CPU days
3D (serial) CPU time: 10 CPU years
Solution: parallel computing
dramatically reduces wallclock time per model
allows efficient use of existing large
supercomputer facilities
1D: 8-16 CPUs for a few hours
3D: 4096 CPUs for one day
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.19

Results: A stars
models work well for A0V’s . . .
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.20

Results: solar type stars
models work well for G2V’s . . .
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.21

Dust formation/destruction
directly couple DRIFT (Helling & Woitke) dust
model to PHOENIX model atmospheres
PHOENIX → provides atmosphere structure
(T,P g ,...)
DRIFT → compute dust formation/destruction
(cloud deck)
→ feedback to PHOENIX
→ new atmosphere structure
iterate to convergence
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.22

DRIFT dust mode
Helling & Woitke
stationary solution
nucleation rates for (TiO 2 ) N seeds
7 most important solids used (TiO 2 , Al 2 O 3 , Fe, SiO 2 ,
MgO, MgSiO 3 , Mg 2 SiO 2 )
mixing by convection + overshooting
grain size distribution via moments
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.23

DRIFT dust mode
Helling et al (2001)
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.24

DRIFT-PHOENIX models
location of convection zone crucial for dust
formation!
considering feedback dust formation vs.
atmosphere structure crucial
cloud deck depends on model parameters
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.25

atmosphere structure feedback
Dissertation M. Dehn (2007)
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.26

Application: good fits
Witte et al (2011)
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.27

Application: good fits
Witte et al (2011)
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.28

Application: good fits
Witte et al (2011)
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.29

Irradiation
temperature structure for different separations
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.30

Irradiation
EGP spectra for different separations
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.31

Results: 2D structure
roll the movie!
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.32

Results: 3DRT w/ irradiation
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.33

Results: 3D w/ irradiation
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.34

spherical 3D coordinates
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.35

PHOENIX 1D vs 3D: 3000K
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.36

PHOENIX 1D vs 3D: 5700K
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.37

PHOENIX 1D vs 3D: 9000K
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.38

3D visualization: hydro model, line
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.39

3D visualization: GCM planet
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.40

Conclusions: The Future
better/more detailed line profiles
optical properties of dust particles
→ materials physics!
detailed models of dust formation
→ composition/sizes/shapes
non-equilibrium effects → NLTE+NLCE
multi-D RT calculations → irradiation
Brussels.tex – The PHOENIX Model Atmosphere Package – Peter H. Hauschildt – 21/6/2011 – 16:49 – p.41