GALPROP tutorial Igor Moskalenko (Stanford U.)
Igor V. Moskalenko 2 November 17, 2005 GALPROP manual/Rome2, Italy
Obtaining GALPROP
The link:http://www.mpe.mpg.de/~aws/dlp/zxc/kty/v42.3p/
Contains c++, fortran routines & input files (dat-files, compass gas maps, and isrf)
Dedicated GALPROP Web-site will go online soon!
– Controlled changes in GALPROP: tests + documentation +…
– New version(s) + archive versions– Post relevant information: best models, gas maps, ISRF,
nuclear cross sections…– Allow for communication with users – Ability to run GALPROP on-line…
Igor V. Moskalenko 3 November 17, 2005 GALPROP manual/Rome2, Italy
I/O
galdef-filegas: COR, HIR, IAQ-filesRFComposite –(fits) file
dat-files (xsec, nuc.network)
GALPROP(c++ & fortran)
nuclei –(fits) file (R=Rsun)nuclei_full –(fits) file (whole galaxy)
γ-ray emissivities –(fits) files (brems, IC, π0)γ-ray skymaps –(fits) files (rings; brems, IC, π0)
FITS
GALDEF
v42.3
v42.3
FITS
sameleveldirs
Heliospheric modulation: on-the-fly in a plotting routine
Igor V. Moskalenko 4 November 17, 2005 GALPROP manual/Rome2, Italy
Example Makefile
#CXX = g++-2.95#FC = g77-2.95CFITSIO = ${GLAST_EXT}/cfitsio/v2470CPPFLAGS = -O3 -Wno-deprecated -I${CFITSIO}/includeFFLAGS =LIBS = -lm -lg2cFITSLIB = -L$(CFITSIO)/lib -lcfitsio -Wl, rpath,$(CFITSIO)/libLDFLAGS = $(FITSLIB) $(LIBS)FOBJS := $(patsubst %.f,%.o,$(wildcard *.f))CCOBJS := $(patsubst %.cc,%.o,$(wildcard *.cc))galprop: ${FOBJS} ${CCOBJS} $(CXX) *.o -o $@ ${LDFLAGS}
Igor V. Moskalenko 5 November 17, 2005 GALPROP manual/Rome2, Italy
Some Editing
Tested for g++ v2.9x compiler.New g++ compiler v3.x is more strict –routines require
some editing:
using namespace std;
#include<iostream>#include<cstdlib>#include<string>#include<cctype>#include<fstream>#include<cmath>
Igor V. Moskalenko 6 November 17, 2005 GALPROP manual/Rome2, Italy
GALPROP Input: galdef-files
GALPROP is parameter-driven (user can specify everything!)
Grids• 2D/3D –options; symmetry options (full 3D, 1/8 -quadrants)• Spatial, energy/momentum, latitude & longitude grids• Ranges: energy, R, x, y, z, latitude & longitude • Time steps
Propagation parameters
• Dxx, VA, VC & injection spectra (p,e)
• X-factors (including R-dependence)
Sources• Parameterized distributions• Known SNRs• Random SNRs (with given/random spectra), time dependent eq.Other• Source isotopic abundances, secondary particles (pbar , e±, γ,
synchro), anisotropic IC, energy losses, nuclear production cross sections…
Igor V. Moskalenko 7 November 17, 2005 GALPROP manual/Rome2, Italy
Algorithm
primary source functions (p, He, C .... Ni)source abundances, spectraprimary propagation -starting from maxA=64
source functions (Be, B...., e+,e-, pbars)using primaries and gas distributions secondary propagation
tertiary source functionstertiary propagation
-rays (IC, bremsstrahlung, πo-decay) radio: synchrotron
(i) CR –fixing propagation
(ii) γ-rays
Igor V. Moskalenko 8 November 17, 2005 GALPROP manual/Rome2, Italy
GALPROP Output/FITS files
Provides literally everything:• All nuclei and particle spectra in every grid point
(x,y,R,z,E) -FITS files
Separately for π0-decay, IC, bremsstrahlung:• Emissivities in every grid point
(x,y,R,z,E,process)• Skymaps with a given resolution (l,b,E,process)
• Output of maps separated into HI, H2, and rings to allow fitting X, metallicity gradient etc.
Igor V. Moskalenko 9 November 17, 2005 GALPROP manual/Rome2, Italy
Spatial Grids
Z
R,x,y0 1 2 3 4 5 6 7
1
-1
Typical grid steps (can be arbitrary!)Δz = 0.1 kpc, ΔΔz = 0.01 kpc (gas
averaging)ΔR = 1 kpcΔE = x1.2 (log-grid)
Igor V. Moskalenko 10 November 17, 2005 GALPROP manual/Rome2, Italy
GALPROP Calculations
Constraints• Bin size (x,y,z) depends on the computer speed, RAM; final run can be
done on a very fine grid ! • No other constraints ! –any required process/formalism can be
implemented
Calculations (γ -ray related)
Vectorization options Now 64 bit to allow unlimited arrays Heliospheric modulation: routinely force-field, more sophisticated
model ?1.For a given propagation parameters: propagate p, e, nuclei, secondaries
(currently in 2D)2.The propagated distributions are stored3.With propagated spectra: calculate the emissivities (π0-decay, IC,
bremss) in every grid point4.Integrate the emissivities over the line of sight: • GALPROP has a full 3D grid, but currently only 2D gas maps (H2, H I, H II)• Using actual annular maps (column density) at the final step• High latitudes above b=40˚ -using integrated H I distribution
Igor V. Moskalenko 11 November 17, 2005 GALPROP manual/Rome2, Italy
Dark Matter in GALPROP
DM annihilation products:χ0χ0−> p, pbar, e+, e−, γ
A set of routines (gen_DM_source.cc) to assign• The DM density profile (NFW, isothermal etc.)• Source functions for p, pbar, e+, e−
• Source function for γ’s• A set of user-defined parameters (10 int, 10
double precision) in galdef-file
DM annihilation products particles are propagated in the same model as CR particles.
Calculation of skymaps for DM γ-rays
Igor V. Moskalenko 16 November 17, 2005 GALPROP manual/Rome2, Italy
Nuclear Reaction Network+Cross Sections
p,EC,p,EC,ββ++
ββ--, , nn
Be7 Be10
Al26
Cl36
Mn54
Plus some dozens of more complicated reactions.But many cross sections are not well known…
V49
Ca41
Cr51
Fe55Co57
Ar37
SecondarySecondary,,radioactive ~1 Myrradioactive ~1 Myr
& & K-captureK-capture isotopesisotopes
Igor V. Moskalenko 17 November 17, 2005 GALPROP manual/Rome2, Italy
Nuclear Reaction Network
III
I
II
IV
V
nuc_package.cc
Igor V. Moskalenko 18 November 17, 2005 GALPROP manual/Rome2, Italy
nuc_package.cc: Stable & Long-lived Isotopes
Igor V. Moskalenko 19 November 17, 2005 GALPROP manual/Rome2, Italy
nuc_package.cc: Long-Lived Isotopes
Igor V. Moskalenko 20 November 17, 2005 GALPROP manual/Rome2, Italy
nuc_package.cc: “Boundary” Nuclei
Igor V. Moskalenko 22 November 17, 2005 GALPROP manual/Rome2, Italy
Transport Equations ~90 (no. of CR Transport Equations ~90 (no. of CR species)species)
ψψ((rr,p,t),p,t) – – density per total momentum
df
Vpdt
dp
p
ppppDp
p
Vxx
D
prqt
tpr
3
1
22
][
),(),,(
sources (SNR, nuclear reactions…)sources (SNR, nuclear reactions…)
convectionconvectiondiffusiondiffusion
diffusive reaccelerationdiffusive reacceleration
E-lossE-loss convectionconvection
fragmentationfragmentation radioactive decayradioactive decay
Igor V. Moskalenko 26 November 17, 2005 GALPROP manual/Rome2, Italy
Coefficients for the Crank-Nicholson Method
Igor V. Moskalenko 27 November 17, 2005 GALPROP manual/Rome2, Italy
Near Future Developments
Full 3D Galactic structure:• 3D gas maps (from S.Digel, S.Hunter and/or smbd else)• 3D interstellar radiation & magnetic fields (A.Strong & T.Porter)Cross sections:• Blattnig et al. formalism for π0-production • Diffractive dissociation with scaling violation (T.Kamae –param.)• Isotopic cross sections (with S.Mashnik, LANL; try to motivate BNL,
JENDL-Japan, other Nuc. Data Centers)Modeling the local structure:• Local SNRs with known positions and ages• Local Bubble, local clouds –may be done at the final calculation
step (grid bin size ??)Energy range:• Extend toward sub-MeV range to compare with INTEGRAL diffuse
emission (continuum; 511 keV line)Heliospheric modulation:• Implementing a modern formalism (Potgieter, Zank etc.)Visualization tool (started) using the classes of CERN ROOT package:
images, profiles, and spectra from GALPROP to be directly compared with data
Improving the GALPROP module structure (for DM studies)
Igor V. Moskalenko 28 November 17, 2005 GALPROP manual/Rome2, Italy
More developments
Point sources: develop algorithm(s) for modeling the background and interface to the rest of GLAST software
Instrumental response: how to implement Diffuse emission analysis has to include point source catalog! At least, two diffuse models: with/without the “excess” Develop test case(s) to test the accuracy of the numerical
model (simple gas distribution, no energy losses, uniform ISRF etc.)
Complete C++ package: rewrite several fortran routines in C++
Develop a fitting procedure to make automatic fitting to B/C ratio, CR spectra and abundances
Develop a dedicated Web-site:– Controlled changes in GALPROP: tests +documentation +…– Allow for communication with users– Post relevant information: best models, gas maps, ISRF, nuclear
cross sections…– Ability to run GALPROP on-line…
Igor V. Moskalenko 29 November 17, 2005 GALPROP manual/Rome2, Italy
Fixing Propagation Parameters: Standard Way
Using secondary/primary nuclei ratio:•Diffusion coefficient and its index•Propagation mode and its
parameters (e.g., reacceleration VA,
convection Vz)
Radioactive isotopes:
Galactic halo size Zh Zh increase
B/C
Be10/Be9
Inte
rste
llar
Ek, MeV/nucleon
Ek, MeV/nucleon
Igor V. Moskalenko 30 November 17, 2005 GALPROP manual/Rome2, Italy
Peak in the Secondary/Primary Ratio
• Leaky-box model: fitting path-length distribution -> free function
B/C
• Diffusion models: Diffusive reacceleration Convection Damping of interstellar
turbulence Etc.
Accurate measurements in a wide energy range may help to distinguish between the models
EEkk, MeV/nucleon, MeV/nucleon
too sharp max?
Igor V. Moskalenko 31 November 17, 2005 GALPROP manual/Rome2, Italy
Distributed Stochastic Reacceleration
Fermi 2-nd order mechanism
BB
Scattering on magnetic turbulences Dpp~ p2Va
2/D
D ~ vR1/3 - Kolmogorov spectrum
Icr
E
strongreaccelerati
onweakreacceleration
ΔE
Simon et al. 1986Seo & Ptuskin
1994
1/3
Dxx = 5.2x1028 (R/3 GV)1/3cm-2 s-1
Va = 36 km s-1
γ ~ R-δ, δ=1.8/2.4 below/above 4 GV
Igor V. Moskalenko 32 November 17, 2005 GALPROP manual/Rome2, Italy
Convection
Galactic wind
Escape length
Xe
E
vR-0.6
wind orturbulentdiffusion
resonantdiffusion
Jones 1979
problem: too broad sec/prim peak
D~R0.
6
Dxx = 2.5x1028 (R/4 GV)0.6cm-2 s-1
dV/dz = 10 km s-1 kpc-1
γ ~ R-δ, δ=2.46/2.16 below/above 20 GV
Igor V. Moskalenko 33 November 17, 2005 GALPROP manual/Rome2, Italy
Damping of Interstellar Turbulence
p
l(p)
Iroshnikov-Kraichnan cascade:
Kolmogorov cascade:
W(k)
k
dissipation
1/1012cm1/1020cm
Simplified case:
• 1-D diffusion• No energy losses
Mean free path
nonlinearcascade
Ptuskin et al. 2003, 2005
Igor V. Moskalenko 34 November 17, 2005 GALPROP manual/Rome2, Italy
Dxx – Diffusion Coefficient
Plain diffusion
Diffusivereacceleration
Reaccelerationwith damping
~R0.6
~β-3
Igor V. Moskalenko 35 November 17, 2005 GALPROP manual/Rome2, Italy
• Positrons/electrons p+p->π,K->e± (MS 1998)– Dermer 1986 method: LE –Stecker Δ-isobar model (isotropic
decay), HE –scaling (inv. x-section: Stephens & Badhwar 1981), plus interpolation in between
– Pion decay “includes” polarization of muons– Kaon decay – scaling (Stephens & Badhwar 1981)
• Antiprotons (M et al. 2002)– pp Inclusive production x-section (Tan & Ng 1983)– pA, AA-> pbar –scaling using Gaisser & Schaeffer 1992 or
Simon et al. 1998 –results similar– Total inelastic x-section (p: TN’83, A: Moiseev & Ormes 1997)
– p+pbar annihilation x-section = (p+pbar)tot – (p+p)tot (LE: TN’83, HE: PDG’00 –Regge parameterization)
How It Is Really Done: Secondary Particles
Igor V. Moskalenko 36 November 17, 2005 GALPROP manual/Rome2, Italy
Elemental Abundances: CR vs. Solar System
CR abundances: ACE
Solar system abundances
LiBeB
CNO
F
Fe
ScTiV
CrMn
Si
Cl
Al
O
Na
S
“input”
“output”
Igor V. Moskalenko 37 November 17, 2005 GALPROP manual/Rome2, Italy
Fitting to Measured CR Abundances (ACE vs HEAO-3)
Fitting to measured CR abundances in the wide energy range (~0.1 – 30 GeV) is problematic: May indicate systematic or cross-calibration errors
Igor V. Moskalenko 38 November 17, 2005 GALPROP manual/Rome2, Italy
Total Nuclear Cross Sections
Ekin, MeV/nucleonWellisch & Axen 1996
Igor V. Moskalenko 39 November 17, 2005 GALPROP manual/Rome2, Italy
Isotopic Production Cross Sections of LiBeB
Semi-empirical systematics are not always correct.
Results obtained by different groups are often inconsistent and hard to test.
Very limited number of nuclear measurements:
Evaluating the cross section is very laborious and can’t be done without modern nuclear codes.
Use LANL nuclear database and modern computer codes.
Igor V. Moskalenko 40 November 17, 2005 GALPROP manual/Rome2, Italy
LiBeB: Major Production Channels
Propagated Abundance * Cross-sectionPropagated Abundance * Cross-section
Be B
C
Li
N
OLi6
79 10
1113
1514
•Well defined (65%):C12, O16 ->LiBeBN14 -> Be7
(see Moskalenko & Mashnik 28 ICRC, 2003)
•Few measurements:C13,N -> LiBeBB -> BeB
•Unknown:LiBeB,C13,N -> LiBeB
“Tertiary” reactions also important! -35%
12 16
A=
Igor V. Moskalenko 41 November 17, 2005 GALPROP manual/Rome2, Italy
Effect of Cross Sections: Radioactive Effect of Cross Sections: Radioactive SecondariesSecondaries
Different Different size from different ratios…size from different ratios…
Zhalo,kpc
STST
WW
2727Al+pAl+p2626AlAl
•ErrorsErrors in CR measurements (HE & LE) in CR measurements (HE & LE)•ErrorsErrors in production cross sections in production cross sections•ErrorsErrors in the lifetime estimates in the lifetime estimates•DifferentDifferent origin of elements (Local origin of elements (Local Bubble ?)Bubble ?)
natnatSi+pSi+p2626AlAl
WW
STST
TT1/21/2==??
Ek, MeV/nucleon
Igor V. Moskalenko 42 November 17, 2005 GALPROP manual/Rome2, Italy
How It Is Really Done: Nucleons
• Calculated for p+A reactions and scaled for α+A (Ferrando et al. 1988)
• Calculation of total nuclear cross sections– Letaw et al. 1983– Wellisch & Axen 1996 (corrected), Z>5– Barashenkov & Polanski 2001
• Calculation of isotopic production cross sections– Webber et al. 1993 (non-renormalized, renormalized); E>200
MeV/nucleon, essentially flat– Silberberg & Tsao 2000 (non-renormalized, renormalized); claim that
it works at all energies, but is problematic sometimes– Fits to the available data (LANL, Webber et al., etc.) in the form of a
function or a table (see .dat files), but data may not be always available
– Use the best of all three, but very time consuming work
• Nuclear reaction network– Nuclear Data Tables (includes several decay channels + branching)– Standard β± -decay, emission of p, n– K-capture isotopes can be treated separately
Igor V. Moskalenko 43 November 17, 2005 GALPROP manual/Rome2, Italy
Interstellar Gas
► Extend CO surveys to high latitudes– newly-found small molecular clouds will otherwise be interpreted as
unidentified sources, and clearly limit dark matter studies
► C18O observations (optically thin tracer) of special directions (e.g. Galactic center, arm tangents)
– assess whether velocity crowding is affecting calculations of molecular column density, and for carefully pinning down the diffuse emission
20
0
-20
-40
Gal
acti
c L
atit
ud
e
220 200 180 160 140 120 100 80 60 40 20 0
CfA 1.2mGalactic Longitude
Dam
e, H
artman
n, & T
haddeus (200
1)D
ame
& T
haddeus (20
04)
Igor V. Moskalenko 44 November 17, 2005 GALPROP manual/Rome2, Italy
Distribution of Interstellar Gas
• Neutral interstellar medium– 21-cm H I & 2.6-mm CO (stand in for H2)
• Near-far distance ambiguity, rotation curve, optical depth effects, …
Dame et al.(1987)
Hartmann &Burton (1997)
(25°, 0°)
W. Keel
CO
H IG.C.
25°
Seth Digel
Igor V. Moskalenko 46 November 17, 2005 GALPROP manual/Rome2, Italy
Gas Distribution
Sun
Molecular hydrogen H2 is traced using J=1-0 transition of 12CO, concentrated mostly in the plane (z~70 pc, R<10 kpc)
Atomic hydrogen H I (radio 21 cm) has a wider distribution (z~1 kpc, R~30 kpc)
Ionized hydrogen H II (visible, UV, X) small proportion, but exists even in halo (z~1 kpc)
Z=0,0.1,0.2 kpc
Igor V. Moskalenko 47 November 17, 2005 GALPROP manual/Rome2, Italy
Gas Rings: HI (Inner & Outer Galaxy)
Seth Digel’05
Igor V. Moskalenko 48 November 17, 2005 GALPROP manual/Rome2, Italy
Seth Digel’05
Gas Rings: HI (Our Neighborhood)
Igor V. Moskalenko 49 November 17, 2005 GALPROP manual/Rome2, Italy
• Bremsstrahlung (Koch & Motz 1959, SMR2000) –many different regimes:– LE: 0.01 < Ekin < 0.07 MeV –nonrelativistic non-screened brems– Intermediate: 0.07 < Ekin <2 MeV– HE: Ekin > 2 MeV arbitrary screening: unshielded charge, 1-, 2-
electron atoms (form factors, Hylleraas, Hertree-Fock wave functions)
– Fano-Sauter limit: k->Ekin • “Anisotropic” IC (MS2000)
– Takes into account the anisotropic angular distribution of background photons
• Neutral pion decay (see “secondary positrons/electrons”)• Synchrotron radiation (Ginzburg 1979, Ghisellini et al. 1988)
– Averaging over pitch angle– Uses total magnetic field (regular + random)
• Emissivities: uses “real” H2, H I gas column densities (“rings”)• Skymap calculations: integration over the line of sight
How It Is Really Done: Gammas
Igor V. Moskalenko 50 November 17, 2005 GALPROP manual/Rome2, Italy
Uncertainties in the Propagation Models
• Production cross sections of isotopes and pbarsTypical errors ~50%
Fitting to B/C ratio may introduce errors in Dxx
• Propagation models and parameters Gas distribution in the Galaxy
Ambient spectrum of CR (solar modulation, GeV excess in γ’s !) Current knowledge of CR diffusion
• Heliospheric modulation Depends on rigidity Similar for all nuclei A/Z~ +2
Different for protons A/Z=+1 and pbars A/Z=-1
• Systematic errors of measurementsDifficult to account for
Simultaneous measurements of Li, Be, B, C, secondary e+, p in a wide energy range ~100 MeV/nucleon – 100 GeV/nucleon are needed to understand CR propagation and distinguish between the models: looking forward to Pamela launch!
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