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Physical Ingredients of Galactic Evolution
Shustov B.M.
Institute of Astronomy, Moscow
Chinese Summer School
“Modeling and Observing the Evolution in Galaxies”
Chinese Astronomical Society Symposium 35
June 20—28, 2002
University of Science and Technology of China,Hefei
and YunNan Observatory, Kunmin
Plan of the lecture
1. Galaxies and their constituents
2. Why, what and how to model
3. Mathematical formulation of chemo-dynamical
evolution of galaxies
4. Physical and chemical ingredients of the models
1. Galaxies and their constituents
1.1. Galaxies as dominant structures in the Universe
– Galactic zoo
– MW is a representative galaxy
1.2. Galactic features
– Baryonic structures of MW
– Dark matter
– Sources of energy
– Most important processes
1.1. Galaxies as dominant structures in the
Universe
Essentially everything of astronomical
interest is either part of a galaxy, or from a
galaxy, or otherwise relevant to the origin
and evolution of galaxies.
B.Tinsley, Fundamentals of Cosmic Physics, 1980
Classification scheme for galaxies, devised in its original form in 1925 by
Edwin P. Hubble (1889–1953), and still widely used today. The Hubble
classification recognizes four principal types of galaxy—elliptical, spiral,
barred spiral and irregular—and arranges these in a sequence that is
called the tuning-fork diagram (in fig. the classification includes
additional types adopted from G.de de Vaucouleurs classification). EAA
The Milky Way is most likely a barred spiral galaxy of Hubble
type SBc.
The Milky Way is most likely a barred spiral galaxy of Hubble
type SBc.
lgLB = 1.00lgM - 0.87,
lgMg = 1.02lgM - 1.55,
lgLFIR = 1.36lgM-5.45,
lgMd= 1.47lgM-9.76,
lgMH2 = 1.52lgM-7.67
Kostyunin1995
Sage 1992
Salucci&Persic (1999) computed the baryonic mass function,
ψS(Mb)dlogMb, of disc galaxies using the luminosity functions
and baryonic mass-to-light ratios reliable for this goal. On
scales from 108Msolar to 1011Msolar this function is featureless,
ψS~Mb-1/2. Outside this mass range ψS is a strong inverse
function of Mb. The contributions to the baryon density from
objects of different mass indicate that spirals have a
characteristic mass scale at 2x1011Msolar, around which more
than 50per cent of the total baryonic mass is concentrated.
Salucci & Persic (1999)
MW is a representative galaxy!
Luminosity and mass functions of galaxies
Salucci & Persic (1999)
MW is a representative galaxy!
1.2. Galactic features
Baryonic structures of MW
•
•
•
•
•
Halo, corona (up to 100 kpc)
Thick disk (1 kpc)
Thin disk (300 pc)
Spiral arms (density waves)
Substructures
– Open star clusters and associations (about 1500
known)
– Globular clusters (about 170 known)
– Remnants of dwarf galaxies ?
– Gaseous structures
Main components of the MW
Mass estimates
• Central section of the Galaxy is (with separations from the
center of <5 kpc) about 2×1011 M
• Halo 4×1011M (Fich and Tremain 1991)
• Corona (3–6)×1012M (Fich and Tremaine 1991)
For the halo and the corona - substantial (up to 90% for
corona) part of matter in exists as dark matter .
Tracers of large scale structures
• Stars
– Stars with known distances (kinematics, counts)
– IR (eg. NIR photometry, IR source counts)
– Chemical abundances
• Gas
– HI 21 cm
– HII
– CO
Structures and populations in the MW
• Halo (H  ~ 1kpc) - HEO, oldest Pop II, [Fe/H] < -1
• Bulge with a bar ~ 23.5 kpc (Eckart, Engmaier, EAA,
2002) - kinematic as for halo stars, -1< [Fe/H] < 1
• Center (here just to mention)
• Thin disk (H < ~ 250 kpc) - circular orbits ~200 km/s at
solar distance, flat rotation curve, [Fe/H] > -0.6 ,
concentration of molecular clouds (star forming regions)
• Thick disk (~ 1kpc ) - intermediate kinematics, -1< [Fe/H] <
-0.6
Substructures
• Flows (stellar: Magellanic Flow, remnats of dwarf galaxies
gaseous: galactic wind)
• Open star clusters and associations (about 1500 known)
• Globular clusters (about 150 known)
• Gaseous structures:
– diffuse clouds
– molecular clouds
– supershells and superbubbles
The gas flow in the
Galactic disk (Englmaier
and Gerhard 1999). The
location of the Sun is
shown at x=−2.7 kpc and
y=−7.5 kpc just outside the
frame. The Orion arm is
possibly a connection
between the Aquila and
Perseus arm in the vicinity
of the Sun. The image is a
result of hydrodynamical
2D modeling using 20 000
particles in a SPH code.
 - HII zones
 - GMC
Structure of MW with mean metallicities of each component (from
Matteucci 1991)
Dark Matter
• MaCHOs (microlensing experiments)
• “Failed stars” — brown dwarfs, ultra-compact gas-dust
globules (sub-mm source counts)
• Small clouds of pure molecular hydrogen (no way to
detect)
• WIMPs and/or other exotic particles
• New physics (MOND)?
Sources of energy
• Gravitation (governs all)
• Nuclear energy
• Kinetic energy
•
•
•
•
Next three energetic ingredientsare dominant for the
ISM
Radiation field — stellar population
Magnetic field (B from synchrotron radiation,
polarization, mapping of linearly polarized spectral-line
emission , B - Faraday rotation of the position angle of
linearly polarized radiation if the density of interstellar
electrons is known, dispersion measures of pulsars (B
weighted by the electron density may be determined),
Zeeman splitting) — dynamo?
Cosmic rays (mostly protons) — SN accelerated
Input of kinetic energy - from outflows, turbulence etc.
Interstellar radiation field (from Black 1987)
Magnetic field in MW
The Galactic interstellar magnetic field has a spiral pattern, with
reversals in field direction in interarm regions. Near the Sun Bt ~5–
10 μG, with a ratio of uniform to random components Bu/Br~ 0.3–
0.7. The field strength increases inward in the Galaxy, with
milligauss fields in the Galactic center. The Galactic magnetic field
is probably maintained by a Galactic dynamo, although the details
are very unclear.
Starlight polarization defining the direction of the Galactic magnetic
field near the Sun (from R.Crutcher 2000 EAA)
Equipartition in the ISM
The different interacting components of the ISM discussed
above have comparable energy densities (and pressures). For
example, the energy density of the ISM radiation field from
91.2 nm to 8 μm is ~0.5 eV cm−3, the cosmic rays have ~1.5 eV
cm−3, and B2/8π for a magnetic field with B=5×10−6 G is 0.6 eV
cm−3. Gas motions associated with turbulence and waves in the
ISM are estimated to have an energy density of ~1 eV cm−3.
The different thermal phases - 0.3 eV cm−3. The similarity of
these energy densities (and pressures) is probably not a
coincidence but is suggestive of a strong interaction and
resulting energy and pressure equipartition among these
different components of the ISM.
Most important processes
Collapse
of primeval
galaxy
Star
formation
Mergers with
other
galaxies
Inflow and
outflow
Stellar
evolution
Stellar
population
Interstellar
medium
Stellar mass
loss and
death
Colors,
spectrum,
etc.
Remnants
Tinsley (1980)
A scenario of cosmic chemical evolution (from Pagel 1997)
2. Why, what and how to model
2.1. Main targets
• Origin of the Galaxy, its past and future
• Study of physical and chemical processes in a great lab –
the Galaxy
• Test for theories (e.g. for explosive nucleosynthesis in SN)
• Life in the Galaxy (e.g Galactic Habitant Zone)
GHZ
Circumstellar Habitable Zone (CHZ) has generally been
defined to be that region around a star where liquid water
can exist on the surface of a terrestrial (i.e., Earth-like)
planet for an extended period of time. Recently Gonzales and
Brownlee (1991) proposed the concept of a "Galactic
Habitable Zone" (GHZ). Analogous to the CHZ, the GHZ is
that region in the Milky Way where an Earth-like planet can
retain liquid water on its surface and provide a long-term
habitat for animal-like aerobic life. Gonzales and Brownlee
examined the dependence of the GHZ on Galactic chemical
evolution. The single most important factor is likely the
dependence of terrestrial planet mass on the metallicity of its
birth cloud. A metallicity at least half that of the Sun is
required to build a habitable terrestrial planet.
GHZ
The mass of a terrestrial planet has important consequences for
interior heat loss, volatile inventory, and loss of atmosphere. A
key issue is the production of planets that sustain plate
tectonics, a critical recycling process that provides feedback
to stabilize atmospheric temperatures on planets with oceans
and atmospheres. Due to the more recent decline from the
early intense star formation activity in the Milky Way, the
concentration in the interstellar medium of the geophysically
important radioisotopes 40K, 235,238U, and 232Th has been
declining relative to Fe, an abundant element in the Earth.
Also likely important are the relative abundances of Si and
Mg to Fe, which affects the mass of the core relative to the
mantle in a terrestrial planet. .
All these elements and isotopes vary with time and location in the
Milky Way, thus, planetary systems forming in other locations and
times in the Milky Way with the same metallicity as the Sun will not
necessarily form habitable Earth like planets. As a result of the radial
Galactic metafficity gradient, the outer limit of the GHZ is set
primarily by the minimum required metallicity to build large
terrestrial planets. Regions of the Milky Way least likely to contain
Earth-mass planets are the halo (including globular dusters), the
thick disk. and the outer thin disk. The bulge should contain Earthmass planets, but stars in it have a mix of elements different from the
Sun's. The existence of a luminosity-metallicity correlation among
galaxies of all types means that many galaxies are too metal-poor to
contain Earth-mass planets. Based on the observed luminosity
function of nearby galaxies in the visual passband, Gonzales and
Brownlee estimated that (1) the Milky Way is among the 1.3% most
luminous (and hence most metal-rich) galaxies and (2) about 23% of
stars in a typical ensemble of galaxies are more metal-rich than the
average star in the Milky Way.
2.2. How to model - model classification
By subject
• Dynamic (plus stellar dynamics)
• Chemical (chemo-dynamic) - primary
topic of the lecture
• Spectrophotometry
• etc.
By computational method
• One zone
• Multizone
• HD — HD+SD — SPH
By interaction with circumgalactic space
• Closed
• Open
CGE - targets
Chemical (chemo-dynamic) models deals with gas
evolution in a galaxy including all processes
Quite a lot of Chemical (chemo-dynamic) models of galactic
evolution do exist. I will not comment on them here (this will be
done in the next lecture) In principle to construct a model is not
a great problem. But “devil is hidden in details”. Full
mathematical and physical description of all relevant processes
and object is still lacking. There are attempts to construct some
comprehensive and software package for study of the galactic
evolution. I just mention th Galaxy Evolution tool (GEtool) that
is a software package currently being developed to selfconsistently model of chemical and spectral evolution of disk
galaxies. It is important that GEtool will soon will be available
to he community thriugh a web-paged interface that will enable
users to predict observable properties of model galaxies such as
colours, spectral gradients, Lick indices and elemental
abundances.
3. Mathematical formulation of chemodynamical evolution of galaxies
• Quite a lot of models do exist. To construct a model is not
a great problem. But “devil is hidden in details”.
• Full mathematical and physical description is still lacking.
• We (Shustov Tutukov Wiebe, all from Institute of
Astronomy, Moscow) elaborated a simple model capturing
all the main features of the galactic evolution (it can be
classified as a toy model, though it turned to be successful
in solving some hard problems of CGE – I’ll touch this
during the next lecture).
“Thermodynamical” Approach
dMg
dt
 M

  (t )  R(t )  M
out
in
dM i
i
i
  Z i (t )  Pi (t )  M out  M in
dt
R(t) is the total gas ejection rate from stars of all masses
and ages
Pi(t) is the total ejection rate of an i-th element from all
stars
Gas and Metal Ejection
M max
R(t ) 
M  M
R
( M , Z ) (t  t M )f ( M )dM
M min
M max
P(t ) 
i
  M  M
R

 Pi ( M , Z )Zi (t  t M )  Pi ( M , Z )  (t  t M )f ( M )dM
M min
f (M) is the initial mass function IMF
(t) is the star formation rate SFR
tM is the lifetime of a star of (initial) mass M
MR is the remnant mass
Pi is the i-th element production in a star
Dynamical features of toy model
Idea: Self regulated disk thickness H. Input of mechanical
energy from massive stars SN versus dissipation.
dH/dt = H+ - HE pot 
GMM g H 2
M g dvt2
2dt
vt 
H
R
R2 H
2GMM g H dH fM g2 M g vt2

 2

R2 H
dt
R H
2t d
3GM
H
4R 2 H
td 
3GM g
……….
Firmani&Tutukov
1992
4. Physical and chemical ingredients of the
models
4.1. Initial conditions
4.2. Star formation
– Quick look
– SFR: theory and observation
– IMF: observations, theory
– Philosophy of the IMF
4.3. Stellar evolution
– Brief conventional picture of evolution of single and
binary stars
– Life times
– Luminosities and ionizing fluxes
– Masses of remnants
– Stellar yields
4. Physical and chemical ingredients of the
models (cont.)
4.4. Inflow and outflow
– Accretion (+dynamic friction)
– HVC and flows
– Galactic wind
– Expelling of dust
– Dynamic stripping
– Interacting galaxies
4.1. Initial conditions
• Properties of protogalaxy (structure, temperature, etc.)
• The primordial abundances from the Big Bang are
typically assumed.
There are models with quick pre-enrichment. This includes
pre-galactic enrichment, or protogalactic processes, or preenrichment from other more evolved system.
Population III
Recent simulations of collapsing clouds in pre-galactic era predict
that gigantic ~100 M stars formed. They lived fast and died so
explosively that new telescopes can be able to see them as
supernovae or gamma ray burst at the margin of the Universe.
Probably some cycles of star formation could happen in the this
epoch and lower long living mass star could form. Population III
is a group name for these first stars
In our Galaxy we never observed such stars, though this research
direction seems to be promising
“To make the leap to Population III some researches use silicon –
not in stars. But in the chips of supercomputers”
R.Irion 2000
Population III
4.2. Star formation
General comments
• Star formation is a a primary ingredient of galactic evolution
• SF theory is still under construction
• SF history - a challenging problem for new instruments
globules
supergiant star Sher 25
The ring structure is
reminiscent of
Supernova 1987a and
Sher 25 itself may be
only a few thousand
years from its own
devastating finale
a cluster of bright hot
blue stars whose strong
winds and ultraviolet
radiation have cleared
away nearby material
NGC 3603: Wolfgang, Grebel, You-Hua Chu, 1999
emission nebulae are
similar to suspected
proto-planetary disks
(proplyds)
encompassing stars in
the Orion Nebula.
Birthrate and Star Formation Rate
B(m, t )   (t ) (m)dtdm
f(m) - initial mass function IMF
(t) - star formation rate SFR
in fact this is a function of other
physical prameters which are
functions of t
The Schmidt law
  a
n
gas
Schmidt’s law (1959): star formation rate is proportional to
some power of the volume gas density
Star formation is a self-regulated process controlled by the
energetic feedback from young stars that prevents new stars
from being formed.
Efficiency of the process is described by a.
Other variants of SFR parametrization
  a
k
gas
  a
k1
total
Schmidt 1959

k2
gas
Dopita&Ryder 1994
  0.017gas gas
Kennicutt 1989
  ae
Tosi 1998
t / t
Comment: these are to fit observation.
Lack of physical basis for such laws
• Various modes of SF from observation
– In disk galaxies sporadic SF
– In gas rich dwarf galaxies bursts separated by long
intervals of time
– Large star bursts – interaction induced
• Various modes of SF from theory
– Stochastic SF
– Self-regulated SF
• Important physical factors: density, temperature, chemical
composition, gravitational potential, rotation, spiral shocks,
collisions, magnetic field etc.
About the physical meaning of the Schmidt
law
Star formation is a self-regulated process controlled by the
energetic feedback from young stars that prevents new stars from
being formed. Sources which could supply significant negative
feedback include stellar winds, ionizing UV, and supernova
explosions. However, in normal case the heating by ionizing UV, is
dominant. The UV production associated with a given amount of
star formation is calculated, and the critical UV production rate
above which the UV heating quenches star formation is estimated
by Tutukov&Krugel (1980), Cox (1983).
The physical meaning of the Smidt law
Ionization balance in a volume V
NLyc  nOB = V  n2
NLycnOB/V ~ OB tOB
 ~ OB
 = a  2
a = 5 107cm3g-1 s-1
“The simplest possible parameterization of the SFR is …Schmidt
law…This at least has the merit of simplicity and of taking into
account the necessity of having gas as the raw material from
which stars are formed, and will be used widely here as it has
been elsewhere, while always bearing in mind that the coefficient
may vary with ambient conditions or stochastically. A number of
the results of CGE theory are insensitive to the SFR, while others
are affected by many other difficulties anyway.”
B.Pagel 1997
Indicators of the SFR
• Counts of luminous supergiants in nearby galaxies under the assumption that
their number is proportional to the SFR.
• The H flux from HII regions, which are ionized by young and hot stars,
under the assumption that such flux is proportional to the SFR
• The integrated UBV colors and spectra of galaxies (one can estimate the
relative proportions of young and old stars and derive the ratio between the
present time SFR and the average SFR in the past)
• The frequency of type II SNe as well as the distribution of SN remnants
and pulsars can be used as tracers of the SFR. These tracers have been used for
deriving the SFR in the Galactic disk
• The radio emission from HII regions can also be a tracer of the SFR
• The UV continuum and the IR continuum (star forming regions are
surrounded by dust) are also connected to the SFR
• From the distribution of molecular clouds
SFR calibration (an example)
Hopkins et al.2001
LFIR ~ Mg
Firmani, Tutukov 1994
SFR in solar vicinities
2 - 10 Mpc -2 Gyr-1
Timmes et al. 1995
Initial Mass Function
 (m)  dN / dm
 (m)  dN / d log m
M max
 m (m)dm  1
M min
 (m)  bm (1 x )
x = 1.35 (Salpeter 1955)
Present day mass function and IMF
IMF 
PDMF
T
 (t )dt
T t ms
There are theories explaining Initial Mass Function though no
unique answer
• Fragmentation of protostellar clouds
(PSO)
• Accumulation of PSO fragments
• Turbulence
• Limiting mechanisms
Computer simulation
of supersonic
turbulence in starforming molecular
clouds Boldyrev et al
2001
clumps
Mass spectrum of 59 pre-stellar fragments extracted from the 1.3mm
 Oph mosaic. The mass spectrum of clumps is more flat (Andre 1999)
Initial Mass Function
Mmin ~ 0.08 M
Mmax ~ 100 M
Questions on IMF
• Is IMF constant in time?
(Does IMF strongly depends on physical parameters: (t),
T(t), did they change in star forming regions?)
• Does IMF depend on chemical composition of parent gas?
• Is Mmin and or Mmax “fixed”?
• Do we really know the IMF for low mass end?
IMF for massive stars (Massey and Meyer 2001 EAA)
The dashed line is for a Salpeter exponent of ?2.35. The metallicities
change by a factor of 4 between these three systems!
x=1
Local Initial Mass Function ( normalised to a total number
of stars ever born of 37 Mpc -2 (Kroupa et al. 1990, Scalo
1986)
My philosophy of the IMF
If there is no dominant physical process - white noise (x = 1).
If some process is dominant - it is responsible for IMF slope.
We are still not able to separate this process.
4.3. Stellar evolution
SE is “responsible” for most important ingredients of any
model of galactic evolution (except pure stellar dynamics)
In any such a model one needs to have estimates of
tM is the lifetime of a star of (initial) mass M
MR is the remnant mass
Pi is the i-th element production in a star
SE gives also theoretical estimates of galactic luminosity
(more general - photometric parameters of galaxies),
Stars (with some exceptions) do not change the surface
composition during their evolution. Thus, surface abundances
reflect the interstellar medium (ISM, out of which the stars
formed) at the time of their formation. Therefore, observations
of the surface composition (via spectra) of stars over a variety
of ages and metallicities give a clue to gas abundances
throughout the evolution of our Galaxy.
Sp Type
Teff
Luminosity
What is
a star?
Radius
Outline of
Stellar
Evolution
HR diagram for early stellar evolution
HR diagram for late stellar evolution
Base information of the star evolution
Initial star
mass, M
Life time,
yr
Evolution
product
Mass of
product, M
Radius of
product, km
1 ~ 50 - 150
~ 2 - 4106
black hole
~ 10
~ 30
2
~ 11 - 50
~ 4 - 20106
neutron star
~ 1.4
~ 10
3
~ 0.8 - 11 ~ 0.2 - 100108
degenerate
dwarf
~ 0.2 - 1.3
~ 104
Рис 5.15 из
Pagel
Evolutionary tracks
Life time
t ms
1010 yrs

( M / M  )3
Masses of remnants
MR = 0.11m +0.45M m<6.8M
MR = 1.5M
m6.8M
Iben&Tutukov 1984
Fig Hoek
Stellar yields
Theory of stellar evolution is an example of successful
construction of might and necessary theoretical instrument for
studying galactic evolution. For last decades the fundamentals
of the theory were established though up to now serious
problems remain:
• Effects of mixing in stars and mass loss
• Nuclear reaction rate (e.g. 12C(, )16O
• Evolution of close binaries
• Chemically dependent bifurcation points in the course of
stellar evolution (e.g. formation of BH is sensitive to
metallicity of massive star)
• Stellar yields are corner stones of the CGE models.
Abundances in the Solar System from solar spectra and metorite samples.
The unit scaled to a Si-abundance of 106 (Grevesse&Sauval 1998)
Origin of elements
Big Bang Nucleosynthesis H, D, He, Li, Be, B
Stellar Nucleosynthesis
Main sequence stars
Giant star cores
Red giant outer shells
He
C, O, Mg, Si, etc.
N, Na, Al
Explosive Nucleosynthesis O, S, Si, iron peak elements
(supernovae)
and heavier
Exotic Nucleosynthesis
(spallation)
Li, Be, B
Hoek (1997)
Yields in SN
(Tsujimoto 1993)
Mixing
In most models the mixing is assumed to be instantaneous and
chemical composition of gas in a given zone is considered to be
uniform. This is probably true for evenly distributed late type
stars – sources of some heavy elements but not for explosive
events. For might starburst regions metals are partially mixed
with the ISM and partially leak into the IGM. (High metallicity
of distant quasars are explained by this?). However observation
of galaxies with less massive starbursts demonstrate that
products of bursts (even for blue compact galaxies) can retain
in galaxies inside the supershells and will be dispersed over the
IGM when Supershell will dissipate. Thus the mixing could
take up to 100 Myr (Tenorio-Tagle 2000)
Low metallicity stars as witnesses of SNII
yields
Recent promising trends in galactic evolution modeling might
provide constraints on individual supernova models rather than
only global properties of SNe II and SNe Ia. The reason for this
possibility is the fact that there is no instantaneous mixing of ejecta
with the interstellar medium, and therefore early phases of galactic
evolution can present a connection between low metallicity star
observations and a single supernova event. On average, each
supernova pollutes a volume of the interstellar medium containing
~ 3-5104M (for references see e.g. Thielemann et al. 2002).
Each volume of the interstellar medium containing ~ 3-5104M
needs to be enriched by ~ 103 SNe in order to obtain solar
metallicities.
Comparision of
observation of
low metallicity
objects (squares)
with
metallicities of
SNII ejecta mixed
with 5104M of
primordial ISM
(circles)
and galactic
evolution model
with non insant
mixing (dots for
model stars)
Argast et al. 2001
4.4. Inflow and outflow
Important role of inflow of matter into galaxies is commonly
recognized. Outflow also is becoming recognized as very
important factor in CGE.
Inflow
• HVC and flows
• Accretion (+dynamic friction)
Outflow
• Galactic wind
• Expelling of dust
• Dynamic stripping
Outflow+inflow+redistributing gas
• Interacting galaxies
Gas Inflow in the Galaxy
Wakker et al. (2000)
Dynamic friction
Dissipation
zone
Dust Expelling from Galaxy
Shustov&Wiebe 1995
Dust loss rate dependence on a disk galaxy mass
Wiebe 1995
Galactic Fountain
Shustov 1989
Galaxy NGC 4388 Expels Huge Gas Cloud NGC 4388 is a member of the
the Virgo Cluster. It is classified as an active galaxy. One hypothesis holds
that the gas was stripped away as NGC 4388 made its way through the
intergalactic medium of the Virgo Cluster. A competing hypothesis holds
that the gas is all that remains of a smaller galaxy that was gravitationally
deconstructed by the larger NGC 4388. (Suprime-Cam, Subaru Telescope,
NAOJ, APOD) .
Conclusion
Plan of the lecture
1. Galaxies and their constituents
1.1. Galaxies as dominant structures in the Universe
• Galactic zoo
• MW is a representative galaxy
1.2. Galactic features
• Baryonic structures of MW
• Dark matter
• Sources of energy
• Most important processes
2. Why, what and how to model
2.1. Main targets
2.2. How to model - model classification
3. Mathematical formulation of chemo-dynamical evolution of galaxies
4. Physical and chemical ingredients of the models
4.1. Initial conditions
4.2. Star formation
• Quick look
•
SFR: theory and observation
• IMF: observations, theory
• Philosophy of the IMF
Plan of the lecture (cont.)
4.3. Stellar evolution
• Brief conventional picture of evolution of single and binary stars
• Life times
• Luminosities and ionizing fluxes
• Stellar yields
• Masses of remnants
4.4. Inflow and outflow
• HVC and flows
• Accretion (+dynamic friction)
• Galactic wind
• Expelling of dust
• Dynamic stripping
• Interacting galaxies
5. Conclusion