LIBRARY OF GALAXY MODELS

Fits and templates


. Work is in progress to build and make available a spectral library of galaxy models computed with GRASIL. Below you can download the models fitting the SEDs of some starburst and spiral galaxies, ULIRGs, GRB host galaxies, and some more sample models for one elliptical and three spirals.  We would appreciate reference to the original GRASIL paper (Silva et al 1998) if using them.

 

 

For the models presented here, the inputs for GRASIL, i.e. the evolution of SFR, gas mass and metallicity, are computed with a chemical evolution code with the following parameters: exponential infall time-scale for gas tinf [Gyr], normalized in order to accrete a mass Minf [Msun] at age tinf [Gyr]; Schmidt like star-formation law nMgask (n in Gyr-1 for k=1); Salpeter IMF (slope in mass=1.35) with boundary mass limits Mlow and Msup. The notation used for GRASIL parameters is from the paper Silva L., Granato G.L., Bressan A., Danese L., 1998, ApJ, 509, 103 and Silva (1999).
The files of the chemical evolution and of the SEDs of the sample models described below can be downloaded. Their formats are the following:

- Chemical evolution: (1) number of time step; (2) age of the model in yr; (3) SFR in M
sun/yr; (4) metallicity Z; (5) Mgas in Msun ; (6) Mstar in Msun; (7) Mtot in Msun; (8) Supernovae rate in yr-1.

- SED: (1) Wavelength in ; (2) Cirrus emission; (3) Starlight extincted by MCs only; (4) Starlight extincted; (5) MCs emission; (6) Total; (7) Starlight unextincted; (8) Subcomponent unextincted; (9) Subcomponent extincted.
Luminosities are in 1e30 ergs/s/; subcomponent in cols. 8,9 is bulge for composite models otherwise=cols.7, 4 respectively.
 


Meaning of files:

name.che
= input file for che_evo code;
name.sf
= star formation history file (output of che_evo and input for grasil);
name.bst
= input file for grasil for a bulge+disk case;
name.par
= input parameter file for grasil;
name.number
= SED file (grasil output);
name.out
= summary of some quantities of the model (grasil output).



M82, ARP220, NGC6090, M51, M100, NGC6946, HR10

 Download the models fitting the SEDs (files name.number) of some starburst and spiral galaxies, presented in the paper Silva et al.  (1998) and Silva (1999) (and then updated following successive GRASIL updates), as well as the input files to run GRASIL (files name.sf and name.par). HR10 is a star forming ERO at z=1.44, the other are nearby galaxies.
 



ULIRGs

We have analyzed the SEDs of a large sample of ULIRGs to get information on the origin of their energy and their evolutionary status. To perform this work we have fitted their NIR to radio SEDs with GRASIL. 
The radio data and properties are in the paper Clemens, M.S., Vega, O., Bressan, A., Granato, G.L., Silva, L., Panuzzo, P., 2008, A&A, 477, 95, "Modeling the spectral energy distribution of ULIRGs. I. The radio spectra"  
The SED analysis is in the paper Vega, O., Clemens, M.S., Bressan, A., Granato, G.L., Silva, L. Panuzzo, P., 2007, A&A, submitted, arXiv:0712.1202, "Modeling the spectral energy distribution of ULIRGs. II. The energetic environment and the dense interstellar medium"

The ULIRGs we have considered are the following: UGC8058 IR14348-1447 IR12112+0305 IR05189-2524 UGC9913 IR08572+3915 UGC8696 IR15250+3609 IR10565+2448 UGC5101 IZW107 IR01364-1042 IR10173+0828 Arp299 UGC4881 CGCG436-30 IC1623 NGC1614 UGC8387 NGC7469 UGC2369 IIIZW35 IC5298 Arp148 NGC2623 Mrk331 NGC34 NGC5256 UGC6436 NGC6286 .

We provide the data and the fitting models in the following Tables, described in Appendix B of Vega et al. 2007 :

sed_data.dat : observed data for each galaxy in our sample. Wavelength (micron) and fluxes (Jy) are in the observed frame

sed_mod_tot.dat : model SEDs fitting the above data. The models include both starburst and AGN components where necessary. Wavelengths (micron) and fluxes (Jy) are in the rest frame. For this reason the second row provides the radial velocity (Km/s).

sed_mod_sb.dat :  starburst component alone of the fitting model. Same format as the full model.
 



SED templates for Gamma-Ray Burst host galaxies by Michal Michalowski et al.


SED template database published in Michalowski et al. (2008, ApJ, 672, 817) and produced using GRASIL.
The SEDs can be downloaded from http://archive.dark-cosmology.dk/  . They corresponds to GRB host galaxies and hence can be used to fit the observations of young, star-forming galaxies. 

 




ELLIPTICAL MODEL     

Local elliptical galaxies show very homogeneus properties and their SED is dominated by old stellar populations. Indeed in the monolithic galaxy formation scenario, they are believed to have formed at early times, at redshift >2, with a short (~1Gyr) and intense star-formation phase, followed by pure stellar evolution. During the star-forming phase dust is expected to play a role shifting the SED from the optical-UV to the FIR-submm spectral region, as observed for local starbursts. Any model following this kind of evolutionary history reproduces the average observed SED of local giant ellipticals.

Below the spectral evolution of a sample model is plotted (left), as resulting from its star-formation history (elli1.sf, right). The SED plotted are for 0.1, 0.2, 0.4, 0.8, 1.5, 13 Gyr.
SED files are elli1_age.0 with age in Gyr: 0.1, 0.2, 0.4, 0.8, 1.5, 2, 3, 4, 5, 8, 11, 13
STAR-FORMATION HISTORY PARAMETERS
(elli1.che):
tinf =0.1 Gyr, Minf =1e12 Msun at age tinf =1 Gyr, n=2 Gyr-1, k=1; Mlow= 0.15 and Msup =120 Msun.
SPECTRO-PHOTOMETRIC PARAMETERS (elli1.par): fmc= 1 with ongoing SF, 0 afterwards; Mmc= 1e6 Msun , rmc= 16 pc, to= 0.1 Gyr;
d=0.45Z (i.e. proportional to the metallicity and equal to the solar neighborhood value of 1/110 at solar Z); King geometry with core radii rc both for stars and dust of 0.5 Kpc with ongoing SF, while 0.5 and 6 Kpc respectively afterwards.

 


N.B.: in the case of composite (bulge + disk) geometry (igeo=-1), in addition to the .sf and .par files as input for grasil, grasil looks also for a file mod_name.bst (that gives a tabulation of the SFR ongoing on the bulge over the total  of the model galaxy as a function of its age)

SPIRAL MODELS
Spiral galaxies are much more complex systems as compared to ellipticals. Their SEDs show variations of a few orders of magnitudes in the IR and to a less extent in the optical-UV spectral region, depending on the SFR, distribution of stars and ISM, and inclination angle with respect to the line of sight. According to the properties of their stellar populations and the amount and chemical abundance of their ISM, local spirals are generally believed to have undergone a slow and continuous evolution, with the ratio of the average past SFR to the current one ~ 5-10. They can be broadly classified into the morphological classes Sa, Sb, Sc according to the bulge/disk magnitude ratio (as a function of the wavelength), and corresponding to an average SED. To have an indication of the morphological class for our models, we have considered the classification in the V band by Solanes et al., 1989, AJ, 98, 798.


Sa model
SEDs along different line of sights (from face-on to edge-on) and the angle-averaged one for a 13 Gyr sample model: spia.0, spia.15, spia.30, spia.45, spia.60, spia.75, spia.90, spia.spe
STAR-FORMATION HISTORY (spia.che spia.sf , spia.bst):
tinf =2 Gyr, Minf =1.5e11 Msun at age tinf =13 Gyr, n=2 Gyr-1, k=1; Mlow= 0.10 and Msup =100 Msun.
SPECTRO-PHOTOMETRIC PARAMETERS (spia.par): fmc= 0.5, Mmc= 1e6 Msun , rmc= 14 pc, to= 0.018 Gyr;
d=0.45Z (i.e. proportional to the metallicity and equal to the solar neighborhood value of 1/110 at solar Z); composite King+double exponential geometry with radii rc = 0.3 Kpc, rd = 5 Kpc, zd = 0.5 Kpc.
 

Sb model
SEDs along different line of sights (from face-on to edge-on) and the angle-averaged one for a 13 Gyr sample model: spib.0, spib.15, spib.30, spib.45, spib.60, spib.75, spib.90, spib.spe .
The SED plotted
below are for 1, 3, 5, 7, 10, 13 Gyr. 
STAR-FORMATION HISTORY (spib.che, spib.sf, spib.bst):
tinf =4 Gyr, Minf =1.5e11 Msun at age tinf =13 Gyr, n=0.6 Gyr-1, k=1; Mlow= 0.10 and Msup =100 Msun.
SPECTRO-PHOTOMETRIC PARAMETERS (spib.par): fmc= 0.5, Mmc= 1e6 Msun , rmc= 14 pc, to= 0.018 Gyr;
d=0.45Z (i.e. proportional to the metallicity and equal to the solar neighborhood value of 1/110 at solar Z); composite King+double exponential geometry with radii rc = 0.3 Kpc, rd = 5 Kpc, zd = 0.5 Kpc.


Sc model
SEDs along different line of sights (from face-on to edge-on) and the angle-averaged one for a 13 Gyr sample model: spic.0, spic.15, spic.30, spic.45, spic.60, spic.75, spic.90, spic.spe .
STAR-FORMATION HISTORY (spic.che, spic.sf, spic.bst):
tinf =4 Gyr, Minf =1.5e11 Msun at age tinf =13 Gyr, n=0.05 Gyr-1, k=1; Mlow= 0.10 and Msup =100 Msun.
SPECTRO-PHOTOMETRIC PARAMETERS (spic.par): fmc= 0.5, Mmc= 1e6 Msun , rmc= 14 pc, to= 0.018 Gyr;
d=0.45Z (i.e. proportional to the metallicity and equal to the solar neighborhood value of 1/110 at solar Z); composite King+double exponential geometry with radii rc = 0.3 Kpc, rd = 5 Kpc, zd = 0.5 Kpc..