How to run a Starburst99-Mappings model

Running a Starburst99-Mappings model is a 2-step process: first the stellar SED is computed at the STScI Starburst99 site, and then this SED is used as input for a Mappings photoionization model at IfA. Users who are familiar with the Starburst99 interface may find the new Starburst99-Mappings interface easy to use. The basic event flow is as follows:

• Specification of the model parameters via the input page
• Initialization of the Starburst99 computation
• Upon completion, automatic transfer of the Starburst99 output to Mappings at IfA
• Initialization of a Mappings photoionization model
• Upon completion, transfer of the Mappings output back to STScI
• Notification of job completion sent to user
• Retrieval of all output files from the Starburst99 site

Users do not have to worry about the file transfer between STScI and IfA. This process occurs entirely behind the scenes. All that needs to be done is to specify the input parameters and wait for an email notification. Those who used Starburst99 before to calculate stellar models should be aware of a few differences between running a pure Starburst99 and a Starburst99-Mappings model:

• Starburst99 produces the input file needed for Mappings, i.e. the SED (called .mapspec1 in the Starburst99 notation). All other Starburst99 outputs are calculated as well, even if they are not needed for Mappings.
• The photoionization model is calculated for one time step only, e.g., at 5 Myr. If more time steps are needed, additional models must be run.
• Although the default method is to feed the Starburst99 SED directly into Mappings, the user has the option to use a scaled Starburst99 SED, e.g., in order to simulate a certain ionizing luminosity.

The input

• MODEL DESIGNATION: -- any identifier you want to assign to the model. The output files will use this name, and you will find it in each header as well.
• CONTINUOUS STAR FORMATION OR FIXED MASS : -- select either continuous or instantaneous star formation.
• TOTAL STELLAR MASS [10⁶ SOLAR MASSES] IF 'FIXED MASS' IS CHOSEN:-- this is the total stellar mass (spread out between the upper and lower cut-off masses). It is only used if an instantaneous burst is specified.
• SFR [SOLAR MASSES PER YEAR] IF 'CONT. SF' IS CHOSEN: -- the star formation rate (only used for a continuous rate). The total accumulated mass is spread out between the upper and lower cut-off masses.
• NUMBER OF IMF INTERVALS (KROUPA = 2): -- users can specify a multi-power-law IMF. This is useful for approximating, e.g., a Kroupa IMF. If two intervals are specified, the program expects two IMF exponents and three IMF boundaries in the next two input fields. Up to ten such intervals may be specified.
• IMF EXPONENT(S) (KROUPA = 1.3,2.3): -- one or more IMF exponent for a power-law can be specified. The exponents refer to the individual power-law intervals, ordered by increasing mass. For instance, 1.3,2.3 specifies an IMF with exponents of 1.3 and 2.3 at low and high masses, respectively, with the boundaries given in the next input field. A single Salpeter-type law would be entered as 2.35. If there is more than one input value, the entries must be comma separated.
• MASS BOUNDARIES FOR THE IMF (KROUPA = 0.1,0.5,100) [SOLAR MASSES]: -- the boundaries of the IMF intervals corresponding to the specified exponents. In this specific example we define two intervals from 0.1 to 0.5 and from 0.5 to 100 solar masses, The former would have a slope of 1.3, and the latter 2.3. A single power law between 1 and 100 solar masses would be entered as 1,100. The input values must be comma separated.
• SUPERNOVA CUT-OFF MASS [SOLAR MASSES]: -- stars with ZAMS masses of 8 M and higher form supernovae. This is the suggested standard value but can be modified if desired. It is not currently used in Starburst99-Mappings but will be in a future release when shocks can be added in Mappings.
• BLACK HOLE CUT-OFF MASS [SOLAR MASSES]: -- stars with ZAMS masses of 120 M and lower form supernovae. An alternative scenario would be to let stars above a certain threshold form a black hole. For instance, BHCUT=40 results in SNe only from the mass range 40 to 8 M. Like the supernovae cut-off mass, this parameter will only be used in the future.
• METALLICITY + TRACKS: -- this selects the evolutionary tracks and their metallicity. Details of the time steps are entered as well.
• GENEVA TRACKS WITH STANDARD MASS LOSS: -- selection of the 1994 Geneva tracks with "standard" mass-loss rates. The lowest mass included in the tracks is 0.8 solar masses.
• GENEVA TRACKS WITH HIGH MASS LOSS: -- selection of the 1994 Geneva tracks with "high" mass-loss rates. Note that these are the tracks recommended by the Geneva group.
• ORIGINAL PADOVA TRACKS: -- selection of the 1992 - 1994 Padova tracks. The lowest mass included in the tracks is 0.15 solar masses.
• PADOVA TRACKS WITH AGB STARS: -- selection of the 1992 - 1994 Padova tracks with thermally pulsing AGB stars added.
• WIND MODEL (EVOLUTION; EMP.; THEOR.; ELSON): -- this selects the wind model to be used for the calculation of the wind power. The four models are discussed in ApJ, 401, 596 (1992). "EVOLUTION" uses the mass-loss rates from either the Geneva or Padova models. "Evolution" is the suggested default parameter. This parameter will be used when shocks can be added to Mappings in a future release.
• TIME STEP [10⁶ YEARS]: -- this is the timestep used for the calculations. It is a very important parameter. On the one hand, the computing time scales with STEP so you want to avoid too high resolution, but on the other, short evolutionary phases can be missed. 0.1 (i.e. 10⁵ yr) is a good value. A larger time step is suggested for tests --- but be aware that WR or RSG numbers are no longer properly calculated for too large STEPs!
• AGE OF THE SPECTRUM [10⁶ YEARS]: -- the age of the emission line spectrum. Starburst99-Mappings computes the nebular spectrum for a stellar population of this age. For numerical reasons, the spectrum of an instantaneous burst will be 0.01 Myr older than this value. The number of digits after the decimal point must match that of the TIME STEP parameter. For instance, if an AGE of 5.04 Myr is specified, the TIME STEP must by 0.01 Myr, not the default of 0.1 Myr.
• SMALL OR LARGE MASS GRID; ISOCHRONE ON LARGE GRID OR FULL ISOCHRONE : -- there are four options for the interpolation in mass. They are explained in the code. Shortly: "SMALL" -- evolutionary synthesis with a mass resolution of 5 M (only recommended for tests); "LARGE" -- same as 0, but with a resolution of 1 M. This method was used in our previously published papers; "ISOCHRONE/LARGE" -- isochrone synthesis with a fixed mass resolution of 1 M; "FULL ISOCHRONE" -- isochrone synthesis with a variable mass grid. This is the fanciest and recommended method.
• LMIN, LMAX : -- LMIN and LMAX are the indices of the evolutionary tracks, sorted by mass. Normally you do not want to mess with the variable and leave it at 0. However, if you want to track down some peculiarity of the output, you may want to compute the parameters for only one track. For instance, specifying 21,21 indicates that only a 100 M star should be used, and everything else is suppressed. The cross-ID's between index and mass are at the bottom of the input file which comes as part of the source code package on the Starburst99 Portal. The example here refers to a large mass grid or isochrone on large grid. For a small mass grid, you would have chosen 5,5. This does not appy to the full isochrone model since the mass grid is variable. If "full isochrone" is selected, LMIN and LMAX are not used.
• ATMOSPHERE FOR SYNTHETIC SPECTRUM: PLANCK, LEJEUNE, LEJEUNE/SCHMUTZ, LEJEUNE/HILLIER, PAULDRACH/HILLIER -- this is the choice of the model atmosphere. "PLANCK" is a bare-bone version with black bodies, good only for tests. "LEJEUNE" uses the Kurucz models as compiled by Lejeune for all stars. "LEJEUNE/SCHMUTZ" uses Lejeune for stars with plane-parallel atmospheres and Schmutz with stars with strong winds. "LEJEUNE/HILLIER uses Lejeune, but replaces the Schmutz by the Hillier atmospheres. "PAULDRACH/HILLIER" is like "LEJEUNE/HILLIER", except for the O atmospheres, for which we use the Pauldrach models. "PAULDRACH/HILLIER" is the recommended value.
• CHEMICAL COMPOSITION OF THE GAS: -- specify the elemental abundances of the gas. The default solar set of abundances from Anders & Grevesse (1989) is shown in the boxes on the right-hand side of the input form.
• DEFAULT ABUNDANCES: -- use the default set of abundances as given in the boxes on the right and scale by the metal abundance to a common fraction of solar. H and He are kept fixed and all metals are multiplied by the Z value in the pull-down menu. More detailed abundance sets should be entered into the itemized boxes (such as those requiring a secondary nature of Nitrogen for specific metallicities).
• TAILORED ABUNDANCES: -- enter individual abundances for the 16 elements as desired. Units: logarithmic with hydrogen = 0.0.
• INCLUSION OF DUST: -- if the include button is checked, dust is considered in Mappings, and all the dust related input parameters must be specified. Otherwise they are ignored.
• DUST DEPLETION: -- specify the depletion factors for the 16 elements listed.
• DEFAULT DEPLETION FACTORS: -- use the default depletion factors as given in the boxes on the right.
• INDIVIDUAL DEPLETION FACTORS: -- enter individual depletion factors for the 16 elements as desired. Depletion factors are defined as the fraction of each element in the gas phase compared to the fraction in dust. Undepleted elements have depletion factors of 1.00, and fully depleted elements have depletion factors of 0.00. Negative values are assumed to be in logarithmic form.
• GRAIN DISTRIBUTION MODEL: -- characterize the dust properties by the model of Mathis, Rumpl, & Nordsiek (1977). Other options for the distribution function will be added in the future.
• CALCULATION OF THE DUST SED: -- switch to enable or disable the calculation of the IR flux distribution of the dust and the dust temperature. Since this step is very time consuming, it should only be turned on if infrared fluxes are required.
• SELECTION OF THE GEOMETRY: -- specify either spherically symmetric or plane-parallel geometry. The choice affects which additional input parameters are necessary for scaling the ionizing radiation field. The parameters below the geometry buttons for either geometry should be used. The default is spherical geometry.
• USE THE STARBURST99 SPECTRUM: -- the default is to use the Starburst99 spectrum directly as an input for Mappings. If this option is selected, no additional input parameters are required for either geometry. Since a Starburst99 spectrum corresponds to a total stellar mass and therefore luminosity, the ionization parameter follows directly from the stellar parameters and the nebular density. It cannot be changed.
• SCALE THE STARBURST99 SPECTRUM: -- this option is useful if the HII region is not defined via a total stellar mass but via the ioniziation parameter, the luminosity, or some other parameter.
• SCALING FACTOR FOR STARBURST99: -- We use only the shape of the Starburst99 output and adjust the absolute luminosity to match the desired scaling requirement.
• RADIUS OF THE STELLAR SOURCE [SOLAR RADII]: -- this is the first of the 3 scaling options. It is most useful if a single stellar source ionizes the HII region. Enter the stellar radius in R_sol, and the scaled Starburst99 spectrum is used to simulate a single star of that radius and having the Starburst99 spectral shape.
• TOTAL LUMINOSITY THE STELLAR SOURCE [log (erg/s)]: -- this is the second of the 3 scaling options. Enter the bolometric luminosity of the star, star cluster, or stellar population. .
• IONIZING LUMINOSITY THE STELLAR SOURCE [log (erg/s)]: -- this is the third of the 3 scaling options. Enter the ionizing luminosity (below 912 A) of the star or star cluster.
• INNER BOUNDARY CONDITION OF THE HII REGION: -- the scaled spectrum for a spherical geometry requires an additional input parameter: the inner radius of the HII region. One of the following three must be chosen.
• DISTANCE OF THE INNER EDGE OF THE HII REGION [cm]: -- the first option is to give the distance between the ionizing star or star cluster and the inner surface of the HII region.
• INNER EDGE AS A FRACTION OF THE STROMGREN RADIUS: -- the second option is to give the distance as a fraction of the total size defined by the Stromgren radius.
• INNER EDGE VIA THE IONIZATION PARAMETER: -- the third option is to define the inner edge via the logarithm of the desired ionization parameter (U). The ionization parameter is dimensionless and is defined as U=ionizing photon flux per unit area/(hydrogen density * c).
• SCALING FACTOR FOR STARBURST99 IN PLANE-PARALLEL GEOMETRY: -- We use only the shape of the Starburst99 output and adjust the absolute luminosity by one of the three scaling factors.
• INITIAL IONIZATION PARAMETER: -- For plane-parallel geometry, the flux at the inner edge of the nebula can be defined by the logarithm of the dimensionless ionization parameter (U). The ionization parameter is defined as U=ionizing photon flux per unit area/(hydrogen density * c).
• INNER EDGE VIA THE BOLOMETRIC FLUX [log (ergs/s/cm^2)] : -- For plane-parallel models, one can define the inner edge via the bolometric flux. Bolometric flux is defined here as the total energy incident on one cubic centimeter of the inner surface of the nebula per second.
• INNER EDGE VIA THE IONIZING FLUX [log (ergs/s/cm^2)]: -- For plane-parallel models, one can define the inner edge via the ionizing flux. Ionizing flux is defined here as the ionizing energy incident on one cubic centimeter of the inner surface of the nebula per second.
• DENSITY STRUCTURE: -- the density structure can be isochoric or isobaric. In the former case, it is specified by the density, and in the latter by pressure and temperature. A filling factor can be chosen for either case.
• HYDROGEN DENSITY [cm^-3]: -- enter the hydrogen density if the structure is isochoric.
• PRESSURE: -- enter the dimensionless pressure in units of 10⁵ if the structure is isobaric.
• TEMPERATURE [10⁴ K]: -- enter the mean temperature in units of 10⁴ K if the structure is isobaric.
• FILLING FACTOR: -- enter the filling factor for either density option.
• OUTPUT FILES: -- these are the options to generate various outputs, ranging from the minimum to the very detailed output. All files are described in more detail below.

The output

Description of names and acronyms in output files

Note: MappingsIII has been developed over two decades by many people. The variations in naming convention and units reflect this. Work is currently underway to introduce more consistency to the Mappings output naming convention.

ABUND	Abundance
Accuracy	This parameter reflects the reliability of the atomic data used to estimate the emission-line fluxes.
	1 = Accurate to 10% (Hydrogenic lines only)
	2 = Average reliability
	3 = Poor reliability (old data, many atomic levels, or radiative transfer problems
Alpha	Power law model index
Cut-off	Model cut-off energy (Ryd)
De	Electron density (cm^-3)
DH	Hydrogen density (cm^-3)
DIend	Distance at end of density bounded models (cm)
	(Not applicable to web-based models)
DISav	Average radius of each shell (cm)
DIST.Ave.	Average radius of each shell (cm)
DISfin	Final radius of the nebula (cm)
DISout	Radius at the outer edge of each shell (cm)
DILUav	Average geometric dilution factor. For plane parallel models, DILUav will be 0.5. For spherical models, it will be close to zero
DLOsav	Average differential loss between heating and cooling. This should be close to zero if energy has been conserved in the model
Dn	Ion density (cm^-3)
Dnum	Ion density (cm^-3)
dr	thickness of each shell (cm)
dR	thickness of each shell (cm)
dTau	Model step-size. Default=0.03
dVol	Nebula volume in each shell (cm^3)
El.Dens	Electron density (cm^-3)
Ending	Model ending = A (fraction of HI = 99%)
FHI	Fraction of HI in each shell of the nebula
FHII	Fraction of HII in each shell of the nebula
FHXF	Final fraction of HII at the end of the nebula
Fill.F. or F.F.	Filling factor
Fren	Required final fraction of ionized hydrogen at model end (1%)
FQHeI	Flux of He+ ionizing photons(photons/s/cm^2)
FQHeII	Flux of He++ ionizing photons(photons/s/cm^2)
FQHI	Flux of H+ ionizing photons(photons/s/cm^2)
FQtot	Total Flux of ionizing photons(photons/s/cm^2)
Hden	Hydrogen density (cm^-3)
Hdens	Hydrogen density (cm^-3)
Ielen	Atomic number of element whose ionized fraction determines the model ending (this is always hydrogen=1).
Input	Will always read `interactive' for Mappings On-line models
Int./H-beta	Integrated line intensity divided by the intensity of H-beta
Jden	Density model chosen by user: c=isochoric, b=isobaric
Jeq	Equilibrium model chosen (always E)
Jgeo	Geometry model chosen by user: s=spherical, p=plane parallel
Jpoen	Ionization state of required model ending
	Web-based models: 1 (99% HI)
MOD	model choice: X=external, B=blackbody, P=power law
Ndens	Ion density (cm^-3). For solar abundance, Ndens ~ 1.1*Hdens (hydrogen density)
nH	Hydrogen density (cm^-3)
ne	Electron density (cm^-3)
Output	Output photoionization file (See description in the Table above)
P5	Photoionization model version IIId used
QHDN	Ionization parameter (cm/s) defined as: ionizing photon flux per unit area/ion density . For solar abundance, the ion density, Ndens ~ 1.1*Hdens (hydrogen density)
QHDH	Ionization parameter (cm/s) defined as: ionizing photon flux per unit area/hydrogen density. Note: the dimensionless ionization parameter is defined as U=QHDH/c, not as QHDN/c
QHDNin	Ionization parameter at the inner edge of the nebula as defined in QHDN above (cm/s)
QHDNav	Average ionization parameter as defined in QHDN above(cm/s)
Remp	Initial radius of the nebula (cm)
Rmax	Maximum radius of model (cm)
Rsou	Source Radius (cm)
Run	Model designation entered by user
Tauen	Optical depth at model end for optical-depth limited models
	Not applicable to web-based moels
TauXF	Optical depth at Hydrogen edge (912A): optically thick if TauXF > 1, optically thin if TauXF < 1
Teav	Average electron temperature (K)
Te Ave.	Average electron temperature (K)
Teini	Initial electron temperature (K)
Temp	Blackbody model temperature (K)
Tend	Temperature at model end (K)
Tfinal	Temperature at model end (K)
TOTLOSS	Total energy losses + total heating. This should be close to zero if energy has been conserved in the model.
Turn-on	Model turn-on energy (Ryd)
Z-star	Metallicity of mappings internal stellar atmosphere models
	Not applicable to web-based models
ZETAef	Alternative (archaic) measure of ionization parameter

Starburst99 output files

1. Computation of the number of ionizing photons. Output is the number of ionizing photons in the HI, HeI, and HeII continuum, their fractions relative to the total luminosity, and the total luminosity. Default filename: quanta
2. Calculation of the supernova rate and the mechanical luminosities. Default filename: snr
3. Mechanical luminosity and related quantities due to winds and supernovae. Default filename: power
4. Two output files containing the stellar spectral types during each time step and the relative numbers of WR stars. The spectral types follow the scheme by Schmidt-Kaler, oversampled by a factor of 2. For instance, there are 18 entries for spectral type B. They are the number of stars for types B0, B0.5, B1,...B9.5 (total of 18). Schmidt-Kaler's table has B0, B1,....B9 (total of 9). Default filenames: sptyp1,sptyp2
5. The mass in individual elements released via stellar winds and supernovae. No other subroutines are needed. Default filename: yield
6. The spectrum of the stellar population for each time step. The columns are time, wavelength, stellar+nebular, stellar only, and nebular only fluxes. This SED is used as input for Mappings. Default filename: spectrum
7. The ultraviolet line spectrum at 0.75 A resolution from 1200 to 1600 A (LMC/SMC library) or to 1800 A (Milky Way library). The columns have time, wavelength, absolute luminosity, and rectified (continuum=1) luminosity. Default filename: uvline
8. Calculation of colors and magnitudes. The filter system is defined in the code. Default filename: color
9. Calculation of the strengths of H_alpha, H_beta, Pa_beta, and Br_gamma. For each line we give the continuum luminosity, the line luminosity, and the equivalent width (everything logarithmic). Default filename: ewidth
10. Calculation of the strength of various IR spectral features. First is the CO index as computed by Doyon et al. (1994, ApJ, 421, 101). (Please note that this calculation has no metallicity dependence. A later version of this routine will compute the CO index using the model atmospheres themselves and give metallicity-dependent results.) Next are two computations of the CaII IR triplet using the relations of Diaz et al. (1989, 239, 325). The relations from Diaz et al. have no temperature dependence; the first calculation has the feature present in stars of all temperatures; the second has the index set to zero strength for stars with T>7200K (spectral type A or earlier). Next come the 1.62 and 2.29 micron CO features, and the 1.59 micron Si feature, which were modeled for individual stars by Origlia et al. (1993, A&A, 280, 536.) The indices can be computed for solar [Si/Fe] and [C/Fe], or a model with enhanced [Si/Fe] and depleted [C/Fe] (as for young systems enriched primarily by Type II SNe), and for stellar atmospheric microturbulent velocities (MTVs) of 1-6 km/s. (Note that the changes to the abundance ratios and MTVs are are self-contained in this routine and have no effect upon the other outputs, e.g., colors, of the code.) Default filename: irfeature
11. This subroutine is equivalent to (8), but it computes the spectral region between 1000 and 1180 A. Default filename: ovi
12. Calculates fully theoretical spectra between 3000 and 7000 A at 0.3 A resolution. These spectra are independent of the calculation of the low-resolution spectra in output 7. The file structure is the same as in (8). Presently, we do not yet have a complete library of spectra for the theoretical continua. Therefore the file lists "1" for the continuum location. In spring 2005 we will deliver the continuum file, which will be a simple auxiliary file that substitutes the current placeholder. Once the file is in place, the continuum locations will be calculated without the need of any coding. Default filename: hires
13. Calculation of the most important WR emission lines using the line luminosities of Schaerer & Vacca (1998, ApJ, 497, 658). These are only those lines originating in WR winds --- not the nebular lines in the HII region. Quantities given are the line fluxes and the equivalent widths. Default filename: wrlines
14. SED used as input for Mappings. It is identical to the stellar spectrum in the file .spectrum1, except for the units. The Mappings input file has the Eddington flux in frequency units, and the wavelength grid is in eV. Default filename: mapspec