Help for the Accretion Disk Model Database
Contents of the tables
Sample structure table
The tables contain all physical parameters for each model, they are arranged in
such a way that for each Structure file there are several (usually four) S.E.D. files
for different inclination angles and maximum radius of the disk. The parameters
listed in the structure file table are:
- Mass accretion rate of the model in M/yr
- Maximum radius of the disk in AU. Spectral Energy Distributions will be calculated
using this radius or truncating the disk at an smaller radius which will be quoted in the
- Inner radius of the disk in stellar radii. It is the dust destruction radius, computed taking
into account the star and the accretion luminosities (see D'Alessio
et al. 2004 for more details). The value of the stellar radius for each
central star is given in the table of star properties.
- Adimensional parameter for the viscosity according to the prescription from Shakura and Sunyaev (1973),
the usual value for this parameter ( = 0.01) was used for these models, except for the models with 4000 K and 1 Myr where we used = 0.1, 0.01, and 0.001. See D'Alessio et al. 2004 for more details.
- Mass of the disk in solar masses. This value is calculated integrating the Surface density in the
disk from the inner radius to the outer radius.
- Slope of the adopted distribution of sizes for the dust grains. Two values are given for p (3.5 and 2.5), see
D'Alessio et al. 2004 for more details.
- Maximum size of dust grains in dust the distribution given by n(a) ~ a-p, being n the number of grains with size a.The minimum size is set to be 0.005 mu.
- By clicking here you will see a plot of the dependence of the characteristic physical variables with radius for this structure file. Here you can see a sample plot with some explanations.
- By clicking here you can access the data file that was used to make the plot, it contains all physical information of the
variation of the disk physical variables with radius.
Sample Spectral Energy Distribution (S.E.D.) table
For each of the structure files listed in the table above, this table will provide
the different S.E.D. files made from it. The only difference between them is the
inclination angle (cos i) and radius of the disk (Rdisk). Along with this
data we provide some observational properties calculated from the S.E.D. that may
help constraining the suitable models for fitting any observed data.
|| cos i
- Maximum radius of the disk in AU. This value can be equal to the radius of the
structure file or smaller than it.
- cos i
- cosine of the inclination angle of the disk. There are two possible values for this, cos i = 0.5 (i = 60, closer to edge-on) and cos i = 0.85 (i = 30, closer to pole-on)
- Luminosity of the central star in solar units. It is calculated by integrating the actual Kurucz model flux adopted as the flux from the central star. It's the same value quoted in the table of the central star properties.
- Infrared excess, it is estimated by integrating the area below the model flux and subtracting from it the area of the reddened kurucz model flux.
- Extinction to the central star caused by the disk itself. This is a lower limit to the extinction that the star should show if a disk with these characteristics were present.
- Continuum flux of the model in 1.3 mm for a star and disk system at 140 pc (measured in Jy).
- Slope of the S.E.D. in submillimeter wavelengths, it's calculated as submm=logF(870mu)-logF(400mu)) / log(870mu)-log(400mu).
- Slope of the S.E.D. in the millimiter wavelengths, it's calculated as mm=logF(1300mu)-logF(2675mu) / log(2675mu)-log(1300mu).
- Spitzer/IRAC magnitude in the 3.6 micron band, calculated integrating the model S.E.D. times the Relative Spectral Response Curve for this magnitude. The magnitude is calculated at 140 pc. The Zero flux for this magnitude was taken as F_o([3.6])= 277.5 Jy.
- Color between the first and the second IRAC passbands. Both calculated by integrating the model flux times the Relative Spectral Response Curves. The Zero flux for [4.5] was taken as F_o([4.5])= 179.5 Jy 277.
- Color between the second and the third IRAC passbands. The Zero flux for [5.8] was taken as F_o([5.8])= 116.6 Jy.
- Color between the third and the fourth IRAC passbands. The Zero flux for [8.0] was taken as F_o([8.0])= 63.1 Jy.
- By clicking here you will see a plot of the Synthetic Spectral Energy Distribution for the inclination angle and disk radius quoted in the table. Here you can see a sample plot with some explanations.
- File with the wavelength and flux for the synthetic S.E.D., also are given the optical depth tau to the central star for each wavelength.
Contents of the plots
Sample Structure plot
In this plot we can see:
|Upper left panel|
|* Midplane temperature in thin line, log(Tc) in file.|
|* Irradiation temperature in dashed line, log(Tirr) in file.|
|* Surface temperature in dotted line, log(To) in file.|
|* Viscous effective temperature in dot-dashed line, log(Tvis) in the file.|
|* Temperature in the height where Rosseland mean optical depth is 2/3 in circles.|
|Upper right panel|
|* Surface density in g/cm-2 against radius in AU.|
|Medium left panel|
|* Hydrostatic scale height in thin line, log (H) in file|
|* Irradiation surface height in dotted line, log(Ztauss) in file|
|* Surface height in dashed line,log(Zinf) in file|
|Medium right panel|
|* Ratios of heights over radius.|
|Lower left pannel|
|* Rosseland mean opacity|
Sample Spectral Energy Distribution plot
In this plot we can see:
* The model flux in ergs/cm2/s1 against wavelength in micron in thin black line. Flux is nu*F_nu and lambda is Lambda(mu) in the file.
* The kurucz model flux for the central star in dashed red line. This spectrum has not been reddened, so it may appear higher than the model for big values of AV. It's shown to illustrate the emission from the star.
Last modified: Mon Sep 27 14:39:57 MET DST 2004