WM-basic

This submodule (BolometricCorrections.YBC.WMbasic) enables interaction with the "YBC" bolometric correction (BC) grid of hot star (O and B-type) atmospheres calculated with the WM-basic code by Chen et al. (2015) – see section 3.2 in particular. Section 3.3 of Chen et al. (2019) discusses the calculation of BCs from these models. Radiation-driven outflows can significantly impact the SEDs for stars of these types, and the models are calculated for three different values of mass outflow rate: $\text{log} (\dot{M}) = (-7, -6, -5)$ where $\dot{M}$ is in units of solar masses per year. The full grid coverage is given below.

	min	max
Teff	19,952 K	100,000 K
logg	2.5	6.0
Mdot	1e-7	1e-5
Av	0.0 mag	20.0 mag
Rv	3.1	3.1

Warning

These models cannot be used without specifying a mass outflow rate (Mdot). Not all stellar evolutionary libraries provide this quantity. Even when they do, these outflow rates are often based on scaling relations with other stellar evolutionary quantities (e.g., metallicity, luminosity) rather than being self-consistently inferred from the interior model. We provide utilities to estimate outflow rates from other stellar quantities using scaling relations here.

Types

BolometricCorrections.YBC.WMbasic.WMbasicYBCGrid — Type

WMbasicYBCGrid(grid::AbstractString)

Load and return the YBC WM-basic bolometric corrections for the given photometric system grid, which must be a valid entry in BolometricCorrections.YBC.systems. This type is used to create instances of WMbasicYBCTable that have fixed dependent grid variables ([M/H], Av). This can be done either by calling an instance of WMbasicYBCGrid with (mh, Av) arguments or by using the appropriate constructor for WMbasicYBCTable.

julia> using BolometricCorrections.YBC.WMbasic: WMbasicYBCGrid

julia> grid = WMbasicYBCGrid("acs_wfc")
YBC WM-basic bolometric correction grid for photometric system YBC/acs_wfc.

julia> grid(-1.01, 0.11) # Can be called to construct table with interpolated [M/H], Av
YBC WM-basic bolometric correction table for system YBC/acs_wfc with [M/H] -1.01 and V-band extinction 0.11

source

BolometricCorrections.YBC.WMbasic.WMbasicYBCTable — Type

WMbasicYBCTable(grid::WMbasicYBCGrid, mh::Real, Av::Real)

Interpolates the YBC WM-basic bolometric corrections in grid to a fixed value of [M/H] (mh), V-band extinction (Av), leaving only Teff, logg, and Mdot as dependent variables (the YBC WM-basic BCs have only one Rv value). Returns an instance that is callable with arguments (Teff [K], logg [cgs], Mdot [solMass / yr]) to interpolate the bolometric corrections as a function of temperature, surface gravity, and mass outflow rate.

julia> using BolometricCorrections.YBC.WMbasic: WMbasicYBCGrid, WMbasicYBCTable

julia> grid = WMbasicYBCGrid("acs_wfc")
YBC WM-basic bolometric correction grid for photometric system YBC/acs_wfc.

julia> table = WMbasicYBCTable(grid, -1.01, 0.011) # Interpolate table from full grid
YBC WM-basic bolometric correction table for system YBC/acs_wfc with [M/H] -1.01 and V-band extinction 0.011

julia> length(table(25_0254.0, 2.54, 5e-6)) == 12 # Returns BC in each filter
true

julia> size(table([25_0254.0, 25_0354.0], [2.54, 2.56], [4e-6, 5e-6])) # `table(array, array)` is also supported
(12, 2)

julia> using TypedTables: Table # `table(Table, array, array)` will return result as a Table

julia> table(Table, [25_0254.0, 25_0354.0], [2.54, 2.56], [4e-6, 5e-6]) isa Table
true

julia> table((logg = 2.54, Teff = 25_054.0, Mdot = 2e-5)) == table(25_054.0, 2.54, 2e-5) # can use NamedTuple argument
true

When providing a single argument (like a NamedTuple), we support automatic estimation of the mass-loss rate from other quantities using mass loss models. An example of this usage is given below using the Bjorklund2021MassLoss model, which calculates the stellar mass-loss rate from the metallicity (i.e., Z(table)) and the luminosity logL. logg and Teff are treated normally.

julia> using BolometricCorrections: Bjorklund2021MassLoss # Load stellar mass-loss model

julia> table(Bjorklund2021MassLoss(), (logg = 2.54, Teff = 25_054.0, logL = 5)) isa AbstractVector
true

source

Chemistry

These models use the same solar chemical abundances as are used for the PARSEC stellar evolutionary library (Bressan et al., 2012), which is represented by the BolometricCorrections.YBC.PARSECChemistry type.

WM-basic References

This page cites the following references:

Bressan, A.; Marigo, P.; Girardi, L.; Salasnich, B.; Dal Cero, C.; Rubele, S. and Nanni, A. (2012). PARSEC : stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code. MNRAS 427, 127–145.
Chen, Y.; Bressan, A.; Girardi, L.; Marigo, P.; Kong, X. and Lanza, A. (2015). PARSEC evolutionary tracks of massive stars up to 350 M⊙ at metallicities 0.0001 ≤ Z ≤ 0.04. MNRAS 452, 1068–1080. Accessed on Mar 24, 2024. ADS Bibcode: 2015MNRAS.452.1068C.
Chen, Y.; Girardi, L.; Fu, X.; Bressan, A.; Aringer, B.; Dal Tio, P.; Pastorelli, G.; Marigo, P.; Costa, G. and Zhang, X. (2019). YBC: a stellar bolometric corrections database with variable extinction coefficients. Application to PARSEC isochrones. A & A 632, A105, arXiv:1910.09037 [astro-ph.SR].