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The SKIRT project
advanced radiative transfer for astrophysics
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The SKIRT project
advanced radiative transfer for astrophysics
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#include <LyaGaussianSED.hpp>
Public Member Functions | |
| double | dispersion () const |
| double | generateWavelength () const override |
| double | integratedLuminosity (const Range &wavelengthRange) const override |
| Range | intrinsicWavelengthRange () const override |
| double | specificLuminosity (double wavelength) const override |
| void | specificLuminosityArray (Array &lambdav, Array &pv, const Range &wavelengthRange) const override |
| virtual double | specificLuminosity (double wavelength) const =0 |
| virtual void | specificLuminosityArray (Array &lambdav, Array &pv, const Range &wavelengthRange) const =0 |
 Public Member Functions inherited from SED | |
| virtual double | generateWavelength () const =0 |
| virtual double | integratedLuminosity (const Range &wavelengthRange) const =0 |
| virtual Range | intrinsicWavelengthRange () const =0 |
| Range | normalizationWavelengthRange () const |
| Public Member Functions inherited from SimulationItem | |
| template<class T > | |
| T * | find (bool setup=true) const |
| template<class T > | |
| T * | interface (int levels=-999999, bool setup=true) const |
| virtual string | itemName () const |
| void | setup () |
| string | typeAndName () const |
| Public Member Functions inherited from Item | |
| Item (const Item &)=delete | |
| virtual | ~Item () |
| void | addChild (Item *child) |
| const vector< Item * > & | children () const |
| virtual void | clearItemListProperty (const PropertyDef *property) |
| void | destroyChild (Item *child) |
| virtual bool | getBoolProperty (const PropertyDef *property) const |
| virtual vector< double > | getDoubleListProperty (const PropertyDef *property) const |
| virtual double | getDoubleProperty (const PropertyDef *property) const |
| virtual string | getEnumProperty (const PropertyDef *property) const |
| virtual int | getIntProperty (const PropertyDef *property) const |
| virtual vector< Item * > | getItemListProperty (const PropertyDef *property) const |
| virtual Item * | getItemProperty (const PropertyDef *property) const |
| virtual string | getStringProperty (const PropertyDef *property) const |
| int | getUtilityProperty (string name) const |
| virtual void | insertIntoItemListProperty (const PropertyDef *property, int index, Item *item) |
| Item & | operator= (const Item &)=delete |
| Item * | parent () const |
| virtual void | removeFromItemListProperty (const PropertyDef *property, int index) |
| virtual void | setBoolProperty (const PropertyDef *property, bool value) |
| virtual void | setDoubleListProperty (const PropertyDef *property, vector< double > value) |
| virtual void | setDoubleProperty (const PropertyDef *property, double value) |
| virtual void | setEnumProperty (const PropertyDef *property, string value) |
| virtual void | setIntProperty (const PropertyDef *property, int value) |
| virtual void | setItemProperty (const PropertyDef *property, Item *item) |
| virtual void | setStringProperty (const PropertyDef *property, string value) |
| void | setUtilityProperty (string name, int value) |
| virtual string | type () const |
Protected Member Functions | |
| LyaGaussianSED () | |
| void | setupSelfBefore () override |
| Protected Member Functions inherited from ContSED | |
| ContSED () | |
| Protected Member Functions inherited from SED | |
| SED () | |
| Random * | random () const |
| void | setupSelfBefore () override |
| Protected Member Functions inherited from SimulationItem | |
| SimulationItem () | |
| virtual bool | offersInterface (const std::type_info &interfaceTypeInfo) const |
| virtual void | setupSelfAfter () |
| virtual void | setupSelfBefore () |
| Protected Member Functions inherited from Item | |
| Item () | |
Private Types | |
| using | BaseType = ContSED |
| using | ItemType = LyaGaussianSED |
Private Attributes | |
| double | _dispersion |
| double | _wavelengthCenter |
| double | _wavelengthDispersion |
| Range | _wavelengthRange |
Friends | |
| class | ItemRegistry |
The LyaGaussianSED class implements a Gaussian spectrum around the central Lyman-alpha wavelength \(\lambda_\alpha\), reflecting the thermal sub-grid motion in the source. Using the photon velocity shift
\[ v = \frac{\lambda - \lambda_\alpha} {\lambda_\alpha} \,c \]
as the spectral variable, and a dispersion \(s\) configured by the user in velocity units, the normalized Gaussian spectrum can be written as
\[ L_v(v) = \frac{1}{s\,\sqrt{2\pi}} \,\exp\left( -\frac{v^2}{2s^2} \right). \]
The thermal velocity corresponding to the dispersion \(s\) is given by
\[ v_\mathrm{th}=\sqrt{2}\,s \]
and the full width at half maximum of the Gaussian line profile is given by
\[ \text{FWHM} = 2\sqrt{2\ln2}\,s \approx 2.35482\,s. \]
This SED can be implemented analytically and it can sampled using the standard procedure for a Gaussian deviate. To simplify some numerical operations, such as tabulating the SED, we limit the intrinsic range of the SED to \(\pm 9s\) from the center. We have \(L_v(9s)/L_v(0) < 3\times10^{-18}\) so that values outside this range will never contribute to the results anyway.
To simplify normalization of this SED, the source wavelength range configured by the user must fully contain the intrinsic wavelength range defined by
\[ \lambda_\alpha \left(1 \pm \frac{9\,s}{c}\right) \]
This item type is displayed only if the Boolean expression "Lya|Level3" evaluates to true after replacing the names by true or false depending on their presence.
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inlineprotected |
Default constructor for concrete Item subclass LyaGaussianSED : "a Gaussian spectrum around the central Lyman-alpha wavelength" .
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inline |
This function returns the value of the discoverable double property dispersion : "the Gaussian velocity dispersion" .
This property represents a physical quantity of type "velocity" .
The minimum value for this property is "]0 km/s" .
The maximum value for this property is "1000 km/s]" .
The default value for this property is given by the conditional value expression "50 km/s" .
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overridevirtual |
This function draws a random wavelength from the normalized spectral energy distribution.
Implements SED.
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overridevirtual |
This function returns the normalized integrated luminosity \(L\) (i.e. radiative power) over the specified wavelength range.
Implements SED.
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overridevirtual |
This function returns the intrinsic wavelength range of the SED. For our Gaussian profile, we limit the range to \(\pm 9s\) from the Lyman-alpha line center, as decribed in the class header.
Implements SED.
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overrideprotectedvirtual |
This function precalculates some values for later use.
Reimplemented from SimulationItem.
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overridevirtual |
This function returns the normalized specific luminosity \(L_\lambda\) (i.e. radiative power per unit of wavelength) at the specified wavelength.
Implements ContSED.
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overridevirtual |
This function returns the normalized specific luminosity \(L_\lambda\) (i.e. radiative power per unit of wavelength) at a number of wavelength points within the specified wavelength range. The intrinsic wavelength range \(\pm 9s\) of the SED is covered by 1800 wavelength points on a regular linear grid.
Implements ContSED.