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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 <LyaDoublePeakedSED.hpp>
Public Member Functions | |
| double | generateWavelength () const override |
| double | integratedLuminosity (const Range &wavelengthRange) const override |
| Range | intrinsicWavelengthRange () const override |
| double | scale () const |
| 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 | |
| LyaDoublePeakedSED () | |
| 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 = LyaDoublePeakedSED |
Private Attributes | |
| double | _scale |
| double | _wavelengthCenter |
| Range | _wavelengthRange |
| double | _wavelengthScale |
Friends | |
| class | ItemRegistry |
The LyaDoublePeakedSED class implements a double-peaked SED, centered on the Lyman-alpha line wavelength \(\lambda_\alpha\), and corresponding to the spectrum that emerges from a static sphere of hydrogen gas surrounding a Lyman-alpha point source. This SED can be used as a simple model to represent sub-grid gas embedded in the source.
The spectrum can be expressed analytically (see Dijkstra et al. 2006a, ApJ, 649, 14-36). Using the photon velocity shift
\[ v = \frac{\lambda - \lambda_\alpha} {\lambda_\alpha} \,c \]
as the spectral variable and a velocity scale \(s\) configured by the user, the normalized spectrum can be written as
\[ L_v(v) = \frac{3v^2} {2s^3\left[1+\cosh(v^3/s^3)\right]}. \]
The two peaks of this profile are situated at \(v_* \approx \pm 1.06938 \,s\).
The cumulative distribution is
\[ \int_{-\infty}^{v} L_v(v') \,\mathrm{d}v' = \frac{1} {1+\exp(-v^3/s^3)}, \]
which can be inverted so that we can obtain a sample from the distribution through
\[ v = s \left( \ln\frac{\mathcal{X}}{1-\mathcal{X}} \right)^{1/3}, \]
where \(\mathcal{X}\) is a uniform deviate.
To simplify some numerical operations, such as tabulating the SED, we limit the intrinsic range of the SED to \(\pm 3.6s\) from the center. We have \(L_v(3.6s)/L_v(v_*) < 4\times10^{-19}\) 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
\[ \lambda_\alpha \left(1 \pm \frac{3.6\,s}{c}\right) \]
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 LyaDoublePeakedSED : "a double-peaked spectrum around the central Lyman-alpha wavelength" .
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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 double-peaked spectrum, we limit the range to \(\pm 3.6s\) from the Lyman-alpha line center, as decribed in the class header.
Implements SED.
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inline |
This function returns the value of the discoverable double property scale : "the velocity scale" .
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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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 \(\pm 3.6s\) of the SED is covered by 720 wavelength points on a regular linear grid.
Implements ContSED.