LinearDiskBulge

class dysmalpy.models.LinearDiskBulge(invq_disk=5, invq_bulge=1, noord_flat=False, light_component='disk', baryon_type='gas+stars', **kwargs)[source]

Bases: MassModel, _LightMassModel

Mass distribution with a disk and bulge

Parameters:

total_mass (float) – Combined disk and bulge mass in solar units
r_eff_disk (float) – Effective radius of the disk in kpc
n_disk (float) – Sersic index of the disk
r_eff_bulge (float) – Effective radius of the bulge
n_bulge (float) – Sersic index of the bulge
bt (float) – Bulge-to-total mass ratio
invq_disk (float) – Effective radius to effective height ratio for the disk
invq_bulge (float) – Effective radius to effective height ratio for the bulge
noord_flat (bool) – If True, use circular velocity profiles derived in Noordermeer 2008. If False, circular velocity is derived through v_circular
light_component ({'disk', 'bulge', 'total'}) – Which component to use as the flux profile
baryon_type ({'gas+stars', 'stars', 'gas'}) – What type of baryons are included. Used for dlnrhogas/dlnr

Notes

This model is the exactly the same as DiskBulge except that total_mass is in linear units instead of log.

Attributes Summary

`bt`
`mass_to_light`
`n_bulge`
`n_disk`
`noord_flat`
`param_names`	Names of the parameters that describe models of this type.
`r_eff_bulge`
`r_eff_disk`
`total_mass`
`tracer`

Methods Summary

`circular_velocity`(r)	Total Circular velocity as a function of radius
`circular_velocity_bulge`(r)	Circular velocity of the bulge as a function of radius
`circular_velocity_disk`(r)	Circular velocity of the disk as a function of radius
`enclosed_mass`(r)	Disk+Bulge total enclosed mass
`enclosed_mass_bulge`(r)	Enclosed mass of the bulge component
`enclosed_mass_disk`(r)	Enclosed mass of the disk component
`evaluate`(r, total_mass, r_eff_disk, n_disk, ...)	Disk+Bulge mass surface density
`light_profile`(r)	Conversion from mass to light as a function of radius
`velocity_profile`(r, modelset)	Total rotational velocity due to the disk+bulge
`velocity_profile_bulge`(r, modelset)	Rotational velocity due to the bulge
`velocity_profile_disk`(r, modelset)	Rotational velocity due to the disk

Attributes Documentation

bt = DysmalParameter('bt', value=0.2, bounds=(0, 1), prior=<dysmalpy.parameters.UniformPrior object>)

mass_to_light = DysmalParameter('mass_to_light', value=1.0, fixed=True, prior=<dysmalpy.parameters.UniformPrior object>)

n_bulge = DysmalParameter('n_bulge', value=4.0, fixed=True, bounds=(0, 8), prior=<dysmalpy.parameters.UniformPrior object>)

n_disk = DysmalParameter('n_disk', value=1.0, fixed=True, bounds=(0, 8), prior=<dysmalpy.parameters.UniformPrior object>)

noord_flat

param_names = ('total_mass', 'r_eff_disk', 'n_disk', 'r_eff_bulge', 'n_bulge', 'bt', 'mass_to_light')

Names of the parameters that describe models of this type.

The parameters in this tuple are in the same order they should be passed in when initializing a model of a specific type. Some types of models, such as polynomial models, have a different number of parameters depending on some other property of the model, such as the degree.

When defining a custom model class the value of this attribute is automatically set by the Parameter attributes defined in the class body.

r_eff_bulge = DysmalParameter('r_eff_bulge', value=1.0, bounds=(0, 50), prior=<dysmalpy.parameters.UniformPrior object>)

r_eff_disk = DysmalParameter('r_eff_disk', value=1.0, bounds=(0, 50), prior=<dysmalpy.parameters.UniformPrior object>)

total_mass = DysmalParameter('total_mass', value=10.0, bounds=(5, 14), prior=<dysmalpy.parameters.UniformPrior object>)

tracer = 'mass'

Methods Documentation

circular_velocity(r)[source]

Total Circular velocity as a function of radius

Parameters:: r (float or array) – Radii at which to calculate the circular velocity
Returns:: vcirc – Circular velocity in km/s
Return type:: float or array

circular_velocity_bulge(r)[source]

Circular velocity of the bulge as a function of radius

Parameters:: r (float or array) – Radii at which to calculate the circular velocity
Returns:: vcirc – Circular velocity in km/s
Return type:: float or array

circular_velocity_disk(r)[source]

Circular velocity of the disk as a function of radius

Parameters:: r (float or array) – Radii at which to calculate the circular velocity
Returns:: vcirc – Circular velocity in km/s
Return type:: float or array

enclosed_mass(r)[source]

Disk+Bulge total enclosed mass

Parameters:: r (float or array) – Radii at which to calculate the enclosed mass
Returns:: menc – Enclosed mass profile
Return type:: float or array

enclosed_mass_bulge(r)[source]

Enclosed mass of the bulge component

Parameters:: r (float or array) – Radii at which to calculate the enclosed mass
Returns:: menc – Enclosed mass profile
Return type:: float or array

enclosed_mass_disk(r)[source]

Enclosed mass of the disk component

Parameters:: r (float or array) – Radii at which to calculate the enclosed mass
Returns:: menc – Enclosed mass profile
Return type:: float or array

static evaluate(r, total_mass, r_eff_disk, n_disk, r_eff_bulge, n_bulge, bt, mass_to_light)[source]: Disk+Bulge mass surface density

light_profile(r)[source]

Conversion from mass to light as a function of radius

Parameters:: r (float or array) – Radii at which to calculate the enclosed mass
Returns:: light – Relative line flux as a function of radius
Return type:: float or array

Notes

The resulting light profile depends on what DiskBulge.light_component is set to. If ‘disk’ or ‘bulge’ then only the mass associated with the disk or bulge will be converted into light. If ‘total’, then both components will be used.

velocity_profile(r, modelset)[source]

Total rotational velocity due to the disk+bulge

Parameters:

r (float or array) – Radii at which to calculate the circular velocity in kpc
modelset (ModelSet) – Full ModelSet this component belongs to

Returns:

vrot – Rotational velocity in km/s

Return type:

float or array

Notes

This method requires a ModelSet input to be able to apply the pressure support correction due to the gas turbulence.

velocity_profile_bulge(r, modelset)[source]

Rotational velocity due to the bulge

Parameters:

r (float or array) – Radii at which to calculate the circular velocity in kpc
modelset (ModelSet) – Full ModelSet this component belongs to

Returns:

vrot – Rotational velocity in km/s

Return type:

float or array

Notes

This method requires a ModelSet input to be able to apply the pressure support correction due to the gas turbulence.

velocity_profile_disk(r, modelset)[source]

Rotational velocity due to the disk

Parameters:

r (float or array) – Radii at which to calculate the circular velocity in kpc
modelset (ModelSet) – Full ModelSet this component belongs to

Returns:

vrot – Rotational velocity in km/s

Return type:

float or array

Notes

This method requires a ModelSet input to be able to apply the pressure support correction due to the gas turbulence.