Efrho¶
- class sbpy.activity.dust.Efrho(value, unit=None, dtype=None, copy=True)[source]¶
Bases:
sbpy.activity.dust.DustComaQuantity
Coma dust quantity for thermal emission.
Efrho
behave likeQuantity
objects with units of length.- Parameters
Notes
εfρ is the product of dust emissivity, dust filling factor, and circular aperture radius. It is nominally a constant for a steady-state coma in free expansion, and is the thermal emission equivalent for the Afρ quantity. See Kelley et al. (2013) for details.
References
A’Hearn et al. 1984, AJ 89, 579-591. Kelley et al. 2013, Icarus 225, 475-494.
Examples
>>> from sbpy.activity import Efrho >>> print(Efrho(1000, 'cm')) 1000.0 cm
Methods Summary
from_fluxd
(wfb, fluxd, aper, eph, **kwargs)Initialize from spectral flux density.
to_fluxd
(wfb, aper, eph[, unit, Tscale, T, B])Express as spectral flux density in an observation.
Methods Documentation
- classmethod from_fluxd(wfb, fluxd, aper, eph, **kwargs)[source]¶
Initialize from spectral flux density.
- Parameters
- wfb
Quantity
,SpectralElement
, list Wavelengths, frequencies, bandpass, or list of bandpasses of the observation. Bandpasses require
synphot
.- fluxd
Quantity
Flux density per unit wavelength or frequency.
- aper
Quantity
orAperture
Aperture of the observation as a circular radius (length or angular units), or as an
Aperture
.- eph: dictionary-like, `~sbpy.data.Ephem`
Ephemerides of the comet. Required fields: ‘rh’, ‘delta’. Optional: ‘phase’.
- **kwargs
Keyword arguments for
to_fluxd
.
- wfb
- to_fluxd(wfb, aper, eph, unit=None, Tscale=1.1, T=None, B=None)[source]¶
Express as spectral flux density in an observation.
Assumes the small angle approximation.
- Parameters
- wfb
Quantity
,SpectralElement
, list Wavelengths, frequencies, bandpass, or list of bandpasses of the observation. Bandpasses require
synphot
. Ignored ifS
is provided.- aper: `~astropy.units.Quantity`, `~sbpy.activity.Aperture`
Aperture of the observation as a circular radius (length or angular units), or as an sbpy
Aperture
.- eph: dictionary-like, `~sbpy.data.Ephem`
Ephemerides of the comet. Required fields: ‘rh’, ‘delta’. Optional: ‘phase’.
- unit
Unit
, string, optional The flux density unit for the output.
- Tscalefloat, optional
Scale factor for blackbody in LTE with sunlight. Ignored if
T
orB
is provided.- T
Quantity
, optional Blackbody temperature. Ignored if
B
is provided.- B
Quantity
, optional Observed spectral flux density from a blackbody sphere, i.e., pi * Planck function. Overrides
T
andTscale
.
- wfb
- Returns
- fluxd
Quantity
Spectral flux density.
- fluxd
Examples
>>> from sbpy.activity import Efrho >>> import astropy.units as u >>> efrho = Efrho(120.0, 'cm') >>> freq = 15.8 * u.um >>> aper = 11.1 * u.arcsec >>> eph = {'rh': 4.42 * u.au, 'delta': 4.01 * u.au} >>> fluxd = efrho.to_fluxd(freq, aper, eph=eph, unit='Jy') >>> print(fluxd) 0.006519545281786034 Jy