SNRTrueloveMcKee#
- class gammapy.astro.source.SNRTrueloveMcKee(*args, **kwargs)[source]#
Bases:
gammapy.astro.source.snr.SNR
SNR model according to Truelove & McKee (1999).
Reference: https://ui.adsabs.harvard.edu/abs/1999ApJS..120..299T
Attributes Summary
Characteristic time scale when the Sedov-Taylor phase starts.
Characteristic time scale when the Sedov-Taylor phase of the SNR's evolution ends.
Methods Summary
luminosity_tev
(t[, energy_min])Gamma-ray luminosity above
energy_min
at aget
.radius
(t)Outer shell radius at age t.
radius_inner
(t[, fraction])Inner radius at age t of the SNR shell.
Reverse shock radius at age t.
Attributes Documentation
- sedov_taylor_begin#
Characteristic time scale when the Sedov-Taylor phase starts.
Given by \(t_{ST} \approx 0.52 t_{ch}\).
- sedov_taylor_end#
Characteristic time scale when the Sedov-Taylor phase of the SNR’s evolution ends.
The end of the Sedov-Taylor phase of the SNR is defined by the condition, that the temperature at the shock drops below T = 10^6 K.
The time scale is given by:
\[t_{end} \approx 43000 \left(\frac{m}{1.66\cdot 10^{-24}g}\right)^{5/6} \left(\frac{E_{SN}}{10^{51}erg}\right)^{1/3} \left(\frac{\rho_{ISM}}{1.66\cdot 10^{-24}g/cm^3}\right)^{-1/3} \text{yr}\]
Methods Documentation
- luminosity_tev(t, energy_min='1 TeV')#
Gamma-ray luminosity above
energy_min
at aget
.The luminosity is assumed constant in a given age interval and zero before and after. The assumed spectral index is 2.1.
The gamma-ray luminosity above 1 TeV is given by:
\[L_{\gamma}(\geq 1TeV) \approx 10^{34} \theta \left(\frac{E_{SN}}{10^{51} erg}\right) \left(\frac{\rho_{ISM}}{1.66\cdot 10^{-24} g/cm^{3}} \right) \text{ s}^{-1}\]Reference: https://ui.adsabs.harvard.edu/abs/1994A%26A…287..959D (Formula (7)).
- radius(t)[source]#
Outer shell radius at age t.
The radius during the free expansion phase is given by:
\[R_{SNR}(t) = 1.12R_{ch}\left(\frac{t}{t_{ch}}\right)^{2/3}\]The radius during the Sedov-Taylor phase evolves like:
\[R_{SNR}(t) = \left[R_{SNR, ST}^{5/2} + \left(2.026\frac{E_{SN}} {\rho_{ISM}}\right)^{1/2}(t - t_{ST})\right]^{2/5}\]Using the characteristic dimensions:
\[R_{ch} = M_{ej}^{1/3}\rho_{ISM}^{-1/3} \ \ \text{and} \ \ t_{ch} = E_{SN}^{-1/2}M_{ej}^{5/6}\rho_{ISM}^{-1/3}\]- Parameters
- t
Quantity
Time after birth of the SNR
- t
- radius_inner(t, fraction=0.0914)#
Inner radius at age t of the SNR shell.
- Parameters
- t
Quantity
Time after birth of the SNR
- t
- radius_reverse_shock(t)[source]#
Reverse shock radius at age t.
Initially the reverse shock co-evolves with the radius of the SNR:
\[R_{RS}(t) = \frac{1}{1.19}r_{SNR}(t)\]After a time \(t_{core} \simeq 0.25t_{ch}\) the reverse shock reaches the core and then propagates as:
\[R_{RS}(t) = \left[1.49 - 0.16 \frac{t - t_{core}}{t_{ch}} - 0.46 \ln \left(\frac{t}{t_{core}}\right)\right]\frac{R_{ch}}{t_{ch}}t\]- Parameters
- t
Quantity
Time after birth of the SNR
- t