def test_bb_flux_nounits_returns_expected_flux(self):
expected = (np.pi * u.sr) \
* planck_function(self.wavelength, self.temperature) \
* (self.angular_radius)**2
result = bb_flux_nounits(self.wavelength, self.temperature,
self.angular_radius)
self.assertEqual(expected.value, result)
def test_planck_function_expected_value(self):
wavelength = 5000 * u.Angstrom
expected = (self.C1 / wavelength**5) / \
(np.exp(self.C2 / (wavelength * self.temperature)) - 1) / u.sr
expected = expected.to(u.erg / (u.s * u.cm**2 * u.AA * u.sr))
result = planck_function(wavelength, self.temperature)
self.assertAlmostEqual(expected.value, result.value)
def test_planck_function_expected_value(self):
wavelength = 5000 * u.Angstrom
expected = (self.C1 / wavelength**5) / \
(np.exp(self.C2 / (wavelength * self.temperature)) - 1) / u.sr
expected = expected.to(u.erg / (u.s * u.cm**2 * u.AA * u.sr))
result = planck_function(wavelength, self.temperature)
self.assertAlmostEqual(expected.value, result.value)
def test_rayleigh_jeans_law_short_wavelength(self):
# The Rayleigh-Jeans law should NOT work for short wavelength
wavelength = 2.9E7 * u.K * u.AA / self.temperature
expected = self.C1/self.C2 * self.temperature / (wavelength)**(4)
expected = expected.to(u.erg / (u.s * u.cm**2 * u.AA))
result = planck_function(wavelength, self.temperature)
self.assertNotAlmostEqual(expected.value, result.value, delta = 0.01 * expected.value)
def test_wien_approx_long_wavelength(self):
# The Wien approximation should NOT work for long wavelength
wavelength = 7.8E9 * u.K * u.AA / self.temperature
expected = self.C1 * (wavelength)**(-5) * np.exp(-self.C2 /
(wavelength * self.temperature))
expected = expected.to(u.erg / (u.s * u.cm**2 * u.AA))
result = planck_function(wavelength, self.temperature)
self.assertNotAlmostEqual(expected.value, result.value, delta = 0.01 * expected.value)
def test_rayleigh_jeans_law_short_wavelength(self):
# The Rayleigh-Jeans law should NOT work for short wavelength
wavelength = 2.9E7 * u.K * u.AA / self.temperature
expected = self.C1 / self.C2 * self.temperature / (wavelength)**(4)
expected = expected.to(u.erg / (u.s * u.cm**2 * u.AA))
result = planck_function(wavelength, self.temperature)
self.assertNotAlmostEqual(expected.value,
result.value,
delta=0.01 * expected.value)
def test_rayleigh_jeans_law_long_wavelength(self):
# The Planck function should be within 1% of the Rayleigh-Jeans
# approximation for lambda * T > 7.7E9 angstrom * K
wavelength = 7.8E9 * u.K * u.AA / self.temperature
# Expected value is the Rayleigh-Jeans approximation
expected = self.C1/self.C2 * self.temperature / (wavelength)**(4)
expected = expected.to(u.erg / (u.s * u.cm**2 * u.AA))
result = planck_function(wavelength, self.temperature)
self.assertAlmostEqual(expected.value, result.value, delta = 0.01 * expected.value)
def test_wien_approx_long_wavelength(self):
# The Wien approximation should NOT work for long wavelength
wavelength = 7.8E9 * u.K * u.AA / self.temperature
expected = self.C1 * (wavelength)**(-5) * np.exp(
-self.C2 / (wavelength * self.temperature))
expected = expected.to(u.erg / (u.s * u.cm**2 * u.AA))
result = planck_function(wavelength, self.temperature)
self.assertNotAlmostEqual(expected.value,
result.value,
delta=0.01 * expected.value)
def test_wien_approx_short_wavelength(self):
# The Planck function should be within 1% of the Wein approximation
# for lambda * T < 3.0E7 angstrom * K
wavelength = 2.9E7 * u.K * u.AA / self.temperature
# Expected value is the Wein approximation
expected = self.C1 * (wavelength)**(-5) * np.exp(-self.C2 /
(wavelength * self.temperature))
expected = expected.to(u.erg / (u.s * u.cm**2 * u.AA))
result = planck_function(wavelength, self.temperature)
self.assertAlmostEqual(expected.value, result.value, delta = 0.01 * expected.value)
def test_rayleigh_jeans_law_long_wavelength(self):
# The Planck function should be within 1% of the Rayleigh-Jeans
# approximation for lambda * T > 7.7E9 angstrom * K
wavelength = 7.8E9 * u.K * u.AA / self.temperature
# Expected value is the Rayleigh-Jeans approximation
expected = self.C1 / self.C2 * self.temperature / (wavelength)**(4)
expected = expected.to(u.erg / (u.s * u.cm**2 * u.AA))
result = planck_function(wavelength, self.temperature)
self.assertAlmostEqual(expected.value,
result.value,
delta=0.01 * expected.value)
def test_wien_approx_short_wavelength(self):
# The Planck function should be within 1% of the Wein approximation
# for lambda * T < 3.0E7 angstrom * K
wavelength = 2.9E7 * u.K * u.AA / self.temperature
# Expected value is the Wein approximation
expected = self.C1 * (wavelength)**(-5) * np.exp(
-self.C2 / (wavelength * self.temperature))
expected = expected.to(u.erg / (u.s * u.cm**2 * u.AA))
result = planck_function(wavelength, self.temperature)
self.assertAlmostEqual(expected.value,
result.value,
delta=0.01 * expected.value)
