profile = profiles.NFWProfile()
# Adopt standard values used in HESS
profiles.DMProfile.DISTANCE_GC = 8.5 * u.kpc
profiles.DMProfile.LOCAL_DENSITY = 0.39 * u.Unit("GeV / cm3")
profile.scale_to_local_density()
position = SkyCoord(0.0, 0.0, frame="galactic", unit="deg")
geom = WcsGeom.create(binsz=0.05, skydir=position, width=3.0, coordsys="GAL")
# In[ ]:
jfactory = JFactory(geom=geom,
profile=profile,
distance=profiles.DMProfile.DISTANCE_GC)
jfact = jfactory.compute_jfactor()
# In[ ]:
jfact_map = WcsNDMap(geom=geom, data=jfact.value, unit=jfact.unit)
fig, ax, im = jfact_map.plot(cmap="viridis", norm=LogNorm(), add_cbar=True)
plt.title("J-Factor [{}]".format(jfact_map.unit))
# 1 deg circle usually used in H.E.S.S. analyses
sky_reg = CircleSkyRegion(center=position, radius=1 * u.deg)
pix_reg = sky_reg.to_pixel(wcs=geom.wcs)
pix_reg.plot(ax=ax, facecolor="none", edgecolor="red", label="1 deg circle")
plt.legend()
def jfact(geom):
jfactory = JFactory(geom=geom,
profile=profiles.NFWProfile(),
distance=8 * u.kpc)
return jfactory.compute_jfactor()