The density and temperature structures of dense cores in the L1495 cloud of the Taurus star-forming region are investigated using Herschel SPIRE and PACS images in the 70 \mu m , 160 \mu m , 250 \mu m , 350 \mu m and 500 \mu m continuum bands .
A sample consisting of 20 cores , selected using spectral and spatial criteria , is analysed using a new maximum likelihood technique , COREFIT , which takes full account of the instrumental point spread functions .
We obtain central dust temperatures , T _ { 0 } , in the range 6–12 K and find that , in the majority of cases , the radial density falloff at large radial distances is consistent with the asymptotic r ^ { -2 } variation expected for Bonnor-Ebert spheres .
Two of our cores exhibit a significantly steeper falloff , however , and since both appear to be gravitationally unstable , such behaviour may have implications for collapse models .
We find a strong negative correlation between T _ { 0 } and peak column density , as expected if the dust is heated predominantly by the interstellar radiation field .
At the temperatures we estimate for the core centres , carbon-bearing molecules freeze out as ice mantles on dust grains , and this behaviour is supported here by the lack of correspondence between our estimated core locations and the previously-published positions of H ^ { 13 } CO ^ { + } peaks .
On this basis , our observations suggest a sublimation-zone radius typically \sim 10 ^ { 4 } AU .
Comparison with previously-published N _ { 2 } H ^ { + } data at 8400 AU resolution , however , shows no evidence for N _ { 2 } H ^ { + } depletion at that resolution .