News & Updates


2017-04-13

CLUMPY website has moved

www.clumpy.org has moved from UKY to NOAO.

Together with the move we are retiring the outdated *txt file models, and provide the model database an a single hdf5 file.

We are also retiring the capacity to compute own models online, since we have computed an almost exhaustive grid of parameters. If you need very different models, please contact me and we'll talk.

Please stay tuned, as we are working on updated SEDs, and on a hypercube of brightness maps!


2014-10-15

The CLUMPY models have been updated

The emission of CLUMPY clouds is the angle-averaged emission of all slab orientations. To "label" such "synthetic" clouds we previously used the optical depth along the normal of the slab.

We recently compared the synthetic clouds to spherical clouds (3-d radiative transfer). For a sphere, the optical depth along a central ray is the highest possible of all rays. For a slab the optical depth along the normal is the smallest of all rays. The calculations show that the effective optical depth through a synthetic cloud is two times higher than the optical depth along a slab normal.

The absorption caused by clouds is not affected by this (the spectral shape doesn't change, only the "optical depth label" assigned to the clouds is now two times higher). However, the cloud emission does change, because the cloud source function is a wavelength-dependent function τ(λ). Thus, the overall spectral shape of the model SEDs does change (up to 20 percent at any given wavelength, in our experience).

These new results will be published in Heymann, Nikutta, and Elitzur (in prep.). Meanwhile, we make available the newly calculated CLUMPY model database as an HDF5 file (1.2 GB). The old online model database is still active, but we discourage you from using it in favor of the new models.

Note that the optical depth values in the new models are now "effective optical depths", rather than the optical depth along the slab normal used before.


2010-09-24

Bug in SED normalization found and fixed

We have found a bug in the old code that caused the torus models to have incorrect normalization. The spectral shapes of the SEDs were not affected by the bug, only the absolute flux levels were. The bug has been fixed, and the models re-generated. The catalog and the online creation of models are now re-enabled. An erratum to Nenkova et al. 2008b (ApJ, 685, 160) has been published in Nenkova et al. 2010 (ApJ, 723, 1827).

Renamed Pnorm to f2 in model files

The torus covering factor 'f2' -- see Eq. 9 in Nenkova et al. 2008a (ApJ, 685, 147) -- is now called 'f2' in the CLUMPY output files (it used to be called 'Pnorm').

Increased the number of models that can be computed online

Together with the catalog update we have increased the number of Y values that can be selected (multiple selections OK now). The maximum number of models that can be calculated online in one run is now 1000 (up from 100). Finally, the models will now be generated faster (more CPUs).