Merge branch 'development' into main

CHANGES.md

@@ -1,3 +1,20 @@
+# 20.11
+
+   * The minimum C++ standard supported by Castro is now C++14. Most modern compilers
+     support C++14; the notable exception is RHEL 7 and its derivatives like CentOS 7,
+     where the default compiler is gcc 4.8. In that case a newer compiler must be loaded,
+     particularly a version of gcc >= 5.0, for example by installing devtoolset-7 or (if
+     running on an HPC cluster that provides modules) using a more recent gcc module. (#1284)
+
+   * A new option, `castro.retry_small_density_cutoff`, has been added. In some
+     cases a small or negative density retry may be triggered on an update that
+     moves a zone already close to small_dens just below it. This is not uncommon
+     for "ambient"/"fluff" material outside a star. Since these zones are not
+     dynamically important anyway, triggering a retry is unnecessary (and possibly
+     counterproductive, since it may require a very small timestep to avoid). By
+     setting this cutoff value appropriately, the retry will be skipped if the
+     density of the zone prior to the update was below the cutoff. (#1273)
+
 # 20.10
 
    * A new refinement scheme using the inputs file rather than the Fortran

CITATION.md

@@ -6,7 +6,25 @@ describing the capabilities you used.
 
 ## General code use
 
-If you use Castro, we appreciate you citing the main code paper:
+If you use Castro, we appreciate you citing the most recent code paper:
+
+```
+@article{Almgren2020,
+  doi = {10.21105/joss.02513},
+  url = {https://doi.org/10.21105/joss.02513},
+  year = {2020},
+  publisher = {The Open Journal},
+  volume = {5},
+  number = {54},
+  pages = {2513},
+  author = {Ann Almgren and Maria Barrios Sazo and John Bell and Alice Harpole and Max Katz and Jean Sexton and Donald Willcox and Weiqun Zhang and Michael Zingale},
+  title = {CASTRO: A Massively Parallel Compressible Astrophysics Simulation Code},
+  journal = {Journal of Open Source Software}
+}
+```
+
+You are welcome to cite the original code paper as well (which
+provides some details on the algorithmic implementations):
 
 ```
     @ARTICLE{2010ApJ...715.1221A,