Families of fragmenting granules and their relation to meso– and supergranular flow fields
1
Laboratoire d'Astrophysique, Observatoire Midi-Pyrénées, 57 avenue d'Azereix, BP 826, 65008 Tarbes, France
2
Laboratoire d'Astrophysique, Observatoire Midi-Pyrénées, 14 avenue E. Belin, 31400 Toulouse, France
3
Institut Universitaire de France, France
4
Kiepenheuer–Institut für Sonnenphysik, Schöneckstrasse 6, 79104 Freiburg, Germany
5
LESIA, Observatoire de Paris, Section de Meudon, 92195 Meudon, France
Corresponding author: Th. Roudier, roudier@bagn.obs-mip.fr
Received:
17
February
2003
Accepted:
10
June
2003
3D analysis 
of the granular intensity field
(11–hour time sequence from the Swedish Vacuum Solar Telescope on
La Palma, Canary Islands), demonstrates that a significant fraction
of the granules in the photosphere are organized in the form of
“Trees of Fragmenting Granules" (TFGs). A TFG consists of a family of
repeatedly splitting granules, originating from a single granule at
its beginning. A striking result is that TFGs can live much longer
(up to 8 h) than individual granules (10 min). We find that 62%
of the area covered by granules belongs to TFGs of a lifetime >1.5 h.
When averaged in time,
such long–lived TFGs correspond to coherent diverging flows which may be
identified as mesogranules. We also find a correlation between the
network and the spatial distribution of TFGs.
Key words: Sun: photosphere / Sun: granulation
© ESO, 2003