Bibcode
Tancredi, Gonzalo; Fernández, Julio A.; Rickman, Hans; Licandro, Javier
Referencia bibliográfica
Icarus, Volume 182, Issue 2, p. 527-549.
Advertised on:
6
2006
Revista
Número de citas
95
Número de citas referidas
84
Descripción
We present a new catalog of absolute nuclear magnitudes of Jupiter
family (JF) comets, which is an updated version of our previous catalog
[Tancredi, G., Fernández, J.A., Rickman, H., Licandro, J., 2000.
Astron. Astrophys. Suppl. Ser. 146, 73 90]. From the new catalog we find
a linear cumulative luminosity function (CLF) of slope 0.54±0.05
for JF comets with q≲2.5 AU. By considering this CLF combined with
the few measured geometric albedos with their respective uncertainties,
and assuming a canonical albedo of 0.035±0.012 for those comets
with undetermined albedos, we derive a cumulative size distribution that
follows a power-law of index -2.7±0.3. The slope is similar
to that derived from some theoretical collisional models and from some
populations of Solar System bodies like the trans-neptunian objects. We
also discuss and compare our size distribution with those by other
authors that have recently appeared in the literature. Some striking
differences in the computed slopes are explained in terms of biases in
the studied samples, the different weights given to the brightest
members of the samples, and discrepancies in the values of a few
absolute nuclear magnitudes. We also compute sizes and fractions of
active surface area of JF comets from their estimated absolute nuclear
magnitudes and their water production rates. With the outgassing model
that we use, about 60% of the computed fractions f of active surface
area are found to be smaller than 0.2, with one case (28P/Neujmin 1) of
no more than 0.001, which suggests that JF comets may transit through
stages of very low activity, or even dormancy. There is an indication
that JF comets with radii R≳3 km have active fractions
f≲0.01, which might be due to the rapid formation of insulating
dust mantles on larger nuclei.