Our answers to the reviewer's comments follow below:

> Reviewer's Comments:
>
> Referee Report on the paper 'Asteroids Families in the First Order
> Resonances with Jupiter' by M. Broz and D. Vokrouhlický.
>
> The authors approach three specific questions associated with
> asteroids in first order mean motion resonance with Jupiter (the J2/1
> Hecuba gap, the J3/2 Hilda's group and the J4/3 Thule group). 
>
> The first question concerns the determination of new members for each
> of the resonant group, through a numerical/statistical analysis. In
> particular, they determine two new members for the Thule group, which,
> with Thule itself, form a three-members group now.
> 
> The question of the determination of possible collisional families
> among the resonant groups is most interesting. The authors conclude
> with good confidence that that are two collisional families in the
> Hilda group, the Schubart family and the Hilda collisional family.
> They also estimate their age, being Schubart family relatively young
> whereas the Hilda family probably comes from the Late Heavy
> Bombardment about 3.8 billion years ago.
>
> Lastly, the authors study the asteroidal resonant groups under the
> point of view of their stability vis-ŕ-vis the primordial  planetary
> migration that must have occurred in the first hundred million years
> after Solar System formation. Last of all, they also evaluate to which
> size of bodies the Yarkovsky effect could have depleted the Jupiter
> resonant regions.
>
> I think the paper is quite interesting and gives an important
> contribution to the understanding of the present orbital configuration
> of the resonant groups of asteroids as well as contributes to our
> knowledge of new collisional families within the specific resonant
> asteroid belt. I also think the contribution for the understanding of
> how planetary migration could have affected the stability or even
> survival of the asteroidal resonant group is good, however my main
> comments concern this point.
> 
> It seems to me that section 4.1 is a little outside the global aim of
> the paper. Moreover it is just barely developed. Figure 23, which
> summarizes the results of that section, is not able to answer the
> question on whether the resonant groups could survive or not the
> primordial planetary migration. It is true that Fig. 27 is much more
> conclusive in this respect, however it is placed in the conclusions
> section, as a "work still being done". My suggestion is that this
> information might be displaced into section 4.1. Another suggestion is
> that the theme on resonant asteroids stability during planetary
> migration could be removed from the paper and be part of a more
> complete paper on this subject, which seems that the authors are
> already doing. I think the increment of new resonant asteroids to the
> present inventory and the establishment of collisional families in the
> resonant groups are already quite interesting results to turn the
> paper complete enough.

We decided to move Fig.~27 and the relevant discussion to the Section 4.1,
as suggested.

> A scientific remark: the Yarkovsky drift in eccentricity due to the
> trapping in the J3/2 resonance is systematic and not chaotic as
> commented by the authors. In this case, one could not associate
> smaller objects with a larger dispersion and this could not be checked
> in the observed population? 

Yes, such relationship of de/dt vs size exists indeed. We mention this
only briefly in our conclutions, paragraph 4, as "triangular plots"
and also in Figure 28. We can also supply another figure of the
expected da/dt vs observed de/dt, where the size dependence is
clearly visible - see the attachment. It is intended for the next
publication concerning a new `(e,H) method' of the family age
determination.

> Other points:
> 
> - in Eq (7), isn't there also a condition on \Omega - \Omega' ?

No, this condition was relaxed, because it is hard to fulfill
in practice (due to higher-order perturbations). The provided
reference Roig et al. (2001) discusses this point.

> - I think there needs some English improvement in the middle of the
> paragraph just before Section 2.1, around the text: "...we modify
> their and asteroids', initial conditions ...".

Corrected.

> - In the second paragraph of Section 2.2: it is hard to see the outer
> separatrix that the escapees should be closer in Fig. 6 (there is no
> separatrix either in Fig. 5).

We included the libration centre in both figures. (Separatrix
is further to the right.)

> - The panels in Figs. 16-18 that associates common J3/2 objects to a
> dot is hard to see either. In fact we see many dots inside the panel,
> belonging to the Figure itself. Maybe the dots should be removed from
> the panels or the panel put outside the figure...

Corrected, we enlarged the dots a bit and moved the description boxes
outside the plots.

> - it is a little hard to read Figure 23 (also 24 and 25). Thicker and
> thinner lines get mixed together and one looses their path. Would
> different types of lines improve?

In the re-submitted paper we tried to include a figure with
different line types.

> My final comment is that the paper is a nice contribution to our
> understanding of the resonant asteroidal group and collisional
> families within the groups and for this reason I recommend its
> publication in the MNRAS. My main comments about the stability under
> migration must be considered as a suggestion. I am not contrary to the
> publication of section 4.1 as it is, but I encourage the authors to at
> least improve it with added results from the conclusions section.
> Since my review does not include anything too restrictive, I do not
> need to see the paper again although I'm ready to see it if the
> authors so wish.

Thank you very much for your comments.

Regards, Miroslav Broz