-- AntonZensus - 19 Aug 2004

Comments on the draft

#	Issue	Owner	Born	Done	Comment
101	A general comment I have is that I find some "decoupling" between figures and text. The figures are OK, but probably a bit more could be said in the text, describing and interpreting them more extensively.	er	04-08-13
102	in the introduction, maybe we can say a bit more on the 1.5 over-resolution factor, and why this is important for the hybrid maps but is different for the (u,v)-model fitting, which is the approach we have chosen.	er	04-08-13
103	we include a mention to the high resolution that will be achieved by Radioastron, accessing to the gravitational radius of M87. I would not stress much that here, we should not forget that we may have the resolution, but the opacity can prevent us from seeing what is really around the core (other question is the widening expected at the base of the jet).	er	04-08-13
104	Throughout the paper I would refer Kellerman'98, Zensus'02 and Kellerman'04 as Papers I, II, and III (that stresses the fact that this is part of a very large effort, I am sure the VLBA referees like it).	er	04-08-13
105	After Sect. 2, I would describe in detail what is presented in the three tables. I believe they are not properly referred in the text. They can be discussed later in more detail, but it is nice to tell exhaustively that we observed the sources, we got these parameters and these others, and that some of them are presented graphically here and there. So we help the reader to get the whole more easily.	er	04-08-13
106	In Sect. 3 I miss more details in the call to Figure 2 (since the figure occupies so much space).	er	04-08-13
107	Again in Sect. 3, we divide the fringe visibilities in three classes. Should we detail quantitatively how many belong to each class and which conclusions do we draw from that?	er	04-08-13
108	At the beginning of page 7, we can explain better the distinction between core and nucleus (or jet engine, or jet base, or whatever).	er	04-08-13
109	Following in Page 3, should we give a reference for the resolution criterion, or is that very basic and it is not needed?	er	04-08-13
110	I would discuss more Figs. 7 and 8 in Sect. 5.2	er	04-08-13
111	Concerning the discussion on Figs. 13 & 14, I assume that it has still to be written, isn't it?	er	04-08-13
112	I would also expand or discuss more in detail the variability questions from Fig. 3 and Fig 12 in Sect. 5.4.	er	04-08-13
113	Concerning Fig. 40, I have one idea. We could plot the "real size" (and not the resolution) from our analysis, that is, size in parsecs versus redshift, drawing two lines with the 0.5 and 1 mas resolution we get from the beam, to show there how the (u,v) analysis tells us more things that just mapping.	er	04-08-13
114	On Figs. 13 and 14 there is a problem with the colours to relate what are symbols with upper/lower limits (arrows), at least in my printer (the figures will be plotted in small format, occupying a 6th of the page).	er	04-08-13
115	To keep the aspect of the figures in the paper, I would put Fig 16 left on the top of Fig 16 right, since all of them will be printed in the same format, occupying 1 column width. (They will have the same width as Fig. 7 and 8)	er	04-08-13
116	Concerning Table 1, I would put column 7 between 4 and 5, and I think it is possible to compress columns 4 and 5, something like "Membership" or "Belonging to ...", saying, i.e.: T - observed at the 2cm Survey / M - observed at the MOJAVE sample / V' - observed at the VSOP survey, not yet with VSOP / V - observed at the VSOP survey sample and with VSOP / PR - Pearson-Readhead sample / In this way, BL Lac would be T,M,V,PR. After this compression the table would probably fit within one column (you can check it with the emulateapj style).	er	04-08-13
117	In Table 3 I am missing some labelling at the headers, as it is done in Table 1.	er	04-08-13
118	As a last suggestion, to make its reading easier, you could try to compile it with "emulateapj" to have the figures closer to the text. If you don't want very detailed comments on grammar, spelling, etc., the "referee" format is not needed, the "preprint" one can do well.	er	04-08-13
119	In reading this, I am still finding myself overwhelmed by the figures. The ratio of figures to text is still very high. We may decide to keep all the figures, but I think the results and figure presentation need to be structured to emphase the key results -- right now I find the key results are buried in the paper.	dh	04-08-13
120	My suggestion is that we try to come up with a list of the main results and make a figure list to support those results. I see a few key results immediately... a) Gamma ray sources tend to be more compact. I think figures 15 and 16 make this result clear. b) Brightness temperature limits can exceed 1013 + discussion of distribution as a whole. Fig. 11 is fine for this. c) While it is not mentioned in the text, all but one fast source (beta > 10 c) has a brightness temperature in excess of 1012. Fig. 14 makes this point. d) Galaxies are less compact than quasars. The middle histogram panel from figure 5 is fine for this, and figure 7 also shows this nicely. I like the combination. e) Sources contain a significant fraction of unresolved flux. I think the middle histogram panel from figure 5 is fine for this too, and again figure 7 supports this picture nicely. f) Variability index is higher for the more compact flux. Figure 12 makes this point, but I think we should either drop a couple of panels or explain them all in the text.	dh	04-08-13
121	Abstract: Last sentence of paragraph 2. It reads "This suggests that the emission mechanisms at radio and gamma-ray wavelengths are related" Is this true? Couldn't the two just share a common Doppler factor, or is this what you mean?	dh	04-08-13
122	Section 1, Last sentence of paragraph 2. It reads in part "... it is dangerous to attempt to improve the resolution by more than a factor of about 1.5". We should probably make clear that this limit refers to super-resolution of clean images. We might also want to state some reasons why this limit should not also apply to model-fitting to the eata.	dh	04-08-13
123	Section 3, I still think Fig 2 would be best as a single example panel with the rest available on the journal website.	dh	04-08-13
124	Section 4, SNR should be defined when discussing equation (1). It might also be a good idea to mention some typical SNR values.	dh	04-08-13
125	Section 5.1, I don't find figure 4 very useful, and other than the last panel, it doesn't contribute any results to the text. I suggest keeping at most the last panel of figure 4 (unresolved flux).		04-08-13
126	Figure 6 has the same info as 4 and 5, so I think it is also largely unnecessary. However, I do like the integrated versus total VLBI flux plot. One panel might be nice to make the point about calibration, but I don't think it is crucial.	dh	04-08-13
127	Figure 5: I think only the middle panel (unres/total VLBI) is really important here. The others aren't iscussed in the text.	dh	04-08-13

| 128 | Paragraph 5 of section 5.1. The discussion of the K-S test on the middle panel of figure 5 points out that radio galaxies are less compact than quasars. I assume this has also been seen in other studies... if so, we should reference those studies here. | dh | 04-08-13 | | |

129	We might also want to make a clearer statement about the effects of limited resolution and the redshift difference between the two groups before we make this conclusion too strongly. This problem is alluded to in the next paragraph, but I think it should be discussed specifically.	dh	04-08-13
130	Section 5.2, Figure 7 could be naturally folded into the discussion of galaxies versus quasars. This leaves little reason to have section 5.2, so I suggest deleting it and figure 8. After reading it, I am not sure the discussion of the VSOP distribution is useful, and no results come from it.	dh	04-08-13
131	Section 5.3, Figure 9 is misleading because the major and minor axis are in angular units and are not physical parameters as they are given.	dh	04-08-13

| 132 | I think it would be more interesting to look at projected linear size and/or the axial ratio of the cores. angular size distributions are misleading because of redshift differences between classes of objects. Projected linears size is the obvious remedy for this problem, but I also think that axial ratio would be interesting because it would tell us something about the apparent opening angle of the jets. Comparing these quantities to brightness temperature and superluminal motion might be quite interesting.| dh | 04-08-13 | | |

133	Section 5.5, 3rd paragraph. Last two sentences. We conclude that all the MOJAVE sources should be strong gamma-ray emitters, but this is based on the incomplete sample. I don't think such a strong statement should be made here. At most we can say that more compact sources have a higher probability of being gamma-ray emitters, which we have already said above.	dh	04-08-13
134		dh	04-08-13