David J. Jeffery Department of Physics New Mexico Tech 801 Leroy Place Socorro, New Mexico 87801-4796 U.S.A. Office Tel: 505-835-5610 Email: jeffery@kestrel.nmt.edu Office: Rm 349, Bldg. Workman Center Homepage: http://www.physics.nmt.edu/jeffery/jefferyfrontpage Departmental Tel: 505-835-5328 Departmental FAX: 505-835-5707 Departmental Email: physics@kestrel.nmt.edu Departmental Homepage: http://www.physics.nmt.edu/ 2002 August 11 Hi Koji: Sorry again. I've inadvertently sent you my old version of the reply. The new one with new suggestions highlighted by question marks follows. Regards David --------------------------- Major Concern: The referee believes that the jet model is ruled out already. However, the referee has not given a demonstration of or a reference for this conclusion. He/she in his/her first report have merely referenced an observational report in IAUC circular 7817 by Berger et al. whose most relevant remark is that ``SN 2002ap is thus > 3 orders of magnitude less luminous in the radio band than SN 1998bw." We don't think that this report without theoretical interpretation by itself rules out a jet. Shortly after our letter was submitted and posted at astro-ph, a paper by Berger et al. was posted at astro-ph (Berger et al., 2002, astro-ph/0206183) reporting their radio results and modeling of SN 2002ap. %They address our jet model briefly in their conclusion and %apparently rule it on the grounds that %``Such a jet, regardless of geometry, would have produced %copious radio emission.'' %We have to say ``apparently'' since they do no not directly %say they have ruled it out. * They address our jet model briefly in their conclusion and * implicitly rule it out on the grounds that ``Such a jet, * regardless of geometry, would have produced copious radio * emission.'' %In this paper, Berger et al. do not give a demonstration %as to why the model should be ruled out or a reference %for such a demonstration. * In the paper, Berger et al. do not give either a demonstration * as to why the model should be ruled out nor a reference for * such a demonstration. We need to point out that Berger et al.'s remarks regarding the jet model were based on the suggested jet parameters in the first version of our letter. Although we explicitly said those parameters were not reliable values, Berger et al. seem to have read them as such: it is hard to say what Berger et al. understood since they are vague and brief. We have since eliminated most of the suggested parameters and what Berger et al. would now say about our jet ???model??? we do not know. Two further remarks are needed about Berger et al. First, all of their detailed modeling assumes spherical symmetry for the supernova ejecta and circumstellar environment. Thus, their assertation that geometry does not matter does * assertion not follow self-evidently from their analysis. ??? Second, we believe that geometry does matter. ???? A simple argument shows ???this???. Say the progenitor and circumstellar environment had a special axis along which there was no significant circumstellar matter and along which the jets propagated. Then there would be no significant radio emission from the jet. This argument is speculative, but not wildly so. The one supernova (i.e., SN 1987A) for which we have a detailed picture of the circumstellar environment and the shape of the ejecta, shows that both have a complicated structure and and axis of symmetry (e.g., Wang et al., 2002, astro-ph/0205337; * an axis... Crotts & Heathcote 2000, ApJ, 528, 426). There ??is?? also a speckle interferferometry analysis (Nisenson & Papaliolios 1999, ApJ, 518, L29) that suggests that relativistic jets emerged from SN 1987A although apparently not along the axis of symmetry shown by the other analyses. That speckle interferferometry analysis is subject to doubts, but we are not aware that the analysis on its own grounds has ever been refuted. We conclude that radio observations and modeling have not hitherto absolutely ruled out a jet in SN 2002ap of any kind. %Given that and that our letter is not about about %radio modeling and observations, we do not believe we need to %discuss the radio radio observations and modeling and %what they may or may not rule out under different assumptions. * Given that our letter is not about radio observation and modeling, * we do not believe we need to discuss the radio studies and * what they may or may not rule out under different assumptions. It might be argued that we should respond to Berger et al. Frankly, their remarks are so brief and vague that we would have to discuss what we think they intended to say just as we have had to in this response. ??? We do not think it appropriate to try to clarify their remarks for them in a publication. ??? Minor Concern: The referee does not understand how a redshift can give rise to a wavelength dependent polarization from electron scattering. We do not understand why he/she does not understand. We have shown clearly both in our first response and in our revised paper how a redshift will cause wavelength polarization: it is not a subtle effect. The referee is correct that there will be some wavelength dependence due to the different epochs of the direct spectrum from the bulk ejecta and scattered spectrum from a jet. However, this is a lesser effect. Say the jet is moving at speed beta perpendicular to the line of sight. The time delay between the two spectra (not counting relativistic effects) will be of order Delta t = (beta c t)/c = beta t , where t is the time since explosion. If beta=0.2 say (which of order the number we suggest for the jet) and t is of order 10 days, ??? then Delta t=2 days. ??? Near maximum light, the spectrum and light curve are changing relatively slowly over time scales of 2 days. Our observations relevant to the jet model are from near maximum light (i.e., of order 10 to 11 days after explosion). Thus, we think that differences in the spectral epoch will not greatly affect the polarization. However, in detailed modeling the time delay should be incorporated. But that is beyond the scope of our letter. Conclusion: We think that the referee's ??? judgment ??? has failed in regard to our letter and that the revised version we submitted in response to the first referee's report is acceptable. We ask for a second referee to consider that version.