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Date: Thu, 25 Mar 1999 10:05:54 -0600 (CST) From: Javier Ballesteros <javier@astroscu.unam.mx> To: "Alyssa A. Goodman" <agoodman@cfa.harvard.edu> cc: Paola Caselli <caselli@arcetri.astro.it> Subject: Re: coordination MIME-Version: 1.0 Status: RO Hi Alyssa & Paola: here are the reduced data: /data/huracan/jballest/IRAM/Cores C17O(1-0): c17o10_fit.dat --> ascii file including the parameters of the fits to the spectra in c17o10_red_resampl_suma.fit c17o10_red_resampl_suma.fit --> spectra. Here we have resampled in order to avoid the problem with the frequency between 1997 and 1998. C17O(2-1): c17o21_9798bis.fit_gauss --> spectra. Includes 97 and 98 seasons, and the gaussian fit used. c17o21_9798bis.fit_hfs --> The same than the previous, but now it includes the hfs fit. c17o21_fit_gauss.dat --> ascii file with the parameters of the gaussian fits c17o21_fit_hfs.dat --> ascii file with the parameters of the hfs fits. C18O(2-1): c18o21_97_98_suma.cls.fit --> spectra. Includes the fit. c18o_fit.dat --> ascii file with the parameters of the fits. C34S(2-1): c34s21_97_98_suma.cls.fit --> spectra with the fits. Includes the 97 and 98 seasons. c34s_fit.dat --> ascii file with the parameters of the fits. N2H+(1-0): n2hp10_fit2.dat --> ascii file with the parameters of the fits n2hp10_red.fit2 --> spectra with the fits. My problem with this is that some spectra show double peaks, and structure, and then I'm not sure that by fitting a single gaussian is ok... Could it be an effect of the opticall depth, or it is a dynamical effect? how to know it? Please let me know if you want me to make something else... Take care, Javier
Date: Mon, 15 Feb 1999 14:28:02 -0500 (EST) From: Javier Ballesteros <jballest@cfa0.harvard.edu> To: agoodman@cfa.harvard.edu Subject: IRAM X-Sun-Charset: US-ASCII Status: RO Hi Alyssa... Yesterday I finished the IRAM ``reduction'' you asked me for. I include both 97 and 98 observations... Here are some thoughts and comments about this: - In some positions, the profiles look with strongly self-absortion. - Not always the fit done could reproduce very well all the lines of the hiperfine structure - N2H+, C17O(1-2) and C17O(2-1) - - Not always the fit done could reproduce the single lines C18O(2-1), C34S(2-1) - I also tried to make iterations, but the results of make them didn't improve the first fit. - I feel that the fit in N2H+ was particularly bad in the more red line: the fit was always below the intensity of the line in almost all the spectra. - In the cases where there was hiperfine structure - N2H+, C17O(1-2) and C17O(2-1)-, some cases appears that some lines were strongly self-absorpted. I talked about this with Hector, and it seems that he has found the same with the FCRAO data... So, I don't know if these fits are enough, or if we have to do some more sophisticated... On the other hand, I noticed that some times, the self-absorption in the hiperfine structure was different for some of the multiple lines than for others... I would think this is an effect of the optical depth... Nevertheless, in some other cases, there were more or less the same assymetries in all the lines (e.g., `collapse' or `expand' profiles in all the components, or `strong' wing in one side in all the lines, etc...). Can this be trace of larger scale, sistematic motions!? Finally, I'm wonder if there are some cases where the asymetries observed with one tracer are similar with the assymetries observed in other tracer at the same position... Anyway, I'll show you the results tomorrow... I just want to tell you that I'm very sorry for the delay with the IRAM reduction, but I think it was just because of all the diferent work that I've been doing, but not lack of interest... Nevertheless, my first priority now must be the SCF, and I would like to show you some draft version of a posible paper before I leave Boston... sincerely, Javier
Date: Sat, 13 Feb 1999 12:35:02 -0500 From: heyer@fermat.phast.umass.edu (Mark Heyer) To: caselli@arcetri.astro.it, agoodman@cfa.harvard.edu Subject: Re: questions... Cc: jballesteros@cfa.harvard.edu, dwilner@cfa.harvard.edu, harce@cfa.harvard.edu, heyer@fcrao1.phast.umass.edu, jpwilliams@cfa.harvard.edu X-Sun-Charset: US-ASCII Status: RO I do not think the discrepancy between the 14m and the 30m is as bad as it would seem. If the beam efficiency of the 30m is 0.7, then the appropriate scaling factor between the 2 telescopes is 0.7/0.45=1.56. From my eyeballing the 2 figures, the vel. widths are rather consistent with the errors for a given value of T_mb. Is 0.7 too high a main beam efficiency? Mark .
Date: Fri, 12 Feb 1999 12:19:05 +0100 (MET) From: Paola Caselli <caselli@arcetri.astro.it> To: agoodman@cfa.harvard.edu Subject: questions... Dear Alyssa, thanks for your messages. I was able to look at your web pages (and even print them!) this morning. Your FCRAO results look very interesting. I have a few comments: 1) about C17O(1-0) you say that "it's possible that IRAM and FCRAO plots are consistent--if we use only the better than 5 sigma points". However, in the IRAM plot the "low Ta" points which are present in the first FCRAO plot (with Ta ~ 0.2 K) are missing. So we should probably only compare those parts of the plots with similar Ta (the beam efficiencies of the two telescopes are not very different-- factor of ~ 1.4?). If we do this, i.e. we limit the comparison for Ta > 0.3 K, then things look quite similar. However... 2) I do not understand why C17O lines observed at IRAM are broader than those observed at FCRAO (limiting the comparison in the range Ta = 0.3 - 0.7 K; stronger lines are not present in the FCRAO plots). For example, concentrate on the point with Ta ~ 0.5 K in the IRAM plot: this has a Dv ~ 0.55 km/s. In the FCRAO plot, the corresponding point is the one at Ta ~ 0.35 K which has a Dv ~ 0.38 km/s well below the IRAM value (even considering the errors). This is confusing me a little because I was expecting the contrary (given that FCRAO has a larger beam) if no difference at all. Anyway, I'm probably missing something here.. 3) I remember that in the C17O(1-0) map of TMC-1C we found a position at the edge of the core with very narrow (about thermal) lines. Has that point been considered in the IRAM plot? Did you find any similar narrow line in the FCRAO data? 4) About the C34S plot: are we sure that C34S is optically thin?? I'm asking this because C34S in L1544 is clearly thick at the core "center". Given that "double peaked" profiles have been also observed in TMC-1C, then one can argue that the C34S "flattening" may be caused by self-absorption... Are you noticing any funny structure in the C34S profiles ? The other possibility of the flattening may be the depletion of this species in the densest part of the core. Or, as you said, some evolution in the chemistry. How to decide which one of the above pictures is correct? Probably we should start in observing a) higher J transitions of C34S (which trace high gas density and then are less affected by self-absorption), but probably this will take a long time... or b) an even rarer isotopomer, e.g. C33S which should not take too long to be detected given that 34S/33S is only about 6 (do you want to try observing it with FCRAO?). 5) About the bolometer proposal for the 30m, I talked to Malcolm and he said that yes, he can help, BUT we have to wait the next 30m deadline (September 99) because the bolometer will not be available during the summer session. BEST WISHES, Paola P.S. It's ok with me to work on our project during the week 15-19 March.
Date: Fri, 29 Jan 1999 15:37:27 -0500 From: heyer@fermat.phast.umass.edu (Mark Heyer) To: agoodman@cfa.harvard.edu Subject: Re: yesterday & data Cc: harce@huracan.harvard.edu X-Sun-Charset: US-ASCII Status: Alyssa, Thanks for the visit yesterday. As we both agree, our time seems to be the most precious commodity nowdays so your effort to come here is appreciated. Don't forget to send me your expenses! The C34S and N2H+ data still reside on the anon. ftp on the workstation gemini.phast.umass.edu in ./pub/heyer/vcoh. Note that it is N2H+ not C17o that i observed in december since this was given a higher priority. However, it still requires more integration time. The C34S map is complete. -- Mark
Date: Wed, 20 Jan 1999 12:55:04 -0500 (EST) From: "Paola D'Alessio" <pdalessi@skywalker.harvard.edu> To: agoodman@cfa.harvard.edu Subject: IRAM Mime-Version: 1.0 Status: Hello Alyssa This is the directory with the IRAM data. /data/huracan/jballest/IRAM
Date: Thu, 17 Dec 1998 09:31:56 -0500 From: heyer@fermat.phast.umass.edu (Mark Heyer) To: harce@huracan.harvard.edu, agoodman@cfa.harvard.edu Subject: N2H+ X-Sun-Charset: US-ASCII Status: Hector and Alyssa, I observed 2/3 of last night before the clouds moved in. One N2H+ footprint is finished but the other (which partially overlaps with the first) requires more time. It does not appear that any observing will occur tonight. The raw data file (n2hp.bur) is on the ftp site (gemini.phast.umass.edu) and my attempt to coadd the data is in the file n2hp.sum. - Mark
Date: Wed, 11 Nov 1998 16:29:33 +0100 (MET) From: Paola Caselli <caselli@arcetri.astro.it> To: agoodman@cfa.harvard.edu Subject: news Status: Hi Alyssa, I think Hector and Javier told you that everything was ok in the past nights. We only got some fog this morning which prevents us in completing the C17O map, but I think we reached the half maximum (although I have to check). The N2H+(1-0) map looks quite good. We were able to full sample the South East part of the core (where the peak is) but a 40" spacing grid has been used to map the region to the North West (this core is huge!). We may have detected infall in one position (offset -40 40). The reason for this claim is that both N2H+ and DCO+(2-1) show strong self absorption whereas the DCO+(3-2) line is only slightly absorbed, and the separation between the red and blue features is smaller than in the 2-1 line. Anyway, we have to check it carefully. This is interesting also because it is the first time (I think) there are hints of collapse in TMC-1C; in fact, previous observations by Takakuwa et al 1998 did not detect any self absorbed profile and actually they assumed in their study that H13CO+ and CH3OH were optically thin! So, things are more complicated than we thought (as usual). CIAO, Paola
Date: Mon, 9 Nov 1998 07:34:53 +0100 (MET) From: Paola Caselli <caselli@arcetri.astro.it> To: agoodman@cfa.harvard.edu Subject: update Status: RO Hello Alyssa, this night we started the N2H+(1-0)-DCO+(2-1)-DCO+(3-2) map. Unfortunately the frequency switching was not working (software problems) so we lost time during the mapping. Of course, we will complain with Clemens Thum about this. So far, we have maps with a 40" spacing (the 20" spacing was too time consuming, given the extension of the core). Some interesting things are appearing: 1) the N2H+ and DCO+(2-1) maps look pretty similar, extending from South-East to North-West (as NH3); 2) the DCO+(3-2) map looks quite different from the N2H+(1-0) and DCO+(2-1) maps. In particular, it clearly shows two separated condensations instead of a "quasi-continous" filament. Given that DCO+(3-2) is tracing the high density material, it is possible that in fact we do see to separated dense clumps inside the bigger core traced by N2H+ and DCO+(2-1). 3) N2H+ and DCO+(2-1) lines are optically thick in a few positions. In particular, at one of the DCO+(3-2) peaks, DCO+(2-1) clearly show an infall asymmetry (another starless infalling core?), and the DCO+(3-2) line fills the self-absorbed portion of the 2-1 line. I'm getting very excited about this core, also because the C17O does not show any relative peak towards the two density peaks (=> depletion going on?). Well, let's cross our fingers and hope for other beautiful nights.. CIAO, Paola
Date: Sun, 8 Nov 1998 01:10:08 +0100 (MET) From: Paola Caselli <caselli@arcetri.astro.it> To: agoodman@cfa.harvard.edu Subject: hello! Status: RO Hi Alyssa, here at Pico Veleta everything is OK! Right now I'm observing C17O(1-0) [together with C34S(2-1), C17O(2-1), and C18O(2-1)] and I hope to be able to complete the map. Unfortunately we cannot use frequency switching because of some technical problems, which should be fixed on Monday. I'll send you more informations tomorrow. Now, I just want to tell you that I observed the narrowest CO lines in my life: in the offset (40",220") the line width of C17O is only 0.14 km/s, and the line width of C18O(2-1) is 0.26 km/s !! Hector and Havier (I'm not sure if this is the correct spelling) are also doing fine. I saw some very interesting 12CO spectra toward PVCEP. Talk to you soon! Paola
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