Subject: Re: Emma's paper From: jzsargo@esfm.ipn.mx Date: 4/27/12 7:51 PM To: "David Cohen" CC: jzsargo@esfm.ipn.mx Hi David, we will produce the required models, but meanwhile I have also made some figures using the O-star grid of CMFGEN models. I have chosen models that are the closest to 9 Sgr and eps Ori, and one in the middle. The file names contain the Teff and logg (without the dot, therefore logg400 means log(g)=4.00, sorry for this). Also, the mass-loss rates and Vinf of these models are not the same as those of 9 Sgr and eps Ori, but they are in the same order of magnitude. The files with op in their names show the opacity for r~1.5R*, 3R*, and 60R*. Approximate radii because I did not interpolate, just show the closest available radius. I have also enclosed the ionization structure of Oxygen (files with ox in their names) and helium (he in the name). These files show that the opacity you were using are very adequate for the hottest stars, apart from the changing Oxygen dominant stage (O V => O IV => O III). BTW, John's O grid obviously have different abundances than the one you have used for Fig.2 in the paper, and the grid does not have Mg and Ne included in the atomic mode, therefore, some edges are missing in my figures! However, for cooler stars there are some problems with the opacity. First, He++ recombines even close to the stellar surface (increasing the overall opacity, although below 15 A it is not that bad), and there seems to be a huge O III resonance near 20 A. Maybe Maurice can have some comment on this, because I am not apt with the atomic physics part of this. So, food for thoughts! FYI, I forwarded this mail to Maurice as well. Also, if you have further questions or comments, do not hesitate to write I am happy to discuss these issues! Udv, Janos PS: Also, if you would like to include anybody else into the discussion feel free to forward my email! > > Janos, > > > > I'm glad things are going well; congratulations on the grant. > > > > I would very much enjoy visiting you at some point, I'm sure. > > > > The Brasil conference was fun, and there were some good talks -- Jon > > Bjorkman's talk on Be disk thermal and ionization modeling stands out in > > my mind. There's also a fair amount of work on spectro-interferometry > > that looks interesting (e.g. differentiating Keplerian disks from > > spherical winds) that I hadn't been aware of. But overall the meeting > > was somewhat disappointing because there wasn't very much time allocated > > for discussion. > > > > For this paper, some cmfgen models without detailed iterations to match > > data for a couple of stars would be great. > > > > Let's start with the most extreme stars, in terms of Teff -- 9 Sgr and > > epsilon Ori. I'd like to know the ionization fractions of He, C, N, O, > > Ne, Mg, Si, and Fe. > > > > Here are the parameters we're using: > > > > 9 Sgr - 42,900 K, 12.4 Rsun, log g 3.92, vinf = 3100. > > eps Ori - 27,500 K, 32.4 Rsun, log g 3.13, vinf = 1600. > > > > Thanks, > > David > > > > > > On 4/17/12 7:26 PM, jzsargo@esfm.ipn.mx wrote: >> >> >> >> Hi David, >> >> >>> >>> I hope things are going well with you. >> >> >> >> I am getting more and more acostumed of living here so things are >> >> getting >> >> easier and more normal. For example, I got my first Mexican grant (sort >> >> of >> >> NSF-like money), so I can go to conferences, visit or have visitors, >> >> etc. >> >> Talking about visits, what do you think about a trip here sometimes in >> >> the >> >> not too distant future, let us say in the next 1-2 years? Or, we can now >> >> meet in conferences :). I saw that you were in Brasil earlier this year >> >> (too bad that I did not have this grant in time to go there too). How >> >> was >> >> it? >> >> >>> >>> I know we've talked in the past about the possibility of you doing some >>> >>> detailed xcmfgen modeling/analysis of these stars. But I also know >>> >>> you're quite busy (and your xcmfgen paper should probably be a higher >>> >>> priority than spending a lot of time on Emma's paper). That being >>> >>> said, >>> >>> I'd welcome any contribution you think you'd like to make. I have a >>> >>> note >>> >>> in the manuscript suggesting that we might want to explore the range of >>> >>> wind ionization balances (and thus the wind X-ray opacity) in the >>> >>> sample >>> >>> stars. If you think you can do something like that without too much >>> >>> trouble, and you think it would be worthwhile, that's one direction we >>> >>> could go. But if your only additional contribution to this paper is to >>> >>> provide comments on the manuscript, that will be fine, too. >> >> >> >> I have a student here who are interested in using CMFGEN. I can instruct >> >> him to run models with certain parameter sets. He can produce the models >> >> and I can check their sanity. Just let me know what models you have in >> >> mind! >> >> >> >> Udv, >> >> Janos > Attachments: NT27500_logg325_he.ps 27 bytes NT27500_logg325_ox.ps 27 bytes NT27500_logg325_op.ps 27 bytes NT35000_logg350_he.ps 27 bytes NT35000_logg350_ox.ps 27 bytes NT35000_logg350_op.ps 27 bytes NT42500_logg400_he.ps 27 bytes NT42500_logg400_ox.ps 27 bytes NT42500_logg400_op.ps 27 bytes