Skip to main content Accessibility help
×
Home

New line-blanketed model atmospheres and their impact on synthesis models

  • Linda J. Smith (a1), Richard P.F. Norris (a1) and Paul A. Crowther (a1)

Abstract

A new grid of ionizing fluxes for O-type and Wolf-Rayet stars is presented for use with evolutionary synthesis codes and analyses of single star H ii regions. A total of 230 expanding, non-LTE, line-blanketed model atmospheres have been calculated for five metallicities (0.05, 0.2, 0.4, 1 and 2 Z). We have used the wm-basic code of Pauldrach et al. (2001) for O-type stars and the cmfgen code of Hillier & Miller (1998) for WR stars. The stellar wind parameters are scaled with metallicity for both O-type and WR stars. The ionizing fluxes of the new models, incorporated into the evolutionary synthesis code STARBURST99 (Leitherer et al. 1999), are compared with the predictions of the original starburst99 and Schaerer & Vacca (1998) for an instantaneous burst. We find large changes in the output ionizing fluxes as a function of age, especially below the He+ edge. In contrast to previous studies, nebular He ii λ4686 will be at, or just below, the detection limit in low metallicity starbursts during the WR phase. The new models have lower fluxes in the He i continuum for Z ≥ 0.4 Z and ages ≤ 7 Myr because of the increased line-blanketing. The accuracy of the new model atmosphere grid is tested by constructing photo-ionization models for an H ii region where the ionizing flux is provided by an instantaneous burst. The new models occupy the same region in nebular diagnostic diagrams as the observational data of Bresolin et al. (1999), particularly during the WR phase. The new model grid and updated starburst99 code can be downloaded from http://www.star.ucl.ac.uk/starburst.

    • Send article to Kindle

      To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

      Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      New line-blanketed model atmospheres and their impact on synthesis models
      Available formats
      ×

      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

      New line-blanketed model atmospheres and their impact on synthesis models
      Available formats
      ×

      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

      New line-blanketed model atmospheres and their impact on synthesis models
      Available formats
      ×

Copyright

References

Hide All
Bresolin, F., Kennicutt, R.C., Garnett, D.R. 1999, ApJ 510, 104.
Crowther, P.A., Pasquali, A., De Marco, O., et al. 1999, A&A 350, 1007.
Esteban, C., Vílchez, J.M., Smith, L.J., Clegg, R.E.S. 1992, A&A 259, 629.
Esteban, C., Smith, L.J., Vílchez, J.M., Clegg, R.E.S. 1993, A&A 272, 299.
Ferland, G.J. 2002, Hazy, a Brief Introduction to Cloudy, University of Kentucky Department of Physics and Astronomy, Internal Report.
Garnett, D.R., Chu, Y.-H., 1994, PASP 106, 626.
Hillier, D.J., Miller, D.L. 1998, ApJ 496, 407.
Kennicutt, R.C., Bresolin, F., French, H., Martin, P. 2000, ApJ 537, 589.
Kudritzki, R.-P., Puls, J. 2000, Ann. Review Astron. Astrophys. 38, 613.
Lamers, H., Snow, T.P., Lindholm, D.M. 1995, ApJ 455, 269.
Leitherer, C., Robert, C., Drissen, L. 1992, ApJ 401, 596.
Leitherer, C., Schaerer, D., Goldader, J.D., et al. 1999, ApJS 123, 3.
Lejeune, Th., Cuisinier, F., Buser, R. 1997, A&AS 125, 229.
Meynet, G., Maeder, A., Schaller, G., et al. 1994, A&AS 103, 97.
Oey, M.S., Dopita, M.A., Shields, J.C., Smith, R.C. 2000, ApJS 128, 511.
Nugis, T., Lamers, H. 2000, A&A 360, 227.
Pauldrach, A.W.A., Hoffmann, T.L., Lennon, M. 2001, A&A 375, 161.
Prinja, R.K., Barlow, M.J., Howarth, I.D. 1990, ApJ 361, 607.
Schaerer, D., de Koter, A. 1997, A&A 322, 598.
Schaerer, D., Vacca, W.D. 1998, ApJ 497, 618 (SV98).
Schmutz, W., Leitherer, C., Gruenwald, R. 1992, PASP 104, 1164 (SLG92).
Stasińska, G., Schaerer, D., Leitherer, C. 2001, A&A 370, 1.
Vacca, W.D., Garmany, C.D., Shull, J.M. 1996, ApJ 460, 914.
Vílchez, J.M., Pagel, B.E.J. 1988, MNRAS 231, 257.

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed