Jack Baldwin’s work on

Star Forming Regions

From the Orion Nebula:

• The nearest large H II region.

• Mostly powered by the O7 star theta 1 Ori C

• Light from star has evaporated part of dense molecular cloud.

  • formed hot ionized cavity that breaks out of  near edge of cloud.

  • hot gas squirts out towards us (Balick Gammon, R.H. & Hjellming, R.M. 1974, PASP, 86, 616)

• Structure was studied in detail by Baldwin, Ferland, Martin et al. 1991.

...up through larger and larger examples:

NGC 3603 is one of the largest star-forming regions in our own Galaxy. This SOAR Telescope image uses blue for continuum light, green for [O III] 5007 emission, and red for H-alpha emission. The field of view is about 6 arcmin wide.

...to 30 Doradus in the Large Magellanic Cloud:

• The largest Giant Extragalactic H II Region in the Local Group of galaxies.

  • Many times larger than Orion

    • Ionized by over 100 O stars.

      30 Doradus, in the light of the  Ha emission line. SOAR Telescope mosaic image by Lisa May Walker. (click on image for full resolution version)

    • Main ionizing cluster is R136

• We will study this in detail with the SOAR Telescope.

...and on out to the edge of the Universe:

• 30 Doradus is the prototype of Giant Extragalactic H II Regions that can be seen at huge distances.

• Distant GEHR's can be used to trace early history of star formation and metal enrichment.

My collaborators:

• Eric Pellegrini (MSU grad student)

• Gary Ferland (Univ. of Kentucky)

• Margaret Hanson (Univ. of Cincinnati)

• Tom Troland (Univ. of Kentucky)

• Peter Martin (Toronto)

• Bob Rubin (NASA)

• Lisa May Walker (MSU REU student, now at U. of Virginia)

• Norm Murray (CITA)

Some of our relevant papers:

• Pellegrini, E.W., Baldwin, J.A., Brogan, C.L., Hanson, M.M., Abel, N.P., Ferland, G.J. Nemala, H.B., Shaw G. & Troland, T.H. 2007, ApJ, 658, 1119  “A Magnetically-Supported PDR in M17” http://xxx.lanl.gov/abs/astro-ph/0611808

• Blagrave, K. P. M.; Martin, P. G.; Rubin, R. H.; Dufour, R. J.; Baldwin, J. A.; Hester, J. J.; Walter, D. K. 2007, ApJ, 655, 299 “Deviations from He I Case B Recombination Theory and Extinction Corrections in the Orion Nebula” http://xxx.lanl.gov/abs/astro-ph/0610621

• Blagrave, K.P.M., Martin, P.G. & Baldwin, J.A. 2006, ApJ, 644, 1006 “A Photoionized Herbig-Haro Object in the Orion Nebula” http://xxx.lanl.gov/abs/astro-ph/0603167

• Rubin, R.H., Martin, P.G., Dufour, R.J., Ferland, G.J., Blagrave, K.P.M., Liu, X.-W., Nguyen, J.F. & Baldwin, J.A. 2003, MNRAS, 340, 362S  “Temperature Variations from Hubble Space Telescope Spectroscopy of the Orion Nebula" http://xxx.lanl.gov/abs/astro-ph/0212244

• Baldwin, J.A., Verner, E.M., Verner, D.A., Ferland, G.J., Martin, P.G., Korista, K.T. & Rubin, R.H. 2000, ApJS, 129, 229  “High resolution spectroscopy of faint emission lines in the Orion Nebula”  ADS Link