\relax \@writefile{toc}{\contentsline {section}{\numberline {1.}Introduction}{1}} \@writefile{toc}{\contentsline {section}{\numberline {2.}Formation Timescales for Massive Stars}{2}} \@writefile{toc}{\contentsline {section}{\numberline {3.}Formation of a High-Mass Stars}{3}} \@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces The spectral-energy distribution (SED) of the UC\nobreakspace {}H\,{\sc ii} region G29.96$-$0.02 (from Watson et\nobreakspace {}al.\ 1997). }}{5}} \newlabel{sedfig}{{1}{5}} \@writefile{toc}{\contentsline {section}{\numberline {4.}Ultra-Compact H\,{\relax \fontsize {9}{11}\normalfont \abovedisplayskip 8\p@ plus2\p@ minus4\p@ \abovedisplayshortskip \z@ plus\p@ \belowdisplayshortskip 4\p@ plus2\p@ minus2\p@ \def \leftmargin \leftmargini \parsep 4.5\p@ plus2\p@ minus\p@ \topsep 9\p@ plus3\p@ minus5\p@ \itemsep 4.5\p@ plus2\p@ minus\p@ {\leftmargin \leftmargini \topsep 4\p@ plus2\p@ minus2\p@ \parsep 2\p@ plus\p@ minus\p@ \itemsep \parsep }\belowdisplayskip \abovedisplayskip {\bf II}} Regions}{5}} \@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Top panel: observed spectrum of G45.12+0.13; the lower line shows the estimated free-free contribution. Bottom panel: extinction-corrected spectrum after removal of the free-free component. The blue sloping line represents a simple model for the starlight while the red sloping line is for a grey-body law for the local dust; the underlying star in this UC\nobreakspace {}H\,{\sc ii} region is essentially impossible to detect directly. (From Lumsden \& Puxley 1996.)}}{6}} \newlabel{g45}{{2}{6}} \@writefile{lof}{\contentsline {figure}{\numberline {3}{\ignorespaces Left: Br$\gamma $ image of G29.96$-$0.02, with the position of the ionizing source indicated. Right: 2-cm continuum image, smoothed to resolution of the Br$\gamma $ image, showing the position of the ionizing source. In the near-infrared image the stellar source is only just resolved from the strong free-free emission peak to the right. Figure taken from Watson et al.\ (1997).}}{7}} \newlabel{g29image}{{3}{7}} \@writefile{toc}{\contentsline {subsection}{\numberline {4.1.}The Central Ionizing Star of G29.96$-$0.02}{7}} \@writefile{lof}{\contentsline {figure}{\numberline {4}{\ignorespaces $K$-band spectra of G29.96$-$0.02. At the top is the extracted spectrum of the bright nebular peak to the SW of the stellar source. `Stellar\nobreakspace {}A' is the stellar source without nebular correction; Stellar B has the optimum nebular corrections; `Stellar\nobreakspace {}C' is over-corrected (note the over-corrected nebular features of He\,{\sc i} at 2.058\nobreakspace {}$\mu $m and Br$\gamma $ at 2.166\nobreakspace {}$\mu $m). $K$-band spectroscopic standards from Hanson et\nobreakspace {}al.\ (1996) are also shown. }}{8}} \newlabel{g29spectra}{{4}{8}} \@writefile{toc}{\contentsline {subsection}{\numberline {4.2.}Previous Analyses of G29.96$-$0.02}{9}} \@writefile{toc}{\contentsline {section}{\numberline {5.}Final Comments}{9}} \@writefile{toc}{\contentsline {paragraph}{\relax Acknowledgments.}{10}}