Blister Flows

Discussion of papers on structure and dynamics of HII regions:

How to get a particular bibtex entry:

e.g., http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1978A%26A....70..769I&data_type=BIBTEX

How to get a load of bibtex entries

http://adsabs.harvard.edu/cgi-bin/abs_connect?author=henney,+w.&data_type=BIBTEX

http://adsabs.harvard.edu/cgi-bin/abs_connect?object=m+42&sim_query=YES&nr_to_return=1000&data_type=BIBTEX

Observational stuff

Pottasch 1956

A Study of Bright Rims in Diffuse Nebulae

1956BAN....13...77P.pdf

This talks about bright rims in 34 HII regions. They typically have density contrasts of 7 to 23 wrt the mean density of the region. He has little maps of them all and classifies their appearance. More convex rims tend to be closer to the ionizing star.

This is more-or-less consistent with our models, in which concavity tends to increase with time. Interestingly, he suggests that the evolutionary sequence is the opposite.

Israel 1978

HII Regions and CO Clouds: The Blister Model

1978A+A____70__769I.pdf

Compares radio observations of CO clouds and HII regions and concludes that they are all "blister flows" - seems to be the first occurrence in literature of this term. His main line of evidence is radio morphology (core-halo structure) and the mean blueshift of 5 km/s between ionized and molecular gas for optically visible regions. For obscured regions he gets no net velocity shift, suggesting they are obscured by unrelated material along the line of sight rather (otherwise they should show a net redshift).

Other old stuff

Matthews & O'Dell 1969

Evolution of Diffuse Nebulae

1969ARA+A___7___67M.pdf

The Tenorio-Tagle Sequence

Tenorio Tagle 1977

The Time Evolution of a Globule Immersed in an HII Region

1977A&A....54..517T.pdf

Similar to Bertoldi, but earlier.

Tenorio-Tagle 1979

The gas dynamics of H II regions. I - The champagne model

1979A&A....71...59T

The original paper, with a 1-d plane-parallel density discontinuity.

Bodenheimer, Tenorio-Tagle, Yorke 1979

The gas dynamics of H II regions. II - Two-dimensional axisymmetric calculations

1979ApJ...233...85B

Bedijn & Tenorio-Tagle 1981

The gasdynamics of H II regions. IV - The champagne phase and the propagation of ionization fronts into dense clouds

1981A&A....98...85B

This seems to be the one that is most relevant to our work.

They have 1-d plane-parallel models with a high density on one side and a low density on the other. They are mainly studying the non-steady evolution of things. When the champagne flow breaks out on the RHS, then a rarefaction wave travels toward the IF on the RHS and causes the material to flow away from the IF.

Still it is nothing like our models in that it never gets to a steady flow pattern. Never shows anything like our density and velocity profil either.

Tenorio-Tagle & Bedijn 1981

The Gasdynamics of HII Regions: V. The interaction of Weak R ionization Fronts with Dense Clouds

1981A&A....99..305T

Plane-parallel calculation that tries to explain bright rims as due to dense obstacles on the side of the star away from the molecular cloud in a champagne flow. Only seems to be able to reproduce the bright rim properties if the ionizing flux is increasing with time (as it is in the case of a champagne flow that is breaking out of the cloud).

Yorke, Bodenheimer, Tenorio-Tagle 1982

The gas dynamics of H II regions. VI - H II regions in collapsing massive molecular clouds

1982A&A...108...25Y

Tenorio-Tagle & Bedijn 1982

The effects of the coronal gas on the champagne phase

1982A&A...115..207T

Bedijn & Tenorio-Tagle 1984

The formation and evolution of bright rims

1984A&A...135...81B

This is a follow up to 1981A&A....99..305T that uses much-improved numerical resolution and also considers spherical geometry. They contradict much of the findings of the previous paper - they now can produce bright rims with a constant ionizing flux. They say that the flow in the ionized gas is not steady - this may be because their shock is propagating into the undisturbed neutral gas at nearly the ionized sound speed.

Franco, Tenorio-Tagle, Bodenheimer 1989a

The evolution of HII regions in disk-like clouds. The appearance of neutral high velocity outflows

1989RMxAA..18...65F

Franco, Tenorio-Tagle, Bodenheimer 1990

On the formation and expansion of H II regions

1990ApJ...349..126F

Rodriguez-Gaspar, Tenorio-Tagle, Franco 1995

The Disruption of Molecular Cloud Cores by Photoionization

1995ApJ...451..210R

This calculates the line profiles of Hα and [O III] for spherical 1-d champagne flows. They get fast shocks going into the low density medium and the formation of interesting line profiles, especially for OIII.

García-Segura Franco 1996

From Ultracompact to Extended H II Regions

1996ApJ...469..171G

Talks about formation of elephant-trunk like structures by means of thin-shell instabilities.

Castellanos, Díaz, Tenorio 2002

On the Large Escape of Ionizing Radiation from Giant Extragalactic H II Regions

2002ApJ...565L..79C

Find that 10%-73% of the Lyman continuum radiation escapes from nebulae. Sort of consistent with my models.

Other theory

Comerón 1997

Dynamical evolution of wind-driven HII regions in strong density gradients

1997A&A...326.1195C

Shu, Lizano et al 2002

Self-similar Champagne Flows in H II Regions

2002ApJ...580..969S

A bit of an odd paper. They do 1-d spherical models of completely ionized cloud cores with various density distributions and derive semi-analytic models for their champagne evolution. Not surprisingly, they find that they don't last very long.