# Shocked Self-similar Collapses and Flows in Star Formation Processes

@article{Shen2004ShockedSC, title={Shocked Self-similar Collapses and Flows in Star Formation Processes}, author={Yue Shen and Yu-qing Lou}, journal={The Astrophysical Journal Letters}, year={2004}, volume={611}, pages={L117 - L120} }

We propose self-similar shocked flow models for certain dynamical evolution phases of young stellar objects, "champagne flows" of H II regions surrounding OB stars, and shaping processes of planetary nebulae. We analyze an isothermal fluid of spherical symmetry and construct families of self-similar shocked flow solutions that feature (1) either a core expansion with a finite central density or a core accretion at a constant rate with a density scaling proportional to r-3/2 (a free-fall state…

## 21 Citations

### Self-similar shocks in polytropic gas flows around star-forming regions

- Physics
- 2006

Self-similar shock solutions in spherically symmetric polytropic gas flows are constructed and analysed in contexts of protostar formation processes. Among other possible solutions, we model a…

### Spherical isothermal self-similar shock flows

- Physics
- 2005

We explore self-similar dynamical processes in a spherical isothermal self-gravitational fluid with an emphasis on shocks and outline astrophysical applications of such shock solutions. The previous…

### Self‐similar polytropic champagne flows in H ii regions

- Physics
- 2008

We explore large-scale hydrodynamics of H II regions for various self-similar shock flows of a polytropic gas cloud under self-gravity and with quasi-spherical symmetry. We formulate cloud dynamics…

### Formation and Collapse of Quiescent Cloud Cores Induced by Dynamic Compressions

- Physics
- 2007

We present numerical hydrodynamic simulations of the formation, evolution, and gravitational collapse of isothermal molecular cloud cores in spherical geometry. A compressive wave is set up in a…

### Envelope expansion with core collapse - III. Similarity isothermal shocks in a magnetofluid

- Physics
- 2006

We explore magnetohydrodynamic (MHD) solutions for envelope expansions with core collapse (EECC) with isothermal MHD shocks in a quasi-spherical symmetry, and outline potential astrophysical…

### Self-similar shocks and winds in galaxy clusters

- Physics
- 2008

A theoretical model framework of spherical symmetry is presented for a composite astrophysical system of two polytropic fluids coupled together by gravity to explore large-scale shocks and flow…

### New self-similar solutions of polytropic gas dynamics

- Physics
- 2006

We explore semicomplete self-similar solutions for the polytropic gas dynamics involving self-gravity under spherical symmetry, examine behaviours of the sonic critical curve and present new…

### Outflows and Inflows in Astrophysical Systems

- Physics
- 2005

We seek for self-similar solutions describing the time-dependent evolution of self-gravity systems with either spherical symmetry or axisymmetric disk geometry. By assuming self-similar variable x ≡…

### Dynamic voids surrounded by shocked conventional polytropic gas envelopes

- Physics
- 2011

With proper physical mechanisms of energy and momentum input from around the centre of a self-gravitating polytropic gas sphere, a central spherical ‘void’ or ‘cavity’ or ‘bubble’ of very much less…

### Self-similar dynamics of a relativistically hot gas

- Physics
- 2007

In the presence of self-gravity, we investigate the self-similar dynamics of a relativistically hot gas with or without shocks in astrophysical processes of stellar core collapse, formation of…

## References

SHOWING 1-10 OF 33 REFERENCES

### Protostellar Collapse with a Shock

- Physics
- 1995

We reexamine both numerically and analytically the collapse of the singular isothermal sphere in the context of low-mass star formation. We consider the case where the onset of collapse is initiated…

### Envelope expansion with core collapse – I. Spherical isothermal similarity solutions

- Physics
- 2004

We investigate self-similar dynamical processes in an isothermal self-gravitational fluid with spherical symmetry. With reference to the earlier complementary solution results of Larson, Penston,…

### Self-similar Champagne Flows in H II Regions

- Physics
- 2002

We consider the idealized expansion of an initially self-gravitating, static, singular, isothermal cloud core. For t ≥ 0, the gas is ionized and heated to a higher uniform temperature by the…

### Self-similar collapse of isothermal spheres and star formation.

- Physics
- 1977

We consider the problem of the gravitational collapse of isothermal spheres by applying the similarity method to the gas-dynamic flow. We argue that a previous solution obtained by Larson and Penston…

### Evidence for Protostellar Collapse in B335

- Physics, Geology
- 1992

We have observed five rotational transitions of H2CO and CS toward the Bok globule, B335, with high spatial and spectral resolution. The characteristic shape of the observed profiles provides direct,…

### Structure of Protostellar Collapse Candidate B335 Derived from Near-Infrared Extinction Maps

- Physics
- 2001

We present a near-infrared extinction study of the dark globule B335, a protostellar collapse candidate, using data from the Hubble Space Telescope/Near Infrared Camera and Multi-Object Spectrometer…

### On the formation and expansion of H II regions

- Physics
- 1990

The evolution of H II regions in spherical clouds with small, constant-density cores and power-law density distributions r exp -w outside the core is described analytically. It is found that there is…

### Disk Properties and Density Structure of the Star-forming Dense Core B335

- Physics, Geology
- 2003

We present subarcsecond-resolution dust continuum observations of the protostellar collapse candidate B335 made with the IRAM Plateau de Bure Interferometer at wavelengths of 1.2 and 3.0 mm. These…

### Self-similar condensation of spherically symmetric self-gravitating isothermal gas clouds

- Physics
- 1985

The authors show that similarity solutions for the condensation of spherically symmetric self-gravitating isothermal gas clouds are much more abundant than was hitherto believed; they have discovered…

### The Initial Conditions for Formation of Low-Mass Stars: Kinematics and Density Structure of the Protostellar Envelope in B335

- Physics
- 1999

We have observed dense molecular gas toward a deeply embedded protostar in B335 using the Nobeyama 45 m telescope and the Nobeyama Millimeter Array. The H13CO+ and C18O maps taken by the 45 m…