The Dynamical Effects of Hypersonic Stellar Winds on Interstellar Gas

1981 ◽  
pp. 125-150 ◽  
Author(s):  
J. E. Dyson
Keyword(s):  
Stellar Winds ◽  
Interstellar Gas

scholarly journals HI Bubbles around NGC 6888

1996 ◽  
Vol 169 ◽  
pp. 617-618
Author(s):  
C. Cappa de Nicolau ◽  
C. Rogers ◽  
G. Dubner ◽  
N. St.-Louis
Keyword(s):  
Interstellar Medium ◽  
Stellar Winds ◽  
Interstellar Gas ◽  
Ring Nebula ◽  
Optical Ring

The interstellar bubbles are generally the result of the interaction of strong stellar winds with the surrounding material. HI voids and shells have been disclosed around several WR stars in our Galaxy (e.g. Niemela & Cappa de Nicolau 1991, Dubner et al. 1992). We report here an analysis of the interstellar medium in the vicinity of the WR star HD 192163 = WR 136 and the optical ring nebula NGC 6888 based on HI observations. Our aim is to look for the traces left in the cold interstellar gas by the action of the stellar winds of HD 192163.

scholarly journals Possible links between supersonic stellar winds and the origin of cosmic rays

1981 ◽  
Vol 59 ◽  
pp. 155-158
Author(s):  
T. Montmerle ◽  
M. Cassé ◽  
J. Paul
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Scale Height ◽  
Shock Acceleration ◽  
Stellar Winds ◽  
Galactic Magnetic Field ◽  
Interstellar Gas ◽  
Terrestrial Atmosphere ◽  
Recent Advances ◽  
Γ Ray

Cosmic rays (CR) are fast or relativistic protons and electrons (and nuclei), detected on the top of the terrestrial atmosphere. Except at the highest energies (>1017eV) the Larmor radii of the particles in the galactic magnetic field are much smaller than the scale height of the interstellar gas, and the arriving particles have completely lost memory of their sources. Therefore, their origin is unknown, at least directly. But recent advances in γ-ray astronomy, and in shock acceleration mechanisms, have shed a radically new light on a old problem.

scholarly journals Superbubbles in the Magellanic Clouds

1999 ◽  
Vol 190 ◽  
pp. 78-83 ◽  
Author(s):  
M. S. Oey
Keyword(s):  
Magellanic Clouds ◽  
Stellar Winds ◽  
Stellar Content ◽  
Interstellar Gas ◽  
Star Forming ◽  
Gas Phases ◽  
Ob Associations ◽  
Shell Forming ◽  
The Relationship

Superbubbles that result from the stellar winds and supernovae of OB associations probably play a fundamental role in the structure and energetics of the ISM in star-forming galaxies. Their influence may also dominate the relationship between the different interstellar gas phases. How do superbubbles form and evolve? How do they affect the local and global ISM? The Magellanic Clouds provide a superior opportunity to study this shell-forming activity, since both stellar content and gaseous structure can be examined in detail. Here, the results of recent studies of superbubbles in the Magellanic Clouds are reviewed.

scholarly journals Turbulent amplification of interstellar magnetic fields

1991 ◽  
Vol 147 ◽  
pp. 519-522
Author(s):  
Anthony Whitworth
Keyword(s):  
Magnetic Field ◽  
Scaling Law ◽  
Hii Regions ◽  
Turbulent Energy ◽  
Radiative Cooling ◽  
Stellar Winds ◽  
Interstellar Gas ◽  
Stellar Jets ◽  
Supernova Explosions ◽  
The Magnetic Field

We show that the radiative cooling properties of the interstellar gas lead naturally to a scaling law for the magnetic field of the form B ∝ n1/2, if the magnetic field is amplified by a vigorous injection of turbulent energy due to expanding HII regions, stellar winds, supernova explosions, stellar jets, etc.

scholarly journals Turbulent amplification of interstellar magnetic fields

1991 ◽  
Vol 147 ◽  
pp. 519-522
Author(s):  
Anthony Whitworth
Keyword(s):  
Magnetic Field ◽  
Scaling Law ◽  
Hii Regions ◽  
Turbulent Energy ◽  
Radiative Cooling ◽  
Stellar Winds ◽  
Interstellar Gas ◽  
Stellar Jets ◽  
Supernova Explosions ◽  
The Magnetic Field

We show that the radiative cooling properties of the interstellar gas lead naturally to a scaling law for the magnetic field of the form B ∝ n1/2, if the magnetic field is amplified by a vigorous injection of turbulent energy due to expanding HII regions, stellar winds, supernova explosions, stellar jets, etc.

scholarly journals Theoretical models of Herbig-Haro objects

1987 ◽  
Vol 122 ◽  
pp. 159-172
Author(s):  
J. E. Dyson
Keyword(s):  
Theoretical Models ◽  
Stellar Winds ◽  
Interstellar Gas ◽  
General Production ◽  
Hh Objects ◽  
Production Mechanisms

A brief overview of the observational characteristics of HH objects is given. Current models for their production by the interaction of stellar winds and jets with interstellar gas are critically discussed. Models for two specific systems of HH objects, namely, the Orion HH objects and the HH46-47 system are described with reference to the general production mechanisms.

scholarly journals Interstellar gas around WO stars in the Galaxy and the Magellanic Clouds

1991 ◽  
Vol 148 ◽  
pp. 438-439
Author(s):  
Tatiana A. Lozinskaya
Keyword(s):  
Massive Stars ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Stellar Winds ◽  
Small Magellanic Cloud ◽  
Interstellar Gas ◽  
The Galaxy

The four oxygen-sequence WR stars, Sand 1 in the Small Magellanic Cloud (SMC), Sand 2 in the Large Magellanic Cloud (LMC), and WR 102 and WR 142 in the Galaxy represent the latest stage of the evolution of massive stars (Sanduleak 1971, Barlow and Hummer 1982, Moffatet al.1985). We have shown WR 102 to be a stripped CO core of a supermassive star (Dopitaet al.1990), probably seen only several thousand years before a SN explosion. The four stars are characterized by extremely energetic stellar winds –Vw from 4500 to 7400 km/s (Barlow and Hummer 1982, Dopitaet al.1990, Torreset al.1986). Examination of the environments of WO stars leads to the conclusion that the four objects appear to be associated with optical and/or IR shell-like structures, although the short WO-superwind does not prevail in the shell's formation.

scholarly journals The total deuterium abundance in the local Galactic disk: decisions and implications

2009 ◽  
Vol 5 (S268) ◽  
pp. 53-58
Author(s):  
Jeffrey L. Linsky
Keyword(s):  
Gas Phase ◽  
Time Scales ◽  
Chemical Evolution ◽  
Galactic Disk ◽  
Mixing Time ◽  
Stellar Winds ◽  
The Sun ◽  
Galactic Chemical Evolution ◽  
Interstellar Gas ◽  
Wide Range

AbstractAnalyses of FUSE spacecraft spectra have provided measurements of D/H in the gas phase of the interstellar medium for many lines of sight extending to several kpc from the Sun. These measurements, together with the earlier Copernicus, HST, and IMAPS data, show a wide range of D/H values that have challenged both observers and chemical evolution modellers. I believe that the best explanation for the diverse D/H measurements is that deuterium can be sequestered on to carbonaceous grains and PAH molecules and thereby removed from the interstellar gas. Grain destruction can raise the gas phase D/H value to approximately the total D/H value. Supernovae and stellar winds, however, can decrease the total D/H value along lines of sight on time scales less than mixing time scales. I will summarize the theoretical and observational arguments for this model and estimate the most likely range for the total D/H in the local Galactic disk. This range in total D/H presents a constraint on realistic Galactic chemical evolution models or the primordial value of D/H or both.

Interstellar gas in the central region of the Galaxy

1967 ◽  
Vol 31 ◽  
pp. 239-251 ◽  
Author(s):  
F. J. Kerr
Keyword(s):  
Central Region ◽  
Galactic Plane ◽  
Neutral Hydrogen ◽  
Continuum Emission ◽  
Galactic Centre ◽  
Interstellar Gas ◽  
Hydrogen Recombination ◽  
The Galaxy ◽  
Centre Region ◽  
The Relationship

A review is given of information on the galactic-centre region obtained from recent observations of the 21-cm line from neutral hydrogen, the 18-cm group of OH lines, a hydrogen recombination line at 6 cm wavelength, and the continuum emission from ionized hydrogen.Both inward and outward motions are important in this region, in addition to rotation. Several types of observation indicate the presence of material in features inclined to the galactic plane. The relationship between the H and OH concentrations is not yet clear, but a rough picture of the central region can be proposed.

Supernovae and interstellar gas dynamics

1967 ◽  
Vol 31 ◽  
pp. 117-119
Author(s):  
F. D. Kahn ◽  
L. Woltjer
Keyword(s):  
Lower Limit ◽  
High Velocity ◽  
Gas Dynamics ◽  
Interstellar Cloud ◽  
Interstellar Gas ◽  
Random Motions ◽  
Relativistic Particles

The efficiency of the transfer of energy from supernovae into interstellar cloud motions is investigated. A lower limit of about 0·002 is obtained, but values near 0·01 are more likely. Taking all uncertainties in the theory and observations into account, the energy per supernova, in the form of relativistic particles or high-velocity matter, needed to maintain the random motions in the interstellar gas is estimated as 1051·4±1ergs.

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