Collective effects of stellar winds and unidentified gamma-ray sources

AbstractHigh resolution HI observations of nearby dwarf galaxies (most of which are situated in the M81 group at a distance of about 3·2 Mpc) reveal that their neutral interstellar medium (ISM) is dominated by hole-like features most of which are expanding. A comparison of the physical properties of these holes with the ones found in more massive spiral galaxies (such as M31 and M33) shows that they tend to reach much larger sizes in dwarf galaxies. This can be understood in terms of the galaxy's gravitational potential. The origin of these features is still a matter of debate. In general, young star forming regions (OB-associations) are held responsible for their formation. This picture, however, is not without its critics and other mechanisms such as the infall of high velocity clouds, turbulent motions or even gamma ray bursters have been recently proposed. Here I will present one example of a supergiant shell in IC 2574 which corroborates the picture that OB associations are indeed creating these structures. This particular supergiant shell is currently the most promising case to study the effects of the combined effects of stellar winds and supernova explosions which shape the neutral interstellar medium of (dwarf) galaxies.

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The Surroundings of Gamma-Ray Bursts: Constraints on Progenitors

International Astronomical Union Colloquium ◽

10.1017/s0252921100009520 ◽

2005 ◽

Vol 192 ◽

pp. 441-450

Author(s):

Roger A. Chevalier

Keyword(s):

Interstellar Medium ◽

Mass Loss ◽

Massive Star ◽

Gamma Ray ◽

Gamma Ray Bursts ◽

Uniform Density ◽

Stellar Winds ◽

Wind Environment ◽

Low Mass ◽

Pulsar Wind

SummaryThe association of a supernova with a gamma-ray burst (GRB 030329) implies a massive star progenitor, which is expected to have an environment formed by pre-burst stellar winds. Although some sources are consistent with the expected wind environment, many are not, being better fit by a uniform density environment. One possibility is that this is a shocked wind, close to the burst because of a high interstellar pressure and a low mass loss density. Alternatively, there is more than one kind of burst progenitor, some of which interact directly with the interstellar medium. Another proposed environment is a pulsar wind bubble that has expanded inside a supernova, which requires that the supernova precede the burst.

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Variable Gamma Ray Sources, 1: Interactions of Flare Energetic Particles with Solar and Stellar Winds

Astrophysical Sources of High Energy Particles and Radiation ◽

10.1007/978-94-010-0560-9_19 ◽

2001 ◽

pp. 219-230 ◽

Cited By ~ 1

Author(s):

Lev I. Dorman

Keyword(s):

Gamma Ray ◽

Energetic Particles ◽

Stellar Winds

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Inverse-Compton gamma-ray emission from chaotic, early-type stellar winds and its detectability by Gamma Ray Observatory

The Astrophysical Journal ◽

10.1086/186197 ◽

1991 ◽

Vol 381 ◽

pp. L63 ◽

Cited By ~ 22

Author(s):

Wan Chen ◽

Richard L. White

Keyword(s):

Gamma Ray ◽

Stellar Winds ◽

Early Type ◽

Inverse Compton ◽

Gamma Ray Emission

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Angle distribution and time variation of gamma ray flux from solar and stellar winds, 1. Generation by flare energetic particles

10.1063/1.54099 ◽

1997 ◽

Cited By ~ 1

Author(s):

Lev I. Dorman

Keyword(s):

Time Variation ◽

Gamma Ray ◽

Energetic Particles ◽

Stellar Winds ◽

Angle Distribution

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Gamma-ray bursts afterglows in magnetized stellar winds

Monthly Notices of the Royal Astronomical Society Letters ◽

10.1111/j.1745-3933.2011.01144.x ◽

2011 ◽

Vol 418 (1) ◽

pp. L64-L68 ◽

Cited By ~ 3

Author(s):

Martin Lemoine ◽

Guy Pelletier

Keyword(s):

Gamma Ray ◽

Gamma Ray Bursts ◽

Stellar Winds

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Probing the star formation origin of gamma rays from 3FHL J1907.0+0713

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3817 ◽

2020 ◽

Author(s):

T Ergin ◽

L Saha ◽

P Bhattacharjee ◽

H Sano ◽

S J Tanaka ◽

...

Keyword(s):

Gamma Rays ◽

Gamma Ray ◽

Stellar Winds ◽

Stellar Clusters ◽

Giant Molecular Clouds ◽

Data Set ◽

Star Forming ◽

Total Luminosity ◽

Best Fitting ◽

Emission Models

Abstract Star-forming (SF) regions embedded inside giant molecular clouds (GMCs) are potential contributors to Galactic gamma rays. The gamma-ray source 3FHL J1907.0+0713 is detected with a significance of roughly 13σ in the 0.2 − 300 GeV energy range after the removal of gamma-ray pulsation periods of PSR J1906+0722 from the Fermi-LAT data set of about 10 years. The energy spectrum of 3FHL J1907.0+0713 is best-fitted to a power law model with a spectral index of 2.26 ± 0.05. The CO(J = 1−0) data taken by NANTEN2 revealed that 3FHL J1907.0+0713 is overlapping with a GMC having a peak velocity of about 38 km s−1. The best-fitting location of 3FHL J1907.0+0713 is measured to be approximately 0.13 degrees away from the Galactic supernova remnant (SNR) 3C 397 and it overlaps with a star that is associated with a bow-shock nebula. We show that there is no physical connection between 3FHL J1907.0+0713, 3C 397, as well as any positional coincidence with the pulsar. The spectrum of 3FHL J1907.0+0713 is fitting to both hadronic and leptonic gamma-ray emission models and the total luminosity at a distance of 2.6 kpc is calculated to be 1.1 × 1034 erg s−1. We also discuss possible SF origins of gamma rays from 3FHL J1907.0+0713, where SNRs, massive protostar outflows, stellar winds from runaway stars, colliding wind binaries, and young stellar clusters are considered as candidate sources.

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