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Related papers: Clumpy ultracompact HII regions -- III. Cometary m…

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At present, the heliosphere is embedded in a warm low density interstellar cloud that belongs to a cloud system flowing through the local standard of rest with a velocity near ~18 km/s. The velocity structure of the nearest interstellar…

Astrophysics · Physics 2011-02-11 Hans-R. Mueller , Priscilla C. Frisch , Vladimir Florinski , Gary P. Zank

We suggest that Bipolar H{\sc ii} Regions may be the aftermath of collisions between clouds. Such a collision will produce a shock-compressed layer, and a star cluster can then condense out of the dense gas near the centre of the layer. If…

Astrophysics of Galaxies · Physics 2018-11-19 Anthony Whitworth , Oliver Lomax , Scott Balfour , Pierre Mège , Annie Zavagno , Lise Deharveng

Resolution of nearby giant HII regions into their stellar and nebular constituents provides fundamental insights for interpreting more distant and powerful starburst activity. The following summarizes recent advances in our understanding of…

Astrophysics · Physics 2007-05-23 William H. Waller

We have developed a full numerical method to study the gas dynamics of cometary ultra-compact (UC) H II regions, and associated photodissociation regions (PDRs). The bow-shock and champagne-flow models with a $40.9/21.9 M_\odot$ star are…

Solar and Stellar Astrophysics · Physics 2015-10-21 Feng-Yao Zhu , Qing-Feng Zhu , Juan Li , Jiang-Shui Zhang , Jun-Zhi Wang

We present the properties of 8 star-forming regions, or 'clumps,' in 3 galaxies at z~1.3 from the WiggleZ Dark Energy Survey, which are resolved with the OSIRIS integral field spectrograph. Within turbulent discs, \sigma~90 km/s, clumps are…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Emily Wisnioski , Karl Glazebrook , Chris Blake , Gregory B. Poole , Andrew W. Green , Ted Wyder , Chris Martin

Aims. We are trying to probe conditions in the youngest super star clusters, those still embedded in dense obscuring clouds. Methods. The hydrogen recombination lines in the radio and infrared can be observed through the obscuration, as the…

Astrophysics · Physics 2009-11-13 S. C. Beck

If massive stars form by disk accretion, then bipolar outflows should be generated as in the case of low-mass star formation. High accretion rates lead to high outflow rates and make the wind density very large near the protostar. We…

Astrophysics · Physics 2007-05-23 Jonathan C. Tan , Christopher F. McKee

The role of ionization feedback on high-mass (>8 Msun) star formation (HMSF) is still highly debated. Questions remain concerning the presence of nearby HII regions changes the properties of early HMSF and whether HII regions promote or…

Astrophysics of Galaxies · Physics 2020-05-13 S. Zhang , A. Zavagno , J. Yuan , H. Liu , M. Figueira , D. Russeil , F. Schuller , K. A. Marsh , Y. Wu

At least 25 per cent of massive stars are ejected from their parent cluster, becoming runaways or exiles, travelling with often-supersonic space velocities through the interstellar medium (ISM). Their overpressurised H II regions impart…

Astrophysics of Galaxies · Physics 2014-08-25 Jonathan Mackey , Norbert Langer , Vasilii V. Gvaramadze

Winds from massive stars have velocities of 1000 km/s or more, and produce hot, high pressure gas when they shock. We develop a theory for the evolution of bubbles driven by the collective winds from star clusters early in their lifetimes,…

Astrophysics of Galaxies · Physics 2021-06-30 Lachlan Lancaster , Eve C. Ostriker , Jeong-Gyu Kim , Chang-Goo Kim

We present multiwavelength investigation of morphology, physical-environment, stellar contents and star formation activity in the vicinity of star-forming region Sh 2-100. It is found that the Sh 2-100 region contains seven HII regions of…

Astrophysics of Galaxies · Physics 2015-05-18 M. R. Samal , A. K. Pandey , D. K. Ojha , S. K. Ghosh , V. K. Kulkarni , N. Kusakabe , M. Tamura , B. C. Bhatt , M. A. Thompson , R. Sagar

We study the presence of low intensity high velocity components, which we have termed wing features in the integrated Halpha emission line profiles of the HII region populations of the spiral barred galaxies NGC 1530, NGC 3359 and NGC 6951.…

Astrophysics · Physics 2009-11-10 M. Relano , J. E. Beckman

Aims: We offer a new, simpler picture of the local interstellar medium, made of a single continuous cloud enveloping the Sun. This new outlook enables the description of a diffuse cloud from within and brings to light some unexpected…

Astrophysics of Galaxies · Physics 2014-09-05 Cecile Gry , Edward B. Jenkins

Due to their short lifetimes but their enormous energy release in all stages of their lives massive stars are the major engines for the comic matter circuit. They affect not only their close environment but are also responsible to drive…

Astrophysics · Physics 2009-11-13 Gerhard Hensler

We analyze the dynamical expansion of the HII region, photodissociation region, and the swept-up shell, solving the UV- and FUV-radiative transfer, the thermal and chemical processes in the time-dependent hydrodynamics code. Following our…

Astrophysics · Physics 2009-11-13 Takashi Hosokawa , Shu-ichiro Inutsuka

At the end of their lives low mass stars such as our Sun lose most of their mass. The resulting planetary nebulae show a wide variety of shapes, from spherical to highly bipolar. According to the generalized interacting stellar winds model,…

Astrophysics · Physics 2007-05-23 Erik-Jan Rijkhorst , Vincent Icke , Garrelt Mellema

We present a model of the interaction of interstellar dust grains with a stellar environment, that predicts the distribution of interstellar dust grains in the size range between $0.1 {\rm \mu m}$ and $1 {\rm \mu m}$ around a star for the…

Astrophysics · Physics 2007-05-23 M. Landgraf , P. C. Frisch

Stars form in regions of the galaxy that are denser and cooler than the mean interstellar medium. These regions are called Giant Molecular Clouds. At the beginning of their life, up to $10^5-10^6$ years, stars accrete matter from their rich…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 Marco Belan , Sergio de Ponte , Daniela Tordella , Silvano Massaglia , Attilio Ferrari , Andrea Mignone , Eberhard Bodenschatz

Revealing the 3D dynamics of HII regions and their associated molecular clouds is important for understanding the longstanding problem as to how stellar feedback affects the density structure and kinematics of the interstellar medium. We…

High-mass microquasars consist of a massive star and a compact object, the latter producing jets that will interact with the stellar wind. The evolution of the jets, and ultimately their radiative outcome, could depend strongly on the…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Manel Perucho , Valenti Bosch-Ramon