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By means of grid-based, 3D hydrodynamical simulations we study the formation of second generation (SG) stars in a young globular cluster (GC) of mass 10^7 Msun, the possible progenitor of an old GC with a present mass ~(1-5) * 10^6 Msun.…

Solar and Stellar Astrophysics · Physics 2019-08-07 F. Calura , A. D'Ercole , E. Vesperini , E. Vanzella , A. Sollima

We present millimetre-line imaging of the Galactic HII region Sh 104. We show that it is surrounded by a ring of molecular gas and dust. Four large molecular condensations are regularly spaced around the ring. These condensations are…

Astrophysics · Physics 2009-11-10 L. Deharveng , B. Lefloch , A. Zavagno , J. Caplan , A. P. Whitworth , D. Nadeau , S. Martin

We present ALMA observations with a 800 au resolution and radiative-transfer modelling of the inner part ($r\approx6000$ au) of the ionized accretion flow around a compact star cluster in formation at the center of the luminous…

The hypothesis that massive stars form by accretion can be investigated by simple analytical calculations that describe the effect that the formation of a massive star has on its own accretion flow. Within a simple accretion model that…

Astrophysics · Physics 2011-02-11 Eric Keto

The formation mechanism of CO clouds observed with NANTEN2 and Mopra telescope toward the stellar cluster Westerlund 2 is studied by three-dimensional magnetohydrodynamic (MHD) simulations taking into account the interstellar cooling. These…

High Energy Astrophysical Phenomena · Physics 2017-02-27 Yuta Asahina , Tomohisa Kawashima , Naoko Furukawa , Rei Enokiya , Hiroaki Yamamoto , Yasuo Fukui , Ryoji Matsumoto

The C$^{+}$ ion is an important coolant of interstellar gas, and so the [CII] fine structure line is frequently observed in the interstellar medium. However, the physical and chemical properties of the [CII]-emitting gas are still unclear.…

Widespread, high altitude, diffuse ionized gas with scale heights of around a kiloparsec is observed in the Milky Way and other star forming galaxies. Numerical radiation-magnetohydrodynamic simulations of a supernova-driven turbulent…

We propose that a significant fraction of the ultracompact HII regions found in massive star-forming clouds are the result of the interaction of the wind and ionizing radiation from a young massive star with the clumpy molecular cloud gas…

Astrophysics · Physics 2015-06-24 J. E. Dyson , R. J. R. Williams , M. P. Redman

We present an analysis of multi-wavelength observations of an area of 0.27 deg x 0.27 deg around the Galactic HII region G18.88-0.49, which is powered by an O-type star (age ~10^5 years). The Herschel column density map reveals a shell-like…

Astrophysics of Galaxies · Physics 2020-11-04 L. K. Dewangan , D. K. Ojha , Saurabh Sharma , S. del Palacio , N. K. Bhadari , A. Das

The history of star formation in the strong gravitational potential of the Galactic center has been of much interest, recently. We propose that the sub-parsec-scale disk of massive stars orbiting the massive black hole at the Galactic…

Astrophysics · Physics 2007-12-11 F. Yusef-Zadeh , M. Wardle

High-mass stars form in much richer environments than those associated with isolated low-mass stars, and once they reach a certain mass, produce ionised (HII) regions. The formation of these pockets of ionised gas are unique to the…

The diffuse interstellar medium is dynamic, and its chemistry and evolution is determined by shock fronts as well as photodissociation. Shocks are implied by the supersonic motions and velocity dispersion often statistically called…

Astrophysics of Galaxies · Physics 2021-03-17 William T. Reach , Carl Heiles

Aiming at studying the physical properties of Galactic IR bubbles and to explore their impact in triggering massive star formation, we perform a multiwavelength analysis of the bubble HII region Sh2-39 (N5) and its environs. To analyze the…

Astrophysics of Galaxies · Physics 2017-09-27 N. U. Duronea , C. E. Cappa , L. Bronfman , J. Borissova , M. Gromadzki

We suggest that molecular clouds can be formed on short time scales by compressions from large scale streams in the interstellar medium (ISM). In particular, we argue that the Taurus-Auriga complex, with filaments of 10-20 pc $\times$ 2-5…

Astrophysics · Physics 2010-04-06 Javier Ballesteros-Paredes , Lee Hartmann , Enrique Vazquez-Semadeni

We discuss the theory of coupled ionization--dissociation fronts produced when molecular clouds are exposed to $\lambda < 1110$\AA\ radiation from hot stars. A steady, composite structure is developed, which generally includes an ionized…

Astrophysics · Physics 2009-10-28 Frank Bertoldi , B. T. Draine

Massive stars produce copious quantities of ultraviolet radiation beyond the Lyman limit, photoionizing the interstellar medium (ISM) and producing H II regions. As strong sources of recombination- and forbidden-line emission, infrared…

Astrophysics of Galaxies · Physics 2012-02-06 Matthew S. Povich

Low-velocity large-scale shocks impacting on the ISM may efficiently shape molecular clouds and trigger star formation within them. These shocks, both driven by galactic bubbles and/or cloud-cloud collisions, leave specific signatures in…

Astrophysics of Galaxies · Physics 2025-09-24 G. Cosentino , I. Jiménez-Serra , R. Liu , C. -Y. Law , J. C. Tan , J. D. Henshaw , A. T. Barnes , F. Fontani , P. Caselli , S. Viti

The Large Magellanic Cloud (LMC) exhibits vigorous high-mass star formation, including the HII regions 30~Dor that is the most active site of star formation in the local group. The present paper focuses on the Giant Molecular Cloud (GMC) in…

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

Our objective is to investigate the physical properties of the ionised gas of the low-metallicity dwarf galaxy, IC 10, at various spatial scales: from individual HII regions to the entire galaxy scale and examine whether diagnostics for…