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Related papers: Hydrodynamical models of cometary HII regions

200 papers

Massive stars influence the surrounding universe far out of proportion to their numbers through ionizing radiation, supernova explosions, and heavy element production. Their formation requires the collapse of massive interstellar gas clouds…

Astrophysics of Galaxies · Physics 2015-05-19 Ralf S. Klessen , Thomas Peters , Robi Banerjee , Mordecai-Mark Mac Low , Roberto Galvan-Madrid , Eric R. Keto

We present HST/WFC3 narrowband imaging of the H-alpha emission in a sample of eight gravitationally-lensed galaxies at z = 1 - 1.5. The magnification caused by the foreground clusters enables us to obtain a median source plane spatial…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 R. C. Livermore , T. Jones , J. Richard , R. G. Bower , R. S. Ellis , A. M. Swinbank , J. R. Rigby , Ian Smail , H. Ebeling , R. A. Crain

We perform numerical hydrodynamic modeling of various physical processes that can form an HI ring as is observed in Holmberg I. Three energetic mechanisms are considered: multiple supernova explosions (SNe), a hypernova explosion associated…

Astrophysics · Physics 2009-11-10 E. I. Vorobyov , Shantanu Basu

We present a new set of analytic models for the expansion of HII regions powered by UV photoionisation from massive stars and compare them to a new suite of radiative magnetohydrodynamic simulations of turbulent, self-gravitating molecular…

Astrophysics of Galaxies · Physics 2016-06-08 Sam Geen , Patrick Hennebelle , Pascal Tremblin , Joakim Rosdahl

Within the framework of the Herschel M 33 extended survey HerM33es we study the Spectral Energy Distribution (SED) of a set of HII regions in M 33 as a function of the morphology. We present a catalogue of 119 HII regions morphologically…

We present semi-analytic dynamical models for giant molecular clouds evolving under the influence of HII regions launched by newborn star clusters. In contrast to previous work, we neither assume that clouds are in virial or energetic…

Astrophysics · Physics 2008-11-26 Mark R. Krumholz , Christopher D. Matzner , Christopher F. McKee

We investigate the size--density relation in extragalactic HII regions, with the aim of understanding the role of dust and different physical conditions in the ionized medium. First, we compiled several observational data sets for Galactic…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 L. K. Hunt , H. Hirashita

We present the results of 450 and 850 micron continuum mapping of the HII region KR 140 using the SCUBA instrument on the JCMT. KR 140 is a small (5.7 pc diameter) HII region at a distance of 2.3+/-0.3 kpc. Five of the six IRAS point…

Astrophysics · Physics 2009-11-06 C. R. Kerton , P. G. Martin , D. Johnstone , D. R. Ballantyne

We present a detailed characterization of the population of compact radio-continuum sources in W51 A using subarcsecond VLA and ALMA observations. We analyzed their 2-cm continuum, the recombination lines (RL's) H77$\alpha$ and H30$\alpha$,…

Astrophysics of Galaxies · Physics 2020-08-26 Rudy Rivera-Soto , Roberto Galván-Madrid , Adam Ginsburg , Stan Kurtz

Bright-rimmed clouds (BRCs) found in H II regions are probable sites of triggered star formation due to compression by ionization/shock fronts, and it is hypothesized that star formation proceeds from the exciting star(s) side outward of…

We present chemical evolution models of the Galactic disk with different Z-dependent yields. We find that a moderate mass loss rate for massive stars of solar metallicity produces an excellent fit to the observed C/H and C/O gradients of…

Astrophysics of Galaxies · Physics 2011-02-08 Leticia Carigi , Manuel Peimbert

We present general properties of ionized hydrogen (HII) bubbles and their growth based on a state-of-the-art large-scale (100 Mpc/h) cosmological radiative transfer simulation. The simulation resolves all halos with atomic cooling at the…

Astrophysics · Physics 2009-11-13 Min-Su Shin , Hy Trac , Renyue Cen

A sample of 69 galaxies with radial velocities less than 2500 km/s was selected from the HI Parkes All Sky Survey (HIPASS) to deduce details about star formation in nearby disk galaxies selected with no bias to optical surface brightness…

Astrophysics · Physics 2009-11-11 J. F. Helmboldt , R. A. M. Walterbos , G. D. Bothun , K. O'Neil

HII regions are the ionized spheres surrounding high-mass stars. They are ideal targets for tracing Galactic structure because they are predominantly found in spiral arms and have high luminosities at infrared and radio wavelengths. In the…

Astrophysics of Galaxies · Physics 2015-09-09 L. D. Anderson , L. A. Hough , T. V. Wenger , T. M. Bania , Dana S. Balser

The destruction of Giant Molecular Clouds is a key component in galaxy evolution. We theoretically model the destruction of GMCs by HII regions, which evaporate ionized gas and eject neutral gas during their expansion. HII regions follow…

Astrophysics of Galaxies · Physics 2025-11-05 David Hollenbach , Antonio Parravano , Christopher McKee

The shape of the OB-star spectral energy distribution is a critical component in many diagnostics of the ISM and galaxy properties. We use single-star HII regions from the LMC to quantitatively examine the ionizing SEDs from widely…

Astrophysics of Galaxies · Physics 2013-06-28 Jordan Zastrow , M. S. Oey , E. W. Pellegrini

Because of their relatively simple morphology, "bubble" HII regions have been instrumental to our understanding of star formation triggered by HII regions. With the far-infrared (FIR) spectral coverage of the Herschel satellite, we can…

We present a near-infrared spectroscopic and imaging analysis of the star-forming region IRAS 16475-4609, based on TripleSpec/SOAR spectroscopy and NEWFIRM/CTIO imaging, complemented by archival radio and sub-millimeter data. Our…

Astrophysics of Galaxies · Physics 2025-06-11 Felipe Navarete , Sean D. Points , Augusto Damineli

This is the second paper of a series reporting the results from the PopStar evolutionary synthesis models. Here we present synthetic emission line spectra of H{\sc ii} regions photoionized by young star clusters, for seven values of cluster…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 M. L. Martín-Manjón , M. L. García-Vargas , M. Mollá , A. I. Díaz

We have obtained accurate CCD narrow band H_beta and H_alpha photometry of Giant HII Regions in M 33, NGC 6822 and M 101. Comparison with previous determinations of emission line fluxes show large discrepancies; their probable origins are…

Astrophysics · Physics 2009-11-07 G. L. Bosch , E. Terlevich , R. Terlevich