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Related papers: HII galaxies in 4D

200 papers

We study the properties of low-column density gas clumps in the halo of the Milky Way based on high-resolution 21-cm observations. Using interferometric data from the WSRT and the VLA we study HI emission at low-, intermediate- and high…

Astrophysics of Galaxies · Physics 2015-05-13 N. Ben Bekhti , P. Richter , B. Winkel , F. Kenn , T. Westmeier

Star-forming galaxies with nebular HeII emission contain very energetic ionizing sources of radiation, which can be considered as analogs to the major contributors of the reionization of the Universe in early epochs. It is therefore of…

Astrophysics of Galaxies · Physics 2020-11-11 E. Pérez-Montero , C. Kehrig , J. M. Vílchez , R. García-Benito , S. Duarte Puertas , J. Iglesias-Páramo

Massive stars play an important role in the Universe. Unlike low-mass stars, the formation of these objects located at great distances is still unclear. It is expected to be governed by some combination of self-gravity, turbulence, and…

Astrophysics of Galaxies · Physics 2024-08-07 A. G. Pazukhin , I. I. Zinchenko , E. A. Trofimova

We have detected over 400 HI clouds in the lower halo of the Galaxy within the pilot region of the Galactic All-Sky Survey (GASS), a region of the fourth quadrant that spans 18 degrees in longitude, 40 degrees in latitude and is centered on…

In this study we perform a comparative analysis of the properties of the HII regions located in different areas of barred galaxies, with the aim of investigating the impact of bars on the physical properties of the ionised gas. Based on…

The determination of chemical abundances in star-forming galaxies and the study of their evolution on cosmological timescales are powerful tools for understanding galaxy formation and evolution. This contribution presents the latest results…

Astrophysics · Physics 2007-05-23 T. Contini , M. -A. Treyer , M. Mouhcine , M. Sullivan , R. S. Ellis

Neutral hydrogen traces gravitational potentials. In the nearby universe, 21cm emission-line surveys show that the bulk of the HI resides in well-formed, optically-luminous galaxies. At high redshift, 21cm line absorption against background…

Astrophysics · Physics 2007-05-23 F. H. Briggs

We report on the detection of low-column density neutral hydrogen clumps in the halo of the Milky Way. Using high-resolution (FWHM~7 km/s) optical spectra obtained with the VLT/UVES spectrograph we detect narrow interstellar absorption by…

Astrophysics · Physics 2009-11-11 Philipp Richter , Tobias Westmeier , Christian Bruens

We present results of our ongoing study of the morphology and kinematics of the ionised gas in 48 representative nearby elliptical and lenticular galaxies using the SAURON integral-field spectrograph on the 4.2m William Herschel Telescope.…

The properties of galaxies follow scaling relations related to the physics that govern galaxy evolution. Based on these, we can identify galaxies undergoing specific evolutionary processes such as HI-excess galaxies, which have relatively…

Astrophysics of Galaxies · Physics 2024-12-12 H. Denes , V. A. Capa

We present long slit optical spectroscopy of 67 HII regions in 21 dwarf irregular galaxies to investigate the enrichment of oxygen, nitrogen, neon, sulfur, and argon in low mass galaxies. Oxygen abundances are obtained via direct detection…

Astrophysics · Physics 2009-11-13 L. van Zee , M. P. Haynes

We present a new observation of the compact HII region, G29.96-0.02, that allows us to compare the velocity structure in the ionised gas and surrounding molecular gas directly. This allows us to remove most of the remaining ambiguity about…

Astrophysics · Physics 2009-10-31 S. L. Lumsden , M. G. Hoare

We present a model for the interstellar medium of NGC4214 with the objective to probe the physical conditions in the two main star-forming regions and their connection with the star formation activity of the galaxy. We used the spectral…

Astrophysics of Galaxies · Physics 2015-08-19 A. Dimaratos , D. Cormier , F. Bigiel , S. C. Madden

This paper presents a statistical explanation of filament formation in the galactic atomic hydrogen. Recently developed technique allows to determine the 3D spectrum of random HI density. We claim that even in the absence of dynamical…

Astrophysics · Physics 2009-10-28 Alex Lazarian , Dmitri Pogosyan

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…

We study the shapes of spatially integrated H I emission-line profiles of galaxies in the EAGLE simulation using three separate measures of the profile's asymmetry. We show that the subset of EAGLE galaxies whose gas fractions and stellar…

Astrophysics of Galaxies · Physics 2021-12-30 Aditya Manuwal , Aaron D. Ludlow , Adam R. H. Stevens , Ruby J. Wright , Aaron S. G. Robotham

We present our ongoing work on integral field spectroscopy of three prototypical HII galaxies: IIZw70, IIZw71 and IZw18. The data are mainly used to study the ionized gas and stellar clusters. Our main goal is to investigate the presence of…

Astrophysics · Physics 2007-05-23 C. Kehrig , J. M. Vilchez , S. F. Sanchez , E. Telles , D. Martin-Gordon , L. Lopez-Martin

We have studied the viability of new theoretical models which combine a chemical evolution code, an evolutionary synthesis code and a photoionization code, to understand the star formation and evolution of H{\sc ii} galaxies. The emission…

Astrophysics · Physics 2007-12-04 M. Martín Manjón , M. Mollá , A. I. Díaz

We have carried out the largest and most unbiased search for hypercompact (HC) HII regions. Our method combines four interferometric radio continuum surveys (THOR, CORNISH, MAGPIS and White2005) with far-infrared and sub-mm Galactic Plane…

Astrophysics of Galaxies · Physics 2018-11-28 A. Y. Yang , M. A. Thompson , W. W. Tian , S. Bihr , H. Beuther , L. Hindson

The Galactic HII region G353.2+0.9 is excited by the massive open cluster Pismis-24. By analyzing (sub-)mm molecular-line and -continuum we study the detailed morphology of the gas and dust, as well as their physical parameters and their…

Astrophysics of Galaxies · Physics 2015-06-03 A. Giannetti , J. Brand , F. Massi , A. Tieftrunk , M. T. Beltran