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Related papers: Expansive components in H II regions

200 papers

The S254-258 star-forming complex is a place of massive star formation where five OB-stars have created HII regions, visible as optical nebulae, and disrupted the parental molecular gas. In this work, we study the 3D structure of these \HII…

Astrophysics of Galaxies · Physics 2024-02-14 Maria S. Kirsanova , Alexei V. Moiseev , Paul A. Boley

We present a study of the kinematical properties of a small sample of nearby near-infrared bright massive and intermediate mass young stellar objects using emission lines sensitive to discs and winds. We show for the first time that the…

Solar and Stellar Astrophysics · Physics 2015-06-05 S. L. Lumsden , H. E. Wheelwright , M. G. Hoare , R. D. Oudmaijer , J. E. Drew

We present an evolutionary sequence of models of the photoionized disk-wind outflow around forming massive stars based on the Core Accretion model. The outflow is expected to be the first structure to be ionized by the protostar and can…

Solar and Stellar Astrophysics · Physics 2016-02-17 Kei E. I. Tanaka , Jonathan C. Tan , Yichen Zhang

Various types of galaxies observed in the cosmological scales show P-Cygni type profiles in the Lyman alpha emission lines. A Monte Carlo code is developed to investigate the Lyman alpha line transfer in an optically thick and moving medium…

Astrophysics · Physics 2016-08-30 Sang-Hyeon Ahn , Hee-Won Lee

High mass proto-stars create Ultra-Compact Hii regions (UCHII) at the stage of evolution when most of the accretion is finished but the star is still heavily embedded in molecular material. The morphologies of UCHII regions reflect the…

Astrophysics of Galaxies · Physics 2021-11-17 Dan Beilis , Sara Beck , John Lacy

We analyse the internal dynamics of star-forming HII regions and their efficiency in interacting with the ISM. We use GHaFaS (Fabry-Perot) data of the nearby spiral galaxy M83 to perform multiple-Gaussian fitting to the integrated Halpha…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-23 Javier Blasco-Herrera , Kambiz Fathi , John Beckman , Leonel Gutiérrez , Andreas Lundgren , Joan Font , Olivier Hernandez , Claude Carignan

We have imaged the extended HI environment of M31 with an unprecedented combination of high resolution and sensitivity. We detect a number of distinct High Velocity Cloud components associated with M31. A sub-set of the features within 30…

Astrophysics · Physics 2007-05-23 Robert Braun , David Thilker

The variations of oxygen abundance and ionization parameter in HII regions are usually thought to be the dominant factors that produced variations seen in observed emission line spectra. However, if and how these two quantities are…

We have mapped the superwind/halo region of the nearby starburst galaxy M82 in the mid-infrared with $Spitzer-IRS$. The spectral regions covered include the H$_2 S(1)-S(3)$, [NeII], [NeIII] emission lines and PAH features. We estimate the…

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…

Rotation curves and velocity dispersion profiles are presented for both the stellar and gaseous components along five different position angles (P.A.=5, 50, 95, 125 and 155 degrees) of the nearby barred spiral NGC 6221. The observed…

We performed Herschel/HIFI observations of intermediate-excitation molecular lines in the far-infrared/submillimeter range in a sample of ten protoplanetary nebulae and young planetary nebulae. The high spectral resolution provided by HIFI…

Solar and Stellar Astrophysics · Physics 2015-05-30 V. Bujarrabal , J. Alcolea , R. Soria-Ruiz , the HIFISTARS team

Galaxies in Hickson Compact Group 91 (HCG 91) were observed with the WiFeS integral field spectrograph as part of our ongoing campaign targeting the ionized gas physics and kinematics inside star forming members of compact groups. Here, we…

Astrophysics of Galaxies · Physics 2015-05-20 F. P. A. Vogt , M. A. Dopita , S. Borthakur , L. Verdes-Montenegro , T. M. Heckman , M. S. Yun , K. C. Chambers

Using deep Subaru/FOCAS spectra of 34 HII regions in both the inner and outer parts of the extended ultraviolet (XUV) disc galaxy NGC 4625 we have measured an abundance gradient out to almost 2.5 times the optical isophotal radius. We…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Q. E. Goddard , F. Bresolin , R. C. Kennicutt , E. V. Ryan-Weber , F. F. Rosales-Ortega

We present empirical HII region oxygen abundances for a sample of low-luminosity starburst galaxies which are in a short lived evolutionary state. All five galaxies are characterized by centrally concentrated star formation, which is…

Astrophysics · Physics 2011-02-11 K. E. Dellenbusch , J. S. Gallagher , P. M. Knezek

The integrated 21 cm H I emission profile of a galaxy encodes valuable information on the kinematics, spatial distribution, and dynamical state of its cold interstellar medium. The line width, in particular, reflects the rotation velocity…

Astrophysics of Galaxies · Physics 2020-08-05 Niankun Yu , Luis C. Ho , Jing Wang

We present 7mm Very Large Array continuum images of the starburst galaxy M82. On arcsecond scales, two-thirds of the 7mm continuum consists of free-free emission from HII regions. In the subarcsecond resolution map, we identify 14 compact…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-13 Chao-Wei Tsai , Jean L. Turner , Sara C. Beck , David S. Meier , Paul T. P. Ho

We present the first results on the diffuse transition clouds observed in [CII] line emission at 158 microns (1.9 THz) towards Galactic longitudes near 340deg (5 LOSs) and 20deg (11 LOSs) as part of the GOT C+ survey. Out of the total 146…

Astrophysics of Galaxies · Physics 2015-05-19 T. Velusamy , W. D. Langer , J. L. Pineda , P. F. Goldsmith , D. Li. , H. W. Yorke

A survey of 329 nearby galaxies (redshift z < 0.045) has been conducted to study the distribution of mass and light within spiral galaxies over a range of environments. The 18 observed clusters and groups span a range of richness, density,…

Astrophysics · Physics 2009-11-10 Nicole P. Vogt , Martha P. Haynes , Terry Herter , Riccardo Giovanelli

We report the first results of a programme aimed at studying the properties of high redshift galaxies with on-going massive and dominant episodes of star formation (HII galaxies). We use the $L(\mathrm{H}\beta) - \sigma$ distance estimator…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Roberto Terlevich , Elena Terlevich , Jorge Melnick , Ricardo Chávez , Manolis Plionis , Fabio Bresolin , Spyros Basilakos