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相关论文: The internal dynamical equilibrium of HII regions:…

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We have discovered a number of very small isolated HII regions 20-30 kpc from their nearest galaxy. The HII regions appear as tiny emission line dots (ELdots) in narrow band images obtained by the NOAO Survey for Ionization in Neutral Gas…

天体物理学 · 物理学 2007-05-23 E. V. Ryan-Weber , M. E. Putman , K. C. Freeman , G. R. Meurer , R. L. Webster

The accepted explanation of the observed dichotomy of two orders of magnitude between in situ measurements of electron density in HII regions, derived from emission line ratios, and average measurements based on integrated emission measure,…

天体物理学 · 物理学 2016-08-16 C. Giammanco , J. E. Beckman , A. Zurita , M. Relaño

We investigate the kinematic properties of Galactic HII regions using radio recombination line (RRL) emission detected by the Australia Telescope Compact Array (ATCA) at 4-10 GHz and the Jansky Very Large Array (VLA) at 8-10 GHz. Our HII…

Spectroscopic observations of 63 HII regions in six spiral galaxies (NGC 628, NGC 783, NGC 2336, NGC 6217, NGC 7331, and NGC 7678) were carried out with the 6-meter telescope (BTA) of Russian Special Astrophysical Observatory with the…

宇宙学与河外天体物理 · 物理学 2012-06-21 Alexander S. Gusev , Leonid S. Pilyugin , Firouz Sakhibov , Sergey N. Dodonov , Olga V. Ezhkova , Maria S. Khramtsova

We study the gas emission of galaxies with active star formation, consisting mostly of HII galaxies and Starbursts, as well as some Seyfert 2s, and determine chemical and physical parameters. The data consist of 19 high signal-to-noise…

天体物理学 · 物理学 2009-07-22 D. Raimann , T. Storchi-Bergmann , E. Bica , J. Melnick , H. Schmitt

We present a new, detailed, analysis of the spatial distribution of Galactic HII regions, exploiting a far richer database than used in previous analyses. Galactocentric distances have been derived for 550 objects. Distances from the Sun…

天体物理学 · 物理学 2009-11-10 R. Paladini , G. DeZotti , R. D. Davies

A number of very small isolated HII regions have been discovered at projected distances up to 30 kpc from their nearest galaxy. These HII regions appear as tiny emission line objects in narrow band images obtained by the NOAO Survey for…

天体物理学 · 物理学 2015-06-24 E. V. Ryan-Weber , G. R. Meurer , K. C. Freeman , M. E. Putman , R. L. Webster , the SINGG team

We present long-slit observations in the optical and near infrared of fourteen HII regions in the spiral galaxies: NGC 628, NGC 925, NGC 1232 and NGC 1637, all of them reported to have solar or oversolar abundances according to empirical…

天体物理学 · 物理学 2009-11-07 Marcelo Castellanos , Angeles Diaz , Elena Terlevich

We resolve the kinematic distance ambiguity for 266 inner Galaxy HII regions out of a sample of 291 using existing HI and 13CO sky surveys. Our sample contains all HII regions with measured radio recombination line (RRL) emission over the…

天体物理学 · 物理学 2008-12-18 L. D. Anderson , T. M. Bania

We present the first results of an ongoing project to investigate the present-day chemical abundances of the extreme outer parts of galactic disks, as probed by the emission line spectra of a new sample of HII regions. The galaxies studied…

天体物理学 · 物理学 2009-10-30 Annette M. N. Ferguson , Jay Gallagher , Rosemary F. G. Wyse

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…

宇宙学与河外天体物理 · 物理学 2015-05-20 Q. E. Goddard , F. Bresolin , R. C. Kennicutt , E. V. Ryan-Weber , F. F. Rosales-Ortega

We present a new catalog of HII regions in M31. The full disk of the galaxy is covered in a 2.2 deg^2 mosaic of 10 fields observed with the Mosaic Camera as part of the Local Group Galaxies survey. We used HIIphot, a code for automated…

宇宙学与河外天体物理 · 物理学 2015-05-30 Mohaddesseh Azimlu , Ryan Marciniak , Pauline Barmby

We have obtained optical spectrophotometry of 11 HII regions in the polar ring of NGC 2685 (the Helix galaxy), and have used these data to study the physical characteristics of the polar-ring HII regions. The HII regions have normal spectra…

天体物理学 · 物理学 2009-10-30 Paul B. Eskridge , Richard W. Pogge

We use the catalogue of HII regions obtained from a high quality continuum-subtracted H$\alpha$ image of the grand design spiral galaxy NGC 7479, to construct the luminosity function (LF) for the HII regions (over 1000) of the whole galaxy.…

天体物理学 · 物理学 2009-10-31 Almudena Zurita , Maite Rozas , John E. Beckman

We report subarcsecond-resolution VLA imaging of four nearby spiral galaxies: IC 342, Maffei II, NGC 2903, and NGC 6946. In each galaxy, compact radio continuum sources are identified in the central ~ 15" x 15" region. These compact sources…

天体物理学 · 物理学 2008-11-26 Chao-Wei Tsai , Jean L. Turner , Sara C. Beck , Lucian P. Crosthwaite , Paul T. P. Ho , David S. Meier , ;

Galactic HI emission profiles in an area where several large-scale filaments at velocities ranging from -46 km/s to 0 km/s overlap were decomposed into Gaussian components. Eighteen families of components defined by similarities of center…

星系天体物理 · 物理学 2015-06-15 Gerrit L Verschuur

The oxygen abundance gradients among nebular emission line regions in spiral galaxies have been used as important constraints for models of chemical evolution. We present the largest ever full-wavelength optical spectroscopic sample of…

宇宙学与河外天体物理 · 物理学 2013-10-17 Nathan Sanders , Nelson Caldwell , Jonathan McDowell , Paul Harding

A re-analysis of the radio continuum emission from circumnuclear regions of the barred galaxies NGC 1022, 1326 & 4314 is presented. The spatial distributions of Halpha and radio continuum are similar and suggest the existence of several…

天体物理学 · 物理学 2009-10-31 Jose Franco , J. Antonio Garcia-Barreto , Eduardo de la Fuente

As part of a large study to map the distribution of star formation across galactic disks, we have obtained deep Halpha images of the nearby Sculptor Group spirals NGC 247 and NGC 7793. These images are of sufficiently high quality that they…

天体物理学 · 物理学 2007-05-23 Annette M. N. Ferguson , Rosemary F. G. Wyse , J. S. Gallagher , Deidre A. Hunter

We present spatially-resolved spectroscopic observations of 10 isolated Galactic HII regions using data from the LAMOST Medium-Resolution Spectroscopic Survey of Nebulae (LAMOST MRS-N). The high spatial resolution of the data allows us to…