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Related papers: Ultracompact HII Regions

200 papers

We use SCUBA 850 micron and CO observations to analyze the surroundings of three Galactic ring-like HII regions, KR 7, KR 81, and KR 120 (Sh 2-124, Sh 2-165 and Sh 2-187), with the aim of finding sites of triggered star formation. We find…

Astrophysics of Galaxies · Physics 2015-05-27 Kim Arvidsson , Charles R. Kerton

Using data from the all-sky Wide-Field Infrared Survey Explorer (WISE) satellite, we made a catalog of over 8000 Galactic HII regions and HII region candidates by searching for their characteristic mid-infrared (MIR) morphology. WISE has…

Astrophysics of Galaxies · Physics 2015-06-18 L. D. Anderson , T. M. Bania , Dana S. Balser , V. Cunningham , T. V. Wenger , B. M. Johnstone , W. P. Armentrout

We study the presence of low intensity high velocity components, which we have termed wing features in the integrated Halpha emission line profiles of the HII region populations of the spiral barred galaxies NGC 1530, NGC 3359 and NGC 6951.…

Astrophysics · Physics 2009-11-10 M. Relano , J. E. Beckman

We use narrow-band Halpha+[NII] imaging data gathered during VESTIGE, a blind survey of the Virgo cluster carried out with MegaCam at the CFHT, to identify HII regions in 385 galaxies showing ionised gas emission. We identify 76645 HII…

Astrophysics of Galaxies · Physics 2026-05-07 A. Boselli , M. Fossati , Y. Roehlly , M. Boquien , J. Braine , P. Cote , J. C. Cuillandre , B. Epinat , L. Ferrarese , S. Gwyn , G. Hensler

The scaling behaviour of the diffraction intensity near the origin is investigated for (partially) ordered systems, with an emphasis on illustrative, rigorous results. This is an established method to detect and quantify the fluctuation…

Metric Geometry · Mathematics 2021-06-15 Michael Baake , Uwe Grimm

This review is not a compendium of strong-line methods to derive abundances in giant HII regions. It is mostly intended for readers who wish to use such methods but do not have a solid background on the physics of HII regions. It is also…

Astrophysics of Galaxies · Physics 2019-08-09 Grazyna Stasinska

Near-infrared imaging of the emission from molecular hydrogen is a powerful method for discovering outflows in star-forming regions. We present new near-infrared images, long slit and integral field spectroscopy of the ultra-compact HII…

Astrophysics · Physics 2009-11-13 S. P. Todd , S. K. Ramsay Howat

We present a new model of the optical nebular emission from HII regions by combin- ing the results of the Binary Population and Spectral Synthesis (bpass) code with the photoion- ization code cloudy (Ferland et al. 1998). We explore a…

Astrophysics of Galaxies · Physics 2017-11-15 Lin Xiao , J. J. Eldridge , Elizabeth Stanway , L. Galbany

By collecting the information from 24 previously published lists and catalogs, we produce a comprehensive catalog (Master Catalog) of 1442 Galactic HII regions. For each object, we quote the original fluxes and diameters as well as the…

Mon R2, at a distance of 830 pc, is the only ultracompact HII region (UC HII) where the photon-dominated region (PDR) between the ionized gas and the molecular cloud can be resolved with Herschel. HIFI observations of the abundant compounds…

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

We report multi-frequency Very Large Array observations of three massive star formation regions (MSFRs) containing radio continuum components that were identified as broad radio recombination line (RRL) sources and hypercompact (HC) H II…

Astrophysics of Galaxies · Physics 2015-05-28 M. Sewilo , E. Churchwell , S. Kurtz , W. M. Goss , P. Hofner

We have carried out 21 cm radio continuum, H76_\alpha radio recombination line, and various (CO, ^13CO, CS, & C^34S) molecular line observations of the W31 complex. Our radio continuum data show that W31 is composed of two extended HII…

Astrophysics · Physics 2009-11-07 Kee-Tae Kim , Bon-Chul Koo

We present observations of the H91$\alpha$ recombination line emission towards a sample of nine HII regions associated with 6.7-GHz methanol masers, and report arcsecond-scale emission around compact cores. We derive physical parameters for…

Astrophysics · Physics 2009-11-11 Stanislav Shabala , Simon Ellingsen , Stan Kurtz , Larry Forbes

In this work we quantify the degree to which star-forming events are clumped. We apply a precise and accurate technique to calculate the correlation dimension Dc of the distribution of HII regions in a sample of disk galaxies. Our reliable…

Astrophysics · Physics 2010-11-08 Nestor Sanchez , Emilio J. Alfaro

Extremal elements and a h-hull of sets in the n-dimensional hypercomplex space are investigated. Introduced a class of H-quasiconvex sets including strongly hypercomplex convex sets and being closed with respect to intersections.

Metric Geometry · Mathematics 2015-10-05 M. V. Stefanchuk

HI spectral line mapping studies are a unique probe of morphologically peculiar systems. Not only does HI imaging often reveal peculiarities that are totally unsuspected at optical wavelengths, but it opens a kinematic window into the outer…

Astrophysics · Physics 2007-05-23 J. E. Hibbard

We analyze empirical relationships between the optical, near infrared, and HI characteristics of isolated galaxies from the 2MIG Catalog covering the entire sky. Data on morphological types, K_S-, and B-magnitudes, linear diameters, HI…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Yu. N. Kudrya , V. E. Karachentseva , I. D. Karachentsev

We investigate the possibility of constraining the ionization state of the intergalactic medium (IGM) close to the end of reionization (z ~ 6) by measuring the size of the HII regions in high-z quasars spectra. We perform a combination of…

Astrophysics · Physics 2008-11-26 A. Maselli , S. Gallerani , A. Ferrara , T. R. Choudhury

Spinning dust appears to be the best explanation for the anomalous emission that has been observed at $\sim 10-60$ GHz. One of the best examples of spinning dust comes from a HII region in the Perseus molecular cloud. Observations of other…

Astrophysics · Physics 2008-08-05 C. Dickinson