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Related papers: Spatial distribution of Galactic HII regions

200 papers

Gas-phase abundances provide insights into the baryon cycle, with radial gradients and 2D metallicity distributions tracking how metals build up and redistribute within galaxy disks over cosmic time. We use a catalog of 22,958 HII regions…

Using ACS-HST images to yield continuum subtracted photometric maps in H\alpha of the Sbc galaxy M51 and the dwarf irregular galaxy NGC 4449, we produced extensive (over 2000 regions for M51, over 200 regions for NGC4449) catalogues of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Leonel Gutiérrez , John E. Beckman

We analyze line-of-sight atomic hydrogen (HI) line profiles of 31 nearby, low-mass galaxies selected from the Very Large Array - ACS Nearby Galaxy Survey Treasury (VLA-ANGST) and The HI Nearby Galaxy Survey (THINGS) to trace regions…

Using the HI Emission/Absorption method, we resolve the kinematic distance ambiguity and derive distances for 149 of 182 (82%) HII regions discovered by the Green Bank Telescope HII Region Discovery Survey (GBT HRDS). The HRDS is an X-band…

Astrophysics of Galaxies · Physics 2015-06-05 L. D. Anderson , T. M. Bania , Dana S. Balser , Robert T. Rood

Using HIPASS data, we have searched for HI in a ~25x25 sq.deg. region centred on the Fornax cluster. Within a velocity search range of 300 - 3700 km/s and a lower flux limit of ~40 mJy, 110 galaxies with HI emission were detected, one of…

We use observations of the neutral atomic hydrogen (HI) 21-cm emission line to study the spatial distribution of the HI gas in a 80$\degree\times~$90$\degree$ region of the Galaxy halo. The HI column densities in the range of…

Astrophysics of Galaxies · Physics 2017-09-20 Ericson López , Jairo Armijos , Mario Llerena , Franklin Aldás

We present a study of the filamentary structure in the atomic hydrogen (HI) emission at the 21 cm wavelength toward the Galactic plane using the observations in the HI4PI survey. Using the Hessian matrix method across radial velocity…

We present some developments in determining H-alpha distances to high-velocity clouds (HVCs) in the Galactic halo. Until recently, it was difficult to assess the nature and origin of HVCs because so little was known about them. But now…

Astrophysics · Physics 2007-05-23 J. Bland-Hawthorn , P. R. Maloney

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…

Astrophysics of Galaxies · Physics 2021-11-24 Dana S. Balser , Trey V. Wenger , L. D. Anderson , W. P. Armentrout , T. M. Bania , J. R. Dawson , John M. Dickey

We performed a spectroscopic survey of nearly 700 stars probing the galactic thick disc far from the solar neighbourhood towards the galactic coordinates (l~277, b~47). The derived effective temperatures, surface gravities and overall…

Astrophysics of Galaxies · Physics 2015-05-30 G. Kordopatis , A. Recio-Blanco , P. de Laverny , G. Gilmore , V. Hill , R. F. G. Wyse , A. Helmi , A. Bijaoui , M. Zoccali , O. Bienaymé

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

Very sensitive HI 21cm observations have been made in 860 directions at dec >= -43deg in search of weak, Galactic, high-velocity HI emission lines at moderate and high Galactic latitudes. One-third of the observations were made toward…

Astrophysics · Physics 2009-11-07 Felix J. Lockman , Edward M. Murphy , Sara Petty-Powell , Vincent J. Urick

We present deep optical spectroscopy of eight HII regions located in the anticentre of the Milky Way. The spectra were obtained at the 10.4m GTC and 8.2m VLT. We determined Te([NII]) for all objects and Te([OIII]) for six of them. We also…

Astrophysics of Galaxies · Physics 2017-08-16 C. Esteban , X. Fang , J. Garcia-Rojas , L. Toribio San Cipriano

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 present CCD images of a sample of 39 HII galaxies taken at the Danish 1.54m telescope on La Silla. The images are used to analyse the morphology of these emission line dwarfs, and the structural properties of the knots of star formation…

Astrophysics · Physics 2015-06-24 Eduardo Telles , Jorge Melnick , Roberto Terlevich

We use spectroscopic data from HST and FUSE to study the wide range of ionization states of the "highly ionized high-velocity clouds". Studied extensively in OVI absorption, these clouds are usually assumed to be infalling gas in the…

Astrophysics · Physics 2009-11-10 J. A. Collins , J. M. Shull , M. L. Giroux

We derive infrared and radio flux densities of all ~1000 known Galactic HII regions in the Galactic longitude range 17.5 < l < 65 degree. Our sample comes from the Wide-Field Infrared Survey Explorer (WISE) catalog of Galactic \hii regions…

Astrophysics of Galaxies · Physics 2017-09-06 Z. Makai , L. D. Anderson , J. L. Mascoop , B. Johnstone

We have tested the method of determining the solar Galactocentric distance R_0 and Galactic rotation velocity $V_0$ modified by Sofue et al. using near-solar-circle objects. The motion of objects relative to the local standard of rest has…

Astrophysics of Galaxies · Physics 2013-01-01 V. V. Bobylev

The distribution of metals within a galaxy traces the baryon cycle and the buildup of galactic disks, but the detailed gas phase metallicity distribution remains poorly sampled. We have determined the gas phase oxygen abundances for 7,138…

We present NOT optical observations of a clump (l = 127.9435 deg, b = +1.8298 deg), embedded in an extended, irregularly shaped, diffuse optical nebula. This condensation shows an emission-line spectrum typical of classic HII regions.…

Astrophysics · Physics 2009-11-10 S. Temporin , R. Weinberger