Related papers: Electron density distribution in HII regions in IC…
We aim to understand the contribution of the ionized, atomic and molecular phases of the ISM to the [CII] emission from clouds near the dynamical center and the BCLMP302 HII region in the north of the nearby galaxy M33 at a spatial…
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…
Auroral lines enable accurate measurements of chemical abundances in ionized gaseous nebulae thanks to their sensitivity to electron temperature. However, metal-enriched systems remain a challenge, as even deep observations cannot retrieve…
The most important cooling lines of the neutral interstellar medium (ISM) lie in the far-infrared (FIR). We present measurements by the Infrared Space Observatory Long Wavelength Spectrometer of seven lines from neutral and ionized ISM of…
Although variations in elemental abundance ratios in the Milky Way Galaxy certainly exist, details remain uncertain, particularly in the inner Galaxy, where stars and H II regions in the Galactic plane are obscured optically. In this paper…
We use the full-disk VLT-MUSE mosaic of NGC 253 to identify 2492 HII regions and study their resolved structure. With an average physical resolution of 17 pc, this is one of the largest samples of highly resolved spectrally mapped…
This paper presents [CII], [CI] and CO emission line maps of the star-forming regions N66, N25+N26, and N88 in the metal-poor Local Group dwarf galaxy SMC. The spatial and velocity structure of the large HII region N66 reveals an expanding…
We have obtained deep optical, long-slit spectrophotometry of the Galactic HII regions M 17, NGC 3576 and of the Magellanic Cloud HII regions 30 Doradus, LMC N11B and SMC N66, recording the optical recombination lines (ORLs) of CII, NII and…
Most observational studies of galactic-scale magnetic fields using Faraday rotation rely on estimates of thermal electron densities in galaxies and their radial variations. However, the spatial distribution of electrons in the interstellar…
We present results of the near-infrared (IR) spectroscopy of six quasars whose redshifts range from 0.158 to 1.084. Combined with the satellite ultraviolet data, the relative line strengths of OI 1304, OI 8446, OI 11287, and the near-IR…
We present results from Subaru/FMOS near-infrared (NIR) spectroscopy of 118 star-forming galaxies at $z\sim1.5$ in the Subaru Deep Field. These galaxies are selected as [OII]$\lambda$3727 emitters at $z\approx$ 1.47 and 1.62 from…
Context. The derived physical parameters for young HII regions are normally determined assuming the emission region to be optically thin. However, this assumption is unlikely to hold for young HII regions such as hyper-compact HII(HCHII)…
We report the results obtained from a multi-wavelength study of the HII region, G18.148$-$0.283, using the upgraded Giant Metre-wave Radio Telescope (uGMRT) at 1350 MHz along with other archival data. In addition to the radio continuum…
We present Very Large Telescope/Xshooter spectrophotometric observations of eleven low-redshift (z<0.085) compact star-forming galaxies (`high O32 sample'). These galaxies are characterised by extremely high emission-line ratios…
We present observations of the H-alpha, H-beta, [SII] 6716, 6731 and [NII] 6583 emission lines in the galactic HII region Sh2-235 with the Mapper of Narrow Galaxy Lines (MaNGaL), a tunable filter at the 1-m telescope of Special…
Recent radio surveys have revealed pulsars with dispersion and scattering delays induced by ionized gas that are larger than the rest of the observed pulsar population, in some cases with electron column densities (or dispersion measures;…
The emission line ratios [OIII]5007/H-beta and [NII]6584/H-alpha have been adopted as an empirical way to distinguish between the fundamentally different mechanisms of ionization in emission-line galaxies. However, detailed interpretation…
Electron fraction and cosmic-ray ionization rates (CRIR) in star-forming regions are important quantities in astrochemical modeling and are critical to the degree of coupling between neutrals, ions, and electrons, which regulates the…
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…
(Abridged) We present fine structure and recombination lines observations of the ionized gas toward a sample of 18 sources located within 300 pc of the center of the Galaxy (GC). The fine structure lines from [NII] and [SIII] have been…