Related papers: A Spectral Diagnostic for Density-Bounded HII Regi…
The spectra of AGN from the ultraviolet to the near infrared, exhibit emission lines covering a wide range of ionisation states, from neutral species such as [O I] 6300A, up to [Fe XIV] 5303A. Here we report on some recent studies of the…
In order to investigate the contribution of diffuse components to their total HI emission, we have obtained high precision HI line flux densities with the 100m Green Bank Telescope for a sample of 100 isolated spiral and irregular galaxies…
We have obtained deep Hubble Space Telescope far-UV images of 15 starburst galaxies at z~1.3 in the GOODS fields to search for escaping Lyman continuum photons. These are the deepest far-UV images m_{AB}=28.7, 3\sigma, 1" diameter) over…
The TYPHOON program is producing an atlas of spectroscopic data cubes of 44 large-angular-sized galaxies with complete spatial coverage from 3650-9000 A. This survey provides an unparalleled opportunity to study variations in the…
We derive the synchrotron distribution in the Milky Way disk from HII region absorption observations over -40{\deg} < l < 40{\deg} at six frequencies of 76.2, 83.8, 91.5, 99.2, 106.9, and 114.6 MHz with the GaLactic and Extragalactic…
Observations indicate that some extended outer disks have a sharp cut off in the surface density of neutral hydrogen when this approaches the value of $\sim 2\times 10^{19}$ cm$^{-2}$. In this paper we model these HI edges as places where…
The southern Galactic high mass star-forming region, G351.6-1.3, is a HII region-molecular cloud complex with a luminosity of 2.0 x 10^5 L_sun, located at a distance of 2.4 kpc. In this paper, we focus on the investigation of the associated…
We have used the images from the ACS on HST in Halpha, and in the neighboring continuum, to produce flux calibrated images of the large spiral galaxy M51, and the dwarf irregular NGC 4449. From these images we have derived the absolute…
In this paper we present the results of observations of seventeen HII regions in thirteen galaxies from the SIGRID sample of isolated gas rich irregular dwarf galaxies. The spectra of all but one of the galaxies exhibit the auroral [OIII]…
In this work we analyze the spectroscopic properties of a large number of H ii regions, \sim2600, located in 38 galaxies. The sample of galaxies has been assembled from the face-on spirals in the PINGS survey and a sample described in…
We present high spectral-resolution optical spectra of 49 Herbig Ae/Be stars in a search for the [O I] 6300A line. The vast majority of the stars in our sample show narrow (FWHM < 100 km/s) emission lines, centered on the stellar radial…
We propose an innovative method for measuring the neutral hydrogen (HI) content of an optically-selected spectroscopic sample of galaxies through cross-correlation with HI intensity mapping measurements. We show that the HI-galaxy…
We use the optical integral field observations with Multi-Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope, together with CLOUDY photoionization models to study ionization structure and physical conditions of two luminous HII…
A population of early star-forming galaxies is the leading candidate for the re-ionization of the universe. It is still unclear what conditions and physical processes would enable a significant fraction of the ionizing photons to escape…
We analyze the distribution of the interstellar matter in the environs of the HII region Gum31, excited by the open cluster NGC3324, located in the complex Carina region, with the aim of investigating the action of the massive stars on the…
At redshifts beyond z>6, as the mean fraction of neutral hydrogen x_HI in the intergalactic medium (IGM) increases, the line flux of Lyman alpha (Lya) emitters can be significantly suppressed, which can result in a decrease in the observed…
(ABRIDGED) We present an analysis of NGC588 based on IFS data with PMAS, together with Spitzer images at 8 mi and 24 mi. The extinction distribution in the optical shows complex structure, with maxima correlating in position with those of…
We present spectroscopic observations of FIR fine-structure lines of 26 Seyfert galaxies obtained with the Herschel-PACS spectrometer. These observations are complemented by spectroscopy with Spitzer-IRS and Herschel-SPIRE. The ratios of…
We present a set of photoionization models that reproduce simultaneously the observed optical and mid-infrared spatial distribution of the HII region NGC595 in the disk of M33 using the code CLOUDY. Both optical (PMAS-Integral Field…
We present spectrophotometry in the 3600-9700 A region for a sample of 39 H II regions in the Galaxy and Magellanic Clouds, for which independent information is available on the spectral types and effective temperatures of the ionizing…