相关论文: HII galaxies as standard candles: evolutionary cor…

We present H-alpha and red continuum observations for a sample of late-type low surface brightness (LSB) dwarf irregular galaxies(DIGs), consisting of all the m_B<17.2 ImIV and V galaxies in the Virgo cluster (VC), and compare them with a…

The proposal to use HII galaxies (HIIGx) and giant extragalactic HII regions (GEHR) as standard candles to construct the Hubble diagram at redshifts beyond the current reach of Type Ia supernovae has gained considerable support recently…

We present a study of HI-rich galaxies in the local universe selected from blind emission-line surveys. These galaxies represent the emission-line counterparts of local damped Lyman-alpha systems. We find that the HI cross-section of…

We present the first results from a program of near-infrared spectroscopy aimed at studying the familiar rest-frame optical emission lines from the H II regions of Lyman break galaxies at z = 3. By targeting redshifts which bring the lines…

We present new Halpha+[NII] imaging data of late-type galaxies in the Herschel Reference Survey aimed at studying the star formation properties of a K-band-selected, volume-limited sample of nearby galaxies. The Halpha+[NII] data are…

We study the stellar population of galaxies with active star formation, determining ages of the stellar components by means of spectral population synthesis of their absorption spectra. The data consist of optical spectra of 185 nearby ($z…

(Abridged) We investigate optical and near-IR color gradients in a sample of 172 low-inclination galaxies spanning Hubble types S0--Irr. The colors are compared to stellar population synthesis models from which luminosity-weighted average…

We report on the strengths of three spectral indicators - Mg_2, Hbeta, and Hn/Fe - in the integrated light of a sample of 100 field and cluster E/S0 galaxies. The measured indices are sensitive to age and/or and metallicity variations…

The main objective of this work is to derive the distribution of the the metal content of HII galaxies using sulphur as an abundance tracer. This increases the metallicity range that can safely be reached. We selected a sample of…

In this paper we present measurements of velocity dispersions and Lick indices for 509 galaxies in the local Universe, based on high signal-to-noise, long slit spectra obtained with the 1.52 m ESO telescope at La Silla. The conversion of…

We study the relationship between the mid-IR (5-18 $\mu$m) emission of late-type galaxies and various other star formation tracers in order to investigate the nature of the dust heating sources in this spectral domain. The analysis is…

Large high-quality samples of HII regions and their parent Giant Molecular Clouds (GMC) are now available for local galaxies. It is therefore possible to investigate links between the CO and H$\alpha$ luminosity functions and whether…

We have identified the H-alpha absorption feature as a new spectroscopic diagnostic of luminosity class in K- and M-type stars. From high-resolution spectra of 19 stars with well-determined physical properties (including effective…

The [CII] 157.74 \mu m line is an important coolant for the neutral interstellar gas. Since [CII] is the brightest spectral line for most galaxies, it is a potentially powerful tracer of star formation activity. In this paper we present a…

We report an extremely tight, linear relation between ${\rm H\alpha}$ and [O~III] line fluxes in logarithm, discovered using a large sample of low and mid-resolution spectra (totaling 563) obtained by the James Webb Space Telescope (JWST)…

We present a calibration of the massive star formation rate vs. [CII] luminosity relation based on a sample of nearby, late-type galaxies observed with ISO-LWS and imaged in the Halpha+[NII] line. The relation holds for far-IR luminosities…

A study of star formation is carried out on 35 giant extragalactic HII regions (GEHRs) in seven galaxies using optical photometric data in BVR broad bands and in the emission line of H alpha. Interstellar extinction, metallicity and nebular…

As a result of a systematic NIR H-band (1.65 micron) imaging survey of normal galaxies in the local universe, we are able to measure in a highly homogeneous way photometric and structural properties for a sample of 1143 galaxies. We base…

The low column density gas at the outskirts of galaxies as traced by the 21 cm hydrogen line emission (HI) represents the interface between galaxies and the intergalactic medium, i.e., where galaxies are believed to get their supply of gas…

In this paper, we investigate the behaviour of the number of Lyman continuum ionizing photons as compared to the actual number of hydrogen recombinations in HII galaxies. We evaluate the number of ionizing photons from the population…