相关论文: The flat oxygen abundance gradient in the extended…
The extended HI disk and tidal tails of M81 present an interesting environment to study the effects of galaxy interaction on star formation and chemical evolution of the outer disk of a large spiral galaxy. We present H{\alpha} imaging of…
Ultraviolet imaging with the Galaxy Evolution Explorer (GALEX) has revealed an extensive sample of UV-bright stellar complexes in the extreme outer disk of M83, extending to about four times the radius where the majority of HII regions are…
We present spectra obtained with the 10.4 m Gran Telescopio Canarias telescope of 13 Galactic HII regions, most of them of very low ionisation degree. The objects are located along the Galactic disc, with R_G from 5.7 to 16.1 kpc. We…
We present optical spectra of nine Galactic H II regions observed with the 10.4 m Gran Telescopio Canarias telescope and located at Galactocentric distances (RG) from 4 to 8 kpc. The distances of the objects have been revised using Gaia DR2…
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…
We present the results from the analysis of optical spectra of 31 Halpha-selected regions in the extended UV (XUV) disks of M83 (NGC5236) and NGC4625 recently discovered by GALEX. The spectra were obtained using IMACS at Las Campanas…
New optical spectra of 28 H II regions in the M101 disk have been obtained, yielding 10 new detections of the [O III]{\lambda}4363 auroral line. The oxygen abundance gradient measured from these data, combined with previous observations,…
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…
Spectra of 34 H II regions in the late-type galaxies NGC1087, NGC2967, NGC3023, NGC4030, NGC4123, and NGC4517A were observed with the South African Large Telescope (SALT). In all 34 H II regions, oxygen abundances were determined through…
We present a search for outlying HII regions in the extended gaseous outskirts of nearby (D < 40 Mpc) galaxies, and subsequent multi-slit spectroscopy used to obtain the HII region nebular oxygen abundances. The galaxies in our sample have…
Optical spectra of 25 H II regions in the inner two kpc of the M33 disk have been obtained with the GMOS spectrograph at the Gemini North telescope. The oxygen abundance gradient measured from the detection of the [O III]4363 auroral line…
We present deep spectrophotometry of 18 HII regions in the nearby massive spiral galaxies M101 and M31. We have obtained direct determinations of electron temperature in all the nebulae. We detect the CII 4267 line in several HII regions,…
To test the existence of a possible radial gradient in oxygen abundances within the Local Group dwarf irregular galaxy NGC 6822, we have obtained optical spectra of 19 nebulae with the EFOSC2 spectrograph on the 3.6-m telescope at ESO La…
The spectra of 413 star-forming (or HII) regions in M33 (NGC 598) were observed by using the multifiber spectrograph of Hectospec at the 6.5-m Multiple Mirror Telescope (MMT). By using this homogeneous spectra sample, we measured the…
Spectroscopic observations of 63 HII regions in six spiral galaxies (NGC 628, NGC 783, NGC 2336, NGC 6217, NGC 7331, and NGC 7678) were carried out with the 6-meter telescope (BTA) of Russian Special Astrophysical Observatory with the…
We investigate the oxygen and nitrogen abundance distributions across the optical disks of 130 nearby late-type galaxies using around 3740 published spectra of HII regions. We use these data in order to provide homogeneous abundance…
We present deep spectrophotometry of several Hii regions in the nearby low-mass spiral galaxies NGC 300 and M33. The data have been taken with UVES and OSIRIS spectrographs attached to the 8m VLT and 10.4m GTC telescopes, respectively. We…
This paper presents a spectroscopic investigation of 11 HII regions in the nearby galaxy NGC 2403. The HII regions are observed with a long-slit spectrograph mounted on the 2.16 m telescope at XingLong station of National Astronomical…
We present new HI observations of the nearby massive spiral galaxy M83, taken with the VLA at $21^{\prime\prime}$ angular resolution ($\approx500$ pc) of an extended ($\sim$1.5 deg$^2$) 10-point mosaic combined with GBT single dish data. We…
We present spectroscopic observations of a sample of 72 emission-line objects, including mainly HII regions, in the spiral galaxy M 33. Spectra were obtained with the multi-object, wide field spectrograph AF2/WYFFOS at the 4.2m WHT…