- ID:
- ivo://CDS.VizieR/J/A+A/354/823
- Title:
- HII region catalogue of NGC 3359
- Short Name:
- J/A+A/354/823
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- From an H-{alpha} image of the spiral barred galaxy NGC 3359, an HII region catalogue is composed. The catalogue comprises the position, mean radius and the calibrated H-alpha luminosity of each HII region. The observations of the image of NGC 3359 in H-{alpha} were carried out in February 1996, on the Isaac Newton telescope in La Palma in the context of the BARS international time project of the Canary Islands Observatories. A CCD TeK-7 detector was used with a projected pixel size of 0.59".
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- ID:
- ivo://CDS.VizieR/J/MNRAS/500/2359
- Title:
- HII region emission-line fluxes analysis
- Short Name:
- J/MNRAS/500/2359
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Studies of gas-phase radial metallicity profiles in spirals published in the last decade have diminished the importance of galactic bars as agents that mix and flatten the profiles, contradicting results obtained in the 1990s. We have collected a large sample of 2831 published HII region emission-line fluxes in 51 nearby galaxies, including objects both with and without the presence of a bar, with the aim of revisiting the issue of whether bars affect the radial metal distribution in spirals. In this first paper of a series of two, we present the galaxy and the HII region samples. The methodology is homogeneous for the whole data sample and includes the derivation of HII region chemical abundances, structural parameters of bars and discs, galactocentric distances, and radial abundance profiles. We have obtained O/H and N/O abundance ratios from the Te-based (direct) method for a sub-sample of 610 regions, and from a variety of strong-line methods for the whole HII region sample. The strong-line methods have been evaluated in relation to the Te-based one from both a comparison of the derived O/H and N/O abundances for individual HII regions, and a comparison of the abundance gradients derived from both methodologies. The median value and the standard deviation of the gradient distributions depend on the abundance method, and those based on the O3N2 indicator tend to flatten the steepest profiles, reducing the range of observed gradients. A detailed analysis and discussion of the derived O/H and N/O radial abundance gradients and y-intercepts for barred and unbarred galaxies is presented in the companion Paper II (Zurita et al., 2021MNRAS.500.2380Z). The whole HII region catalogue including emission-line fluxes, positions and derived abundances is made publicly available on the CDS VizieR facility, together with the radial abundance gradients for all galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/602/200
- Title:
- HII regions abundances in blue compact galaxies
- Short Name:
- J/ApJ/602/200
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use spectroscopic observations of a sample of 82 HII regions in 76 blue compact galaxies to determine the primordial helium abundance Yp and the slope dY/dZ from the Y-O/H linear regression. To improve the accuracy of the dY/dZ measurement, we have included new spectrophotometric observations of 33 HII regions that span a large metallicity range, with oxygen abundance 12+log(O/H) varying between 7.43 and 8.30 (Z_{sun}_/30<=Z<=Z_{sun}_/4). Most of the new galaxies were selected from the First Byurakan, the Hamburg/SAO, and the University of Michigan objective prism surveys.
- ID:
- ivo://CDS.VizieR/J/MNRAS/445/1412
- Title:
- HII regions and GMC in the Antennae
- Short Name:
- J/MNRAS/445/1412
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have combined observations of the Antennae galaxies from the radio interferometer ALMA (Atacama Large Millimeter/submillimeter Array) and from the optical interferometer GH{alpha}FaS (Galaxy H{alpha} Fabry-Perot System). The two sets of observations have comparable angular and spectral resolutions, enabling us to identify 142 giant molecular clouds (GMCs) and 303 HII regions. We have measured, and compared, their basic physical properties (radius, velocity dispersion, luminosity).
- ID:
- ivo://CDS.VizieR/J/ApJ/636/214
- Title:
- HII regions in dwarf irregular galaxies
- Short Name:
- J/ApJ/636/214
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present long-slit optical spectroscopy of 67 HII regions in 21 dwarf irregular galaxies to investigate the enrichment of oxygen, nitrogen, neon, sulfur, and argon in low-mass galaxies. Oxygen abundances are obtained via direct detection of the temperature-sensitive emission lines for 25 HII regions; for the remainder of the sample, oxygen abundances are estimated from strong-line calibrations. The direct abundance determinations are compared to the strong-line abundance calibrations of both McGaugh (1991ApJ...380..140M) and Pilyugin (2000A&A...362..325P).
- ID:
- ivo://CDS.VizieR/J/MNRAS/451/1307
- Title:
- HII regions in 10 galaxies
- Short Name:
- J/MNRAS/451/1307
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have observed 10 interacting galaxy pairs using the Fabry-Perot interferometer GH{alpha}FaS (Galaxy H{alpha} Fabry-Perot system) on the 4.2m William Herschel Telescope (WHT) at the Observatorio del Roque de los Muchachos, La Palma. We present here the H{alpha} surface brightness, velocity and velocity dispersion maps for the 10 systems we have not previously observed using this technique, as well as the physical properties (sizes, H{alpha} luminosities and velocity dispersion) of 1259 HII regions from the full sample. We also derive the physical properties of 1054 HII regions in a sample of 28 isolated galaxies observed with the same instrument in order to compare the two populations of HII regions. We find a population of the brightest HII regions for which the scaling relations, for example the relation between the H{alpha} luminosity and the radius, are clearly distinct from the relations for the regions of lower luminosity. The regions in this bright population are more frequent in the interacting galaxies. We find that the turbulence, and also the star formation rate, are enhanced in the HII regions in the interacting galaxies. We have also extracted the H{alpha} equivalent widths for the HII regions of both samples, and we have found that the distribution of HII region ages coincides for the two samples of galaxies. We suggest that the SFR enhancement is brought about by gas flows induced by the interactions, which give rise to gravitationally bound gas clouds which grow further by accretion from the flowing gas, producing conditions favourable to star formation.
- ID:
- ivo://CDS.VizieR/J/A+A/481/645
- Title:
- HII regions in interacting galaxies
- Short Name:
- J/A+A/481/645
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Studies of interacting galaxies have shown that dwarf galaxies may be produced in tidal tails during collisions. Numerical simulations suggest that the total detachment of the tidal dwarf requires the companion's mass to be comparable to or higher than that of the parent galaxy. This would imply that minor mergers (interaction between unequal mass galaxies) might not form tidal dwarf galaxies (TDGs). The objectives of the paper is to analyse the main properties of a sample of 116 HII regions previously selected from H{alpha} images of 11 minor mergers of galaxies and discuss the nature of these regions comparing their properties with those observed in HII regions in normal and isolated galaxies and TDG candidates. Individual parameters such as: blue absolute magnitude, MB, H{alpha} luminosity, L(H{alpha}), star formation rate, SFR(H{alpha}) and mass, M/M_{sun}_ of these regions were derived and compared with those of the HII regions in normal isolated galaxies, as well as in tidal dwarf candidates.
- ID:
- ivo://CDS.VizieR/J/other/RAA/14.1393
- Title:
- HII regions in interacting system Arp 86
- Short Name:
- J/other/RAA/14.1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of the metallicity and star formation activities of HII regions in the interacting system Arp 86, based on the first scientific observations using multi-object spectroscopy with the 2.16m telescope at the Xinglong Observing Station. We find that the oxygen abundance gradient in Arp 86 is flatter than that in normal disk galaxies, which confirms that gas inflows caused by tidal forces during encounters can flatten the metallicity distributions in galaxies. The companion galaxy NGC 7752 is currently experiencing a galaxy-wide starburst with a higher star formation rate surface density than the main galaxy NGC 7753, which can be explained in that the companion galaxy is more susceptible to the effects of interaction than the primary. We also find that the galaxy 2MASX J23470758+2926531 has similar abundance and star formation properties to NGC 7753, and may be a part of the Arp 86 system.
- ID:
- ivo://CDS.VizieR/J/A+A/428/837
- Title:
- HII regions in minor mergers of galaxies
- Short Name:
- J/A+A/428/837
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the B, V and I photometry of eleven southern minor mergers. The total apparent B magnitude, integrated B-V and V-I colours were measured. We built B, V, and I equivalent profiles for each galaxy and decomposed them into bulge and disk components when possible. From H{alpha}+N[II] images we have estimated the basic photometric parameters of the HII regions, such as position, size, B-V and V-I colours, H{alpha}+[NII] luminosity and EW(H{alpha}+[NII]) equivalent width.
- ID:
- ivo://CDS.VizieR/J/ApJS/105/93
- Title:
- H II Regions in Nearby Seyfert Galaxies
- Short Name:
- J/ApJS/105/93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Continuum-subtracted Halpha images of 17 nearby Seyfert galaxies are presented. The images are calibrated astrometrically using the Hubble Space Telescope Guide Star Catalog reference frame. For each galaxy, an inventory of H II regions detected using the COSMOS image classifier and centroider is provided. Salient features of each galaxy are described, including the distribution of the H II regions with reference to the galaxy morphology. Relevant abundance data from the literature are noted for each object. These images will find use as finding charts for follow-up spectrophotometric investigations of abundances, abundance gradients, and kinematics of H II regions in active galaxies, and for detailed studies of H II region populations in these objects.