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- 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/529/A149
- Title:
- HII regions in low-metallicity galaxies
- Short Name:
- J/A+A/529/A149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep spectroscopy of a large sample of low-metallicity emission-line galaxies. The main goal of this study is to derive element abundances in these low-metallicity galaxies. We analyze 121 VLT spectra of HII regions in 46 low-metallicity emission-line galaxies. Of these spectra 83 are archival VLT/FORS1+UVES spectra of HII regions in 31 low-metallicity emission-line galaxies that are studied for the first time with standard direct methods to determine the electron temperatures, the electron number densities, and the chemical abundances.
6325. H II regions in M 101
- ID:
- ivo://CDS.VizieR/J/ApJS/73/661
- Title:
- H II regions in M 101
- Short Name:
- J/ApJS/73/661
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A previous survey of the H II regions in M101 (Hodge and Kennicutt) has been extended by a series of CCD images and image tube plates of the galaxy, approximately tripling the number of known emission regions. This paper provides maps and a catalog of a total of 1264 H II regions in M101.
- 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.
6328. HII regions in NGC 628
- ID:
- ivo://CDS.VizieR/J/A+A/466/905
- Title:
- HII regions in NGC 628
- Short Name:
- J/A+A/466/905
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Properties of HII region populations in spiral galaxies provide important information about the physics of star formation as well as regional turbulent motions in the interstellar medium. We present a set of 376 photometrically calibrated HII regions in the nearby late-type spiral galaxy NGC 628. We have studies the mean velocity and velocity dispersion for the H-alpha-emitting gas in NGC 628 and found with widely distributed star formation in the disc plane. The H-alpha emission from the HII regions dominates any emission from the diffuse component in this galaxy.
6329. HII regions in NGC 6384
- ID:
- ivo://CDS.VizieR/J/other/Ap/50.426
- Title:
- HII regions in NGC 6384
- Short Name:
- J/other/Ap/50.42
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The galaxy NGC6384 has been observed with an IPCS through H{alpha} and [NII] narrow-band interference filters for direct imagery with the 2.6-m Byurakan telescope. We studied the main physical parameters of the identified 98 HII regions, their diameter and luminosity functions, as well the [NII]/H{alpha} ratio distribution.
- ID:
- ivo://CDS.VizieR/J/A+A/545/A43
- Title:
- HII regions in NGC 628 and NGC 6946
- Short Name:
- J/A+A/545/A43
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present here two HII region catalogues with azimuthal resolution for the two grand design galaxies NGC 628 and NGC 6946. With the help of these catalogues, we study several properties of the star-forming processes occurring in spiral galaxies. We obtained direct imaging in the narrow-band filters centred at H{alpha}, H{beta}, [OII]{lambda}3727, and [OIII]{lambda}{lambda}4959, 5007 and their respective continua. After the calibration and correction of the data, we obtained for each HII region the de-reddened fluxes in the aforementioned lines, the size, the H{alpha} equivalent width, and, using two different empirical calibrations, the metallicity. Employing a method based on the Delaunay triangulation, a two-dimensional (2D) representation of the metallicity was obtained.