- ID:
- ivo://CDS.VizieR/J/A+AS/91/285
- Title:
- HII galaxies spectrophotometric catalogue
- Short Name:
- J/A+AS/91/285
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a spectrophotometric catalogue of 425 emission line galaxies discovered in objective prism surveys for which we derived redshifts, emission line intensities, equivalent widths, and absolute fluxes. The vast majority of objects in the catalogue are HII region-like galaxies (HII galaxies). In more than 80 HII galaxies the line [OIII]{lambda}4363 was measured with accuracy good enough to permit precise electron temperature determinations. The observational parameters that define the properties of HII galaxies as a class are characterized and discussed.
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- ID:
- ivo://CDS.VizieR/J/A+AS/139/1
- Title:
- HI in Byurakan blue compact galaxies
- Short Name:
- J/A+AS/139/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a neutral hydrogen survey of 79 galaxies from a statistical sample of 88 Blue Compact Galaxies (BCGs) selected from the First and Second Byurakan objective prism surveys to have a HII region-like spectrum, an equivalent width of the [O III] {lambda}5007 line larger than ~50{AA}, and a velocity <=6000km/s. The detection rate for the statistical sample is 74%. HI masses range between 4x10^7^M_{sun}_ and 5x10^9^M_{sun}_ with the HI mass distribution peaking at 3x10^8^M_{sun}_. The full width at half-maximum of the HI profile varies between ~30km/s and 160km/s, with a mean of ~92km/s. These small widths are characteristic of dwarf galaxies. For comparison, we have also observed an additional 92 BCGs with weaker star formation and/or larger distances, and/or interesting astrophysical properties. These in general have larger widths and HI masses.
- ID:
- ivo://CDS.VizieR/J/A+A/506/677
- Title:
- HI in Local Supercluster dwarf galaxies
- Short Name:
- J/A+A/506/677
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have observed 71 dwarf galaxies of low surface brightness using the 100-m radio telescope at Effelsberg in a search for new members of 27 northern galaxy groups with characteristic distances of 8 to 15Mpc. We present radial velocities, HI-fluxes, and HI line widths for 17 detected galaxies as well as upper limits for the remaining undetected objects.
- ID:
- ivo://CDS.VizieR/J/A+A/604/A43
- Title:
- HI in nearby radio sources
- Short Name:
- J/A+A/604/A43
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of the properties of neutral hydrogen (HI) in 248 nearby (0.02<z<0.25) radio galaxies with S_1.4GHz_>30mJy and for which optical spectroscopy is available. The observations were carried out with the Westerbork Synthesis Radio Telescope as the last large project before the upgrade of the telescope with phased array feed receivers (Apertif). The sample covers almost four orders of magnitude in radio power from logP_1.4GHz_=22.5W/Hz and 26.2W/Hz. We detect HI in absorption in 27%+/-5.5% of the objects. The detections are found over the full range of radio power. However, the distribution and kinematics of the absorbing HI gas appear to depend on radio power, the properties of the radio continuum emission, and the dust content of the sources. Among the sources where HI is detected, gas with kinematics deviating from regular rotation is more likely found as the radio power increases.In the great majority of these cases, the HI profile is asymmetric with a significant blue-shifted component. This is particularly common for sources with logP_1.4GHz_>24W/Hz, where the radio emission is small, possibly because these radio sources are young. The same is found for sources that are bright in the mid-infrared, i.e. sources rich in heated dust.In these sources, the HI is outflowing likely under the effect of the interaction with the radio emission. Conversely, in dust-poor galaxies, and in sources with extended radio emission, at all radio powers we only detect HI distributed in a rotating disk. Stacking experiments show that in sources for which we do not detect HI in absorption directly, the HI has a column density that is lower than 3.5x10^17^(T_spin_/c_f_)cm^-2^. We use our results to predict the number and type of HI absorption lines that will be detected by the upcoming surveys of the Square Kilometre Array precursors and pathfinders (Apertif, MeerKAT, and ASKAP).
- ID:
- ivo://CDS.VizieR/J/MNRAS/477/4152
- Title:
- H II region candidates in NGC628
- Short Name:
- J/MNRAS/477/4152
- Date:
- 17 Jan 2022 00:25:45
- Publisher:
- CDS
- Description:
- This is the first paper of a series dedicated to nebular physics and the chemical evolution of nearby galaxies by investigating large samples of H II regions with the Canada-France-Hawaii Telescope imaging spectrograph SITELLE (Spectro-Imageur a Transformee de Fourier pour l'Etude en Long et en Large des raies d'Emission). We present a technique adapted to imaging spectroscopy to identify and extract parameters from 4285 H II region candidates found in the disc of NGC 628. Using both the spatial and spectral capabilities of SITELLE, our technique enables the extraction of the position, dust extinction, velocity, H{alpha} profile, diffuse ionized gas (DIG) background, luminosity, size, morphological type, and the emission-line fluxes for individual spaxels and the integrated spectrum for each region. We have produced a well-sampled H II region luminosity function and studied its variation with galactocentric radius and level of the DIG background. We found a slope {alpha} of -1.12+/-0.03 with no evidence of a break at high luminosity. Based on the width of the region profile, bright regions are rather compact, while faint regions are seen over a wide range of sizes. The radius function reveals a slope of -1.81+/-0.02. BPT diagrams of the individual spaxels and integrated line ratios confirm that most detections are H II regions. Also, maps of the line ratios show complex variations of the ionization conditions within HII regions. All this information is compiled in a new catalogue for HII regions. The objective of this data base is to provide a complete sample which will be used to study the whole parameter space covered by the physical conditions in active star-forming regions.
- ID:
- ivo://CDS.VizieR/J/MNRAS/297/255
- Title:
- HII region catalogue of M100
- Short Name:
- J/MNRAS/297/255
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- From a new mosaic image in the H-{alpha} line of the complete disc of the spiral galaxy M100, a catalogue is composed listing 1948 individual HII regions. For each HII region, the catalogue gives its position relative to the centre of the galaxy, its deprojected distance to the centre, its radius, and its calibrated luminosity. An indication is included as to whether the HII region is located in the arms, between them, or in the circumnuclear star-forming region. The H-{alpha} image of M100 was obtained during two observing runs with the 4.2m WHT on La Palma, using the TAURUS camera in imaging mode. Since the field of view in this setup is limited by the filter size to around 5' diameter, four fields of the galaxy were imaged, two (eastern half of M100) during the night of 27 May 1991, and two (western half) during the night of 14 March 1992. Narrow band redshifted H-{alpha} filters with width of 15{AA} were used for the observations, centred at 6601{AA} for the H-{alpha} line observations (redshifted using the galaxy's systemic velocity of 1571km/s) and at 6577{AA} and 6565{AA} for the continuum. Exposure times were 1200 seconds for both the on-line and the continuum image on the first night, and 2x900 seconds on the second night. An EEV CCD chip was used during both observing runs, with a projected pixel size of 0.279arcsec, and a size of 1180x1280 pixels.
- ID:
- ivo://CDS.VizieR/J/A+AS/135/145
- Title:
- HII region catalogue of NGC 7479
- Short Name:
- J/A+AS/135/145
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- HII region catalogue of the barred galaxy NGC 7479. The catalogue contains the position, mean radius and the calibrated H-alpha luminosity of each HII region. The HII region catalogue has been composed using a new semi-automated technique applied to a high quality continuum-subtracted H-alpha image of the galaxy obtained from observations through the TAURUS camera in imaging mode with the 4.2m WHT on La Palma. An EEV CCD 7 detector was used with a projected pixel size of 0.279". More details about the reduction and the catalogue production procedures are given in the paper.
- 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".
- 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.
