- ID:
- ivo://CDS.VizieR/J/A+A/659/A14
- Title:
- HI observations of the MATLAS dwarfs
- Short Name:
- J/A+A/659/A14
- Date:
- 25 Feb 2022 07:33:51
- Publisher:
- CDS
- Description:
- The presence of HI gas in galaxies is inextricably linked to their morphology and evolution. This paper aims to understand the HI content of the already identified 2210 dwarfs located in the low-to-moderate density environments of the MATLAS deep imaging survey. We combine the HI observations from the ATLAS3D survey, with the extragalactic HI sources from the ALFALFA survey, to extract the HI line width, velocity and mass of the MATLAS dwarfs. From the 1773 dwarfs in our sample with available HI observations, 8% (145) have an HI line detection. The majority of the dwarfs show irregular morphology, while 29% (42) are ellipticals, the largest sample of HI-bearing dwarf ellipticals (dEs) to date. Of the HI dwarf sample, 2% (3) are ultra-diffuse galaxies (UDGs), 12% have a transition-type morphology, 5% are tidal dwarf candidates, and 10% appear to be disrupted objects. In our optically selected sample, 9.5% of the dEs, 7% of the UDGs and 10% of the classical dwarfs are HI-bearing. The HI-bearing dwarfs have on average bluer colors than the dwarfs without detected HI. We find relations between the stellar and HI masses, gas fraction, color and absolute magnitude consistent with previous studies of dwarfs probing similar masses and environments. For 79% of the dwarfs identified as satellites of massive early-type galaxies, we find that the HI mass increases with the projected distance to the host. Using the HI line width, we estimate dynamical masses and find that 5% (7) of the dwarfs are dark matter deficient.
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Search Results
- ID:
- ivo://CDS.VizieR/VIII/73
- Title:
- HI Parkes All Sky Survey Catalogue (HIPASS)
- Short Name:
- VIII/73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The HI Parkes All-Sky Survey (HIPASS) Catalogue forms the largest uniform catalogue of HI sources compiled to date, with 4315 sources identified purely by their HI content. The catalogue data comprise the southern region DE<+2{deg} of HIPASS, the first blind HI survey to cover the entire southern sky. RMS noise for this survey is 13mJy/beam and the velocity range is -1280 to 12700km/s. Data search, verification and parametrization methods are discussed along with a description of measured quantities. Full catalogue data is made available to the astronomical community including positions, velocities, velocity widths, integrated fluxes and peak flux densities. Also available are on-sky moment maps, position- velocity moment maps and spectra of catalogue sources. A number of local large-scale features are observed in the space distribution of sources including the Super-Galactic plane and the Local Void. Notably, large-scale structure is seen at low Galactic latitudes, a region normally obscured at optical wavelengths.
- ID:
- ivo://CDS.VizieR/J/MNRAS/361/34
- Title:
- HIPASS catalogue. III.
- Short Name:
- J/MNRAS/361/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the largest catalogue to date of optical counterparts for H i radio-selected galaxies, HOPCAT. Of the 4315 H i radio-detected sources from the HI Parkes All Sky Survey (HIPASS) catalogue, we find optical counterparts for 3618 (84 per cent) galaxies. Of these, 1798 (42 per cent) have confirmed optical velocities and 848 (20 per cent) are single matches without confirmed velocities. Some galaxy matches are members of galaxy groups. From these multiple galaxy matches, 714 (16 per cent) have confirmed optical velocities and a further 258 (6 per cent) galaxies are without confirmed velocities. For 481 (11 per cent), multiple galaxies are present but no single optical counterpart can be chosen and 216 (5 per cent) have no obvious optical galaxy present. Most of these "blank fields" are in crowded fields along the Galactic plane or have high extinctions. Isolated "dark galaxy" candidates are investigated using an extinction cut of A_Bj_<1mag and the blank-fields category. Of the 3692 galaxies with an A+Bj_ extinction <1mag, only 13 are also blank fields. Of these, 12 are eliminated either with follow-up Parkes observations or are in crowded fields. The remaining one has a low surface brightness optical counterpart. Hence, no isolated optically dark galaxies have been found within the limits of the HIPASS survey.
- ID:
- ivo://CDS.VizieR/I/311
- Title:
- Hipparcos, the New Reduction
- Short Name:
- I/311
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A new reduction of the astrometric data as produced by the Hipparcos mission has been published, claiming accuracies for nearly all stars brighter than magnitude Hp=8 to be better, by up to a factor 4, than in the original catalogue. The new Hipparcos astrometric catalogue is checked for the quality of the data and the consistency of the formal errors as well as the possible presence of error correlations. The differences with the earlier publication are explained. Methods. The internal errors are followed through the reduction process, and the external errors are investigated on the basis of a comparison with radio observations of a small selection of stars, and the distribution of negative parallaxes. Error correlation levels are investigated and the reduction by more than a factor 10 as obtained in the new catalogue is explained. Results. The formal errors on the parallaxes for the new catalogue are confirmed. The presence of a small amount of additional noise, though unlikely, cannot be ruled out. Conclusions. The new reduction of the Hipparcos astrometric data provides an improvement by a factor 2.2 in the total weight compared to the catalogue published in 1997, and provides much improved data for a wide range of studies on stellar luminosities and local galactic kinematics.
- ID:
- ivo://CDS.VizieR/J/A+A/324/877
- Title:
- HI properties of spiral and irregular galaxies
- Short Name:
- J/A+A/324/877
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the analysis of neutral hydrogen properties of 108 galaxies, based on short 21-cm observations with the Westerbork Synthesis Radio Telescope (WSRT). The results of two HI surveys are analysed to investigate the existence of relations between optical and HI properties, like diameters, hydrogen masses and average surface densities. For all galaxies in our sample we find that the HI diameter, defined at a surface density level of 1M_{sun}_/pc^2^, is larger than the optical diameter, defined at the 25^th^mag/arcsec^2^ isophotal level. The Hi-to-optical-diameter ratio does not depend on morphological type or luminosity. The strongest, physically meaningful, correlation for the sample of 108 galaxies is the one between logM_HI_ and logD_HI_, with a slope of 2. This implies that the HI surface density averaged over the whole HI disc is constant from galaxy to galaxy, independent of luminosity or type. The radial HI surface density profiles are studied using the technique of principal component analysis. We find that about 81% of the variation in the density profiles of galaxies can be explained by two dimensions. The most dominant component can be related to "scale" and the second principal component accounts for the variance in the behaviour of the radial profile in the central parts of galaxies (i.e. "peak or depression") . The third component accounts for 7% of the variation and is most likely responsible for bumps and wiggles in the observed density profiles.
- ID:
- ivo://CDS.VizieR/J/MNRAS/460/2143
- Title:
- HI size-mass relation of galaxies
- Short Name:
- J/MNRAS/460/2143
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We revisit the HI size-mass (D_HII_-M_HI_) relation of galaxies with a sample of more than 500 nearby galaxies covering over five orders of magnitude in HI mass and more than 10 B-band magnitudes. The relation is remarkably tight with a scatter {sigma}~0.06dex, or 14 per cent. The scatter does not change as a function of galaxy luminosity, HI richness or morphological type. The relation is linked to the fact that dwarf and spiral galaxies have a homogeneous radial profile of HI surface density in the outer regions when the radius is normalized by D_HI_. The early-type disc galaxies typically have shallower HI radial profiles, indicating a different gas accretion history. We argue that the process of atomic-to-molecular gas conversion or star formation cannot explain the tightness of the D_HI_-M_HI_ relation. This simple relation puts strong constraints on simulation models for galaxy formation.
- ID:
- ivo://CDS.VizieR/VII/239A
- Title:
- History and Accurate Positions for the NGC/IC Objects
- Short Name:
- VII/239A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The files icpos.dat and ngcpos.dat are intended to provide a handy source for fairly accurate positions for the NGC/IC objects. They have only one entry per object, giving an unweighted mean position followed by the number of positions used in calculating that mean, the calculated standard deviations in RA and Dec, and the sources used. The precision to which the position is given reflects the precision of the most precise position in the full list. Note that precision does not necessarily reflect accuracy, especially with unweighted means. However, obvious blunders have been rejected, and many objects have enough accurately-measured positions now that overall accuracy will not suffer much from poor positions out on the wings of the "bell curve". Note also that the standard deviations reflect more accurately the uncertainties in the unweighted mean positions rather than the mean errors. Errors in published positions (see the "refs.dat" file) are almost always underestimated, so quoting the standard deviation increases the qualitative perception of the errors to about what they should be in an ideal world. Mean errors can be easily calculated by dividing the standard deviations by the square root of the number of positions used. Finally, these positions are on the FK5 system, and are not reduced to the International Celestial Reference Frame (ICRF). However, the FK5 optical system is consistent with ICRF to within the known errors of the older system (see Ma et al, 1998AJ....116..516M and references therein for more information about ICRF). The individual positions are reported in the files icdata.dat and ngcdata.dat. The files icnotes.txt and ngcnotes.txt contain discussions about ambiguous, non-existent or other mysterious NGC/IC objects. A detailed introduction to the contents of these discussion files can be found in the "ninotes.txt" file.
- ID:
- ivo://CDS.VizieR/J/MNRAS/467/1083
- Title:
- HIX galaxy survey. I.
- Short Name:
- J/MNRAS/467/1083
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the HI eXtreme (HIX) galaxy survey targeting some of the most HI rich galaxies in the Southern hemisphere. The 13 HIX galaxies have been selected to host the most massive HI discs at a given stellar luminosity. We compare these galaxies to a control sample of average galaxies detected in the HI Parkes All Sky Survey (HIPASS). As the control sample is matched in stellar luminosity, we find that the stellar properties of HIX galaxies are similar to the control sample. Furthermore, the specific star formation rate and optical morphology do not differ between HIX and control galaxies. We find, however, the HIX galaxies to be less efficient in forming stars. For the most HI massive galaxy in our sample (ESO075-G006, logM_HI_[M_{sun}_]=(10.8+/-0.1)), the kinematic properties are the reason for inefficient star formation and HI excess. Examining the Australian Telescope Compact Array (ATCA) HI imaging and Wide Field Spectrograph (WiFeS) optical spectra of ESO075-G006 reveals an undisturbed galaxy without evidence for recent major, violent accretion events. A tilted ring fitted to the HI disc together with the gas-phase oxygen abundance distribution supports the scenario that gas has been constantly accreted on to ESO075-G006 but the high specific angular momentum makes ESO075-G006 very inefficient in forming stars. Thus, a massive HI disc has been built up.
- ID:
- ivo://CDS.VizieR/J/MNRAS/476/3744
- Title:
- HIX galaxy survey. II.
- Short Name:
- J/MNRAS/476/3744
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- By analysing a sample of galaxies selected from the HI Parkes All Sky Survey (HIPASS) to contain more than 2.5 times their expected HI content based on their optical properties, we investigate what drives these HI eXtreme (HIX) galaxies to be so HI-rich. We model the HI kinematics with the Tilted Ring Fitting Code TiRiFiC and compare the observed HIX galaxies to a control sample of galaxies from HIPASS as well as simulated galaxies built with the semi-analytic model DARK SAGE. We find that (1) HI discs in HIX galaxies are more likely to be warped and more likely to host HI arms and tails than in the control galaxies, (2) the average HI and average stellar column density of HIX galaxies is comparable to the control sample, (3) HIX galaxies have higher HI and baryonic specific angular momenta than control galaxies, (4) most HIX galaxies live in higher spin haloes than most control galaxies. These results suggest that HIX galaxies are HI-rich because they can support more HI against gravitational instability due to their high specific angular momentum. The majority of the HIX galaxies inherits their high specific angular momentum from their halo. The HI content of HIX galaxies might be further increased by gas-rich minor mergers. This paper is based on data obtained with the Australia Telescope Compact Array through the large program C2705.
- ID:
- ivo://CDS.VizieR/J/A+A/635/A69
- Title:
- HIX galaxy survey. III.
- Short Name:
- J/A+A/635/A69
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents the analysis of optical integral field spectra for the HI eXtreme (HIX) galaxy sample. HIX galaxies host at least 2.5 times more atomic gas (HI) than expected from their optical R-band luminosity. Previous examination of their star formation activity and HI kinematics suggested that these galaxies stabilise their large HI discs (radii up to 94kpc) against star formation due to their higher than average baryonic specific angular momentum. A comparison to semi-analytic models further showed that the elevated baryonic specific angular momentum is inherited from the high spin of the dark matter host. In this paper we now turn to the gas-phase metallicity as well as stellar and ionised gas kinematics in HIX galaxies to gain insights on recent accretion of metal-poor gas or recent mergers. To do so we compare the stellar, ionised and atomic gas kinematics, and examine the variation of the gas-phase metallicity throughout the stellar disc of HIX galaxies. We find no indication for counter-rotation in any of the components, the central metallicities tend to be lower than average but as low as expected for galaxies of similar HI mass. Metallicity gradients are comparable to other less HI-rich, local star forming galaxies. We conclude that HIX galaxies show no conclusive evidence for recent major accretion or merger events. Their overall lower metallicities are likely due to them living in high spin halos, which slows down their evolution and thus enrichment of their interstellar medium.
