- ID:
- ivo://CDS.VizieR/J/A+AS/117/39
- Title:
- Hickson Compact Groups of Galaxies I.
- Short Name:
- J/A+AS/117/39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Far Infrared (FIR) properties of galaxies which are members of compact groups bear relevant information on the dynamical status and the physical properties of these structures. All studies published so far have been undermined by the poor sensitivity and spatial resolution of the IRAS-PSC and IRAS Sky Survey data. We used the HIRAS software available at the IRAS server at the Laboratory for Space Research in Groningen to fully exploit the redundancy of the IRAS data and to approach the theoretical diffraction limit of IRAS. Among the 97 groups which were observed by IRAS, 62 were detected in at least one band, while reliable upper limits were derived for all the others. Among the detected groups, 49 were fully or partially resolved, i.e. it was possible to discriminate which member or members emit most of the FIR light. At 60{mu}m, for instance, 87 individual sources were detected in 62 groups. In order to ease the comparison with data obtained at other wavelengths - and in particular in the X and radio domains - we give co-added and HIRAS maps for all the detected groups.
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- ID:
- ivo://CDS.VizieR/VII/213
- Title:
- Hickson's Compact groups of Galaxies
- Short Name:
- VII/213
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog of groups (file "groups.dat") is a list of 100 compact groups of galaxies identified by a systematic search of the Palomar Observatory Sky Survey red prints. Each group contains four or more galaxies, has an estimated mean surface brightness brighter than 26.0 magnitude per arcsec^2^ and satisfies an isolation criterion. Dynamical parameters were derived for 92 of the 100 groups, which are listed in file "dynamics.dat"; the Hubble constant was assumed to be Ho=100km/s/Mpc. Data about individual galaxies in these groups are merged into the "galaxies.dat" file; these data include photometric parameters, morphology, redshifts and absolute magnitudes originally published in four different papers. They result from CCD observations at CFHT (Canada-France-Hawaii Telescope) in 1983-1985. Redshifts were observed at the 1.5m telescope of the F.L. Whipple Observatory on Mt. Hopkins, Arizona, over the period 1984-1986, in wavelength range 470-710nm; the remaining fainter galaxies were observed with the CFHT.
- ID:
- ivo://CDS.VizieR/J/AJ/157/241
- Title:
- HI clouds in LITTLE THINGS dwarf irregular galaxies
- Short Name:
- J/AJ/157/241
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We identify 814 discrete H I clouds in 40 dwarf irregular galaxies from the LITTLE THINGS survey using an automated cloud-finding algorithm. The cloud masses range from ~10^3^ to 10^7^ M_{sun}_, have a surface density averaged over all of the clouds of ~9.65 M_{sun}_/pc^2^, and constitute 2%-53% of the total H I mass of the host galaxy. For individual clouds, the mass including He varies with cloud radius as logM_gas_=(2.11+/-0.04)xlogR_cl_+(0.78+/-0.08) and the internal velocity dispersion varies as logV_disp_=0.5xlogR_cl_-0.57+/-0.21. The H I clouds tend to be in the outer regions of the galaxies, with 72% of the galaxies having more than 70% of their clouds outside one disk scale length and 32% of the galaxies having more than 50% of their clouds outside the radius encircling the H II emission. Thirty-six percent of the clouds are essentially non-self-gravitating from H I alone, with a virial parameter that exceeds {alpha}_vir_~10, and 5% have {alpha}_vir_=<2. We estimate the missing molecular mass, based on the total star formation rate and a typical molecular consumption time of 2 Gyr, as observed in CO-rich galaxies. The resulting molecular fraction has a value averaged over the galaxies of 0.23 and correlates with both the surface density of star formation and the fraction of H I clouds in the outer regions. We conclude that a significant fraction of the inner parts of these dwarf galaxy disks is in the form of dark molecular gas, and that this fraction could be high enough to make the inner disks mildly gravitationally unstable as a precursor to star formation.
- ID:
- ivo://CDS.VizieR/J/MNRAS/465/588
- Title:
- HI 21-cm absorption survey of QSO-galaxy pairs
- Short Name:
- J/MNRAS/465/588
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results from our survey of HI 21-cm absorption, using Giant Metrewave Radio Telescope, Very Large Array and Westerbork Radio Synthesis Telescope, in a sample of 55 z<0.4 galaxies towards radio sources with impact parameters (b) in the range ~0-35kpc. In our primary sample (defined for statistical analyses) of 40 quasar-galaxy pairs, probed by 45 sightlines, we have found seven HI 21-cm absorption detections, two of which are reported here for the first time. Combining our primary sample with measurements having similar optical depth sensitivity ({int}{tau}dv<=0.3km/s) from the literature, we find a weak anti-correlation (rank correlation coefficient =-0.20 at 2.42{sigma} level) between {int}{tau}dv and b, consistent with previous literature results. The covering factor of HI 21-cm absorbers (C21) is estimated to be 0.24^+0.12^_-0.08_ at b<=15kpc and 0.06^+0.09^_-0.04_ at b=15-35kpc. {int}{tau}dv and C_21_ show similar declining trend with radial distance along the galaxy's major axis and distances scaled with the effective HI radius. There is also tentative indication that most of the HI 21-cm absorbers could be co-planar with the extended HI discs. No significant dependence of {int}{tau}dv and C_21_ on galaxy luminosity, stellar mass, colour and star formation rate is found, though the HI 21-cm absorbing gas cross-section may be larger for the luminous galaxies. The higher detection rate (by a factor of ~4) of HI 21-cm absorption in z<1 damped Lyman-{alpha} systems compared to the quasar-galaxy pairs indicates towards small covering factor and patchy distribution of cold gas clouds around low-z galaxies.
- ID:
- ivo://CDS.VizieR/J/AJ/133/1104
- Title:
- HI 21cm observations of Pegasus galaxies
- Short Name:
- J/AJ/133/1104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present neutral hydrogen observations of 54 galaxies in the Pegasus Cluster. The observations include single-dish HI measurements, obtained with the Arecibo telescope for all 54 galaxies in the sample, as well as HI images obtained with the Very Large Array (VLA) for 10 of these.
- ID:
- ivo://CDS.VizieR/J/A+A/650/A76
- Title:
- HI content in Coma cluster substructure
- Short Name:
- J/A+A/650/A76
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Galaxy clusters are some of largest structures in the universe. These very dense environments tend to be home to higher numbers of evolved galaxies than found in lower-density environments. It is well known that dense environments can influence the evolution of galaxies through the removal of the neutral gas (HI) reservoirs that fuel star formation. It is unclear which environment has a stronger effect: the local environment (i.e. the substructure within the cluster), or the cluster itself. Using the new HI data from the Westerbork Coma Survey, we explore the average HI content of galaxies across the cluster comparing galaxies that reside in substructure to those that do not. We applied the Dressler-Shectman test to our newly compiled redshift catalogue of the Coma cluster to search for substructure. With so few of the Coma galaxies directly detected in HI, we used the HI stacking technique to probe the average HI content below what can be directly detected. Using the Dressler-Shectman test, we find 15 substructures within the footprint of the Westerbork Coma Survey. We compare the average HI content for galaxies within substructure to those not in substructure. Using the HI stacking technique, we find that those Coma galaxies not detected in HI are more than 10-50 times more HI deficient than expected, which supports the scenario of an extremely efficient and rapid quenching mechanism. By studying the galaxies that are not directly detected in HI, we also find Coma to be more HI deficient than previously thought.
- ID:
- ivo://CDS.VizieR/J/MNRAS/447/1531
- Title:
- HI data collection update
- Short Name:
- J/MNRAS/447/1531
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Cosmic Flows is an international multi-element project with the goal to map motions of galaxies in the local Universe. Kinematic information from observations in the radio HI line and photometry at optical or near-infrared bands are acquired to derive the large majority of distances that are obtained through the luminosity-linewidth or Tully-Fisher relation. This paper gathers additional observational radio data, frequently unpublished, retrieved from the archives of Green Bank, Parkes and Arecibo telescopes. Extracted HI profiles are consistently processed to produce linewidth measurements. Our current 'All-Digital HI Catalog' contains a total of 20343 HI spectra for 17738 galaxies with 14 802 galaxies with accurate linewidth measurement useful for Tully-Fisher galaxy distances. This addition of 4117 new measurements represents an augmentation of 34 percent compared to our last release.
- ID:
- ivo://CDS.VizieR/J/A+A/587/L3
- Title:
- HI datacubes if Pisces A and B
- Short Name:
- J/A+A/587/L3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Pisces A and Pisces B are the only two galaxies found via optical imaging and spectroscopy out of 22 HI clouds identified in the GALFAHI survey as dwarf galaxy candidates. We derive the HI content and kinematics of Pisces A and B. Our aperture synthesis HI observations used the seven-dish Karoo Array Telescope (KAT-7), which is a pathfinder instrument for MeerKAT, the South African precursor to the mid-frequency Square Kilometre Array (SKA-MID).
- ID:
- ivo://CDS.VizieR/J/A+A/582/A18
- Title:
- HI data cubes of 4 edge-on spiral galaxies
- Short Name:
- J/A+A/582/A18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Edge-on galaxies can offer important insight into galaxy evolution because they are the only systems where the distribution of the different components can be studied both radially and vertically. The HEROES project was designed to investigate the interplay between the gas, dust, stars, and dark matter (DM) in a sample of 7 massive edge-on spiral galaxies. In this second HEROES paper, we present an analysis of the atomic gas content of 6 out of 7 galaxies in our sample. The remaining galaxy was recently analysed according to the same strategy. The primary aim of this work is to constrain the surface density distribution, the rotation curve, and the geometry of the gas disks in a homogeneous way. In addition we identify peculiar features and signs of recent interactions. We have constructed detailed tilted-ring models of the atomic gas disks based on new GMRT 21-cm observations of NGC 973 and UGC 4277 and re-reduced archival HI data of NGC 5907, NGC 5529 IC 2531, and NGC 4217. Potential degeneracies between different models were resolved by requiring good agreement with the data in various representations of the data cubes. From our modelling we find that all but one galaxy are warped along the major axis. In addition, we identify warps along the line of sight in three galaxies. A flaring gas layer is required to reproduce the data for only one galaxy, but (moderate) flares cannot be ruled out for the other galaxies either. A coplanar ring-like structure is detected outside the main disk of NGC 4217, which we suggest could be the remnant of a recent minor merger event. We also find evidence of a radial inflow of 15 +/-5km/s in the disk of NGC 5529, which might be related to the ongoing interaction with two nearby companions. For NGC 5907 the extended, asymmetric, and strongly warped outer regions of the HI disk also suggest a recent interaction. In contrast, the inner disks of these three galaxies (NGC 4217, NGC 5529, and NGC 5907) show regular behaviour and seem largely unaffected by the interactions. Our models further support earlier claims of prominent spiral arms in the disks of IC 2531 and NGC 5529. Finally, we detect a dwarf companion galaxy at a projected distance of 36 kpc from the centre of NGC 973.
- ID:
- ivo://CDS.VizieR/J/A+A/113/61
- Title:
- HI data for 392 spiral galaxies
- Short Name:
- J/A+A/113/61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- 392 spiral galaxies with type Sb or later have been detected in the 21-cm line of neutral hydrogen with the Nancay radiotelescope, and among them 172 HI fluxes are obtained for the first time. The source of any possible bias has been carefully analyzed and only the Malmquist bias appears to be significant. In order to obviate this observational effect, the range of radial velocities has been properly truncated for all statistical studies. A mean value of each global parameter has been determined for each morphological type and compared to previous results.
