- ID:
- ivo://CDS.VizieR/J/A+A/386/140
- Title:
- HI survey of polar ring galaxies. IV.
- Short Name:
- J/A+A/386/140
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A total of 33 polar ring galaxies and polar ring galaxy candidates were observed in the 21-cm HI line with the 64-m Parkes radio telescope. The objects, selected by their optical morphology, are all south of declination -39{deg} and in only 5 of them had been reported previously. HI line emission was detected towards 18 objects, though in 3 cases the detection may be confused by another galaxy in the telescope beam, and one is a marginal detection. Eight objects were detected for the first time in HI, of which 5 did not have previously known redshifts.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/370/765
- Title:
- HI synthesis observations in UMa cluster
- Short Name:
- J/A+A/370/765
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this data paper we present the results of an extensive 21 cm-line synthesis imaging survey of 43 spiral galaxies in the nearby Ursa Major cluster using the Westerbork Synthesis Radio Telescope. Detailed kinematic information in the form of position-velocity diagrams and rotation curves is presented in an atlas together with HI channel maps, 21 cm continuum maps, global HI profiles, radial HI surface density profiles, integrated HI column density maps, and HI velocity fields. The relation between the corrected global HI linewidth and the rotational velocities Vmax and Vflat as derived from the rotation curves is investigated. Inclination angles obtained from the optical axis ratios are compared to those derived from the inclined HI disks and the HI velocity fields. The galaxies were not selected on the basis of their HI content but solely on the basis of their cluster membership and inclination which should be suitable for a kinematic analysis. The observed galaxies provide a well-defined, volume limited and equidistant sample, useful to investigate in detail the statistical properties of the Tully-Fisher relation and the dark matter halos around them.
- ID:
- ivo://CDS.VizieR/J/A+A/610/A20
- Title:
- HITEP. II. Transiting exoplanets imaging
- Short Name:
- J/A+A/610/A20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the second part of a high resolution imaging survey of hot Jupiter host stars. We search for binary companions to known transiting exoplanet host stars, in order to determine the multiplicity properties of hot Jupiter host stars. We also search for and characterise unassociated stars along the line of sight, allowing photometric and spectroscopic observations of the planetary system to be corrected for contaminating light.
- ID:
- ivo://CDS.VizieR/J/A+A/643/A36
- Title:
- HI-to-H2 transition in local diffuse ISM dataset
- Short Name:
- J/A+A/643/A36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The amount of data collected by spectrometers from radio to ultraviolet (UV) wavelengths opens a new era where the statistical and chemical information contained in the observations can be used concomitantly to investigate the thermodynamical state and the evolution of the interstellar medium (ISM). In this paper, we study the statistical properties of the HI-to-H_2_ transition observed in absorption in the local diffuse and multiphase ISM. Our goal is to identify the physical processes that control the probability of occurrence of any line of sight and the origins of the variations of the integrated molecular fraction from one line of sight to another. The turbulent diffuse ISM is modeled using the RAMSES code, which includes detailed treatments of the magnetohydrodynamics, the thermal evolution of the gas, and the chemistry of H_2_. The impacts of the UV radiation field, the mean density, the turbulent forcing, the integral scale, the magnetic field, and the gravity on the molecular content of the gas are explored through a parametric study that covers a wide range of physical conditions. The statistics of the HI-to-H_2_ transition are interpreted through analytical prescriptions and compared with the observations using a modified and robust version of the Kolmogorov-Smirnov test. The analysis of the observed background sources shows that the lengths of the lines of sight follow a flat distribution in logarithmic scale from ~100pc to ~3kpc. Without taking into account any variation of the parameters along a line of sight or from one line of sight to another, the results of one simulation, convolved with the distribution of distances of the observational sample, are able to simultaneously explain the position, the width, the dispersion, and most of the statistical properties of the HI-to-H_2_ transition observed in the local ISM. The tightest agreement is obtained for a neutral diffuse gas modeled over ~200pc, with a mean density n_H_=1-2cm^-3^, illuminated by the standard interstellar UV radiation field, and stirred up by a large-scale compressive turbulent forcing. Within this configuration, the 2D probability histogram of the column densities of H and H_2_, poetically called the kingfisher diagram, is remarkably stable and is almost unaltered by gravity, the strength of the turbulent forcing, the resolution of the simulation, or the strength of the magnetic field B_x_, as long as B_x_<4{mu}G. The weak effect of the resolution and our analytical prescription suggest that the column densities of HI are likely built up in large-scale warm neutral medium and cold neutral medium (CNM) structures correlated in density over ~20pc and ~10pc, respectively, while those of H_2_ are built up in CNM structures between ~3 and ~10pc. Combining the chemical and statistical information contained in the observations of HI and H_2_ sheds new light on the study of the diffuse matter. Applying this new tool to several atomic and molecular species is a promising perspective to understanding the effects of turbulence, magnetic field, thermal instability, and gravity on the formation and evolution of molecular clouds.
6415. Hitomi Master Catalog
- ID:
- ivo://nasa.heasarc/hitomaster
- Title:
- Hitomi Master Catalog
- Short Name:
- HITOMASTER
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table records high-level information for the observations obtained with Hitomi and provides access to the data archive. The Hitomi mission was launched on a JAXA H-IIA into low Earth orbit on February 17, 2016, at 5:45 pm JPS from Tanegashima Space Center. Hitomi was equipped with four different instruments that together cover a wide energy range 0.3-600 keV. The Soft X-ray Spectrometer (SXS), which combined a lightweight Soft X-ray Telescope paired with a X-ray Calorimeter Spectrometer, provided non-dispersive 7-eV resolution in the 0.3-10 keV bandpass with a field of view of about 3 arcminutes. The Soft X-ray Imager (SXI) expanded the field of view with a new generation CCD camera in the energy range of 0.5-12 keV at the focus of the second lightweights Soft X-ray Telescope; the Hard X-ray Imager (HXI, two units) performed sensitive imaging spectroscopy in the 5-80 keV band; the non-imaging Soft Gamma-ray Detector (SGD, two units) extended Hitomi's energy band to 600 keV. On March 27, 2016, JAXA lost contact with the satellite and, on April 28, announced the cessation of the efforts to restore mission operations. At that time Hitomi was in check-out phase and had started the calibration observations. Data were collected from six celestial objects (Perseus, N132D, IGR_J16318-4848, RXJ1856.5-3754, G21.5-0.9, and Crab) as well as black sky for a total of about one month of data. The data from these observations were divided into intervals of one day if the observation of a specific pointing was longer that one day. A sequence number was assigned to each observing day and within data from all instruments are included. The day division was mainly to limit the data size within a sequence number. There are in total 42 sequences, and each record in this database table is dedicated to a single sequence. The early observations do not contain data from all instruments and in cases the object was not always placed at the aim point. This database contains parameters to indicate which instrument was on and if the celestial source was in the field of view. The SXS was the first instrument to turn on and therefore all observations contain SXS data, although the thermal equilibrium was reached after March 4 2016. The second instrument was the SXI followed by the HXIs and, finally, the two SGDs. This database table was generated at the Hitomi Science Data Center processing site (Angelini, L., Terada, Y, et al., 2016, SPIE 9905E, 14) with additions to indicate which instrument was on and if the source was in the FOV. It was ingested into the HEASARC database in June 2017. This is a service provided by NASA HEASARC .
6416. HIX galaxy survey. I.
- 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.
6417. HIX galaxy survey. II.
- 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.
6418. HIX galaxy survey. III.
- 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.
- ID:
- ivo://CDS.VizieR/J/ApJ/832/99
- Title:
- HK', CN & CH chemical indexes in NGC 362 & NGC 6723
- Short Name:
- J/ApJ/832/99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Most globular clusters (GCs) are now known to host multiple stellar populations with different abundances of light elements. Here we use narrow-band photometry and low-resolution spectroscopy for NGC 362 and NGC 6723 to investigate their chemical properties and radial distributions of subpopulations. We confirm that NGC 362 and NGC 6723 are among the GCs with multiple populations showing bimodal CN distribution and CN-CH anticorrelation without a significant spread in calcium abundance. These two GCs show more centrally concentrated CN-weak, earlier generation stars compared to the CN-strong, later generation stars. These trends are reversed with respect to those found in previous studies for many other GCs. Our findings, therefore, seem contradictory to the current scenario for the formation of multiple stellar populations, but mass segregation acting on the two subpopulations might be a possible solution to explain this reversed radial trend.
6420. HKE Sydney Catalog
- ID:
- ivo://CDS.VizieR/I/73
- Title:
- HKE Sydney Catalog
- Short Name:
- I/73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The methods for constructing a catalogue of 20457 star positions for the epoch 1964 between -48 and -58{deg} declination are described. The positions were obtained by the overlap method, and images generated by a coarse diffraction grating were employed to control magnitude-related effects on the position. A selection of about 2 faint Astrographic Catalog (AC) stars per square degree was included to serve as material for the eventual determination of magnitude effects on the AC positions. The standard error of a catalogued position estimate based on 2 images is 0.12'' in either coordinate.