- ID:
- ivo://CDS.VizieR/J/ApJ/753/62
- Title:
- Kinematic distance ambiguity in HII regions
- Short Name:
- J/ApJ/753/62
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using H I absorption spectra from the International Galactic Plane Survey, a new method is implemented to resolve the kinematic distance ambiguity for 75 H II regions with known systemic velocities from radio recombination lines. A further 40 kinematic distance determinations are made for H II region candidates without known systemic velocities through an investigation of the presence of H I absorption around the terminal velocity. New kinematic distance determinations can be used to further constrain spiral arm parameters and the location and extent of other structures in the Milky Way disk. H I absorption toward continuum sources beyond the solar circle is also investigated. Follow-up studies of H I at higher resolution than the 1' to 2' of existing Galactic Plane Surveys will provide kinematic distances to many more H II regions on the far side of the Galactic center. On the basis of the velocity channel summation technique developed in this paper, a much larger sample of H II regions will be analyzed in a future paper to remove the near-far distance ambiguity.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/668/94
- Title:
- Kinematics across the Hubble sequence
- Short Name:
- J/ApJ/668/94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The correlation between the maximum rotational velocity of the disk (vm) and the central stellar velocity dispersion of the bulge (sigma0) offers insights into the relationship between the halo and the bulge. We have assembled integrated HI line widths and central stellar velocity dispersions to study the vm-sigma0 relation for 792 galaxies spanning a broad range of Hubble types.
- ID:
- ivo://CDS.VizieR/J/A+A/599/A104
- Title:
- Kinematics of the Local Universe. XVI.
- Short Name:
- J/A+A/599/A104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents 828 new 21-cm neutral hydrogen line measurements carried out with the FORT receiver of the meridian transit Nancay radio telescope (NRT) in the years 2000-2007. This observational program was part of a larger project aiming at collecting an exhaustive and magnitude-complete HI extragalactic catalog for Tully-Fisher applications. Through five massive data releases, the KLUN series has collected an homogeneous sample of 4876 HI-spectra of spiral galaxies, complete down to a flux of 5Jy.km/s and with declination {delta}>-40^{deg}. We publish here the last release of the KLUN HI observational program, corresponding to the faint end of the survey, with HI masses ranging from 5x10^8^ to 5x10^10^ solar masses. The size of this final sample is comparable to the catalogs based on the Arecibo and Parkes radio telescope campaigns, and it allows general HI-mass distribution studies from a set of homogeneous radio measurements.
- ID:
- ivo://CDS.VizieR/J/A+A/547/A12
- Title:
- Leading arm Magellanic Cloud Catalog
- Short Name:
- J/A+A/547/A12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Magellanic Cloud system (MCS) interacts via tidal and drag forces with the Milky Way galaxy. Using the Parkes Galactic All-Sky Survey (GASS) of atomic hydrogen we explore the role of drag on the evolution of the so-called Leading Arm (LA).
- ID:
- ivo://CDS.VizieR/VIII/76
- Title:
- Leiden/Argentine/Bonn (LAB) Survey of Galactic HI
- Short Name:
- VIII/76
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The LAB survey contains the final data release of observations of 21-cm emission from Galactic neutral hydrogen over the entire sky, merging the Leiden/Dwingeloo Survey (LDS: Hartmann & Burton 1997, Cat. VIII/54) of the sky north of -30{deg} with the Instituto Argentino de Radioastronomia Survey (IAR: Arnal et al. 2000A&AS..142...35A and Bajaja et al. 2005, Cat. VIII/75) of the sky south of -25{deg}. The angular resolution of the combined material is HPBW ~ 0.6{deg}. The LSR velocity coverage spans the interval -450 km/s to +400 km/s, at a resolution of 1.3km/s. The data were corrected for stray radiation at the Institute for Radioastronomy of the University of Bonn, refining the original correction applied to the LDS. The rms brightness-temperature noise of the merged database is 0.07-0.09 K. Residual errors in the profile wings due to defects in the correction for stray radiation are for most of the data below a level of 20-40 mK. It would be necessary to construct a telescope with a main beam efficiency of {eta}MB>99% to achieve the same accuracy. The merged and refined material entering the LAB Survey of Galactic H I is intended to be a general resource useful to a wide range of studies of the physical and structural characteristices of the Galactic interstellar environment. The LAB Survey is the most sensitive Milky Way H I survey to date, with the most extensive coverage both spatially and kinematically. The Survey is available as 3-D maps, with or without Hanning smoothing, covering the whole +/-458km/s or limited to +/-250km/s range. The resolution of the 3-D maps is 0.5{deg} in galactic longitude and latitude, and up to 1km/s in velocity. The survey exists also as (b,v) maps at longitude intervals stepped by 0.5{deg} -- these files supersedes the FITS files given in the Hartmann and Burton Atlas (Cat. VIII/54)
- ID:
- ivo://CDS.VizieR/J/AJ/160/66
- Title:
- LITTLE THINGS catalog of HI holes in 41 galaxies
- Short Name:
- J/AJ/160/66
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of holes and shells in the neutral atomic hydrogen (HI) of 41 gas-rich dwarf galaxies in LITTLE THINGS (Local Irregulars That Trace Luminosity Extremes, The HI Nearby Galaxy Survey). We analyzed their properties as part of an investigation into the relation between star formation and structures and kinematics in the HI of small galaxies. We confirmed 306 holes between 38pc (our resolution limit) and 2.3kpc, with expansion velocities up to 30km/s. The global star formation rates (SFRs) measured by H{alpha} and far-UV (FUV) emission are consistent with those estimated from the energy required to create the cataloged holes in our sample. Although we found no obvious correlation between global star forming regions (SFRs) and the HI surface and volume porosities of our sample, two of the four galaxies with the lowest porosity and the two galaxies with the highest porosity have no recent star formation as measured by H{alpha} and FUV emission.
- ID:
- ivo://CDS.VizieR/J/AJ/144/134
- Title:
- LITTLE THINGS survey of nearby dwarf galaxies
- Short Name:
- J/AJ/144/134
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present LITTLE THINGS (Local Irregulars That Trace Luminosity Extremes, The HI Nearby Galaxy Survey), which is aimed at determining what drives star formation in dwarf galaxies. This is a multi-wavelength survey of 37 dwarf irregular and 4 blue compact dwarf galaxies that is centered around HI-line data obtained with the National Radio Astronomy Observatory (NRAO) Very Large Array (VLA). The HI-line data are characterized by high sensitivity ({<=}1.1mJy/beam per channel), high spectral resolution ({<=}2.6km/s), and high angular resolution (~6"). The LITTLE THINGS sample contains dwarf galaxies that are relatively nearby ({<=}10.3Mpc; 6" is {<=}300pc), that were known to contain atomic hydrogen, the fuel for star formation, and that cover a large range in dwarf galactic properties. We describe our VLA data acquisition, calibration, and mapping procedures, as well as HI map characteristics, and show channel maps, moment maps, velocity-flux profiles, and surface gas density profiles. In addition to the HI data we have GALEX UV and ground-based UBV and H{alpha} images for most of the galaxies, and JHK images for some. Spitzer mid-IR images are available for many of the galaxies as well. These data sets are available online.
- ID:
- ivo://CDS.VizieR/J/A+A/632/A106
- Title:
- LMC-N11 (LHA 120-N11) [CII], HI, CO spectra
- Short Name:
- J/A+A/632/A106
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ambiguous origin of the [CII] 158um line in the interstellar medium complicates its use for diagnostics concerning the star-formation rate and physical conditions in photodissociation regions. We investigate the origin of [CII] in order to measure the total molecular gas content, the fraction of CO-dark H_2_ gas, and how these parameters are impacted by environmental effects such as stellar feedback. We observed the giant HII region N 11 in the Large Magellanic Cloud with SOFIA/GREAT. The [CII] line is resolved in velocity and compared to HI and CO, using a Bayesian approach to decompose the line profiles. A simple model accounting for collisions in the neutral atomic and molecular gas was used in order to derive the H_2_ column density traced by C^+^. The profile of [CII] most closely resembles that of CO, but the integrated [CII] line width lies between that of CO and that of HI. Using various methods, we find that [CII] mostly originates from the neutral gas. We show that [CII] mostly traces the CO-dark H_2_ gas but there is evidence of a weak contribution from neutral atomic gas preferentially in the faintest components (as opposed to components with low [CII]/CO or low CO column density). Most of the molecular gas is CO-dark. The CO-dark H_2_ gas, whose density is typically a few 100s/cm^3^ and thermal pressure in the range 10^3.5-5^K/cm^3^, is not always in pressure equilibrium with the neutral atomic gas. The fraction of CO-dark H_2_ gas decreases with increasing CO column density, with a slope that seems to depend on the impinging radiation field from nearby massive stars. Finally we extend previous measurements of the photoelectric-effect heating efficiency, which we find is constant across regions probed with Herschel, with [CII] and [OI] being the main coolants in faint and diffuse, and bright and compact regions, respectively, and with polycyclic aromatic hydrocarbon emission tracing the CO-dark H_2_ gas heating where [CII] and [OI] emit. We present an innovative spectral decomposition method that allows statistical trends to be derived for the molecular gas content using CO, [CII], and HI profiles. Our study highlights the importance of velocity-resolved photodissociation region (PDR) diagnostics and higher spatial resolution for HI observations as future steps.
- ID:
- ivo://CDS.VizieR/J/MNRAS/478/1611
- Title:
- Local Volume H I Survey (LVHIS)
- Short Name:
- J/MNRAS/478/1611
- Date:
- 19 Jan 2022 11:54:59
- Publisher:
- CDS
- Description:
- The 'Local Volume HI Survey' (LVHIS) comprises deep HI spectral line and 20-cm radio continuum observations of 82 nearby, gas-rich galaxies, supplemented by multiwavelength images. Our sample consists of all galaxies with Local Group velocities v_LG_<550km/s or distances D<10Mpc that are detected in the HI Parkes All Sky Survey (HIPASS). Using full synthesis observations in at least three configurations of the Australia Telescope Compact Array (ATCA), we obtain detailed HI maps for a complete sample of gas-rich galaxies with {delta}~-30{deg}. Here we present a comprehensive LVHIS galaxy atlas, including the overall gas distribution, mean velocity field, velocity dispersion, and position-velocity diagrams, together with a homogeneous set of measured and derived galaxy properties. Our primary goal is to investigate the HI morphologies, kinematics, and environment at high resolution and sensitivity. LVHIS galaxies represent a wide range of morphologies and sizes; our measured HI masses range from ~10^7^ to 10^10^M_{sun}_, based on independent distance estimates.
- ID:
- ivo://CDS.VizieR/J/ApJ/653/240
- Title:
- Low-mass SDSS dwarf galaxy properties
- Short Name:
- J/ApJ/653/240
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the gas content and baryonic Tully-Fisher relationship for extremely low luminosity dwarf galaxies in the absolute magnitude range -13.5>M_r_-5logh_70_>-16. The sample is selected from the Sloan Digital Sky Survey and consists of 101 galaxies for which we have obtained follow-up HI observations using the Arecibo Observatory and Green Bank Telescope. This represents the largest homogeneous sample of dwarf galaxies at low luminosities with well-measured HI and optical properties. The sample spans a range of environments, from dense groups to truly isolated galaxies.
