Search

Start Over Subject h i line emission Content Level Research
241. SDSS-DR8 isolated low-mass galaxies
ID:
ivo://CDS.VizieR/J/ApJ/809/146
Title:
SDSS-DR8 isolated low-mass galaxies
Short Name:
J/ApJ/809/146
Date:
21 Oct 2021
Publisher:
CDS
Description:
We study the baryon content of low-mass galaxies selected from the Sloan Digital Sky Survey (SDSS DR8), focusing on galaxies in isolated environments where the complicating physics of galaxy-galaxy interactions are minimized. We measure neutral hydrogen (HI) gas masses and line widths for 148 isolated galaxies with stellar mass between 10^7^ and 10^9.5^M_{sun}_. We compare isolated low-mass galaxies to more massive galaxies and galaxies in denser environments by remeasuring HI emission lines from the Arecibo Legacy Fast ALFA survey 40% data release. All isolated low-mass galaxies either have large atomic gas fractions or large atomic gas fractions cannot be ruled out via their upper limits. We measure a median atomic gas fraction of f_gas_=0.81+/-0.13 for our isolated low-mass sample with no systems below 0.30. At all stellar masses, the correlations between galaxy radius, baryonic mass, and velocity width are not significantly affected by environment. Finally, we estimate a median baryon to total dynamical mass fraction of f_baryon,disk_=0.15+/-0.17. We also estimate two different median baryon to halo mass fractions using the results of semi-analytic models (f_baryon,disk_=0.04+/-0.06) and abundance matching (f_baryon,halo_=0.04+/-0.02). Baryon fractions estimated directly using HI observations appear independent of environment and maximum circular velocity, while baryon fractions estimated using abundance matching show a significant depletion of baryons at low maximum circular velocities.
242. SDSS-III DR9 DLA catalogue
ID:
ivo://CDS.VizieR/J/A+A/547/L1
Title:
SDSS-III DR9 DLA catalogue
Short Name:
J/A+A/547/L1
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a study of the column density distribution and cosmological mass density of neutral gas from a survey of Damped Lyman-alpha systems in the Sloan Digital Sky Survey III Data Release 9.
243. SDSS photometry of HI-selected galaxies
ID:
ivo://CDS.VizieR/J/MNRAS/394/340
Title:
SDSS photometry of HI-selected galaxies
Short Name:
J/MNRAS/394/340
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have used the Parkes Multibeam system and the Sloan Digital Sky Survey to assemble a sample of 195 galaxies selected originally from their HI signature to avoid biases against unevolved or low surface brightness objects. For each source nine intrinsic properties are measured homogeneously, as well as inclination and an optical spectrum. The sample, which should be almost entirely free of either misidentification or confusion, includes a wide diversity of galaxies ranging from inchoate, low surface brightness dwarfs to giant spirals. Despite this diversity there are five clear correlations among their properties. They include a common dynamical mass-to-light ratio within their optical radii, a correlation between surface brightness and luminosity and a common HI surface density. Such correlation should provide strong constrains on models of galaxy formation and evolution.
244. SDSS post-merger galaxies HI data
ID:
ivo://CDS.VizieR/J/MNRAS/478/3447
Title:
SDSS post-merger galaxies HI data
Short Name:
J/MNRAS/478/3447
Date:
10 Dec 2021 00:08:38
Publisher:
CDS
Description:
We present a detailed assessment of the global atomic hydrogen gas fraction (f_gas_=log[M_HI_/M*) in a sample of post-merger galaxies identified in the Sloan Digital Sky Survey (SDSS). Archival HI measurements of 47 targets are combined with new Arecibo observations of a further 51 galaxies. The stellar mass range of the post-merger sample, our observing strategy, detection thresholds and data analysis procedures replicate those of the extended GALEX Arecibo SDSS Survey (xGASS) which can therefore be used as a control sample. Our principal results are (1) the post-merger sample shows a ~50 per cent higher HI detection fraction compared with xGASS; (2) accounting for non-detections, the median atomic gas fraction of the post-merger sample is larger than the control sample by 0.3-0.6dex; and (3) the median atomic gas fraction enhancement ({Delta}f_gas_), computed on a galaxy-by-galaxy basis at fixed stellar mass, is 0.51dex. Our results demonstrate that recently merged galaxies are typically a factor of ~3 more HI rich than control galaxies of the same M* If the control sample is additionally matched in star formation rate, the median H I excess is reduced to {Delta}f_gas_=0.2dex, showing that the enhanced atomic gas fractions in post-mergers are not purely a reflection of changes in star formation activity. We conclude that merger-induced starbursts and outflows do not lead to prompt quenching via exhaustion/expulsion of the galactic gas reservoirs. Instead, we propose that if star formation ceases after a merger, it is more likely due to an enhanced turbulence which renders the galaxy unable to effectively form new stars.
245. SDSS, WISE and HI data of local spiral galaxies
ID:
ivo://CDS.VizieR/J/ApJ/884/82
Title:
SDSS, WISE and HI data of local spiral galaxies
Short Name:
J/ApJ/884/82
Date:
21 Oct 2021
Publisher:
CDS
Description:
The emerging light from a galaxy is under the influence of its own interstellar medium, as well as its spatial orientation. Considering a sample of 2239 local spiral galaxies in optical (Sloan Digital Sky Survey u, g, r, i, and z) and infrared bands (WISE W1, W1), we study the dependency of the global intrinsic attenuation in spiral galaxies on their morphologies, sizes, and spatial inclinations. Reddening is minimal at the extremes of low mass and gas depletion and maximal in galaxies that are relatively massive and metal-rich and still retain substantial gas reserves. A principal component constructed from observables that monitor galaxy mass, relative H i content to old stars, and infrared surface brightness is strongly correlated with the amplitude of obscuration. We determine both a parametric model for dust obscuration and a nonparametric model based on the Gaussian process formalism. An average dust attenuation curve is derived for wavelengths between 0.36 and 4.5{mu}m.
246. Second list of the Karachentsev catalog
ID:
ivo://CDS.VizieR/J/A+AS/147/187
Title:
Second list of the Karachentsev catalog
Short Name:
J/A+AS/147/187
Date:
21 Oct 2021
Publisher:
CDS
Description:
Table2 presents the results of HI observations of 78 'nearby dwarf galaxies' from Karachentseva et al. (1999A&AS..135..221K) obtained with the 100-m radio telescope at Effelsberg. This survey covers an area limited by R.A.[14h,23h30] and Dec[-20d,+60d] including the nearest cosmic void : R.A.[18h38m], Dec[+18d], V_0_<1500km/s.
247. SFI++ II. A new I-band Tully-Fisher catalog
ID:
ivo://CDS.VizieR/J/ApJS/172/599
Title:
SFI++ II. A new I-band Tully-Fisher catalog
Short Name:
J/ApJS/172/599
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the SFI++ data set, a homogeneously derived catalog of photometric and rotational properties and the Tully-Fisher distances and peculiar velocities derived from them. We make use of digital optical images, optical long-slit spectra, and global HI line profiles to extract parameters of relevance to disk scaling relations, incorporating several previously published data sets as well as a new photometric sample of some 2000 objects. According to the completeness of available redshift samples over the sky area, we exploit both a modified percolation algorithm and the Voronoi-Delaunay method to assign individual galaxies to groups as well as clusters, thereby reducing scatter introduced by local orbital motions. We also provide corrections to the peculiar velocities for both homogeneous and inhomogeneous Malmquist bias, making use of the 2MASS Redshift Survey density field to approximate large-scale structure. The final SFI++ peculiar velocity catalog contains 4861 field and cluster galaxies.
248. SIGRID galaxy sample
ID:
ivo://CDS.VizieR/J/AJ/142/83
Title:
SIGRID galaxy sample
Short Name:
J/AJ/142/83
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using an optically unbiased selection process based on the HIPASS neutral hydrogen survey, we have selected a sample of 83 spatially isolated, gas-rich dwarf galaxies in the southern hemisphere with cz between 350 and 1650km/s, and with R-band luminosities and HI masses less than that of the Small Magellanic Cloud. The sample is an important population of dwarf galaxies in the local universe, all with ongoing star formation, and most of which have no existing spectroscopic data. We are measuring the chemical abundances of these galaxies, using the integral-field spectrograph on the Australian National University 2.3m telescope, the Wide-Field Spectrograph. This paper describes our survey criteria and procedures, lists the survey sample, and reports on initial observations.
249. Small-scale structures in HI hole of M33
ID:
ivo://CDS.VizieR/J/A+A/229/362
Title:
Small-scale structures in HI hole of M33
Short Name:
J/A+A/229/362
Date:
21 Oct 2021
Publisher:
CDS
Description:
Recent high-resolution HI observations of M33 reveal a large number of regions that are devoid of emission. We interpret these regions as holes formed by interstellar winds; a catalogue containing 148 of these HI holes has been compiled. Their diameters range from the survey resolution limit (>40pc) to 1kpc. The swept-up mass, estimated from surrounding HI densities, ranges from 10^3^M_{sun}_ to 10^7^M_{sun}_. Energies needed to excavate such holes are between 10^49^ to 10^54^erg. Indicative ages, based on derived expansion velocities and diameters, show a cutoff near 7x10^6^yr. Three statistical analysis techniques are applied to determine positional correlation of the H I holes with H II regions, OB associations, and supernova remnants.
250. SMC HI shells velocities
ID:
ivo://CDS.VizieR/J/MNRAS/289/225
Title:
SMC HI shells velocities
Short Name:
J/MNRAS/289/225
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of a survey of neutral hydrogen emission in the Small Magellanic Cloud (SMC) with the Australia Telescope Compact Array (ATCA). The survey consists of a mosaic of 320 separate pointings of the 375-m array, resulting in a resolution of 1.6arcmin (28pc, for a distance of 60kpc) over a field of 20deg^2^. The rms brightness temperature sensitivity is 1.4K, corresponding to an H I column density sensitivity of 4x^18^cm^-2^ for each velocity channel of width 1.6km/s. The HI distribution is complex and, on scales <=1kpc, appears to be dominated by the effects of expanding H I shells, which are probably driven by the combined effects of supernovae and stellar winds from massive stars. The picture of the SMC that arises from the current data seems to challenge the earlier belief that the SMC consists of two or more spatially separate structures with different systemic velocities. We find that the observed multiple components are, in many cases, caused by the combined effects of the numerous shells and supershells. Altogether, we identify six supershells (defined here as those with radii greater than 300pc) and 495 giant shells. For each of these, we measure positions. radii, velocities and expansion rates, and derive ages and kinetic energy requirements. The apparent age distribution of shells is remarkably narrow, with a mean age of 5.4Myr and an intrinsic dispersion of 2Myr. Southern shells appear to be older, on average, by 2.5Myr. The kinetic energy of the shells is a large fraction of the gravitational binding energy of the SMC, implying that further disintegration of the SMC will occur with time, and especially at the next close passage with the Large Magellanic Cloud (LMC) or the Galaxy, unless the SMC possesses a massive halo. Because of their interferometric nature, the images presented here are insensitive to structures of size >=0.6{deg}, and should not be used for deriving total H I column densities

Limit your search

more »

  • 2286