The Westerbork HI survey of spiral and irregular galaxies

Swaters, R. A.; Albada, T. S. van; Hulst, J. M. van der; Sancisi, R.

doi:10.1051/0004-6361:20011755

Cited by 313 publications

(421 citation statements)

References 30 publications

Supporting

Mentioning

391

Contrasting

Unclassified

Order By: Relevance

“…The trend with M K is inverted; the most luminous galaxies contain the largest amount of gas, but the lowest relative gas content. Correlations with total luminosity, morphological type, and color are consistent with overall trends along the Hubble sequence and these trends are well known from previous studies (Roberts & Haynes 1994;Broeils & Rhee 1997;Verheijen & Sancisi 2001;Swaters et al 2002). The linear fits to the correlations are presented in the figure panels, as well as the Spearman rank-order coefficient (r s ) of the relations, calculated following Paper VIII.…”

Section: Hi Massessupporting

confidence: 86%

“…Others point out the diversity in the radial behavior of Σ HI (R) in galaxies with a wide range of global properties (e.g., Verheijen & Sancisi 2001). Swaters et al (2002) found that the outer part of the Σ HI (R) profile in many late-type dwarf galaxies can be well fitted with an exponential decrease, and it can be argued that spiral galaxies in general should display a similar exponential profile at the outer radii. Here, we parameterize the typical radial behavior of Σ HI (R) and study its dependence on global photometric and kinematic properties of the galaxies.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The DiskMass Survey

Martinsson

Verheijen

Bershady³

et al. 2015

A&A

View full text Add to dashboard Cite

We present results from 21 cm radio synthesis imaging of 28 spiral galaxies from the DiskMass Survey obtained with the VLA, WSRT, and GMRT facilities. We detail the observations and data reduction procedures and present a brief analysis of the radio data. We construct 21 cm continuum images, global Hi emission-line profiles, column-density maps, velocity fields, and position-velocity diagrams. From these we determine star formation rates (SFRs), Hi line widths, total Hi masses, rotation curves, and azimuthallyaveraged radial Hi column-density profiles. All galaxies have an Hi disk that extends beyond the readily observable stellar disk, with an average ratio and scatter of R HI /R 25 = 1.35±0.22, and a majority of the galaxies appear to have a warped Hi disk. A tight correlation exists between total Hi mass and Hi diameter, with the largest disks having a slightly lower average column density. Galaxies with relatively large Hi disks tend to exhibit an enhanced stellar velocity dispersion at larger radii, suggesting the influence of the gas disk on the stellar dynamics in the outer regions of disk galaxies. We find a striking similarity among the radial Hi surface density profiles, where the average, normalized radial profile of the late-type spirals is described surprisingly well with a Gaussian profile. These results can be used to estimate Hi surface density profiles in galaxies that only have a total Hi flux measurement. We compare our 21 cm radio continuum luminosities with 60 μm luminosities from IRAS observations for a subsample of 15 galaxies and find that these follow a tight radio-infrared relation, with a hint of a deviation from this relation at low luminosities. We also find a strong correlation between the average SFR surface density and the K-band surface brightness of the stellar disk.

show abstract

Section: Hi Massessupporting

confidence: 86%

Section: Introductionmentioning

confidence: 99%

The DiskMass Survey

Martinsson

Verheijen

Bershady³

et al. 2015

A&A

View full text Add to dashboard Cite

show abstract

“…Note that f Ã also depends on the amount of metals present in dwarf galaxies, but the effects of metallicity will be smaller than the 2 orders-of-magnitude difference in f Ã . Figure 4 shows the distributions of exponential scale radii R d and central surface densities AE 0 for our model galaxies based on the standard model, compared with those for five BCDs by van Zee et al (1998) and a number of late-type dwarf galaxies by Swaters et al (2002). The scale radii and the surface densities of our model galaxies with M d ¼ 10 8 M and ¼ 0:035 and with M d ¼ 10 9 M and ¼ 0:05 at collapse redshift z ¼ 0 are consistent with the observed distributions.…”

Section: Modeling the Star Formation Ratementioning

confidence: 99%

The Influence of Supershells and Galactic Outflows on the Escape of Ionizing Radiation from Dwarf Starburst Galaxies

Fujita

Martin

Low

et al. 2003

ApJ

115

145

View full text Add to dashboard Cite

We study the escape of Lyman continuum radiation from the disks of dwarf starburst galaxies, with and without supershells, by solving the radiation transfer problem of stellar radiation through them. We model disks with M d ¼ 10 8 10 10 M , with exponential surface density profiles as a function of redshift, and model the effects of repeated supernova explosions driving supershells out of the disks, using the hydrodynamic simulation code ZEUS-3D. The amount of star formation is assumed proportional to mass above some density threshold. We vary the threshold to explore the range of star formation efficiencies, f Ã ¼ 0:006, 0.06, and 0.6. We find that the interstellar gas swept up in dense supershells can effectively trap the ionizing photons before the supershells blow out of the disks. The blowouts then create galactic outflows, chimneys that allow the photons to escape directly to the intergalactic medium. Our results are consistent with escape fractions of less than 0.1 measured in local dwarf starburst galaxies, because they are likely observed while the starbursts are young, before blowout. We suggest that high-redshift dwarf starburst galaxies may make a substantial contribution to the UV background radiation with total escape fractions e0.2, as expected if star formation efficiencies are e0:06.

show abstract

“…5, but now with several observed distributions overlaid. The high column density regime is covered by the WHISP data (Swaters et al 2002;Noordermeer et al 2005) in H i emission; a Schechter function fit to this data by Zwaan et al (2005) is shown by the dashed line. The dash-dotted line shows H i emission data from the extended M 31 environment after combining data from a range of different telescopes (Braun & Thilker 2004).…”

Section: H I Distribution Functionmentioning

confidence: 99%

The simulated H I sky at low redshift

Popping

Davé

Braun

et al. 2009

A&A

107

View full text Add to dashboard Cite

Context. Observations of intergalactic neutral hydrogen can provide a wealth of information about structure and galaxy formation, potentially tracing accretion and feedback processes on Mpc scales. Below a column density of N HI ∼ 10 19 cm −2 , the "edge" or typical observational limit for H i emission from galaxies, simulations predict a cosmic web of extended emission and filamentary structures.Current observations of this regime are limited by telescope sensitivity, which will soon advance substantially. Aims. We study the distribution of neutral hydrogen and its 21-cm emission properties in a cosmological hydrodynamic simulation, to gain more insight into the distribution of H i below N HI ∼ 10 19 cm −2 . Such Lyman limit systems are expected to trace out the cosmic web and are relatively unexplored. Methods. Beginning with a 32 h −1 Mpc simulation, we extract the neutral hydrogen component by determining the neutral fraction, including a post-processed correction for self-shielding based on the thermal pressure. We take molecular hydrogen into account, assuming an average density ratio Ω H 2 /Ω HI = 0.3 at z = 0. The statistical properties of the H i emission are compared with observations, to assess the reliability of the simulation. We then make predictions for upcoming surveys. Results.The simulated H i distribution robustly describes the full column density range between N HI ∼ 10 14 and N HI ∼ 10 21 cm −2 and agrees very well with available measurements from observations. Furthermore there is good correspondence in the statistics when looking at the two-point correlation function and the H i mass function. The reconstructed maps are used to simulate observations of existing and future telescopes by adding noise and accounting for the sensitivity of the telescopes.Conclusions. The general agreement in statistical properties of H i suggests that neutral hydrogen, as modelled in this hydrodynamic simulation, is a fair representation of neutral hydrogen in the Universe. Our method can be applied to other simulations, to compare different models of accretion and feedback. Future H i observations will be able to probe the regions where galaxies connect to the cosmic web.

show abstract

The Westerbork HI survey of spiral and irregular galaxies

Cited by 313 publications

References 30 publications

The DiskMass Survey

The DiskMass Survey

The Influence of Supershells and Galactic Outflows on the Escape of Ionizing Radiation from Dwarf Starburst Galaxies

The simulated H I sky at low redshift

Contact Info

Product

Resources

About