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Related papers: What is Driving the HI Velocity Dispersion?

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Neutral hydrogen (HI) velocity dispersions are believed to be set by turbulence in the interstellar medium (ISM). Although turbulence is widely believed to be driven by star formation (SF), recent studies have shown that this driving…

We investigate the relationship between the velocity dispersion of the gas and the SN rate and feedback efficiency in the ISM. We explore the constancy of the velocity dispersion profiles in the outer parts of galactic disks at~6-8 km s^-1,…

Astrophysics · Physics 2009-11-11 Sami Dib , Eric Bell , Andreas Burkert

HI line widths are typically interpreted as a measure of ISM turbulence, which is potentially driven by star formation. In an effort to better understand the possible connections between line widths and star formation, we have characterized…

Astrophysics of Galaxies · Physics 2015-06-12 Adrienne M. Stilp , Julianne J. Dalcanton , Steven R. Warren , Evan Skillman , Juergen Ott , Baerbel Koribalski

It is well known that gas in galaxy discs is highly turbulent, but there is much debate on which mechanism can energetically maintain this turbulence. Among the possible candidates, supernova (SN) explosions are likely the primary drivers…

Astrophysics of Galaxies · Physics 2020-09-16 Cecilia Bacchini , Filippo Fraternali , Giuliano Iorio , Gabriele Pezzulli , Antonino Marasco , Carlo Nipoti

Observations of turbulent velocity dispersions in the HI component of galactic disks show a characteristic floor in galaxies with low star formation rates and within individual galaxies the dispersion profiles decline with radius. We carry…

Astrophysics · Physics 2009-11-13 Oscar Agertz , George Lake , Romain Teyssier , Ben Moore , Lucio Mayer , Alessandro B. Romeo

When present, extended disks of neutral hydrogen around spiral galaxies show a remarkably uniform velocity dispersion of approx 6 km/s. Since stellar winds and supernovae are largely absent in such regions, neither the magnitude nor the…

Astrophysics · Physics 2009-10-30 J. A. Sellwood , S. A. Balbus

We utilize the multi-wavelength data of M33 to study the origin of turbulence in its interstellar medium. We find that the HI turbulent energy surface density inside 8 kpc is $\sim1-3~\times~10^{46}$ erg pc$^{-2}$, and has no strong…

Astrophysics of Galaxies · Physics 2019-01-23 Dyas Utomo , Leo Blitz , Edith Falgarone

Turbulence plays an important role in shaping the interstellar medium, and strongly influences star formation. We aim to identify the physical processes capable of sustaining HI turbulence in the solar neighborhood. We compare recent HI…

HI and CO observations indicate that the cold gas in galaxies is very turbulent. However, the turbulent energy is expected to be quickly dissipated, implying that some energy source is needed to explain the observations. The nature of such…

Astrophysics of Galaxies · Physics 2023-06-28 C. Bacchini , F. Fraternali , G. Pezzulli , G. Iorio , A. Marasco , C. Nipoti

Interstellar turbulence shapes the HI distribution in the Milky Way (MW). How this affects large-scale statistical properties of HI column density across the MW remains largely unconstrained. We use approx 13,000 square-degree GALFA-HI…

Astrophysics of Galaxies · Physics 2023-10-24 Amit K. Mittal , Brian L Babler , Snezana Stanimirovic , Nickolas Pingel

The size-velocity dispersion ($\sigma$) relation, while well established for giant HII regions, remains uncertain for their smaller counterparts (physical radii R < 20 pc). Thanks to the LAMOST MRS-N dataset's large sky coverage and high…

High--resolution 2D--MHD numerical simulations have been carried out to investigate the effects of continuing infall of clumpy gas in extended HI galactic disks. Given a certain accretion rate, the response of the disk depends on its…

Astrophysics · Physics 2009-11-13 A. Santillan , F. J. Sanchez-Salcedo , J. Franco

Gas velocity dispersions provide important diagnostics of the forces counteracting gravity to prevent collapse of the gas. We use the 21 cm line of neutral atomic hydrogen (HI) to study HI velocity dispersion and HI phases as a function of…

Astrophysics of Galaxies · Physics 2015-08-06 R. Ianjamasimanana , W. J. G. de Blok , Fabian Walter , George H. Heald , Anahi Caldu-Primo , Thomas H. Jarrett

Turbulent neutral hydrogen (HI) line widths are often thought to be driven primarily by star formation (SF), but the timescale for converting SF energy to HI kinetic energy is unclear. As a complication, studies on the connection between Hi…

Dealing numerically with the turbulent nature and non-linearity of the physical processes involved in the ISM requires the use of sophisticated numerical schemes coupled to HD and MHD mathematical models. SNe are the main drivers of the…

Astrophysics · Physics 2007-05-23 Miguel A. de Avillez , Dieter Breitschwerdt

We investigate the energy sources of random turbulent motions of ionised gas from H$\alpha$ emission in eight local star-forming galaxies from the Sydney-AAO Multi-object Integral field spectrograph (SAMI) Galaxy Survey. These galaxies…

The interstellar medium (ISM) is ubiquitously turbulent across many physically distinct environments within the Galaxy. Turbulence is key in controlling the structure and dynamics of the ISM, regulating star formation, and transporting…

High surface density, rapidly star-forming galaxies are observed to have $\approx 50-100\,{\rm km\,s^{-1}}$ line-of-sight velocity dispersions, which are much higher than expected from supernova driving alone, but may arise from large-scale…

Astrophysics of Galaxies · Physics 2016-02-17 Sharanya Sur , Evan Scannapieco , Eve C. Ostriker

Frequent supernova explosions in compact starburst regions are a main shaper of these regions' interstellar media (ISM). In most starbursts, the supernova remnants blast open a hot phase that fills the regions and launches a superwind.…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-27 Brian C. Lacki

We use hydrodynamical simulations in a $(256\;{\rm pc})^3$ periodic box to model the impact of supernova (SN) explosions on the multi-phase interstellar medium (ISM) for initial densities $n = 0.5-30$ cm$^{-3}$ and SN rates $1-720$…

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