The SILCC project V. The impact of magnetic fields on the chemistry and the formation of molecular clouds

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F18%3A00497317" target="_blank" >RIV/67985815:_____/18:00497317 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1093/mnras/sty2016" target="_blank" >http://dx.doi.org/10.1093/mnras/sty2016</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1093/mnras/sty2016" target="_blank" >10.1093/mnras/sty2016</a>

Jazyk výsledku

angličtina

Název v původním jazyce

The SILCC project V. The impact of magnetic fields on the chemistry and the formation of molecular clouds

Popis výsledku v původním jazyce

Magnetic fields are ubiquitously observed in the interstellar medium (ISM) of present-day star-forming galaxies with dynamically relevant energy densities. Using three-dimensional magnetohydrodynamic (MHD) simulations of the supernova-driven ISM in the flux-freezing approximation (ideal MHD), we investigate the impact of the magnetic field on the chemical and dynamical evolution of the gas, fragmentation, and the formation of molecular clouds. We follow the chemistry with a network of six species (H+, H, H-2, C+, CO, and free electrons) including local shielding effects. We find that magnetic fields thicken the disc by a factor of a few to a scale height of similar to 100 pc, delay the formation of dense (and molecular) gas by similar to 25 Myr, and result in differently shaped gas structures. The magnetized gas fragments into fewer clumps, which are initially at subcritical mass-to-flux ratios, M/Phi approximate to 0.3(M/Phi)(crit), and accrete gas preferentially parallel to the magnetic field lines until supercritial mass-toflux ratios of up to the order of 10 are reached. The accretion rates onto molecular clouds scale with M proportional to M-1.5. The median of the intercloud velocity dispersion is similar to 2 5 km s(-1) and lower than the internal velocity dispersion in the clouds (similar to 3 7 km s(-1)). However, individual cloud-cloud collisions occur at speeds of a few 10 km s(-1).

Název v anglickém jazyce

The SILCC project V. The impact of magnetic fields on the chemistry and the formation of molecular clouds

Popis výsledku anglicky

Magnetic fields are ubiquitously observed in the interstellar medium (ISM) of present-day star-forming galaxies with dynamically relevant energy densities. Using three-dimensional magnetohydrodynamic (MHD) simulations of the supernova-driven ISM in the flux-freezing approximation (ideal MHD), we investigate the impact of the magnetic field on the chemical and dynamical evolution of the gas, fragmentation, and the formation of molecular clouds. We follow the chemistry with a network of six species (H+, H, H-2, C+, CO, and free electrons) including local shielding effects. We find that magnetic fields thicken the disc by a factor of a few to a scale height of similar to 100 pc, delay the formation of dense (and molecular) gas by similar to 25 Myr, and result in differently shaped gas structures. The magnetized gas fragments into fewer clumps, which are initially at subcritical mass-to-flux ratios, M/Phi approximate to 0.3(M/Phi)(crit), and accrete gas preferentially parallel to the magnetic field lines until supercritial mass-toflux ratios of up to the order of 10 are reached. The accretion rates onto molecular clouds scale with M proportional to M-1.5. The median of the intercloud velocity dispersion is similar to 2 5 km s(-1) and lower than the internal velocity dispersion in the clouds (similar to 3 7 km s(-1)). However, individual cloud-cloud collisions occur at speeds of a few 10 km s(-1).

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

<a href="/cs/project/GB14-37086G" target="_blank" >GB14-37086G: Centrum Alberta Einsteina pro gravitaci a astrofyziku</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Monthly Notices of the Royal Astronomical Society

ISSN

1365-2966

e-ISSN

—

Svazek periodika

480

Číslo periodika v rámci svazku

3

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

30

Strana od-do

3511-3540

Kód UT WoS článku

000449616200050

EID výsledku v databázi Scopus

2-s2.0-85054737784