Home Galactic Efficacy of early stellar feedback in low gas surface density environments. (arXiv:1812.01614v1...

Efficacy of early stellar feedback in low gas surface density environments. (arXiv:1812.01614v1 [astro-ph.GA])


Authors: Rahul Kannan (Harvard/CfA), Federico Marinacci (Harvard/CfA), Christine M. Simpson (U Chicago), Simon C. O. Glover (ITA Heidelberg), Lars Hernquist (Harvard/CfA)

We present a suite of high resolution radiation hydrodynamic simulations of a
small patch ($1 {rm kpc}^2$) of the inter-stellar medium (ISM) performed
with Arepo-RT, with the aim to quantify the efficacy of various feedback
processes like supernovae explosions (SNe), photoheating and radiation pressure
in low gas surface density galaxies ($Sigma_{rm gas} simeq 10 {rm
M}_odot {rm pc}^{-2}$). We show that radiation fields decrease the star
formation rate and therefore the total stellar mass formed by a factor of $sim
2$. This increases the gas depletion timescale and brings the simulated
Kennicutt-Schmidt relation closer to the observational estimates. Radiation
feedback coupled with SNe is more efficient at driving outflows with the mass
and energy loading increasing by a factor of $sim 10$. This increase is mainly
driven by the additional entrainment of medium density ($10^{-2} leq n< 1
{rm cm}^{-3}$), warm ($300 {rm K}leq T<8000 {rm K}$) material.
Therefore including radiation fields tends to launch colder, denser and higher
mass and energy loaded outflows. This is because photoheating of the high
density gas around a newly formed star over-pressurises the region, causing it
to expand. This reduces the ambient density in which the SNe explode by a
factor of $10-100$ which in turn increases their momentum output by a factor of
$sim 1.5-2.5$. Finally, we note that in these low gas surface density
environments, radiation fields primarily impact the ISM via photoheating and
radiation pressure has only a minimal role in regulating star formation.


Source link


Please enter your comment!
Please enter your name here

Enter Captcha Here : *

Reload Image

Must Read

Why everyone is talking about energy storage | MNN

Ever since governments started getting serious about developing renewable energy, naysayers have been arguing that it's a pipe dream — after all, the...

Give charities free ad space on your smartphone’s lock screen with Screen Donor

This app gives free ad space to deserving charities and NGOs on one of our tech-centric culture's most commonly seen screens - our...

Tropicana 100% Juice 3-Flavor Fruit Blend Variety Pack, 10 Fl Oz, Bottles, (Pack of 24)

Price: (as of - Details) Now you can enjoy the refreshing taste of Tropicana’s Fruit Medley, Pineapple Peach Mango and Strawberry Orange Juice...

Cell phones and screens are keeping your kid awake

For children and teens, using cell phones, tablets and computers at night is associated with losing sleep time and sleep quality, new research...