Science-advisor
REGISTER info/FAQ
Login
username
password
     
forgot password?
register here
 
Research articles
  search articles
  reviews guidelines
  reviews
  articles index
My Pages
my alerts
  my messages
  my reviews
  my favorites
 
 
Stat
Members: 3643
Articles: 2'487'895
Articles rated: 2609

28 March 2024
 
  » 1730852

 Article forum


Supernovae and AGN driven galactic outflows
Mahavir Sharma ; Biman B. Nath ;
Date 3 Sep 2012
AbstractWe present analytical solutions for winds from galaxies with NFW dark matter halo. We consider winds driven by energy and mass injection from multiple supernovae, as well as momentum injection due to radiation from a central black hole. We find that the wind dynamics depends on three velocity scales: (a) v_star sim (dot{E} / 2 dot{M})^{1/2} describes the effect of starburst activity, with dot{E}, dot{M} as energy and mass injection rate in a central region of radius R; (b) vbh ~ (Gmbh / 2 R)^{1/2} for the effect of a central black hole of mass mbh on gas at distance R and (c) v_{s} =(GM_h/ 2Cr_s)^{1/2} which is closely related to the virial velocity, with C as a function of halo concentration parameter. We find the wind terminal speed to be 2 (v_star^2 +1.5(Gamma -1) vbh^2 -v_s^2)^{1/2}, where Gamma is the ratio of force due to radiation pressure to gravity of the central black hole. We also find that: (a) winds from quiescent star forming galaxies cannot escape from 10^{11.5} le M_h le 10^{12.5}Msun galaxies, (b) circumgalactic gas at large distances should be present for galaxies in this mass range, (c) for an escaping wind, the wind speed in low to intermediate mass galaxies is ~ 400--1000 km/s, consistent with observed X-ray temperatures; (d) winds from massive galaxies with AGN have speeds gtrsim 1000 km/s. We also find that the ratio [2 v_star ^2 -(1 -Gamma) vbh^2]/ vvir^2 dictates the amount of gas lost. Used in conjunction with an appropriate relation between mbh and M_h, and an appropriate opacity of dust grains in IR (K band), this ratio becomes minimum at a certain halo mass scale (M_h ~ 10^{12--12.5} Msun) that signifies the cross-over of AGN domination in outflow properties from starburst activity at lower masses. We find that stellar mass for massive galaxies scales as M_star propto M_h^{0.26},and for low mass galaxies, M_star propto M_h^{5/3}.
Source arXiv, 1209.0242
Services Forum | Review | PDF | Favorites   
 

No message found in this article forum.  You have a question or message about this article? Ask the community and write a message in the forum.
If you want to rate this article, please use the review section..

Subject of your forum message:
Write your forum message below (min 50, max 2000 characters)

2000 characters left.
Please, read carefully your message since you cannot modify it after submitting.

  To add a message in the forum, you need to login or register first. (free): registration page






ScienXe.org
» my Online CV
» Free


News, job offers and information for researchers and scientists:
home  |  contact  |  terms of use  |  sitemap
Copyright © 2005-2024 - Scimetrica