Source Code for Module pycosmicstar.csfrfromfit

 1  #!/usr/bin/env python3 
 2  # *-* Coding: UTF-8 *-* 
 3  from __future__ import division, absolute_import 
 4   
 5  __author__ = "Eduardo dos Santos Pereira" 
 6  __email__ = "pereira.somoza@gmail.com" 
 7  __credits__ = ["Eduardo dos Santos Pereira"] 
 8  __license__ = "GPLV3" 
 9  __version__ = "1.0.1" 
10  __maintainer__ = "Eduardo dos Santos Pereira" 
11  __status__ = "Stable" 
12   
13  """This module contain the Cosmic Star Formation Rate (CSFR) of the work 
14  of: 
15      Fardal et al. (MNRAS, 379,985,2007) MNRAS, 339,312,2003. 
16      Hopkins and Beacom, Apj, 651, 142, 2006. 
17      Volker, Springel, Lars, Hernquist, MNRAS, 339,312,2003. 
18  """ 
19   
20  from numpy import exp 
21   
22   
23 -def rho_starF(z, h): 
24      """Return CSFR by the work of Fardal et al. (MNRAS, 379,985,2007) 
25      MNRAS, 339,312,2003. 
26      """ 
27      a = 0.0103 
28      b = 0.088 
29      c = 2.4 
30      d = 2.8 
31      rho = ((a + b * z) * h) / (1.0 + (z / c) ** d) 
32      return rho 
33   
34   
35 -def rho_starHB(z, h): 
36      """Return CSFR by the work of Hopkins e Beacom, 
37      Apj, 651, 142, 2006. 
38      """ 
39      a = 0.0170 
40      b = 0.13 
41      c = 3.3 
42      d = 5.3 
43      rho = ((a + b * z) * h) / (1.0 + (z / c) ** d) 
44      return rho 
45   
46   
47 -def rho_starSH(z): 
48      """Return CSFR by the work of Volker, Springel, Lars and Hernquist 
49      MNRAS, 339,312,2003. 
50      """ 
51      #M_{\odot}yr^{-1}Mpc^{-3} 
52      rhom = 0.15 
53      alpha = 3.0 / 5.0 
54      beta = 14.0 / 15.0 
55      zm = 5.4 
56      rho = rhom * (beta * exp(alpha * (z - zm))) / \ 
57                  (beta - alpha + alpha * exp(beta * (z - zm))) 
58      return rho 
59