LORENE
bin_bhns_extr_omegaana.C
1/*
2 * Methods of class Bin_bhns_extr to set analytical value to omega
3 *
4 * (see file bin_bhns_extr.h for documentation).
5 *
6 */
7
8/*
9 * Copyright (c) 2004 Keisuke Taniguchi
10 *
11 * This file is part of LORENE.
12 *
13 * LORENE is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License version 2
15 * as published by the Free Software Foundation.
16 *
17 * LORENE is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with LORENE; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 *
26 */
27
28char bin_bhns_extr_omegaana_C[] = "$Header: /cvsroot/Lorene/C++/Source/Bin_bhns_extr/bin_bhns_extr_omegaana.C,v 1.3 2014/10/13 08:52:42 j_novak Exp $" ;
29
30/*
31 * $Id: bin_bhns_extr_omegaana.C,v 1.3 2014/10/13 08:52:42 j_novak Exp $
32 * $Log: bin_bhns_extr_omegaana.C,v $
33 * Revision 1.3 2014/10/13 08:52:42 j_novak
34 * Lorene classes and functions now belong to the namespace Lorene.
35 *
36 * Revision 1.2 2014/10/06 15:13:00 j_novak
37 * Modified #include directives to use c++ syntax.
38 *
39 * Revision 1.1 2004/11/30 20:46:36 k_taniguchi
40 * *** empty log message ***
41 *
42 *
43 * $Header: /cvsroot/Lorene/C++/Source/Bin_bhns_extr/bin_bhns_extr_omegaana.C,v 1.3 2014/10/13 08:52:42 j_novak Exp $
44 *
45 */
46
47// C headers
48#include <cmath>
49
50// Lorene headers
51#include "bin_bhns_extr.h"
52#include "unites.h"
53
54namespace Lorene {
56
57 using namespace Unites ;
58
59 // BH-NS binary systems should be relativistic
60 // -------------------------------------------
61 if ( !star.is_relativistic() ) {
62
63 cout << "BH-NS binary systems should be relativistic !!!" << endl ;
64 abort() ;
65 }
66
67 double rr = separ ;
68 double mtot = mass_bh ; // Approximates the extreme mass ratio
69
70 // Compaction factor
71 double compact = ggrav * mtot / rr ;
72
73 double omega2 ;
74
75 if ( star.is_irrotational() ) {
76
77 // Irrotational case
78 // -----------------
79
80 omega2 = ggrav * mtot / pow(rr, 3.)
81 * (1. - 2.75 * compact + 8.625 * compact*compact ) ;
82
83 }
84 else {
85 // Corotating case
86 // ---------------
87
88 // a0/R
89 double a0sr = star.ray_eq() / rr ;
90
91 // Rescaled moment of inertia 5 I / (2 M a0^2)
92 double ired = double(5)/double(3) * ( 1. - double(6)/M_PI/M_PI ) ;
93 omega2 = ggrav * mtot / pow(rr, 3.)
94 * (1. - compact * ( 2.75 + 2.*a0sr*a0sr * ired
95 - 0.48*pow(a0sr, 4) * ired*ired )
96 + compact*compact * ( 8.625 + 2.75*a0sr*a0sr * ired
97 + 2.*pow(a0sr, 4) * ired*ired ) ) ;
98
99 }
100
101 omega = sqrt( omega2 ) ;
102
103 // The derived quantities are obsolete:
104 del_deriv() ;
105
106}
107}
Et_bin_bhns_extr star
Neutron star.
double separ
Absolute orbital separation between two centers of BH and NS.
void analytical_omega()
Sets the orbital angular velocity to some 2-PN analytical value (Keplerian value in the Newtonian cas...
double mass_bh
Gravitational mass of BH.
double omega
Angular velocity with respect to an asymptotically inertial observer.
void del_deriv() const
Deletes all the derived quantities.
bool is_irrotational() const
Returns true for an irrotational motion, false for a corotating one.
Definition etoile.h:1092
double ray_eq() const
Coordinate radius at , [r_unit].
bool is_relativistic() const
Returns true for a relativistic star, false for a Newtonian one.
Definition etoile.h:667
Cmp sqrt(const Cmp &)
Square root.
Definition cmp_math.C:220
Cmp pow(const Cmp &, int)
Power .
Definition cmp_math.C:348
Lorene prototypes.
Definition app_hor.h:64
Standard units of space, time and mass.