1. Xinjiang Astronomical Observatory,CAS
Model for pulsar distance
Jumei Yao
Xinjiang Astronomical Observatory,CAS
2014/07/04

2. 1.Background and significance
Outline
1.Background and significance
2.Deficiencies of existing models
3.Improvement of existing models
4.Introduction of my current work
5.Introduction of my future work

3. Background and significance
Pulsar distance (Electron density )model :distribution of electron density in our galaxy
From 2001 the number of pulsars more than doubled. The number of pulsar parallaxes will have increased by a factor>4.The much larger database of DM and D values can be used to revise the existing models
Version
1.5
1.1
Update time
2014/05/06
2003/05/12
Number of
PSR
2328
1297
Independent distance
252
109
PSR with PX 61 17

4. Background and significance
<1>To determine the distance of pulsar
(space density, velocity distribution, luminosities)
<2>To consider effect of DM and SM on pulsar survey
(pulse smearing, sensitivity reduction)
<3>To estimate the location of fast radio transient
(galactic or extragalactic)
<4>to know the large scale structure and variations of B
(Faraday rotation measurements)
<5>To assess the DM and SM of ionized intergalactic medium

5. Improvement of existing models
Deficiencies of NE2001 models
Improvement of existing models
Components: Thin disk, Thick disk
Spiral arms( four arm+ local arm)
Galactic center, Clumps, Void
Local ISM
<1> Thick disk
Chatterjee et al 2009
Many high-latitude pulsars have been substantially underestimated

6. NE2001 n1=0.034 H1=950pc New Model n1=0.013cm-3 H1=2045pc 2009
( Gaensler et al 2008)
NE2001
n1=0.034
H1=950pc
New Model
n1=0.013cm-3
H1=2045pc

7. <2>Spiral arm
NEW2014
L.G.Hou et al 2014
NE2001

8. <3>Equation form
<4> The most updated values of R0=8.34(kpc)
<5> The distance of most pulsars have been revised
Kinematic distance :overestimate
Parallax :underestimate
(Verbiest et al 2012)

9. <6>Warp First and second quadrants: above the Galactic plane
Third and fourth quadrants: below the Galactic plane
Yusifov et al 2004

10. Introduction of my current work
Pulsars with independent distance :
Kinematic distance: Association with SNRs WD OB GC :16
Trigonometric parallax: Association with globular clusters:28

11. Components of current model :
Thick disk+ Thin disk + Spiral arm (26)
Algorithm: (Non-linear, Bound, Multi-dimensional, Derivative-free)
BOBYQA,NELDERMEAD,SBPLX,COBYLA)
Pulsar with Dm/D>1.3
(1) Near Sun( Local arm Local ISM)
(2) Between Sagittarius-Carina and Scutum-Crux arm
Pulsar with Dm/D<0.7
Near GC-some globular cluster
pulsars

12. Compare with NE2001:

13. The new model improve distance of some pulsars
The new model improve distance of some pulsars. For pulsars in globular cluster the improvement is not obvious.

14. Far from Sun: Pulsars with Dm/D larger than 1
Far from Sun: Pulsars with Dm/D larger than 1.3 are located around Gl=3000

15. Introduction of my future work
Thick disk + Thin disk+ Spiral Arm (Now)
(The new model improve distance of some pulsars. For pulsars in globular cluster the improvement is not obvious. Some pulsars whose Dm/D are greater than 1.3 locate in two region (Near Sun, Between Sagittarius-Carina and Scutum-Crux arm))
Thick disk+ Thin disk+ Spiral Arm+ GC+ Gum+… (future)
New model

16. Thanks