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

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

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

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

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

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

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

<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)

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

Introduction of my current work Pulsars with independent distance : Kinematic distance:62 Association with SNRs WD OB GC :16 Trigonometric parallax:61 Association with globular clusters:28

Components of current model : Thick disk+ Thin disk + Spiral arm (26) Algorithm: (Non-linear, Bound, Multi-dimensional, Derivative-free) http://ab-initio.mit.edu/wiki/index.php/Nlopt( 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

Compare with NE2001:

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.

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

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

Thanks