Pulsar Observations in Urumqiastro/FAN4/Presentation/Wang_Na.pdf · Pulsar Observations in Urumqi Na Wang Xinjiang Astronomical Observatory, CAS Jul 8-12, ... (NS 25m) SEFD (Jy) (QTT)

Pulsar Observations in Urumqi

Na Wang

Xinjiang Astronomical Observatory, CAS

FAN4, Hongkong University 1 Jul 8-12, 2013

Jul 8-12, 2013 FAN4, Hongkong University 2

• Pulsar Observations

– Pulsar timing

– Pulsar emission

• The Future



– Pulsar timing

– Pulsar emission

• The Future

4

• 25 m radio telescope

• 18cm cryogenic Rx

• Analog FilterBank + DFB

• 0.4 mJy

• ~300 pulsars, including 38 Fermi pulsars

and 9 MSPs

• Allowing to investigate the instability of

pulsar rotation, electron distribution of ISM,

proper motion and velocity of pulsars.


5

A very large glitch in PSR B2334+61

• Minimal post glitch recovery

• Large ~15%, rapid decay (21d

+147d), and permanent jump

• Post-glitch oscillation period ~ 364(5) days

• Tkachenko oscillation of superfluid vortex

array (Ruderman 1970, Popov 2008)


52 10g

Cf. high-magnetic-field pulsar PSR J1718-3718:

• no exponential recovery

• increasing braking torque

• negative braking index(Manchester et al., 2011)

Yuan J. P. et al., 2010, ApJL

12

T 6~ 1.77 yr ~1 yrP R P

53.3 10g

Glitch in PSR J1835-1106

Zou et al. 2004, MNRAS

• Significant cubic terms in timing residual

• Little or no change in

• The jump in , reverse sign


7

Glitches in the Crab pulsar

• 1969－1999, 12 glitch events

• 2000－2010, 9 glitches (Wang et al. 2012)

• Glitch interval: Poisson distribution, 419 d.

• Trigger of glitch not relevant to the slowdown

• Braking index: 2.454(7) and 2.571(3), cf.

2.51 by Lyne (1993) : varying particle wind

Wang J. B. et al. 2012, APSS Tong H. et al., 2013, ApJ


n for the Crab pulsar

8

Yuan, et al. 2010, MNRAS

Glitches in PSR B1737－30

• 22 glitches in 22 years.

• The amplitudes of the fractional

jump in rotation rate range from

10 – 9 to 10 – 6 .

• Inter-glitch intervals are also

variable.

• No relationship is observed

between interval and the size of

the preceding glitch.



• Vela like permanent change in frequency derivative: PSRs B1800－21, B1823－13, B1046－58, B1610－50, B1706－44, B1727－33, B2334+61

• Others have no permanent change: PSRs B1338－62, J1617－5055, B1737－30, J1708－4009, B1757－24, J2021+3651


Various glitch recoveries


Slow glitches

Also see Shabanova, 2000



Tiny glitches 11 910 10 （）

PSRs B0144+59, B0402+61, B0525+21, J1705−3423, B1815−14, B1900+06, B1907+10 and B2224+65


Origin of timing noise




– Pulsar timing

– Pulsar emission

• The Future


Mode changing of PSR B0329+54

176 events Sep 2003 to Apr

2009.

R=I/III, R~0.56 for normal,

R~1.17 for abnormal mode

R: normal distribution, wider for

abnormal mode: less stable

timescales: gamma distribution,

t_normal~154.2 min

t_abnormal~31.5 min

85% normal

15% abnormal

Chen et al. 2011, ApJ

15 Jul 8-12, 2013 FAN4, Hongkong University

• Polarization Observations reveal previously unknown profile features

in many of the MSPs.

• For MSPs, there are little or no

significant long-term variation in RM

after ionospheric correction.

Significant Rotation Measure variations

for Vela pulsar (Hamilton et al. 1985,

MNRAS):

Yan et al. 2011,

MNRAS

Yan et al. 2011, Ap&SS

16

16 Jul 8-12, 2013 FAN4, Hongkong University

Hu et al. 2011, A&A

The emission mechanism of RRAT J1819-1458 is perhaps similar to that of pulsars with giant pulses.

RRAT J1819-1458

• Tri-band pattern of timing residuals

is observed: core and conal

components

• Flux intensity distribution of bursts

follow a power law: α=1.6

@1.5GHz

• This is similar to those pulsars

with giant pulses, e.g.

PSR B1927+21: α[email protected] GHz

PSR J1824-2452A: α[email protected] GHz

Observations:

Observed at Parkes, 2004 March & June

HOH + Filterbank (576 MHz, 192 channels)

50cm + Filterbank (64 MHz, 256 channels)

35 pulsars observed, 2 hours each mostly

18 single pulse

8 integration 10－30 sec

9 integration ≥ 60 sec

Wang N. et al. 2007, MNRAS


Nullers


Nulls and mode change


Profiles of PSR B1326-6700

• Single pulse

• Trailing component nulls

• Interval 2-10 min (200-1000 pulses)

• Two main components cease for ~1min

• The fourth component appears

• Frequent short intervals during B mode


• On 10-30 min

• NF 1.6%

• Short burst within a null

• Weak leading component


• Large NF pulsars: >1Myr, some >5Myr

• Nulling is related more to age than

period

PSR Name P(s) τc (Myr) NF

1820-0509 0.34 5.7 67%

0525+21 3.75 1.5 25%

1831-1223 2.86 8.3 4%

• Pulsar period vs period derivative.

• Nulling pulsars: circle

• Circle area: proportional to the NF, with a lower bound of 5%.

• Pulsars in this work: cross.


Statistics of NF


• Both nulling and mode changing result from large-scale and

persistent changes in the magnetospheric current distribution.

• Mode changes must be a manifestation of a redistribution of

current flow in the magnetosphere, resulting in changes in the

radio beam emission pattern and hence in the observed pulse

profile.

• Nulls may result from a cessation of (or at least a large

reduction in) the current，but may also result from a current

redistribution which leads to a beam pattern with little or no

power in our direction.



– Pulsar timing

– Pulsar emission

• The Future


Proposed to build 110m radio telescope:

• QTT: QiTai radio Telescope

• General purpose telescope

• Fully Steerable

• Active Surface

• Freq Range 150 MHz – 115 GHz

• Prime/Gregorian paraboloid, Az/El

• Wide-band, Multi-beam & PAF Rx

• Digital backend

……

Secondary Servo

Secondary Focus

5 cm Band

1 cm Band

6 mm Band

3 mm Band

13 / 3.6 cm Band

3.6 / 0.9 cm Band

3 mm Band (MB)

Primary Focus

100 cm Band

30 cm Band

15 cm Band (PAF)

Servo & Control System

Az / El Encoder

Az / El Servo

Active Surface Servo

Safeguard System

Back End

Multi-Function Digital Backend

VLBI Backend

Continuum Total Power Backend

Time & Frequency

Hydrogen Maser

Time & Frequency System

GPS Receiver


Band 100cm 30cm 5cm 1cm 6mm 3mm

Efficiency

(Optimum El.) 60% 63% 63%

60%

~50%

54%

~30%

30%

~12%

System Noise

(K) 30 25 20 20 45 100

QTT Electric Performances


Type

Band

(cm)

RF Freq

(GHz) Focus Feed Poln Science Goals

Single

Pixel

100 0.15 – 0.6 Primary Kildal Linear Pulsar, RRT

30 0.6 – 4 Primary Horn Linear Pulsar, RRT, HI, OH,

Galaxies

5 2 – 12 Greg. Horn Linear Molecular spectrum,

Galaxies; VLBI

1 12 – 36 Greg. Horn Linear Pulsar, H2O, NH3, VLBI

0.6 36 – 50 Greg. Horn Linear Molecular spectrum,

High-z CO

0.3 72 – 115 Greg. Horn Linear Molecular spectrum,

Galaxies

Dual-

Band

13/3.6 2.2 – 2.5

8 – 9 Greg. Horn Circular

VLBI, space

exploration, System

measurement (3.6cm)

3.6/0.9 8 – 9

30 – 34 Greg. Horn Circular

VLBI, space exploration

Multi-

Pixel

15 1 – 2 Primary PAF Linear Pulsar, RRT, HI, OH,

Galaxies

0.3 80 – 115 Greg. Horn(7/13

Beam) Linear

Molecular spectrum,

Galaxies


Astronomy

• High precision pulsar timing

• Molecular spectra observations

• Active galactic nuclei

• Dark matter

• VLBI astrometry, astro-dynamics and space VLBI

• Sky survey: detecting organic molecule and sulphur chain

molecule

Application

• VLBI orbit measurement for space exploration

• Pulsar time standard

• Deep space pulsar autonomous navigation

NASA/GSFC


• China VLBI (CVN): astrometry, space exploration

CVN+QTT: sensitivity increase 1.8 times

CVN+QTT+65m: sensitivity increase 3 times

• EVN

Band (cm) EVN

Available Tele

SEFD (Jy)

(NS 25m)

SEFD (Jy)

(QTT)

Ratio

improvement

18 10 13 9 30%

13 8 61 17 71%

6 10 14 12 16%

3.6 8 31 21 34%

1.3 6 149 101 33%


Shihezi Village

Qitai

Nanshan

Urumqi

Ulastai


• 1.5 kilometers long and 2 kilometers wide rectangle basin

• Altitude range from 1730 m to 2250 m

• Surrounding ridges form an isolated layer with outside region


• Average annual rainfall of area: 180 mm to 200 mm (cf. average

evaporation capacity of Xinjiang area is ~2000mm)

• Precipitable water vapor:

Summer: ~19 mm

Spring and Autumn: ~8 mm to 9.5 mm

Winter: ~3 mm

• Temperature range: maximum +29.3 °, minimum －26.6 °

Temperature drifting Ratio

≤ 5 ℃/hr 99.0%

≤ 3 ℃/hr 92.7%

≤ 2 ℃/hr 82.7%


Roses diagram

• Frequency distribution of extreme wind speed:

Wind speed Ratio

Qitai_Average Qitai_Day Qitai_Night GBT

≤4m/s (3 beaufort scale) 65.9% 48.9% 83.0% 45.9%



≤10m/s (6 beaufort scale) 97.5％ 96.7% 98.3% 88.9％

≥17m/s (8 beaufort scale) 0.14% 0.21% 0.06% 0.5%


RFI

Most interference are recognizable:

• Measured 150 MHz － 13 GHz

• 2 or 3-G mobile wireless communication (UHF, L, S band)

• broadcast television (analog digital, VHF, UHF band)

• differential rotation system of wireless satellite television (UHF, C band)

• satellite navigations


• Evaluations organized by CAS & NAO

• Conferences: Key Tech., Rx, Science

• Support from local government and CAS


2012 Nov. 29—Dec. 1，QTT International Advisory Workshop


• Servo control and very accurate pointing

• Active surface: measurement and adjust: OOF, holography

• Reflector: parabolic dish vs. shaped design

• Dividing the main reflector and number of actuators

• Track and wheels: monolithic track & heavy load

• Structure and electronics: environment under －30℃

• Rx: wide band feed, Multi-beam, PAF

• ……

15°

ring1…… ring22

15°

5m2, 2856 12.5m2, 888

Receiver Monitoring Software

Receiver Selection Software

Antenna Monitor Software

Antenna Servo Software

Antenna Control Software

Telescope and Receiver Softwares

Antenna Measurement Softwares Astronomical Observation Softwares

Time Synchronization

Software

Weather Monitoring Software

Timing Reference Softwares

Environmental Monitoring Softwares

RFI Monitoring Software

Time Comparison

Software

Antenna Holography Measuring Software

Antenna Measuring Software

Active Surface Adjusting Software

Continuum Observation Software

VLBI Observation Software

Spectrum Observation Software

Pulsar Observation Software

Backends Control

Software

H-Maser Environment Monitoring

Software

Time Synchronization Signal

Data Stream Environmental Data

Time Comparison Signal



• Land acquisition: approved

• Herdsman relocate: 130 families, move in 3 years

• Road flattening: done

• Power: satisfy the infrastructure requirement

• Water supply plan: assessed

• Fiber connection: done for construction period


Collaboration are expected!

Documents

Pulsar Observations in Urumqiastro/FAN4/Presentation/Wang_Na.pdf · Pulsar Observations in Urumqi Na Wang Xinjiang Astronomical Observatory, CAS Jul 8-12, ... (NS 25m) SEFD (Jy) (QTT)