Workshop PULSARS Theory and Observations, Paris Obs., Nov 24-26th 2008 Nançay observations
Nançay Pulsars instrumentationsand observations
Ismaël Cognard, CRGilles Theureau, AAGrégory Desvignes, PhDRob Ferdman, PostDocAlessandro Corongiu, PostDoc
Lestrade, BourgoisCognard
CognardTheureauDesvignes(Smith)(Dumora)(Guillemot)
sweptLO
NBPP
BON
LestradeCognardMaitia
CognardTheureau
Cognard
A brief pulsar history with the Nançay Radio Telescope
Cognard(Lestrade)(Hamidouche)
NRL Washington
UCBerkeleyInstrumentations andevolution ofthe number of pulsarsobserved at Nançay
EPTAGLASTHESS
Scientists and Collaborations
telescope UPGRADE
FerdmanCorongiu
Instrumentations
No way to get data without instrumentations
Pulsar timinginstrumentationsat Nançay
NBPP 1998-2003
BON 2004-...
SWEPT LO1988-2005
old BON instrumentationfrom 2004 to 2008
a coherent pulsar dedispersor calledBON (Berkeley-Orléans-Nançay)
a 128MHz spectrometerSerendipV 2 complex polars digitized at 128Ms/s
a dedispersion computer4 dataservers for data distributioncluster a 64-nodes Linux cluster of bi-proc Athlon 1.2GHz
a bandwidth of 64MHz was processedinstalled in 2001 !
How to get more computing powerper Watt, per cm3,... per € ?
More computing power
Use of GPU (Graphics Processing Unit)Nvidia GeForce 8800GTX
Stream processors 128Memory 768MBMemory bandwidth 86.4GB/sMemory interface 384bitsCore clock 575MHzShader clock 1350MHzMemory clock 900MHz
Use of CUDA SDK (Compute Unified Device Architecture - Software Development Kit)
http://www.nvidia.com/object/cuda_home.html
March 2008 : a prototype (one CPU)
Built with great help from P.Lespagnol, NançayGigabyte N680SLI-DQ6 + 2x 8800GTX + watercooling ~2k€
April 2008 : an evolving prototype (dual-CPU + PCI-X 133/100MHz)
Supermicro X7DWA-N + 2x EDT-PCICDa+ 2x 8800GTX (+ watercooling) ~2.5k€
IN from spectrometer2Gb/s
May 2008 : data path is validated
OUTon disk
200kb/s
June 2008 :an operational system
for 128MHz SerendipV(with only 2 units!)
Supermicro X7DWA-N+ EDT-PCI-CDa+ 2x 8800GTX + watercooling
Next large bandwidth coherent pulsar dedispersor
direct sampling of the Nançay 100-500MHz IF400MHz usefull bandwidth ~ 1 MHz channelsbased on iADC and IBOB (or ROACH) provided by CASPER, Berkeley
IBOB : Virtex2, 2x Z-DOK connectors, 2x 10GB ethernet linksFPGA code being developped by Peter MacMahon, KAT
IBOB
ROACH
ROACH : Virtex5, PowerPC, 2x Z-DOK connectors,4x 10GB ethernet links
presently in final integration at Berkeley
Next large bandwidth coherent pulsar dedispersor
iBOB
800MHz clock
PC + 10GbE card (+ GPU)
10GbE Gore cable
Next large bandwidth coherent pulsar dedispersor
Tests already started with IBOB (in Sept 2008)the final ROACH version should be operational mid-2009
Such a strong effort to design and builda very dedicated instrumentation
would probably make a heavy use of the Nançay telescope
Observations
Nançay Pulsars observations schedule
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Multi-scale Gravitational Waves detection (1040hr)Very low frequency GW (background)
via a set of highly stable millisecond pulsars with the EPTAauthor list includes all the EPTA members !
Low frequency GW emitted by relativistic binary systemsvia Double Neutron Star monitoring usually
Gravitational Theories testsHigh frequency GW emitted by the neutron star oscillations triggered by glitches
via monitoring young pulsars and alert sent to VIRGO/LIGO
Multi-wavelength study (390hr)radio monitoring of young and noisy pulsars to ensure
a good folding of the very few high energy photonscrashing from time to time on LAT/GLAST detectors during years...
Globular Clusters pulsars (32hr)Proper motions of GC pulsars
Survey of the Galactic Plane (160hr)Pilot during 2008 128MHz(0.25MHz) 30min
80<l<170 deg -1<b<+1 deg2009 : 4000h, 400MHz(0.25MHz), 32s, 30min)
Nançay Scientific programs (2008B allocation)
Total ~ 1600 hours/semester ~ 50% of available telescope time
EPTA MoU
GLAST MoU
Very low frequency GWUse a set of highly stable pulsars
to probe the cosmological background of gravitational waves
University of Manchester, JBO, UK
ASTRON, NL
Max-Planck Institut fur Radioastronomie, GERINAF Osservatorio Astronomico di Cagliari, IT
Paris-Nançay Observatory, FR
The EPTA is based on a unique feature in Europe :the availability of 4 (and soon 5) 100-m class radiotelescopes
Members of the European Pulsar Timing Array (EPTA)
I.Cognard1, G.Desvignes1, M.Burgay2, A.Corongiu1,N.D'Amico2, R.Ferdman1, R.vanHaasteren3, J.Hessels3,
G.Janssen3, A.Jessner4, C.Jordan5, M.Kramer5,L.Kuo5, K.Lazarides4, A.Lyne5, M.Pilia2,
A.Possenti2, M.Purver5, B.Stappers5, G.Theureau1
1 LPCE-CNRS, Orléans, France2 Osservatorio Astronomico di Cagliari, Italy
3 Astronomical Institut 'Anton Pannekoek', Netherlands4 MPI fur Radioastronomie, Germany
5 University of Manchester, United Kingdom
Why the EPTA ?to achieve a better combined sensitivity to Gravitational Waves and
take advantage of this concentration of large telescopes and experts,a Memorandum of Understanding (MoU)
was signed in Januay 2006 and Nançay joined in October 2006
How works the EPTA ?regular workshops at the different telescopes :
Nançay (Oct 2006), Cagliari (May 2007),Bad Honnef (Jan 2008)... next is Manchester (Sept 2008)
monthly video-conferences (EVO) since Feb 2008actions
Coordinated source lists and partly-coordinated observing sessionsTime Of Arrivals (TOAs) and templates (and later raw data) shared among partnersLibrary of common synthetic multi-frequency templates
(based on excellent experience with double pulsar timing)Open to international collaboration (sharing TOAs for joint goals)MoU with australian PPTA in preparation ;
hope to reach similar agreement with US NANOGrav
Westerbork
WSRT 96 m14 25-m dishes Summed in phase to form Tied-Array
PUMA II8x20 MHz sub-bands splitted in 16/32/64 channels,two complex polarisations, 8 bitscoherent dedispersion
32x 2.0GHz dual-Opteron + 8x4 TB disk space
15% pulsar
Jodrell Bank
JB 76 mrecently resurfaced dish
incoherent filterbank64x1MHz
COBRA IISerendip5 based : expect 64MHz for DM<230dual quad-core computers
future instrumentationbased on ATNF DFB3may use HYDRA (144-nodes dual quad-core)
Digital Filterbank DFB3 from ATNF(BW=1GHz, fully programmable FPGA system)
70% pulsar
Effelsberg
dish 100mEBPP coherent dedispersor
112MHz 32x3.5MHzdual polarisation, 4bits
future instrumentationbased on ATNF DBF3
New 7 beam receiver1290-1430 MHz
15% pulsar
Cagliari
MANGUSTA280 AMD Opteron 2.6GHz CPUs
a 64m antenna still in constructionactive primary mirror0.3-100GHz
future instrumentationbased on ATNF DFB3 summer 2008
Nançay
NRT 94 mcollecting area 35x200mKraus design1.1-3.5GHz
BON (Berkeley-Orléans-Nançay)128 MHz from Serendip5 spectrometer,two complex polarisations 8 bitscoherent dedispersion on GPUs
44% pulsar
To achieve even better sensitivity to GWs we are planning on combining all the telescopes ”coherently”
That gives a telescope with a sensitivity equivalent to Arecibo, but able to see much more of the skyIt will test limits of sensitivity and pulse jitter
LEAP : Large European Array for Pulsars
It also provides excellent tests of SKA-like pulsar observing
Multi-wavelength study
A large number of high energy instrumentsare now available
HESS (HESS-II)FERMI-GLAST
A need for accurate and up-to-date radio ephemerison young and noisy pulsarsis emerging more than ever
Smith et al, 2008, A&A in press
Giant Pulses from the Crab pulsarwere used to test the FERMI-LAT pulsar timing sofware
The four bestmilliseconds pulsars observed at Nançay
J1909-3744 410ns
J1600-3053 542ns
B1937+21 203ns
B1713+07 496ns
no DM correction
A recent result from EPTA ondouble neutron star system PSR J1518+4904
NRT
Eff
WSRT
JB
GB
the different datasets
→ constrains on masses and inclination angle of the orbit
Janssen et al., A&A 490, 753
Simultaneous observationsof the Crab Pulsarin radio and optical
Oosterbroek, Cognard et al. A&A 488, 271
optical-radio lag 255±21μs
Double neutron star PSR J1906+0746
PPA=12arctanU
Q
Desvignes et al., 2008, in prep
PSR B1855+09
P=5.362ms DM=13.305pc.cm-3
PSR B1257+12 the pulsar with planets
3 planets : A, B and Cdue to 3:2 resonnance,B and C show time variable orbital parameters
no perturbed planetary motionsin 'tempo' yet !
residuals obtained without perturbation
Conclusion
The large Nançay radiotelescope has now one of the bestpulsar coherent instrumentation in the world
It's diffinitively possible to observe many pulsarsof different kind
So... as in January 2006,that's a call for collaborations/ideas/help/...