Future Canadian Prospects for PulsarsVicky KaspiMcGill UniversitySept 14, 2017

Pulsar-Relevant Radio Telescopes Used by Canadians

• Arecibo• GBT• JBO, Parkes, Effelsberg• JVLA• ARO• CHIME• ASKAP, MeerKAT• HIRAX• SKA

Now

Soon

Later

Pulsar-Relevant Radio Telescopes Used by Canadians

• Arecibo• GBT• JBO, Parkes, Effelsberg• JVLA• ARO• CHIME• ASKAP, MeerKAT (I. Stairs)• HIRAX• SKA

Now

Soon

Later

Pulsar Radio Astronomy• Pulsar searching: we know just the tip of

the Galactic pulsar iceberg• Looking for the jewels!� More pulsars = more chances� Also interesting population

questions• Still, today, finding the unexpected• Pulsar timing essential post-discovery• Occasional interferometry� Positions� Proper motions� Imaging of associated supernova remnants,

pulsar wind nebulae

Pulsars & Arecibo I• PALFA: Pulsar survey of the Galactic Plane

� 32o < l < 70o, -5o < b < 5o

� 1.4 GHz, 322 MHz bandwidth

• Most sensitive pulsar survey ever done!• ~30 astronomers, 5 countries, McGill-led

Canadians: E. Parent, C. Patel,Z. Pleunis, P. Scholz, I. Stairs, VK

• All processing done on Compute Canada/Calcul Quebec supercomputer• 180 pulsars, 1 FRB discovered so far; survey

started in 2009*; roughly half complete (40 days, 145 sq deg)• Jodrell Bank Observatory times

half of PALFA discoveries

PALFA Science Highlights• New! Most relativistic double-neutron star binary ever, 1.9 hr, omdot = 25.6(2) deg/yr (Stovall et al. in prep.)• First repeating, localized FRB, first FRB redshift (Spitler et al. 2016; Scholz et al. 2017; Chatterjee et al. 2017, Nature; Tendulkar et al. 2017)• Highest DM millisecond pulsar known (Crawford et al. 2012; Scholz et al. 2015)• First pulsar found by global volunteer computing (Knispel et al. 2010, Science)• First eccentric millisecond pulsar binary (Champion et al. 2008, Science)

Pulsars & Arecibo II• NANOGrav Pulsar Timing Array

� Nanograv.org

• Monitoring ~40 millisecond pulsars monthly atArecibo, GBT• ~50 researchers from US, Canada:

Ingrid Stairs, Emmanuel Fonseca, VK• Arzoumanian et al 2016: best limit yet

on stochastic background of gravitationalwaves from merging SMBHs: 1 x 10-15 at 1 yr-1

• Part of the International Pulsar Timing Array� www.ipta4gw.org

Pulsars & GBT• GBNCC pulsar survey

� Entire GBT-visible sky� 80 days so far;

• 350 MHz, 100 MHz bandwidth• ~20 astronomers, US & Canada

Pragya Chawla, VK, Ingrid Stairs• All processing done on Compute

Canada/Calcul Quebec resources• 145 new pulsars so far (Stovall

et al. 2015), 0 FRBs (Chawla et al. 2017)

GBNCC Science Highlights•Pulsar triple system (Ransom et al. 2014, Nature)•Most massive neutron star known (Antoniadis et al. 2013, Science)•First transitioning MSP/LMXB system (Archibald et al. 2009, Science)

PALFA, GBNCC…• Still lots of surveying to do, especially with PALFA…if telescope time available• Still making major discoveries!• RFI situation getting worse, limited resources to solve problems• Grateful to our Southern neighbours for Open Skies policy; have payed back with computing, students, science leadership. Win-win!

Pulsars & ARO• Used for pulsar observations since 2012 by

U. Pen, M. van Kerkwijk, K. Vanderlinde

• ARO operated by Thoth on a user fee basis

• successful pulsar observations in 3 new bands: 100-200 MHz, 200-400 MHz, 400-800 MHz

• ideal frequency coverage in bands where pulsars are brightest, and probe ISM propagation: Scintillometry

• new window on ISM, pulsar magnetosphere, pulsar astrometry (50 pico arcseconds achieved)

• successful VLBI pulsar fringes to Effelsberg, GMRT, LOFAR, Arecibo, DRAO: unique sensitive long baseline

• Figure shows frequency and time evolution of Crab giant pulse, illustrating the power of instantaneous high bandwidth and RFI favourable site. Pulse has successful VLBI fringe with DRAO, potentially enabling scintillometry distance measurements.

46-m Algonquin Radio Observatory

Pulsars & CHIME• See talk by Cherry Ng

• Pulsar Timing: all known pulsars visible to CHIME 24/7� NANOGrav: DM variations� RRATs� Intermittent/Nulling pulsars� Transitioning LMXB/pulsars� Precessing DNSs� Magnetars

• Made possible with NSERC/RTI $150K

• Will be massive data set• Jojo Boyle, Paul Demorest,

Emmanuel Fonseca, VK, Arun Naidu, Cherry Ng, Scott Ransom, Paul Scholz, Ingrid Stairs, ShriharshTendulkar

Searching for Pulsars with CHIME• Pulsar Searching: slow pulsars only

� Computationally too hard to search for MSPs now…1024 GBTs!

� NS/BH binary should involved slow pulsar...

• Slow pulsar search simulations by Emmanuel Fonseca using psrpop.py:� ~3000 new regular pulsars with CHIME � Isolated or long-period binaries� Does NOT include RRATs (will be found

by FRB system)� Magnetars

• New ideas for efficient pulsar searches Kendrick Smith (PI)

• New CFI grant will provide infrastructure, storage

Figure by E. Fonseca

HIRAX Frequency Range:400–800 MHz

Frequency Resolution:390 kHz

Dish size:6 m diameter

Layout: 32×32 square grid, 7 m spacing

Field of View: 15 deg2–56 deg2

Resolution: ∼5’–10’

Beam Crossing Time: 17–32 min

System Temperature: 50 K

South Africa1024 Dishes

Newburgh et al. 2016 arXiv:1607.02059

HIRAX and Pulsars•Nominal plan is to point at sky at fixed declination, change dec every ~6 months•Not ideal for pulsar timing!�Still, ok for some work (RTI-scale)

•Very Useful for pulsar searching�Detailed simulations TBD(?)�My Estimate: several thousand new slow pulsars�Plus RRATs from FRB searching

• Current HIRAX Status:�HIRAX-8 being built: 8 dishes�HIRAX-128 funded�Awaiting funding for rest

Pulsars and SKA• Kramer & Stappers (2015)

arXiv:1507.04423• Everything we are doing now but

more pulsars!• Can find (Keane et al. 2015):

� ~10,000 normal pulsars� ~1000 millisecond pulsars� By searching

� SKA-Low: off the Galactic Plane� SKA-Mid: in Galactic Plane

• Galactic centre pulsars?• Not presently much CDN involvement…

(we’re busy). But...doing highly relevantwork à Should be more back & forth!