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Home , Pulsar

Pulsar Overview

Kevin Stovall NRAO

IPTA 2018 Student Workshop, 11 June, 2018 Pulsars Pulsars

• ~2,700 pulsars known

• Act as clocks, therefore provide a means for studying a variety of physical phenomena

• Strongly affected by the (ISM)

• There are many categories of pulsars (MSPs, RRATs, DNSs, mode-switching, nulling, etc.)

• As a population are steep spectrum sources (alpha~-1.4) Some Pulsar Applications

Populations Study of Interstellar Medium • • •Supernovae / Massive Stars •/Scintillation •Binaries •Faraday rotation •Millisecond Pulsars (MSPs) Extreme Environments Exotic Systems •Large B-field •Double Neutron Stars (DNSs) •Neutron Interior •Triple Systems •Tight Binary systems •Double Pulsar •Fast Spinning •Pulsar-BH Theories of Clocks •Tests of GR • •Alternative Theories •Gravitational Waves Pulsars Pulse “Folding” Interstellar Medium Effects Dispersion 2 Delay DM ⌫ /d DM = 0 ne dl R

From “Essential Radio ”, Condon & Ransom Galactic

Lazio & Cordes, 2002, astro-ph:0207156 Yao, Manchester & Wang, 2017, ApJ, 835 Scintillation Arcs

Scattering Scintillation

From “Handbook of Pulsar Astronomy”, Lorimer & Kramer ISM: Faraday rotation

2 PPA = – RM e3 d⇥ RM = 2 4 ne B dl 2ıme c 0 || R

B =1:23—G RM h ||i DM Profile Temporal Stability Pulsar Timing P-Pdot Diagram Millisecond Pulsars (MSPs)

primary secondary (a) (b) • Spin periods less runaway star than ~10 ms, binary disrupts weaker magnetic young pulsar fields, smaller mildly recycled pulsar spin-down rates binary survives

young pulsar

binary disrupts • Formed through secondary evolves (Roche Lobe overflow)

from a high-mass system Supernova companion star X-rays (therefore most low-mass system binary survives of them are in binaries: 2/3) - binary double binary

Lorimer, 2008, LRR, 11 Pulsar Spatial Distribution Pulsar Sky Distribution Pulsar Surveys (partial list)

Center Sample Bandwidth Integration Survey Frequency Resolution Time Style Survey Region (MHz) Time (s) (MHz) (kHz) (us) All Arecibo Sky AO327 327 57/69 56/24 125/82 64 Drift Dec. between -1 & 38

CRAFTS 600 400 ? ? 40? Drift ?

All GBT Sky GBNCC 350 100 24 82 120 Pointed Dec above -40 deg

HTRU-N/S 1352 340 391 64 4200/540/270 Pointed All Sky

Northern Sky LOTAAS 143 32 12 492 3600 Pointed Dec > about 0 deg Galactic Plane in PALFA 1375 323 336 65 268/180 Pointed Arecibo Dec Range

Arecibo 327 MHz Drift Survey (AO327) - Deneva et al. 2013, ApJ, 775, 51 The Commensal FAST Survey (CRAFTS) Green Bank North Celestial Cap (GBNCC) - Stovall et al. 2014, ApJ, 791, 67 High Time Resolution Universe - South (HTRU-S) - Keith et al. 2010, MNRAS, 409, 619 High Time Resolution Universe - North (HTRU-N) - Barr et al. 2013, MNRAS, 435, 2234 LOFAR Tied-Array All-sky Survey (LOTAAS) - Coenen et al. 2014, A&A, 570, 60 Arecibo L-Band Feed Array Pulsar Survey (PALFA) - Cordes et al. 2006, ApJ, 637, 446 Targeted Pulsar Searches

Fermi Unassociated Gamma-ray sources

Locations of gamma-ray sources are searched using various radio telescopes. Drifting Subpulses & Nulling Mode Changing Rotating Radio Transients B1913+16: First Binary Parameters

Keplerian Binary Parameters Orbital Period: PB Projected Semimajor axis: A1 Time of Periastron Passage: T0 Eccentricity: E Longitude of Periastron: OM Post-Keplerian Parameters

2 2 1 !˙ =6ıf (2ıMf ) 3 (1 e ) b b 2 1 3 m2 m2 ‚ = e(2ıfb) (2ıMfb) M (1 + M )

192ı 5 P˙ = (2ı—f ) 3 F (e) b 5 b r = m2 s = sin(i) Double Pulsar GR Tests PSR J0737-3039A/B

Massive Pulsars & EOS

PSR J1614-2230 PSR J0348+0432 Pulsar Mass = 1.97 +/- 0.04 Pulsar Mass = 2.01 +/- 0.04 Demorest et al. 2010, , 467, 1081 Antoniadis et al. 2013, Science, 340, 448