LMXBs as progenitors of millisecond pulsars Alessandro Patruno Astronomical Institute A. Pannekoek University of Amsterdam
RECYCLING SCENARIO Image credit: Bill Saxton (NRAO) 2
ACCRETING MILLISECOND PULSARS 14 AMXPs known Spin Frequencies:182-599 Hz Page 3
ACCRETING MILLISECOND PULSARS 14 AMXPs known Spin Frequencies:182-599 Hz Ω K = √ GM 3 R Page 4
ACCRETING MILLISECOND PULSARS 14 AMXPs known Spin Frequencies:182-599 Hz Ω K = √ GM 3 R 2 P mag = B 8π >> P gas , P ram Page 5
ACCRETING MILLISECOND PULSARS 14 AMXPs known Spin Frequencies:182-599 Hz Ω K = √ GM 3 R Magnetospheric Radius 2 P mag = B 8π >> ( P gas , P ram ) M 6 / 7 B 2 / 7 ν ∝ ˙ ˙ Page 6
ACCRETING MILLISECOND PULSARS 14 AMXPs known Spin Frequencies:182-599 Hz Ω K = √ GM Hot Spots 3 R Magnetospheric Radius 2 P mag = B 8π >> ( P gas , P ram ) M 6 / 7 B 2 / 7 ν ∝ ˙ ˙ Page 7
AMXP FAMILY P orb > 3.5 hr Peculiarities XTE J1814-338 MS/SubG P orb AQL X-1 (19 hrs)/Intermittent SAX J1748.9-2021 Intermittent IGR J17511-3057 Swift J1749.4-2807 Eclipsing IGR J17498-2921 1 hr < P orb < 3.5 hr BD SAX J1808.4-368 Anomalous orbital evolution HETE J1900.1-2455 Intermittent/B Screening IGR J00291+5934 Fastest spin (599 Hz) P orb < 1 hr WD XTE J1751-305 (He) XTE J0929-314 (He or C/O) XTE J1807-294 (He or C/O) Small donor (0.007 Msun) Swift J1756.9-2508 (He) Small donor (0.007 Msun) NGC 6440 X-2 (He) Small donor (0.007 Msun) See review Patruno & Watts 2012 8
SPIN DISTRIBUTION Accreting ms Pulsars See Galloway's talk on Type I burst sources Patruno & Watts 2012, Tauris 2012 (Science 335), Tauris 2012 (arXiv1210.2598) 9
RECYCLING SCENARIO 3b . 2b . 11
RADIO PULSAR/X-RAY BINARY LINK PSR J1023+0038 1.69 ms spin period 4.8 hr orbital period Accretion disk in 2001 Archibald et al. (2009, 2010), Wang et al. (2009, 2010) 12
RADIO PULSAR/X-RAY BINARY LINK Red-back Does the accretion disk form/destroy on a timescale of ~10 yr ? How can the disk form again ? How does the pulsar spin evolve ? Non-degenerate companion Eclipses for 50% of the time Archibald et al. (2009, 2010), Wang et al. (2009, 2010) 13
AMXP FAMILY P orb > 3.5 hr XTE J1814-338 4.3 hr 314 Hz MS/SubG 19 hr 550 Hz AQL X-1 SAX J1748.9-2021 8.8 hr 442 Hz Redbacks ? IGR J17511-3057 3.5 hr 245 Hz Swift J1749.4-2807 8.8 hr 518 Hz IGR J17498-2921 3.8 hr 401 Hz 1 hr < P orb < 3.5 hr BD SAX J1808.4-368 HETE J1900.1-2455 IGR J00291+5934 P orb < 1 hr WD XTE J1751-305 (He) XTE J0929-314 (He or C/O) XTE J1807-294 (He or C/O) Swift J1756.9-2508 (He) NGC 6440 X-2 (He) 14
SAX J1808.4-3658: A Hidden Radio Pulsar ? 31 erg / s L q = 5 × 10 33 erg / s L irr > 4 × 10 Irradiated Disk Fails to Explain Observations Homer+ (2001); Burderi+ (2003); Campana+ (2004); Deloye+ (2008); Wang+ (2009) See D'Avanzo+ (2009) for optical counterparts of more AMXPs in quiescence See also Iacolina+ (2009, 2010) for AMXPs radio searches 15
Orbital Evolution '11 '08 '98 '00 '00 '00 '05 '02 SAX J1808.4-3658 SAX J1808.4-3658 Time P b − 12 s / s ˙ P b = 3.5 × 10 ≈ 70 Myr Orbital Period: 2.01 hr ˙ P b ¨ − 20 s / s 2 P b = 1.6 × 10 See PSR J2051-0827 in radio (Lazaridis et al. 2011) Patruno et al. 2012; Burderi et al. 2009; Hartman et al. 2008, 2009; Di Salvo et al. 2008 16
AMXP FAMILY P orb > 3.5 hr XTE J1814-338 4.3 hr 314 Hz MS/SubG 19 hr 550 Hz AQL X-1 SAX J1748.9-2021 8.8 hr 442 Hz Redbacks ? IGR J17511-3057 3.47hr 245 Hz Swift J1749.4-2807 8.8 hr 518 Hz IGR J17498-2921 3.8 hr 401 Hz 1 hr < P orb < 3.5 hr BD SAX J1808.4-368 2 hr 401 Hz Black Widows ? HETE J1900.1-2455 1.4 hr 377 Hz IGR J00291+5934 2.5 hr 599 Hz P orb < 1 hr WD XTE J1751-305 (He) XTE J0929-314 (He or C/O) XTE J1807-294 (He or C/O) Swift J1756.9-2508 (He) NGC 6440 X-2 (He) See review Patruno & Watts 2012 17
NON-PULSATING LMXBs Pulsating Non Intermittent pulsating sources Nuclear Powered Accretion powered ? 0 10 20 30 40 50 60 70 80 90 100 Nr. LMXBs 18
MAGNETIC SCREENING 2 / 7 ˙ 6 / 7 ν s ∝ exp (− t / τ) ν s ∝ B ˙ ˙ M Patruno 2012 19
MAGNETIC SCREENING ∂ B ∂ t =∇×( v × B )− c ∇× J σ Cumming et al. 2001, Cumming 2008 20
SPIN DISTRIBUTION Evolutionary processes Magnetic Field Screening Low Accretion Rates 21
MISSING PIECES Do AMXPs turn cyclically on as radio ms pulsars ? Do sub-ms pulsars exist ? Where do we need to look for them ?
Recommend
More recommend
