Many facets of Neutron Stars Astrosat and beyond
Many facets of Neutron Stars Astrosat and beyond Biswajit Paul Raman Research Institute, Bangalore
Many facets of Neutron Stars Astrosat and beyond • Different varieties of neutron stars • X-ray binary studies • Orbital evolution of X-ray binaries • Accretion torque • Quasi periodic oscillations in accreting X-ray pulsars • Self absorption in X-ray and dips in the pulse profiles • Cyclotron scattering resonance feature, pulse phased studies • Thermonuclear bursts, X-ray reprocessing • Future • Astrosat • X-ray polarimeter
Different Types of Neutron Stars Rotation Powered : Ordinary and Millisecond Pulsars
Different Types of Neutron Stars Magnetars
Different Types of Neutron Stars Accretion Powered
Why study orbital evolution • Single star evolution is different from binary evolution • End products : Double compact binaries (Gravitational wave, GRBs) • Stellar physics!!
Orbital Evolution • Conservative mass transfer • Mass transfer + mass loss • Tidal effect • Gravitational wave radiation HMXBs LMC X-4 SMC X-1 Cen X-3 4 U 1538 -52 • Be-XRBs 4 U 0115+63 • LMXBs Her X-1 SAX J 1808. 4 -3658 4 U 1822 -37 XTE J 1710 -281
Measurement Techniques • Pulse timing (Broad pulse, jitters, absorption, statistics) • Eclipse timing (Pre-eclipse dips) • Orbital modulation (Stability of modulation pattern) • Spectroscopic (HMXB ? X-ray Irradiation ? )
Orbital Evolution of HMXB Pulsars • Evolution time scale ~10 5 -6 years Tidal effect
Apsidal advance in 4 U 0115+63: 24. 3 days Ecentricity: 0. 34, apsidal rate: 0. 06+-0. 02 Raichur and Paul 2010
Probing the Stellar Structure
Eclipse timing: XTE J 1710 -281
Eclipse timing: XTE J 1710 -281 Jain and Paul 2010
Eclipse timing: EXO 0748 -676 Wolff et al. 2009
Orbital evolution of X-ray binaries LMC X-4 Cen. X-3 SMC X-1 4 U 1538 -52 XTE J 1808 -5635 XTE J 1710 -281 4 U 1822 -37 Her X-1 Cyg X-3
Disk Magnetosphere Interaction Ghosh and Lamb 1979
QPOs: Luminosity dependence A 0535+262: Finger et al. , (1996), Ghosh (1996)
QPO Discoveries XTE J 1858+034: Paul et al. (1998) 4 U 1907+09: Mukherjee et al. (2001) XTE J 0111. 2 -7317 (Kaur al. 2007)
QPO Discoveries
QPO census Source Type Pulse freq QPO freq Ratio KS 1947+300 HMXB/Be 53 20 0. 38 SAX J 2103. 5+4545 HMXB/? 2. 79 44 15. 77 A 0535+26 HMXB/Be 9. 7 50 5. 15 V 0332+53 HMXB/Be 229 51 0. 223 4 U 0115+63 HMXB/Be 277 62 0. 224 1 A 1118 -616 HMXB/Be 2. 5 92 36. 8 XTE J 1858+034 HMXB/Be 4. 53 110 24. 3 4 U 1901+03 HMXB/? 361. 9 130 0. 359 EXO 2030+375 HMXB/Be 24 200 8. 33 SWIFT J 1626. 6 -5156 HMXB/Be 65 1000 15. 38 XTE J 0111. 2 -7317 HMXB/B 0. 5 -B 1 Ve 32 1270 39. 68 GRO J 1744 -28 LMXB 2100 20000 9. 52 GX 304 -1 HMXB 3. 63 120 33 MAXI J 1409 -619 HMXB 2. 0 192 95 --------------------------------------------------SMC X-1 HMXB/B 0 1410 10 0. 0071 Her X-1 LMXB 806 13 0. 016 LMC X-4 HMXB/O-type 74 0. 65 -20 0. 0087 -0. 27 Cen X-3 HMXB/O-type 207 35 0. 17 4 U 1626 -67 LMXB 130 48 0. 37 X Per HMXB/Be 1. 2 54 45 4 U 1907+09 HMXB/OB 2. 27 69 30. 4
Magnetic Field Estimation with QPOs
Magnetic Field Estimation with QPOs James 2012 (Ph. D Thesi
Dips in Pulse Profiles : Partial Covering Absorption 23
Dips in Pulse Profiles : Partial Covering Absorption 24
Dips in Pulse Profiles : Partial Covering Absorption 25
Accretion onto Neutron Star
Accretion onto Neutron Star Ghosh & Lamb, 1979 Frank, King and Raine: Accretion Power in Astrophysics
Fermi-GBM, CGRO-BATSE
From BATSE Bildstein et al. 1997
Fermi-GBM, CGRO-BATSE
4 U 1626 -67: Period Evolution Camero-Arranz et al. 2010
4 U 1626 -67: Light Curves Aru Beri et al. 2013 32
4 U 1626 -67: Pulse Profiles Aru Beri et al. 2013 33
Accretion torque in 4 U 1626 -67 • X-ray luminosity (mass accretion rate) is not the sole deciding factor in accretion torque • How the disk couples to the magnet is also important
Accreting X-ray pulsars Spectrum 35
Pulsar Cyclotron lines
Cyclotron lines at different pulse phases
Pulsar Cyclotron lines Fundamental and harmonic ratio
Pulsar Cyclotron lines At Different Luminosities 4 U 1907+09
Reprocessing of Thermonuclear X-ray Bursts
Thermonuclear X-ray Burst Reprocessing 41
Reprocessing Region ? Hynes et al. 2006
Reprocessing in EXO 0748 -676: XMM-Newton Observations
Reprocessing in EXO 0748 -676: XMM-Newton Observations
X-ray Pulse Reprocessing 4 U 1626 -67: (Gayathri, Paul, Dipankar, Mohan, 2015)
Low mass X-ray binaries
ASTORSAT
Indian X-ray Astronomy Experiment (1996 -2000)
c
Large Area X-ray Proportional Counter
LAXPC: Effective Area
Hard X-ray Quasi Periodic Oscillations
X-ray Polarimetry
Accreting X-ray Pulsars 54
Black Hole Accretion Disks 55
Rotation Powered Pulsars & Magnetars 56
57
Detectors 58
59
Deep Interplanetary Navigation with X-ray pulsars Becker et al. 2013 ISRO HQ - 22 Apr 2014
Deep Interplanetary Navigation with X-ray pulsars Becker et al. 2013
- Slides: 61