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Close-by young isolated NSs: A new test for cooling curves

Close-by young isolated NSs: A new test for cooling curves. Sergei Popov (Sternberg Astronomical Institute) Co-authors: H.Grigorian, R. Turolla, D. Blaschke (astro-ph/0411618). Plan of the talk. Abstract Close-by NSs Population synthesis Log N – Log S Test of cooling curves

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Close-by young isolated NSs: A new test for cooling curves

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  1. Close-by young isolated NSs: A new test for cooling curves Sergei Popov (Sternberg Astronomical Institute) Co-authors: H.Grigorian, R. Turolla, D. Blaschke (astro-ph/0411618)

  2. Plan of the talk • Abstract • Close-by NSs • Population synthesis • Log N – Log S • Test of cooling curves • Final conclusions

  3. Abstract of the talk We propose a new test of cooling curves. It is based on the Log N – Log S distribution. It should be used together with the standard test temperature vs. age

  4. Isolated neutron stars population: in the Galaxy and at the backyard • INSs appear in many flavours • Radio pulsars • AXPs • SGRs • CCOs • RINSs • Local population of young NSs is different (selection) • Radio pulsars • Geminga+ • RINSs

  5. Close-by radioquiet NSs • Discovery: Walter et al. (1996) • Proper motion and distance: Kaplan et al. • No pulsations • Thermal spectrum • Later on: six brothers RX J1856.5-3754

  6. Magnificent Seven Radioquiet (?) Close-by Thermal emission Long periods

  7. Population of close-by young NSs • Magnificent seven • Geminga and 3EG J1853+5918 • Four radio pulsars with thermal emission (B0833-45; B0656+14; B1055-52; B1929+10) • Seven older radio pulsars, without detected thermal emission. We need population synthesis studies of this population

  8. Population synthesis: ingredients • Birth rate • Initial spatial distribution • Spatial velocity (kick) • Mass spectrum • Thermal evolution • Emission properties • Interstellar absorption • Detector properties A brief review on population synthesis in astrophysics can be found in astro-ph/0411792

  9. Solar vicinity • Solar neighborhood is not a typical region of our Galaxy • Gould Belt • R=300-500 pc • Age: 30-50 Myrs • 20-30 SN per Myr (Grenier 2000) • The Local Bubble • Up to six SN in a few Myrs

  10. The Gould Belt • Poppel (1997) • R=300 – 500 pc • Age 30-50 Myrs • Center at 150 pc from the Sun • Inclined respect to the galactic plane at 20 degrees • 2/3 massive stars in 600 pc belong to the Belt

  11. Mass spectrum of NSs • Mass spectrum of local young NSs can be different from the general one (in the Galaxy) • Hipparcos data on near-by massive stars • Progenitor vs NS mass: Timmes et al. (1996); Woosley et al. (2002) astro-ph/0305599

  12. Cooling of NSs • Direct URCA • Modified URCA • Neutrino bremstrahlung • Superfluidity • Exotic matter (pions, quarks, hyperons, etc.) In our study for illustrative purposes we use a set of cooling curves calculated by Blaschke, Grigorian and Voskresenski (2004) in the frame of the Nuclear medium cooling model

  13. Standard test: temperature vs. age Kaminker et al. (2001)

  14. Log N – Log S calculations -3/2 sphere: number ~ r3 flux ~ r-2 Log of the number of sources brighter than the given flux -1 disc: number ~ r2 flux ~ r-2 Log of flux (or number counts)

  15. Log N – Log S: early results • Task: to understand the Gould Belt contribution • Calculate separately disc (without the belt) and both together • Cooling curves from Kaminker et al. (2001) • Flat mass spectrum • Single maxwellian kick • Rbelt=500 pc astro-ph/0304141

  16. Log N – Log S as an additional test • Standard test: Age – Temperature • Sensitive to ages <105 years • Uncertain age and temperature • Non-uniform sample • Log N – Log S • Sensitive to ages >105 years (when applied to close-by NSs) • Definite N (number) and S (flux) • Uniform sample • Two test are perfect together!!! astro-ph/0411618

  17. Model I. Yes C A Model II. No D B Model III. Yes C B Model IV. No C B Model V. Yes D B Model VI. No E B Model VII. Yes C B’ Model VIII.Yes C B’’ Model IX. No C A Blaschke et al. used 16 sets of cooling curves. They were different in three main respects: Absence or presence of pion condensate Different gaps for superfluid protons and neutrons Different Ts-Tin List of models (Blaschke et al. 2004) Pions Crust Gaps

  18. Model I • Pions. • Gaps from Takatsuka & Tamagaki (2004) • Ts-Tin from Blaschke, Grigorian, Voskresenky (2004) Can reproduce observed Log N – Log S

  19. Model II • No Pions • Gaps from Yakovlev et al. (2004), 3P2 neutron gap suppressed by 0.1 • Ts-Tin from Tsuruta (1979) Cannot reproduce observed Log N – Log S

  20. Model III • Pions • Gaps from Yakovlev et al. (2004), 3P2 neutron gap suppressed by 0.1 • Ts-Tin from Blaschke, Grigorian, Voskresenky (2004) Cannot reproduce observed Log N – Log S

  21. Model IV • No Pions • Gaps from Yakovlev et al. (2004), 3P2 neutron gap suppressed by 0.1 • Ts-Tin from Blaschke, Grigorian, Voskresenky (2004) Cannot reproduce observed Log N – Log S

  22. Model V • Pions • Gaps from Yakovlev et al. (2004), 3P2 neutron gap suppressed by 0.1 • Ts-Tin from Tsuruta (1979) Cannot reproduce observed Log N – Log S

  23. Model VI • No Pions • Gaps from Yakovlev et al. (2004), 3P2 neutron gap suppressed by 0.1 • Ts-Tin from Yakovlev et al. (2004) Cannot reproduce observed Log N – Log S

  24. Model VII • Pions • Gaps from Yakovlev et al. (2004), 3P2 neutron gap suppressed by 0.1. 1P0 proton gap suppressed by 0.5 • Ts-Tin from Blaschke, Grigorian, Voskresenky (2004) Cannot reproduce observed Log N – Log S

  25. Model VIII • Pions • Gaps from Yakovlev et al. (2004), 3P2 neutron gap suppressed by 0.1. 1P0 proton gap suppressed by 0.2 and 1P0 neutron gap suppressed by 0.5. • Ts-Tin from Blaschke, Grigorian, Voskresenky (2004) Can reproduce observed Log N – Log S

  26. Model IX • No Pions • Gaps from Takatsuka & Tamagaki (2004) • Ts-Tin from Blaschke, Grigorian, Voskresenky (2004) Can reproduce observed Log N – Log S

  27. HOORAY!!!! Log N – Log S can select models!!!!! Only three (or even one!) passed the second test! …….still………… is it possible just to update the temperature-age test??? May be Log N – Log S is not necessary? Let’s try!!!!

  28. Brightness constraint • Effects of the crust (envelope) • Fitting the crust it is possible to fulfill the T-t test … • …but not the second test: Log N – Log S !!! (H. Grigorian astro-ph/0507052)

  29. Sensitivity of Log N – Log S • Log N – Log S is very sensitive to gaps • Log N – Log S is not sensitive to the crust if it is applied to relatively old objects (>104-5 yrs) • Log N – Log S is not very sensitive to presence or absence of pions Model I (YCA) Model II (NDB) Model III (YCB) Model IV (NCB) Model V (YDB) Model VI (NEB) Model VII(YCB’) Model VIII (YCB’’) Model IX (NCA) We conclude that the two test complement each other

  30. Resume • Log N – Log S for close-by NSs can serve as a test for cooling curves • Log N – Log S test can include NSs with unknown ages, so additional sources (like the Magnificent Seven) can be used to test cooling curves • Two tests (LogN–LogS and Age-Temperature) are perfect together.

  31. THAT’S ALL. THANK YOU!

  32. Radio detection Malofeev et al. (2005) reported detection of 1RXS J1308.6+212708 (RBS 1223) in the low-frequency band (60-110 MHz) with the radio telescope in Pushchino. (back)

  33. Evolution of NS: spin + magnetic field Ejector → Propeller → Accretor → Georotator 1 – spin-down 2 – passage through a molecular cloud 3 – magnetic field decay astro-ph/0101031 Lipunov (1992)

  34. Model I • Pions. • Gaps from Takatsuka & Tamagaki (2004) • Ts-Tin from Blaschke, Grigorian, Voskresenky (2004) Can reproduce observed Log N – Log S (back)

  35. Model IX • No Pions • Gaps from Takatsuka & Tamagaki (2004) • Ts-Tin from Blaschke, Grigorian, Voskresenky (2004) Can reproduce observed Log N – Log S (back)

  36. Model III • Pions • Gaps from Yakovlev et al. (2004), 3P2 neutron gap suppressed by 0.1 • Ts-Tin from Blaschke, Grigorian, Voskresenky (2004) Cannot reproduce observed Log N – Log S (back)

  37. Model II • No Pions • Gaps from Yakovlev et al. (2004), 3P2 neutron gap suppressed by 0.1 • Ts-Tin from Tsuruta (1979) Cannot reproduce observed Log N – Log S (back)

  38. Model IV • No Pions • Gaps from Yakovlev et al. (2004), 3P2 neutron gap suppressed by 0.1 • Ts-Tin from Blaschke, Grigorian, Voskresenky (2004) Cannot reproduce observed Log N – Log S (back)

  39. Model V • Pions • Gaps from Yakovlev et al. (2004), 3P2 neutron gap suppressed by 0.1 • Ts-Tin from Tsuruta (1979) Cannot reproduce observed Log N – Log S (back)

  40. Model VI • No Pions • Gaps from Yakovlev et al. (2004), 3P2 neutron gap suppressed by 0.1 • Ts-Tin from Yakovlev et al. (2004) Cannot reproduce observed Log N – Log S (back)

  41. Model VII • Pions • Gaps from Yakovlev et al. (2004), 3P2 neutron gap suppressed by 0.1. 1P0 proton gap suppressed by 0.5 • Ts-Tin from Blaschke, Grigorian, Voskresenky (2004) Cannot reproduce observed Log N – Log S (back)

  42. Model VIII • Pions • Gaps from Yakovlev et al. (2004), 3P2 neutron gap suppressed by 0.1. 1P0 proton gap suppressed by 0.2 and 1P0 neutron gap suppressed by 0.5. • Ts-Tin from Blaschke, Grigorian, Voskresenky (2004) Can reproduce observed Log N – Log S (back)

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