Solar vicinity, close-by young isolated NSs, and tests of cooling curves

1. Solar vicinity, close-by young isolated NSs,and tests of cooling curves Sergei Popov (Sternberg Astronomical Institute) Co-authors: H.Grigorian, R. Turolla, D. Blaschke ECT*, Trento, September 14, 2005

2. Plan of the talk • Intro. Close-by NSs • Age-Distance diagram • Solar vicinity. Stars • Spatial distribution • Mass spectrum • Two tests of cooling • Brightness constraint • Sensitivity of two tests • Final conclusions

3. Isolated neutron stars population: in the Galaxy and at the backyard • INSs appear in many flavours • Radio pulsars • AXPs • SGRs • CCOs • RINSs Note a recent discovery by Lyne et al. (submited to Nature, see later) • Local population of young NSs is different (selection) • Radio pulsars • Geminga+ • RINSs

4. 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

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

6. 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.

7. Age-distance diagram A toy-model: a local sphere (R=300 pc) and a flat disk. Rate of NS formation in the sphere is 235 Myr-1 kpc-3 (26-27 NS in Myr in the whole sphere). Rate in the disc is 10 Myr-1 kpc-2 (280 NS in Myr up to 3 kpc). (astro-ph/0407370)

8. More realistic age-dist. diagram Initial distribution from Popov et al. 2005. Spatial evolution is not followed. For the line of “visibility” (solid line in the middle) I assume the limiting flux 10-12 erg s-1 cm-2 and masses are <1.35 (Yakovlev et al. curves).

9. Realistic age-distance diagram Realistic initial distribution. Spatial evolution is taken into account. The line of “visibility” is drawn as the dotted line. Five curves correspond to 1, 4 , 13, 20 and 100 NSs.

10. 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

11. 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

12. Distribution of open clusters (Piskunov et al. astro-ph/0508575)

13. Surface density of open clusters (Piskunov et al.)

14. Spatial distribution of close-by open clusters in 3D Grey contours show projected density distribution of young (log T<7.9) clusters. (Piskunov et al.)

15. Clusters and absorption Triangles – Gould Belt clusters. (Piskunov et al.)

16. Spatial distribution More than ½ are in +/- 12 degrees from the galactic plane. 19% outside +/- 30o 12% outside +/- 40o (Popov et al. 2005 Ap&SS 299, 117) Lyne et al. reported transient dim radio sources with possible periods about seconds in the galactic plane discovered in the Parkes survey (talk by A. Lyne in Amsterdam, august 2005; subm. to Nature). Shall we expect also Lyne’s objects from the Belt???? YES!!! And they even have to be brighter (as they are closer). The problem – low dispersion.

17. 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) (masses of secondary objects in NS+NS) astro-ph/0305599

18. Two tests Age – Temperature & Log N – Log S

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

20. 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)

21. 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

22. 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

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

24. 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

25. 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

26. 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

27. 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

28. 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

29. 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

30. 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

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

32. 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!!!!

33. 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)

34. 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

35. THAT’S ALL. THANK YOU!

36. Resume • We live in a very interesting region of the Milky Way! • 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.

37. 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)

38. 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)

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

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

41. 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)

42. 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)

43. 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)

44. 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)

45. 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)

46. 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)

47. 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)

48. NS+NS binaries Pulsar Pulsar mass Companion mass B1913+16 1.44 1.39 B2127+11C 1.35 1.36 B1534+12 1.33 1.35 J0737-3039 1.34 1.25 J1756-2251 1.40 1.18 (PSR+companion)/2 J1518+4904 1.35 J1811-1736 1.30 J1829+2456 1.25 (David Nice, talk at Vancouver) (Back)

49. P-Pdot for new transient sources Lyne et al. 2005 Submitted to Nature (I’m thankful to Prof. Lyne for giving me an opportunity to have a picture in advance) Estimates show that there should be about 400 000 sources of this type in the Galaxy (back)