New adventures of Uncatchables

1. New adventures of Uncatchables Sergei Popov, Bettina Posselt (astro-ph/0609275 and work in progress)

2. Population of close-by young NSs Abstract We present preliminary results of a new model of population synthesis of close-by young isolated neutron stars. In comparison with the previous models we include detailed initial distribution of NS progenitors and detailed distribution of the ISM. In addition we tried to vary NS mass spectrum and modified the procedure of calculating absorbed ROSAT flux. The results suggest that new isolated cooling neutron stars should we searched at count rates 0.01<cts/s<0.1 in the direction of rich OB associations behind the Gould Belt. These sources are expected to be younger, and so hotter, than the Magnificent Seven. • 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. Where are the rest? UNCATCHABLES

3. Some old results of Pop. Synthesis-I:Log N – Log S and spatial distribution Log N – Log S for close-by ROSAT NSs can be explained by standard cooling curves taking into account the Gould Belt. Log N – Log S can be used as an additional test of cooling curves More than ½ are in +/- 12 degrees from the galactic plane. 19% outside +/- 30o 12% outside +/- 40o

4. Population sythesis – II.recent improvements 1. Spatial distribution of progenitor stars Solid – new initial XYZ Dashed – Rbelt = 500 pc Dotted – Rbelt = 300 pc a) Hipparcos stars up to 500 pc [Age: spectral type & cluster age (OB ass)] b) 49 OB associations: birth rate ~ Nstar c) Field stars in the disc up to 3 kpc

5. Population sythesis – II.recent improvements 2. New cross sections & abundances and new mass spectrum Low mass stars masses are treated following astro-ph/0409422 Solid – new abundances, old mass Dotted – old abundances, old mass Dashed – new abundances, new mass

6. Population synthesis – II.recent improvements 3. Spatial distribution of ISM (NH) instead of : now : Dot-dashed and dot-dot-dashed lines represent two new models of the ISM distribution.

7. Popov et al. 2005 Count rate > 0.05 cts/s b= +90° Cep?Per? Sco OB Ori b= -90° PSRs+ Geminga+ M7 PSRs- First new results: new maps Clearly several rich OB associations start to dominate in the spatial distribution

8. First new results:50 000 tracks, new ISM model Candidates: Agueros Chieregato

9. First new results:Age and distance distributions 1 < cts/s < 10 0.1 < cts/s < 1 0.01 < cts/s < 0.1 Age Distance

10. Where to search for more cavaliers? We do not expect to find much more candidates at fluxes >0.1 cts/s. Most of new candidates should be at fluxes 0.01< f < 0.1 cts/s. So, they are expected to be young NSs (<few 100 Mys) just outside the Belt. I.e., they should be in nearby OB associations and clusters. Most probable candidates are Cyg OB7, Cam OB1, Cep OB2 and Cep OB3. Orion region can also be promising. Name           l-      l+     b-    b+      Dist., pcCyg OB7     84      96    -5     9       600-700Cep OB2     96     108    -1   12       700Cep OB3    108    113     1     7       700-900Cam OB1   130    153    -3    8       800-900 90 130 L=110 10 0 -10 (ads.gsfc.nasa.gov/mw/)

11. Resume • New more detailed population synthesis model for local population of isolated NS is made • New results provide a hint to search for new coolers. • We predict that new objects can be identified at 0.01<cts/s<0.1 behind the Gould Belt in the directions of close-by rich OB associations, in particular Cep OB2. • These objects are expected to be younger and hotter than the Magnificent seven. Task for eRosita?

12. The Magnificent Seven Vs. Uncatchables Born in the Gould Belt. Bright. Middle-aged. Already detected. Born behind the Belt. Dimmer. Younger. Wanted.