Anomalous X-ray Pulsars and Soft Gamma-Ray Repeaters in Supernova Remnants Bryan Gaensler Harvard-Smithsonian Center for Astrophysics Introduction There is little direct information for AXPs/SGRs on: • Distances Robert • Ages • Space velocities Mallozzi • Lifetimes / UAH MSFC • Birthsites • Progenitors • Evolution Indirect information from associations with: Supernova remnants Star clusters Molecular clouds Associations with SNRs For radio pulsars, typical criteria for association are: • Evidence for interaction . • Consistent distances/ages (tPSR = P/2P) • Inferred transverse velocity: V^ = RPSR / t • Proper motion • Probability of random alignment Galactic plane, 4o < l < 200 (11 cm Bonn survey): Gaensler & Frail (2000) 20 SNRs, 66 radio pulsars, 14 “associations” AXPs in SNRs Age (kyr) Pchance V^ (km/s) • 1E 2259+586 in CTB 109 ~10 5 x 10-4 < 400 (Fahlman & Gregory 1981) • 1E 1841-045 in Kes 73 2 1 x 10-4 < 500 (Vasisht & Gotthelf 1997) • AX J1845-0258 in G29.6+0.1 < 8 2 x 10-3 < 500 (Gaensler et al 1999) x CTB 109 (ROSAT; Rho & Petre 1997) Kes 73 (Chandra; Slane et al 2002) G29.6+0.1 (VLA; Gaensler et al 1999) Other AXPs • RX J170849-400910 - complicated region - adjacent SNR? (P = 10%) Are these AXPs • 1E 1048.1-5937 older than or - near ? Carina different from the + • 4U 0142+61 others? - no nearby sources • CXOU J010042.8-721132 - near H II / SNR complex N66 CXOU J010042 (AAT Ha; Ye et al 1991) + + + RX J170849 (VLA; Gaensler et al 2001) 1E 1048 (MOST; Whiteoak 1994) 4U 0142 (DRAO; Gaensler et al 2001) Properties of AXPs • 2 out of 6 AXPs (3 out of 7?) definitely associated with SNRs - at SNR centres; implied velocities V^ < 500 km/s; age < 10 kyr - similar to youngest pulsars and “radio-quiet” neutron stars • AXPs are young neutron stars, lifetimes ~ 10 kyr (birth-rate > 1/2000 yr) ? EM dipole braking: magnetars, but limited lifetimes (Colpi et al 2000; Duncan 2001) ? accretion: exotic models required to attain long P (Chatterjee et al 2000; Alpar 2001) -3 • SNR age, size: high inferred ambient densities, n0 > 1 cm (Marsden et al 2001) - huge uncertainties in age, explosion energy, distance ? ? n0/n0 ~ 100 - selection effect: AXPs all found in targeted observations of SNRs! Kes 73 (Chandra; Slane et al 2002) G11.2-0.3 (Chandra; Kaspi et al 2001) Cas A (Chandra; Tananbaum 1999) SGR 0526-66 • On rim of SNR N49 in the LMC (Cline et al 1982; Rothschild et al 1994) - t ~ 5000 yr, V^ ~ 1000 km/s - P = 2 x 10-3 over whole LMC - but in complicated region… x N49 (HST; Williams et al 2002) Large Magellanic Cloud (IRAS 60 µm) SGR 1806-20 • At centre of catalogued SNR G10.0-0.3 (Kulkarni & Frail 1993) - but SGR offset by 14? from core (Hurley et al 1999; Kaplan et al 2002) - central LBV, time-variable: is G10.0-0.3 a SNR? - coincident with massive star cluster & molecular clouds at 15 kpc (Corbel et al 1997; Fuchs et al 1999; Eikenberry et al 2001) + + G10.0-0.3 (VLA; Kulkarni & Frail 1993) 2.2 µm CTIO 4-m (Eikenberry et al 2001) SGR 1900+14 • 5 arcmin outside rim of SNR G42.8+0.6 (Hurley et al 1999) - complicated area, P = 0.04 (Gaensler et al 2001; Kaplan et al 2002) - adjacent young radio pulsar J1907+0918 (Lorimer & Xilouris 2000) - next to massive star cluster at d > 10 kpc (Vrba et al 2000) ++ + G42.8+0.6 (VLA; Kaplan et al 2002) I-band USNO (Vrba et al 2000) SGR 1627-41 • Next to SNR G337.0-0.1 (Woods et al 1999; Hurley et al 2000) - t < 5000 yr, V^ > 1000 km/s - P = 0.05, very complicated region (Sarma et al 1997; Smith et al 1999) - OH maser, molecular clouds: single complex at 11 kpc (Frail et al 1996; Corbel et al 1999) + G337.0-0.1 (ATCA; Sarma et al 1997) CTB 33 region (ATCA; Sarma et al 1997) SGR 1801-23 • Not well-localised (Cline et al 2000) - error circle passes near/through several SNRs - in dense region of Galactic Plane 11 cm Galactic Plane survey (Bonn; Reich et al 1990) Properties of SGRs • 3 out of 4 SGRs in vicinity of SNRs - outside SNRs; V^ > 1000 km/s; associations not compelling - almost all such PSR/SNR associations are spurious • Clearly associated with recent star formation and SNe activity - SGRs are neutron stars, ages < 100 kyr • If SGR/SNR associations are real… ? high velocity population, distinct from AXPs or radio pulsars asymmetric neutrino recoil? (Duncan & Thompson 1992) • If SGR/SNR associations are spurious... ? SGR ages ~ 50 kyr, SNRs have dissipated older population than AXPs? ? SGRs have massive progenitors, in low n0 bubbles? could explain associations with clusters & molecular clouds Conclusions • AXPs are associated with SNRs ? young (< 10 kyr) neutron stars, low space velocities x • SGRs are probably not associated with SNRs ? older (> 50 kyr) neutron stars whose SNRs have faded ? massive progenitors in low-density bubbles • The future… - proper motion of SGRs with Chandra (Hurley et al 2002) - looking for bubbles around SGRs (Gaensler et al 2002) - surveys of SNRs for compact sources (Kaplan et al 2002) .