1. Wishing you many years of happiness, health, and pulsars. Happy Birthday, Wim!

2. Vicky Kaspi McGill University Montreal, Canada R. Archibald, VK, P. Scholz et al., in prep.

3. 1E 1048.1-5937  6.4-s X-ray pulsar  One of `original’ AXPs: (e.g. Mereghetti et al. 1998)  qLx = 6x10^33 erg/s  Inferred B=4e14 G  qPulsedFraction ~70%  Simple one-peak profile, duty cycle ~0.3  qX-ray spectrum: bbody kT= 0.5 keV, Gamma=2.7  Not yet confirmed at hard X-ray energies

4. 1E 1048.1-5937: The ‘Anomalous’ AXP?  First AXP seen to exhibit SGR-like X-ray bursts (Gavriil, VK, Woods 2002)  Hardest AXP X-ray spectrum  Large timing noise  AXP/SGR transition object? Today, many `transition objects’ known; distinction between AXPs & SGRs blurred to near oblivion!

5. X-ray Pulsed Flux Flares in 1E 1048.1-5937  Regular RXTE monitoring  Initially, pulsed flux stable  Pulsed flux flares in 2001, 2002  Coincident with SGR-like bursts  Note slow flux rise  E=3x10^40 erg, 3x10^41 erg for 5 kpc  Tiengo et al. 2005 show likely double the energy release Gavriil & VK 2004

6. Unusual Torque Variations  Unusual torque variations began 150-200 days after 2 nd flare onset  Always spinning down  Variations by order-of-magnitude!  Note large nudot changes while X-ray flux ~stable 2-10 keV Gavriil & VK 2004

7. A Second Flux Flare Dib, VK & Gavriil 2009  2 nd X-ray flare episode in 2007  Spin-up glitch  Fast rise  ~Linear decay  Note pulse profile changes  Profile returns to normal before flux does

8. Pulse Profile Changes Dib, VK & Gavriil 2009

9. More Torque Variations Dib & VK in prep. RXTE R.I.P 1996-2012

10. A Third Flux Flare… R. Archibald et al. in prep.

11. 3 Similar Events in 1E 1048  Flux flare separations not exactly the same but close: 4.9 yr, 4.6 yr  Peak luminosities very similar; ~3.5x10^35 erg/s for d=9 kpc (Durant & van Kerkwijk 2006)  All flares show spectral hardening  Both kT increases, Gamma decreases (Tam et al. 2008)  Decay times similar  2/3 rises resolved  Large torque variations seen few months after each flare subsiding  Flux stable during torque variations R. Archibald et al. in prep.

12. Archibald et al. in prep. Phase averaged flux

13. Theoretical Interpretation(?)  Torque sensitive to field lines in narrow bundle near magnetic pole (Thompson et al. 2002)  can have decoupling between torque, X-ray luminosity  Overall expect broad correlation between Lx, torque, spectral hardness (Marsden & White 2001; VK & Boydstun 2010)  Beloborodov (2009): Flares due to magnetospheric twisting; large twists  poloidal field line inflation, enhanced torque that eventually decays  Delay due to growth of twist angle to O(1); depends on initial size of twist angle near magnetic axis  But why not seen in other magnetars? And why cyclic only here?

14. Not seen in other sources: Dib & Kaspi in prep. 1E 2259+586

15. Summary  Magnetar 1E 1048.1-5937 has now shown 3 X-ray flares and 3 episodes of enhanced torque variations, delayed  Flux flares different than in other similar sources  Resolved rises, longer decays  Large torque variations not seen in other `classical’ AXP sources  Possibly cyclic behavior predicts mid-end 2016 for next event  Another reason 1E 1048.1-5937 `anomalous’!