Outbursts and State Transitions in Black Hole Candidates observed by MAXI Hitoshi Negoro (Nihon U.) & MAXI Team

Outline Black Hole Transients/Transient Events observed with MAXI Discovery of a new black-hole candidate MAXI J Comparison with.. –XTE J –Soft state transitions in Cyg X-1 and GX Some comments on other BHCs What triggers the state transition ? Summary

Black Hole Candidates XTE J (#2259, 2378*, 2396) GX (#2380) H (#2364, 2378, 2774) 4U (#2363) Cyg X-1 (#2711) GRS Swift J (#2341) LMC X-1, X-3 ATel # in Red : Possible State Transition MAXI J (#2873)

Swift/BAT triggered (Mangano+ GCN 11296) as GRB A Discovery of MAXI J MAXI/GSC triggered (Negoro+ ATel 2783) Nova Alert System: Ozawa+ Suwa+ (MAXI keV)

keV State Transitions in MAXI J see RXTE results by Yamaoka+

Color-Intensity Diagram MAXI J Soft State Hard State “Stable” Intermediate (very high?) State 2-20 keV Flux

Color-Intensity Diagram Comparison with XTE J “stable” 2nd hard state ? Nakahira+ 2010, also see Poster Soft State

Cyg X-1 and GX both in the soft state ? Cyg X-1 GX 339-4

Soft State Transition in GX Yamaoka+ ATel 2380 see Shidatsu+

Color-Intensity Diagram GX Finder+ 04

Soft? State Transition in Cygnus X-1 Negoro+ ATel 2711

Color-Intensity Diagram Cygnus X-1

Color-Intensity Diagram GX (color) and Cyg X-1 (black) Also see Tomida+ SSC result

Short-term Variability Cyg X-1 GX 339-4

Outbursts in H Yamaoka+ ATel 2364, 2378 Nakahira+ ATel 2774

Outburst in 4U Tomida+ ATel 2363 no BG subtraction

Swift J SSC 1 yr Image (Kimura+) Negoro+ ATel 2341

Nature of the Soft Excess Component in Swift J Miller Hiemstra+ 2008Durant Short-term ? ~ days ?

XTE J MAXI J GX Cyg X-1 Dark and Fast Transition Soft-State Source or Intermediate-State Source ? cf. Gierlinski & Newton 2006 Bright and Slow Transition

What makes a big wall of the ratio 0.5 (jet line) ?

Discussion Yu Yu et al. found a positive correlation between the peak luminosities of the hard state and those of the soft state.

Discussion Color Intensity The soft state transition is not directly associated with an absolute m-dot value (?). This suggests magnetic force plays some important role. The disk is still supported magnetically ? magnetically ? Oda+ (2009) explained two types of soft-state transitions by a magnetically supported disk model.

Summary MAXI observed X-ray outbursts from H , 4U , GX 339-4, XTE J , and MAXI J MAXI also observed many state transitions including transitions in Swift J and Cyg X-1. Color-Intensity diagrams of these sources show two types of transitions to the soft (and intermediate) state. –Cyg X-1 and MAXI J are stable in the intermediate (very high) state. –GX and XTE J are stable in the soft state. The magnetically supported disk model is favorable to the observed features of the intermediate state. The following futures are, however, still open questions. –luminosity dependence –Regularity –Environment(?) dependence (difference in initial magnetic force)

End

MAXI J Stable “Intermediate” State Short-term “Soft” State

Neutron Star Studies NGC 6440 (#2360) ATel # in Red : Possible State Transition A (#2277) 4U (#2462) Cir X-1 (#2608, 2674) 4U (#2271) 4U 1711 (#2425) V (#2369, 2427) LMC X-4 GX (#2297) 4U (#2399) Cyg X-3 (#2404, 2635) LS V (#2527) 4U (#2702) XTE J (#2425) ATel # in Yellow : Burst or Flare

Black Hole Studies XTE J (#2259, 2378*, 2396) GX (#2380) H (#2364, 2378) 4U (#2363) Cyg X-1 (#2711) GRS Swift J (#2341) LMC X-1, X-3 ATel # in Red : Possible State Transition PCA ATCA PCA MAXI Swift+MAXI PCA MAXI

Discovery of MAXI J triggered 08:05 triggered 10:08