Search for X-ray Transients with MAXI - Caltech Astronomyvikram/bne_talks/kawai.pdf · Search for...
Transcript of Search for X-ray Transients with MAXI - Caltech Astronomyvikram/bne_talks/kawai.pdf · Search for...
Search for X-ray Transientswith MAXI
Nobuyuki Kawai (Tokyo Tech)M. Serino (RIKEN), H. Negoro (Nihon U.)
on behalf of the MAXI Team
• MAXIInstrumentation andoperation• Observations forGW150914andresults incontext• Observations forGW151226
Monitor of All-Sky X-ray Image
Matsuoka et al. 2009
Mission started August 2009Ops approved until ~ March 2018
Instruments and Observation6 x 2 GSC (Gas Slit Camera)
2-20 keV, Time Resolution 50 µsMihara+ 2011, Sugizaki+ 2011
2 x SSC (Solid-state Slit Camera) 0.7-7 keV, Time Resolution 5.865 s
Tsunemi+ 2010, Tomida+ 2011
SSC
(slit)collimator
ProportionalCounter
slit
NovaAlertSystem
<10sec(Real)~1.5h(Stored)
TKSC/JAXA
RIKEN&
MAXIMLs
(& ATel/GCN)
Nova-Alert System Negoro+2016,PASJ
MAXI Transients : 17 sources in 6 years
J1659-152 (GRB100925A)
J1543-564J1836-194
J1305-704
J1910-057(SwiftJ1910.2-0546)
J1828-249
J1647-227
J0556-332J1409-619
MAXIJ0158-744GRB121225A(SwiftJ1741.5-6548)
J1932+091
1WhiteDwarf, 6NeutronStars,6BlackHoleCandidates, and1unknown
J1735-304(SwiftJ1734-3027?)J1421-613
2.5Blackholes
MAXIJ1659-152(GRB100925A)
MAXI1543-564MAXI1836-194
MAXI1305-704MAXIJ1828-249
6 Black holes discovered by MAXI
MAXIJ1910-057(SwiftJ1910.2-0546)
55500 56000565002009.82014.4
(out of 12 BHCs discovered since Aug 2009)
Negoro etal.(2014)
500days
2.5Blackholes
Negoro 2008
J1543(l,b)=(325.1,-1.1)d >12kpc ?(Stiele+ 2012)
J1305(l,b)=(304.2,-7.6)
8.5 kpc
MAXI watches through the whole Galaxy.12 kpc
F=aLEdd/4pd2
a =0.01-0.04(Maccarone 2003)Soft-to-HardTransition
J1828(l,b)=(8.1,-6.5)d >12kpc !?
2.5Blackholes
MAXI J0158-744: unique soft X-ray transient
• 2011-11-11 05:05:59 (UT)• GRB 111111A• Soft X-ray transient ( < 5 keV)
MAXI GSC All-sky Image
Galactic Coordinate
• Swift follow-up lead to identification to a star near SMC(Be star at 60 kpc)
8
Morii etal.2013
1 10days
X-ra
y F
lux
0.1
X-ray light curve
MAXI SSC
Swift XRT
MAXIGSC
MAXI J0158-744• Duration≈hour
– (1300s<ΔT<1.1x104 s)
• Extremelyluminous– 1040 erg/s– x100solarmassEddingtonluminosity
• supersoft X-raysourceatlatephaseàwhitedwarf– classical/recurrentnova?
• butx104 moreluminous thanknownnovaX-rayemission
– (shockedISM?Lietal.2012)9
Morii et al. 2013
9
10
WD-Be binary system (MAXI J0158-744)
Credit: Takuya Ohkawa
Very massiveO-Ne white dwarf
Be star
Circumstellardisk
PressRelease fromRIKEN(2013.11.14)
Nova ignited with a less accumulation
Luminous (100LE) andExploded out quickly
rare
Thermal Ne line
Morii etal.(2013)Nova(nuclearfusion)explosion
TidalDisruptionEvents- Astarapproaching toagiantblackholeinthe
centerofagalaxyistornintopiecesbythetidalforce.Thedebrisaccretes totheblackhole.
- LongtimemonitoringofMAXIguaranteesasingleevent,notoneoftheAGNactivities.
- MAXI detected threeTDEduring2009-2012.
MJD(DAY)55650 55750 55850
Flux(m
Crab)
0
2
6
4
8
nT=-1.92 (-0.73/+0.58)
MAXI2-10keV
SwiftJ1644+57withSwift/BATandMAXI/GSC SwiftJ2058+05withMAXI/GSC
2011/3/28
2011/5/20
Burrowsetal.Nature2011
GRB Reports to GCN
Swift-BAT Fermi INTEGRALCALET +
othersMAXI MAXI/All
2011 71 8 3 6 3 3.3%
2012 84 17 5 3 11 9.2%
2013 79 28 6 0 4 3.4%
2014 88 32 3 4 8 5.9%
2015 86 28 4 4 18 12.9%
2016 19 5 1 3 5 15.2%note: these numbers are not complete.
MAXI Trigger:XRT follow-up ToO: 160101A (+13.2 ks, afterglow detection)160206A(+46.2 ks, 2 candidates)151205C (+11.1 ks, No), 160102A (+10.8 ks, No)
No ToO: 151216A, 160104B, 160107A (Fermi, CALET)
Swift/BAT (faster) Trigger:detection: 151112A (BAT +36 s), 160227A (BAT +185 s)no detection: 151027A
Alert issued 12 sec
2-4 keV
4-10 keV
10-20 keV
GRB 160102A
MAXI GRBs and transients (2—20 keV)
13
●: only MAXI (43)●: MAXI + other (39 prompt + 7 afterglows)
http://maxi.riken.jp/grbs/Serinoetal.(2014)
GRB localization with MAXI
14
MAXI Short Transient with no XRT counterparts
15
GCN#17772 Atel #7954GCN#17568GCN#16686ATel #6066GCN#14359 ATel #3316
GRB150428CMAXIJ1501-026MAXIJ1540-158 GRB140814A MAXIJ0545+043GRB130407A MAXIJ1631-639
MAXIlightcurvesnotcorrectedforcollimatortransmission
Nofluxinhighenergyband
2015-04-282015-08-262015-03-11 2014-08-142014-04-12 2013-04-072011-04-29
(l,b)=(139.1,+11.3) (354.6,+46.8)(351.6,+30.6) (139.9,+66.4)(201.1,-12.6) (26.4,+35.6)(324.4-10.8)
flux0.16Crab0.44Crab0.1Crab0.23Crab 0.2Crab 0.17Crab0.12Crab
2-4 keV
4-10 keV
10-20 keV
11’FOV
0 1 2 5 10 21 42 85 171 341 680
GW150914 (T0+4~92 min)
(Serino etal.GCN19013)
Sun
2-20 keV 3-s upper limit: 0.1 counts s–1 cm-2 ≈ 30 mCrab≈ 1 × 10–9 erg s–1 cm-2
0 11 31 74 157 326 659 1323 2663 5312 1058
GW150914 (T0+0~1 day)
2-20 keV 3-s upper limit: 8 mCrab ≈ 3 × 10–10 erg s–1 cm-2
MAXI on GW150914
1scan(≤92min)
1day
5min ~
Wherethereisnowill,theremightbeawaytoaGWstar!?
MAXI observations for GW150914 Timescale
(s)Flux
(erg s–1 cm-2)Luminosity*
(erg s–1)Radiated
Energy (erg) EX/EGW
1 orbit 1000 < 9.5 × 10–10 < 1.9 × 1046 < 1.9 × 1049 < 3.5 × 10–6
1 day 8.6 × 104 < 2.3 × 10–10 < 4.6 × 1045 < 4.0 × 1050 < 7.4 × 10–5
10 days 8.6 × 105 < 0.8 × 10–10 < 1.6 × 1045 < 1.4 × 1051 < 2.6 × 10–4
* Distance 410 Mpc assumed
• Eddington luminosity for 62 M☉ BH ≈1040 erg s–1
• Radiated energy in GW: EGW = DMc2 ≈ 5.4 × 1054 erg
MAXI on GW150914
10-2 10-1 100 101 102 103 104 105 10610-15
10-14
10-13
10-12
10-11
10-10
10-9
10-8
10-7
10-6
10-5
10-4
Time since Trigger (sec)
Flux
(erg
/s/c
m^2
)
MAXI on GW150914
▲
10-2 10-1 100 101 102 103 104 105 10610-15
10-14
10-13
10-12
10-11
10-10
10-9
10-8
10-7
10-6
10-5
10-4
Time since Trigger (sec)
Flux
(erg
/s/c
m^2
)
Fermi GBM possible detection(extrapolated to 2–20 keV flux
averaged over 1 second assuming photon index –1.4)
MAXI could have marginally detected GBM SGRB if it was in the field of view
Short GRB 050709The only short GRB observed in soft X-ray
Chandra
HST Fox et al. 2005
z=0.160Dwarf irregular galaxySFR = 0.2 Msun/yr
HETE-2
Short hard pulse
“Soft extended emission”
Villasenor et al. 2005
2–25 keV
HETE-2
●
●
▲
10-2 10-1 100 101 102 103 104 105 10610-15
10-14
10-13
10-12
10-11
10-10
10-9
10-8
10-7
10-6
10-5
10-4
Time since Trigger (sec)
Flux
(erg
/s/c
m^2
)
MAXI sensitivity for
SGRB in GW range
GRB 050709Short pulse
MAXI could easily detect “short pulse” and “soft extended emission” of GRB 050709
GRB 050709Extended emission
GRB 050709Afterglow (Chandra)
▲
●
●
10-2 10-1 100 101 102 103 104 105 10610-15
10-14
10-13
10-12
10-11
10-10
10-9
10-8
10-7
10-6
10-5
10-4
Time since Trigger (sec)
Flux
(erg
/s/c
m^2
)
MAXI sensitivity for
SGRB in GW range
GRB 050709 scaled to 100 Mpc
“Soft extended emission” or X-ray afterglow of a short GRB at O2 BNS range may be detected by MAXI in the following scan
Summary• MAXI scans about 60-80% of the sky in one orbit (92 min), and more than 90%
in a day.• We can provide a fast (<30 sec) alert for bright bursts.• MAXI is detecting ~10 short transients per year. About half of them are
confirmed as GRBs simultaneously detected by other satellites. There can be other class(es) of objects yet to be identified.
• MAXI discovered 17 new sources in 7 years including 6 black hole binaries and a white dwarf/Be system. The latter exhibited a ultra-luminous explosion at ignition of a nova.
• A large fraction of GW150914 region was covered in 1000s, yielding a flux upper limit ~10–10 erg s–1 cm–2.
• MAXI can constrain the short GRB scenarios for DNS merger at <100 Mpc (O2 range)
• Instantaneous field of view of MAXI is 2% of the sky. iWF-MAXI (FoV >10% sky) has been proposed.