 O3 J-GEM    TMT Takayuki Ohgami(Konan Univ.)

11th  13th Sep 2019



Multi-messenger astronomy• Gravitational wave and Electro-Magnetic wave
• BBH,GWBNSastronomy
and BH-NS in the TMT era

J-GEM
EM follow-up
for GW withOp?cal and NIR

We are here

h$ps://wiki.gw-astronomy.org/OpenLVEM/Telecon20190815
Figure 2: The planned
sensitivity
evolution and observing runs of the aLIGO, AdV andhttps://wiki.gw-astronomy.org/OpenLVEM/Telecon20190815

Role of Subaru/HSC• Several events of interest so far• S190408an (BBH, 1473Mpc, 387deg2)• S190412m (BBH, 812Mpc, 156deg2)
very far and very wide
• S190425z (BNS, 156Mpc, 7461deg2)• S190426c (BNS[49%], NSBH[13%], 377Mpc, 1131deg2)• S190510g (BNS[98%] -> Terrestrial[58%], BNS[42%], 227Mpc, 1166deg2)• S190521r (BBH[99%], 1136Mpc, 488deg2)• S190814bv (NSBH[99%], 267Mpc, 23deg2)• Subaru/Hyper Suprime Cam• Diameter:8.2m, FoV:1.77deg2, ~900M pixels• The most powerful camera in the worldEtendue of optical telescopes
500

6.4m

8.2m
92

504m
38

2023 -1.8m

STLSHSCDECAM

17.8PS
1SILL

A

510.2

HT

7.99.7

CF

7.4

1.2m

3.6m

PTF

1.3m

SKYM
APPE
R

Aperture
1m

LA

Etendue [m2deg2]319

Etendue = FoV  mirror size

GW170817
üSearch for an optical counterpart (NT+)üObservations of an optical counterpart (Utsumi+)• Localization with 3 detectors are as narrow as 28deg2 for a
90% credible region.
• Distance is 40+8-14Mpc.
~66%

Tominaga+18

LIGO+17Candidate screening
23.6 deg2, z=21.0, 2 epochs
Aug 18 and 19, 2017

HSC z
IRSF HIRSF Ks

Tominaga+18

J-GEM17btc

Probability in the 3D skymap
The associated objects have grizY magnitudes in PS1 catalog.

• P3D is the possibility that the host galaxy is located inthe 3D skymap, where f is the luminosity function.
: the mean distance to GW170817: LF of galaxies at a rest wavelength λ: abs. mag. of a galaxy with mj at dist. of D: rest wavelength of λj with a dist. of D
NT+18

: surface area at a dist. of D

Survey of S190510g• S190510g (LVC alert)• Preliminary alert: 13:03 May 10, 2019 (JST) 268Mpc• IniHal alert: 14:24 May 10, 2019 (JST)• HSC observaHon start: 14:46 May 10, 2019 (JST)• Update Alert: 19:23 May, 10, 2019 (JST)• GCN 24450
LIGO/Virgo S190510g: HSC Y-band follow-up observaHon
InitialUpdatedaimed region

disappeared…

Survey pointings with Subaru/HSC

12%

1.2%

Survey pointings with Subaru/HSC
Filter : HSC-YExp. ,me : 30s x 2 epochs
Obs. area : 120deg2
Limit mag. : 22.67
1.2%12%

Image subtrac-on to detectObs. − HSC SSP

Obs. − Pan-STARRS1 (PS1)• Area = Obs. ∩ Ref. = 25.9 deg2
• Probability = 0.25 %• Area = 109.6 deg2
• Probability = 1.03 %Reference coverage

Reference images
Blue : HSC SSP
Green : PS1

Candidate selection
Detec%on criteria:• To remove bogus and cosmic rays
• Detected at least twice on May 10
example of bogus• Signal-to-noise ra;o > 5σ
• Elonga;on > 0.65 of point spread func;on (psf)• FWHM 0.7 – 1.3 of psf• Residual aMer psf subtrac;on < 3σ
• CNN candidate• To exclude minor planets• Detected twice at least 1 h apartObs. − HSC SSP

Obs. − Pan-STARRS (PS1)• Remains after selection : 419sources• Remains aMer selec;on :41,649 sourcesCandidates
Obs. − HSC SSP

Obs. − PS1

1 or 2 candidates
on each images

More than 10 candidates
on each images
0.02 x 0.02 deg2

Another detec+on criteria
Brighter than 21.3 mag(Detected twice)

PS1 catalog search (<1’)

812,446

1,480,674

OthersMatched to objects Ext.
flags are NOT set (<1’’)
793,159 (Stars)

19,287(GW src., SN, MP, others)

Are Ext. Obj. nearby?
YES
10,620 (Hosted, Hostless)NO(Hostless)
8,667 No MinerPlanets

Not Galaxy center (>1’’)
2,556

317
Located in 3D map (>50%)

Visual inspection

Cooperation with TMTSpectra• BNSGW170817:
or NS-BH merger• Hint of heavy element
production (r-process)- Smooth spectra• Origin of “kilonova”• Smooth spectra ~0.1c
Smoking gun!!
(SN < 10,000km/s, ~0.03c)- S190425z (BNS, 156Mpc, 7461deg2)- S190426c (BNS[49%], NSBH[13%], 377Mpc,1131deg2)- S190510g (BNS[98%]-> Terrestrial[58%],Spectra
taken w/BNS[42%], 227Mpc, 1166deg2)

VLT/X-shooter- S190814bv (NSBH[99%], 267Mpc, 23deg2)
Data: Pian+2017
Model: MT+2017

Pian+17, Tanaka+17
GW170817
Simulation

Coopera'on with TMT• Subaru/HSC• Limit mag.: 24.4 – 26.5 mag (UD > 28.1mag)• Field of View: 1.77 deg2

• TMT/IRIS(Suzuki 2014)• Limit mag.: 25.2 – 27.8 mag• Wavelength coverage: 0.8 - 2.5 µm• Spectral resoluSon: 4,000 - 8,000• Astrometry: ~30 mas
Search with Subaru and Observe TMT !!

Conclusion• 4 events, which has NS, has been detected sincestarting O3.
• S190425z, S190426c, S190510g, S190814bv• We performed ToO observation with Subaru/HSC atS190510g.
• Our aimed island has disappeared after an update ofskymap.
• After selection, 314 sources (8,667 hostless) remained.
→ visual inspection• TMT era
• Observation of deep kilonova sources will become possible.