Search of primordial black holes from microlensing observa5ons with - - PowerPoint PPT Presentation

▶
search of primordial black holes from microlensing
SMART_READER_LITE
LIVE PREVIEW

Search of primordial black holes from microlensing observa5ons with - - PowerPoint PPT Presentation

Feb 21, 2023 249 likes •524 views

Search of primordial black holes from microlensing observa5ons with HSC and OGLE Hiroko Niikura (UTokyo / Kavli IPMU) Collaborators: Masahiro Takada, Naoki Yasuda (Kavli IPMU), Robert Lupton (Princeton), Takahiro Sumi (Osaka), Surhud More

slide-1
SLIDE 1

Search of primordial black holes from microlensing observa5ons with HSC and OGLE

Hiroko Niikura (UTokyo / Kavli IPMU)

1

@ Moriond EW, 2019

Collaborators: Masahiro Takada, Naoki Yasuda (Kavli IPMU), Robert Lupton (Princeton), Takahiro Sumi (Osaka), Surhud More (IUCAA), Sunao Sugiyama, Toshiki Kurita (Kavli IPMU), Anupreeta More (IUCAA), Masamune Oguri (UTokyo), Masashi Chiba (Tohoku), Shuichiro Yokoyama (Nagoya), Shogo Masaki (Suzuka)

slide-2
SLIDE 2

Target: Primordial black hole as dark matter

  • Searching for dark matter in the

local universe

– Massive Compact Object (MACHO), Weakly Interacting Massive Particle (WIMP), Primordial Black Hole (PBH)

  • Primordial black hole (PBH)

Primordial black hole (PBH)

– Proposed to be generated in the early universe, and can survive as dark matter today if not evaporated (Hawking 1971) – Previous research still leaves some room for PBH to be a part of dark matter

  • primordial

fluctuation

2

horizon scale black hole

slide-3
SLIDE 3

Open widow on PBH abundance around MPBH=[10-15,10-9] M◉

(note: lunar mass ~10-8 M◉)

◉ ◉ 3

Constraint on PBH abundance (previous studies)

PBHs for LIGO

A mass fraction of PBHs to DM

slide-4
SLIDE 4

Constraining PBH with microlensing

Subaru HSC M31 PBH microlensing search Use OGLE (Optical Gravitational Lensing Experiment) for PBH search

PBH

credit: Masahiro Takada

4

slide-5
SLIDE 5

5

Tightest bounds on PBH abundance with HSC observation of M31

Hiroko Niikura, Masahiro Takada, Naoki Yasuda, Sunao Sugiyama, Toshiki Kurita (Kavli IPMU), Robert Lupton (Princeton), Takahiro Sumi (Osaka), Surhud More, Anupreeta More (IUCAA), Masamune Oguri (UTokyo), Masashi Chiba (Tohoku) arXiv: 1701.02151 --> Nature Astronomy in press (Niikura et al. 2019)

slide-6
SLIDE 6

Hyper Suprime-Cam

  • Maunakea, Hawaii

(4200m)

  • largest camera
  • 3m high
  • weigh 3 ton
  • 104 CCDs

(~0.9B pixels)

credit: Masahiro Takada

6

slide-7
SLIDE 7

Andromeda Galaxy (M31)

  • Large spiral galaxy
  • In the northern

hemisphere (not accessible from VLT, DES, LSST)

  • HSC FoV ~ entire M31
  • ~770kpc (𝜈~24.4)
  • HSC can monitor all

stars in the bulge and disk regions of M31 HSC Image of M31 (HSC FoV=1.8 sq. degrees)

7

slide-8
SLIDE 8

102 101 100 101

tFWHM [hrs]

108 107 106 105 104

d2Nevent/dtobsdlntFWHM [events/hrs]

Event rate for a single star in M31

MPBH = 1012M 1011M 1010M 109M 108M 107M

PBH microlensing event rate

ΩPBH ΩDM = 1

6min 60min tE ∼ dLθE vPBH ∼ 34 min ✓ MPBH 108M ◆1/2 ✓ dL 100 kpc ◆ ✓ vPBH 200 km/s ◆1

Event rate per unit obs. time and per a single star in M31 for a given timescale of light curve (time scale of ML light curve)

8

slide-9
SLIDE 9

Result: Distribution of transient candidates

9

fake (incl. RR-Lyrae) Cepheid variable asteroid stellar flare eclipsing binary contact binary

More than 15,000 transient candidates in

  • ne field-of-view
  • f HSC.

(6 min.-) HSC-M31

focal plane

5000 10000 15000 20000 25000 time [sec] 21 22 23 24 25 26 27 mag

WD+BD eclipse

10 min. 2 hours 10 5mes Magnifica5on !

5000 10000 15000 20000 25000 time [sec] 21.0 21.5 22.0 22.5 23.0 23.5 24.0 24.5 25.0 mag

2014

flare

~15,000

Difference image Reference image Target image

  • Detection: Image difference

~ ~

transient candidates

slide-10
SLIDE 10

Analysis: Selec5on of microlensing candidates (6 min. -4 hours)

Total number of events : 15,571

Fitting of ML lightcurve model (for lightcurves in difference images) Noise threshold (S/N > 5 for 3 consecu5ve visits) significant peaks Apart from CCD edge Symmetric shape of peak around the peak in the light curve flare stars, fake events spikes, asteroid or some defects Visual inspec5on fake events, binary stars 89 ccd edge 14 flare 134 spikes 118 noise 102 for nochiin 339 for long including 15 short 227 92 bad chi2 146 66 9 seeing 15 bimyo 1 # of candidates

5000 10000 15000 20000 25000 time [sec] −6000 −4000 −2000 2000 4000 6000 count 5000 10000 15000 20000 25000 time [sec] −4000 −3000 −2000 −1000 1000 2000 3000 count 5000 10000 15000 20000 25000 time [sec] −4000 −2000 2000 4000 6000 count 5000 10000 15000 20000 25000 time [sec] −2000 −1500 −1000 −500 500 1000 1500 2000 2500 count 5000 10000 15000 20000 25000 time [sec] −10000 −5000 5000 10000 15000 count

11,703 noisy events bad fiZng asymmetric peak bad χ2

dof

(tmax out of obs. period) Follow selec5on method by Griest et al., 2014 (Kepler)

10

slide-11
SLIDE 11

11

blue: ±1σ noise

  • n difference

images 移動天体やCCDの欠陥

One remaining candidate..

5000 10000 15000 20000 25000 time [sec] － 1500 － 1000 － 500 500 1000 counts

Total number of events : 15,571

One remaining candidate 134 spikes

slide-12
SLIDE 12

1015 1020 1025 1030 1035

MPBH [g]

105 104 103 102 101

f=ΩPBH/ΩDM

B H E v a p

  • r

a t i

  • n

Femto Kepler CMB EROS/MACHO

HSC M31 constraint (95% limit)

1015 1010 105 100

MPBH [M]

5 4 3 2 1

BH Evaporation Femto Kepler CMB EROS/MACHO

HSC 95% CL (2days): +finite source size effect +wave effect

12

A mass fraction of PBHs to DM

PBH constraint with HSC M31 ML Search

tightest bound on PBH with MPBH=[1020,1028]g 1 HSC night ⇔ 2 years Kepler data

Nature Astronomy in press (Niikura et al. 2019)

  • Wave optics
  • Finite size of

source stars

slide-13
SLIDE 13

Earth mass black hole? PBH constraint with OGLE

Hiroko Niikura, Masahiro Takada (IPMU), Shuichiro Yokoyama (Nagoya), Takahiro Sumi (Osaka), Shogo Masaki (Suzuka)

Image credit: AAS

arXiv: 1901.07120 --> PRD in press (Niikura et al. 2019)

13

slide-14
SLIDE 14

14

Credit: OGLE project

5×107 stars

OGLE: Optical Gravitational Lensing Experiment

  • 1.3m telescope in Las Campanas, Chile
  • Long-term microlensing observation (1996-),

with cadence either 20 or 60 min

slide-15
SLIDE 15

5-years OGLE data (Mroz et al. 2017)

101 100 101 102 103 tE [day] 100 101 102 Number of events OGLE 5yrs

  • 2622 microlensing events: the ML timescale distribution is

provided (now >5000 events) 2622 events / 5 years

Astrophysical

  • rigin

(disk+bulge)

Free-floating planets? PBHs? (halo)

15

slide-16
SLIDE 16

1020 1025 1030 1035

MPBH [g]

104 103 102 101 100

fPBH = ΩPBH/ΩDM

Kepler CMB Caustic EROS/MACHO

OGLE excl. region (95% CL) HSC

1010 106 102 102

MPBH [M]

Null test: PBH upper bounds by OGLE

Fully take into account the likelihood (Poisson uncertainty)

slide-17
SLIDE 17

Detection of Earth-mass PBHs?

17

101 100 101 102

ML LC timescale: tE [days]

100 101 102

Number of events per bin

OGLE data (2622 events) BD MS WD NS Galactic bulge/disk models

PBH

MPBH = 9.5 × 106M fPBH = 0.026

Free-floating (wide-orbit) planets? Earth mass (~10-6Msun) PBHs?

slide-18
SLIDE 18

Results: Allowed parameter space indicated

by detection of Earth-mass PBHs

1026 1027 1028 1029

MPBH [g]

103 102 101 100

fPBH = ΩPBH/ΩDM

OGLE alone OGLE+HSC

allowed region (95% CL)

HSC excl. region

108 107 106 105 104

MPBH [M]

18

slide-19
SLIDE 19

Summary & Future prospect

1015 1020 1025 1030 1035 MPBH [g] 105 104 103 102 101 f=ΩPBH/ΩDM

B H E v a p

  • r

a t i

  • n

Femto Kepler CMB EROS/MACHO HSC OGLE

HSC 95% CL (2days) OGLE 95% CL (5years)

1015 1010 105 100 MPBH [M] Thank you very much for listening!

(Bai & Orlofsky 2018 [1812.01427])

LOFT 300d? (X-ray pulsar @ SMC)

(Sasaki et al. 2016)

Athena 100d

19

PBHs for LIGO

slide-20
SLIDE 20
  • The wide and deep imaging

with Hyper Suprime-Cam (HSC);

« Can cover the entire disk and bulge regions of M31 with its one pointing « 90sec exposure can reach to ~26mag depth for a star

  • Observation for 7-hours,

taking images every 2 minutes at M31-disk region (r- band), performed in 2014/2017

  • Observation: monitor M31 with HSC

~2 min

t

1.5 deg

M31 of Hyper Suprime Cam (r-band) ~1011 stars ~25mag

20

~7 hours

~200 frames

backup

slide-21
SLIDE 21

Detection of transients: difference imaging

21

  • Pixel lensing regime: multiple stars in each CCD pixel

Difference image (seeing~0.7”) Reference image (seeing~0.5”) Target image (seeing~0.7”)

ref. Target

  • diff. diff.-PSF
  • tiny objects (< pixel

size)

  • distorted object
  • high residual after

PSF subtraction

  • diff. (bad)

backup

slide-22
SLIDE 22

Visual inspection…

5000 10000 15000 20000 25000 time [sec] － 4000 － 3000 － 2000 － 1000 1000 2000 counts 5000 10000 15000 20000 25000 time [sec] － 4000 － 3000 － 2000 － 1000 1000 2000 3000 4000 5000 counts

Visual inspection of 66 candidates to identify junks… asteroid spike around a bright star 66 66 ⇒ 65 junks 65 junks

22

backup

slide-23
SLIDE 23
  • Wave effect: wavelength vs. Schwarzschild radius of PBH
  • Magnification

suppressed due to interference and diffraction

  • PBHs with

MPBH< 2.6×10-12 Msun

cannot be detected

magnifica5on

0.001 0.01 0.1 1 10 w 0.5 1 2 y0.5wave y0.5geo

(y=0.5: source position fixed) Matsunaga & Yamamoto +06

Wave effect + finite source size effect

  • Finite source size effect: RE,PBH < Rsource (point source limit not valid)

backup

slide-24
SLIDE 24

Modeling timescale distribution with stellar population

24

102 101 100 101 102

M [M]

10−5 10−4 10−3 10−2 10−1 100 101

Initial or final mass function: dn/dlnM BD MS WD NS BH

IMF (Kroupa+01)

  • Astrophysical lenses: stars and stellar remnants

backup

slide-25
SLIDE 25

Modeling timescale distribution with stellar population

101 100 101 102

ML LC timescale: tE [days]

100 101 102

Number of events per bin

OGLE data (2622 events) BD MS WD NS Galactic bulge/disk models

Explain the event distribution by standard galactic models!

25

backup

slide-26
SLIDE 26

101 100 101 102

ML LC timescale: tE [days]

100 101 102

Number of events per bin

OGLE data (2622 events) BD MS WD NS Galactic bulge/disk models

PBH lens needed?

26

101 100 101 102

ML LC timescale: tE [days]

100 101 102

Number of events per bin

OGLE data (2622 events) BD MS WD NS Galactic bulge/disk models

PBH MPBH = 103M fPBH = 1

backup