Sagan Workshop, Pasadena, 10 August 2017 Łukasz Wyrzykowski (pron: Woo-cash Vi-zhi-kov-ski) Warsaw University Astronomical Observatory, Poland ASTROMETRIC MICROLENSING WITH GAIA
Sagan Workshop, Pasadena, 10 August 2017
Łukasz Wyrzykowski(pron: Woo-cash Vi-zhi-kov-ski)
Warsaw University Astronomical Observatory, Poland
ASTROMETRIC MICROLENSING WITH GAIA
Krzysztof Rybicki(PhD student)
Kasia Kruszyńska (PhD student)
Mariusz Gromadzki (postdoc)
Zuzanna Kostrzewa-Rutkowska (postdoc at SRON, NL)
Alex Hamanowicz (Master student -> PhD @ ESO)
Gaia Alerts team in Cambridge (UK)
COLLABORATORShere
here
MICROLENSING•Gravitational lensing by compact lenses (stellar or remnants)
•Mass range from Earth-like to ~100 MSun
•Sources: background stars (chance: 10-6 in the Bulge, 10-8 in the LMC)
anim
atio
ns b
y S.
Gau
di
photometry (sum of images) astrometry (centroid motion)
~1 month ~1mashttp://www.astronomy.ohio-state.edu/~gaudi/movies.html
•About 0.8% of microlensing events should be due to Black Holes!(Gould 2000)
•2000 events found every year -> ~16 black holes every year!!
•so, where are they?
BLACK HOLES MICROLENSING
M =✓E⇡E
high amplification events/finite source (rare)
astrometry (VLT/AO, HST, Gaia)
Earth parallax
space-based parallax (e.g., Earth-Spitzer)
19 DEC 2013 9:12 UT
GAIA SPACE MISSION
GAIA FOCAL PLANE
windows observed:
Gaia focal plane (106 CCDs)
detection and FOV
discrimination
astrometric measurements
photometry (dispersed
images)
radial velocity (dispersed images)
BAM = basic angle monitor, WFS = wavefront sensor W
FS1
WFS
2 B
AM
2 B
AM
1
SM
1
SM
2
AF1
AF2
AF3
AF4
AF5
AF6
AF7
AF8
AF9
BP RP
RV
S1
RV
S2
RV
S3
0.42
m
0.93 m
AC
AL
Gaia focal plane (106 CCDs)
detection and FOV
discrimination
astrometric measurements
photometry (dispersed
images)
radial velocity (dispersed images)
BAM = basic angle monitor, WFS = wavefront sensor
WFS
1
WFS
2 B
AM
2 B
AM
1
SM
1
SM
2
AF1
AF2
AF3
AF4
AF5
AF6
AF7
AF8
AF9
BP RP
RV
S1
RV
S2
RV
S3
0.42
m
0.93 m
AC
AL
star<20magdetected!
Placewindow.
Gaia focal plane (106 CCDs)
detection and FOV
discrimination
astrometric measurements
photometry (dispersed
images)
radial velocity (dispersed images)
BAM = basic angle monitor, WFS = wavefront sensor W
FS1
WFS
2 B
AM
2 B
AM
1
SM
1
SM
2
AF1
AF2
AF3
AF4
AF5
AF6
AF7
AF8
AF9
BP RP
RV
S1
RV
S2
RV
S3
0.42
m
0.93 m
AC
AL Animation by Berry Holl, Geneva
~45 sec~4.4 sec
Camera: 0.75 deg2
pixel size:10x30 µm
(59x177 mas)
GAIA FOCAL PLANE
figure curtesy: Berry Holl, Geneva
GAIA SKY SCANNING PATTERN
Gaia Science Alerts
Polish 1.3m dedicated telescope in Las Campanas, Chile Surveying continuously since 1992.
ESA space mission with 2x1.4m telescopes located in L2.In operation since 2014.
http://ogle.astrouw.edu.pl
http://gsaweb.ast.cam.ac.uk/alerts
HOW TO FIND BLACK HOLES?
Number of Gaia observations after 5 years Gai
a fig
ure
by N
adia
Bla
goro
dnov
a, O
GLE
fiel
ds b
y Ja
n Sk
owro
n
OGLE-GAIA SKY
OGLE3-ULENS-PAR-02 - candidate ~9MSun BH
OGLE photometryfrom 2001-2008 and microlensing model
Mass, Distance estimate only
STELLAR-MASS BLACK HOLES
OGLE photometry
probability distribution for the proper motion
based on observed PM
Rybicki in prep.
OGLE3-ULENS-PAR-02 - candidate ~9MSun BH
predicted Gaia astrometry for similar event
OGLE photometryfrom 2001-2008 and microlensing model
Mass, Distance
STELLAR-MASS BLACK HOLES
Gaia astrometryOGLE photometry
ASTROMETRIC PRECISION IN GAIA
significant delay for any given source observation to be mapped onto the global astrometric solution(assuming 6 monthly processing windows in the intial design). The IDT includes an astrometricsolution (OGA1) with precision around 10-50 mas with a systematic error of around 50mas. OGA2(produced by First Look) reduces the error to around 100µas and should be available within 24hafter IDT (TBC).
!"#$%"$&'($)*+&,!-&./'-&01&23%$&0454 06
Astrometric accuracy: single observation
� !"#$%&'()*&+,-."(#'-//0+-/1'� (+)".2'*(%-+'*1*.&3
� !"#$%&#'($)*+",&)
� -!&")$,!.*/#
Figure 5: Astrometric performance across-scan for a point source from a single transit as a functionof G magnitude.
4.2 Photometric Performance
The main photometry stream from Gaia is obtained from AF CCDs and is a broad filter photom-etry called G. Another source of the photometry is based on low-resolution, dispersive, spectro-photometry using the Blue and Red Photometers (BP and RP), from which we derive GBP , GRP
magnitudes. DU17 will receive both streams of the photometry in uncalibrated form. Figure 6shows the expected error as a function of magnitude for each field-of-view transit.
4.3 Spectroscopic Performance
The underlying low-resolution epoch spectra from BP and RP will also be available from the IDTin a raw form.
The BP/RP spectrograph comprises two low-resolution fused-silica prisms. The BP disperser covers330-680 nm with resolution 4-32 nm/pixel, while the RP covers 640-1000 nm with resolution 7-15nm/pixel.
8
50 mas : daily calibrations 0.1 mas : fortnightly calibrations final precision (in 2022):
H-band magGould+2017
WFIRSTGaia final
G-band mag
1D precision!
ASTROMETRIC PRECISION IN GAIA
significant delay for any given source observation to be mapped onto the global astrometric solution(assuming 6 monthly processing windows in the intial design). The IDT includes an astrometricsolution (OGA1) with precision around 10-50 mas with a systematic error of around 50mas. OGA2(produced by First Look) reduces the error to around 100µas and should be available within 24hafter IDT (TBC).
!"#$%"$&'($)*+&,!-&./'-&01&23%$&0454 06
Astrometric accuracy: single observation
� !"#$%&'()*&+,-."(#'-//0+-/1'� (+)".2'*(%-+'*1*.&3
� !"#$%&#'($)*+",&)
� -!&")$,!.*/#
Figure 5: Astrometric performance across-scan for a point source from a single transit as a functionof G magnitude.
4.2 Photometric Performance
The main photometry stream from Gaia is obtained from AF CCDs and is a broad filter photom-etry called G. Another source of the photometry is based on low-resolution, dispersive, spectro-photometry using the Blue and Red Photometers (BP and RP), from which we derive GBP , GRP
magnitudes. DU17 will receive both streams of the photometry in uncalibrated form. Figure 6shows the expected error as a function of magnitude for each field-of-view transit.
4.3 Spectroscopic Performance
The underlying low-resolution epoch spectra from BP and RP will also be available from the IDTin a raw form.
The BP/RP spectrograph comprises two low-resolution fused-silica prisms. The BP disperser covers330-680 nm with resolution 4-32 nm/pixel, while the RP covers 640-1000 nm with resolution 7-15nm/pixel.
8
50 mas : daily calibrations 0.1 mas : fortnightly calibrations final precision (in 2022):
Gould+2017
WFIRST
Gaia final
1D precision!
Rybicki in prep.
OGLE3-ULENS-PAR-02 - candidate ~9MSun BH
Combination of ground-based photometry and Gaia astrometry for long events will yield masses of black holes accurate to ~10% percent(brightness dependent)
STELLAR-MASS BLACK HOLES
see Kris Rybicki’s POP
short break :)
MICROLENSING EVENTS FROM GAIA
Gai
a fig
ure
by N
adia
Bla
goro
dnov
a, O
GLE
fiel
ds b
y Ja
n Sk
owro
n
July 2016 - July 2017
16au
aA
SASS
N-1
6oe
16bn
n
16ay
e (b
in)
17ah
k17
ajg
17aq
u
17as
v
17ah
l
17bb
i
17bb
s17
bcu
17bd
k17
bdl
17be
j
17bo
l17bt
s
MICROLENSING EVENTS FROM GAIAGaia16aua (Auala)
Gaia16bnn
Gaia17bej (Bejeweled)
Gaia17aqu (Aqua)
Gaia17bbi (BB Is watching)
Gaia17bbs (BB’s sister)
see Kasia Kruszynska’s poster/POP
*Uluru
Gaia16AYErs Rock*
GAIA16AYE (AYERS ROCK)
GAIA16AYE (AYERS ROCK)More than 20,000 data points collected in multiple bands
by a network of volunteering observatories
~20 active partners, ~30000 data points collected 2014-20162017-2020: continuation under OPTICON H2020
GAIA ALERTS FOLLOW-UP NETWORK
Catching the 4th caustic exit
Model prediction Caustic exit 21 November 2 am UT
GAIA16AYE (AYERS ROCK)
Model prediction Caustic exit 21 November 2 am UT
Catching the 4th caustic exit
GAIA16AYE (AYERS ROCK)
Catching the 4th caustic exit
actual peak: 21 Nov ~16 UTModel prediction Caustic exit 21 November 2 am UT
GAIA16AYE (AYERS ROCK)
tE = 141d piE= 0.39 thetaE=3 mas mu_rel=7mas/yr q=0.57 s=1.0 fs=0.75
model by P.Mroz and J.Skowron
Preliminary full-Keplerian orbital solution of the binary lens
GAIA16AYE (AYERS ROCK)
~8kpc
0.8kpc
M1 = 0.4 MSun M2 = 0.6 MSun
P = 3.4 yrs incl = 60 deg ecc = 0.473
K3 giant R=~10 RSun
2.3AU
PRELIMINARY SOLUTION
First time ever chance to detect binary astrometric microlensing!
Gaia obs moments
~3 mas
ASTROMETRY
Offset in both time and mag between Earth-based and Gaia-based observations
microlensing parallax
Gaia
ground
SPACE PARALLAX FROM GAIA?
Offset in both time and mag between Earth-based and Gaia-based observations
microlensing parallax
Gaia
groundsatellite recovered from safe mode
SPACE PARALLAX FROM GAIA?
GAIA DATA RELEASESwww.cosmos.esa.int/web/gaia
DR1 14 September 2016: - positions for 1 billion stars - astrometric solution for 2 million stars (TGAS)
(proper motion, parallax) DR2 April 2018:
- astrometric solution for 1 biliion stars - colors, temperatures, radial velocity
DR3 2020: - improved astrometry - low-resolution spectra for all objects - radial velocity, variable stars - non-single stars
DR4 (Final) 2022: - Full astrometric, photometric and radial velocity catalogs - All per-epoch astrometry and photometry - Exo-planets
https://gea.esac.esa.int/archive/
SUMMARY
• Gaia will soon provide 3D map of the Milky Way • all data public in 2022 (after your PhD!) • Gaia sampling in the Bulge is too poor for microlensing • but Gaia finds microlensing in the MW Disk • astrometric microlensing from Gaia only for brighter events • space parallax possible Earth — Gaia (in L2) • WFIRST should have astrometric microlensing capability— great for measuring theta_E for black hole lenses!