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Infrared Space Astrometry missionInfrared Space Astrometry mission

for the Galactic Bulge for the Galactic Bulge

Naoteru GoudaNaoteru Gouda JASMINE Project OfficeJASMINE Project Office

National Astronomical Observatory of JapanNational Astronomical Observatory of Japan

3 Dec. 2013

§1. Galactic Bulges

§2. Surveys of the bulge of the Milky Way galaxy

(the Galactic bulge)

§3. Astrometry and Upcoming space astrometry

missions

§4. Small-JASMINE project

§5. WISH as an infrared space astrometry mission

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§1. Galactic Bulges

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Classical bulges: e.g. M81 [NASA]

Disk-like bulges (aka pseudo-bulges): e.g. NGC 6782 [NASA]

Box/Peanut bulges (aka pseudo-bulges): e.g. ESO 597-G 036 [NASA]

Bulges are complex!

Classical bulges Disk-like bulges(aka pseudo-bulges) Box/Peanut bulges(aka pseudo-bulges)

〇 stick out of disk plane (not as flat as the disk)〇 more or less sphroidal〇 featureless: no spiral arms, bars, rings,…〇 mostly old stars〇 kinematically hot: dynamically supported by stellar velocity dispersions〇 seem to be built mostly by mergers, fast bursts of star formation

〇 as flat as the disk〇 substructures: nuclear bars, spiral arms, rings,…〇 young stellar populations or ongoing star formation〇 kinematically cold: dynamically supported by rotation of its stars〇 seem to be built mostly via disk instabilities: continuous, smooth process

〇 stick out of the disk〇 box or peanut-like morphology〇 usually featureless〇 usually does not show young stellar populations or star-forming regions〇 kinematically cold: dynamically supported by rotation of its stars〇 the inner parts of bars that grow vertically thick due to dynamical instabilities!

Key issue:Features of each type,origin and evolution

・ Formations and evolutionary processes of galaxies・ Orbits of stars, phase space density in complex structures of bulges

： key tracers of galaxy formations

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Co-evolutions of super massive BH s and bulges

(STScI/NASA)Magorrian relation (Marconi & Hunt 2003, ApJ, 589, L21)

Origin and evolution of the super massive black hole at the Galactic center? merging of small and/or medium BHs? gas accretion?

★Supper massive BH at the galactic center Activity of the galaxy

★The mass of SMBH correlates with the mass of the bulge.

Connected growth of BHs and bulges!?

§2. Surveys of the bulge of the MW

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The Milky Way box/peanut bulge! COBE/Diffuse Infrared Background Experiment, etc.

=>The Milky Way: very important target galaxy!!It is possible to observe in the Milky Way indivisual stars in many directions and to obtain information on their 3-dimensional positions,3-dimensional velocities and metalicity with good accuracies, which is, in, general, still not possible for galaxies outside the MW.

Vertically thin long bar + vertically thick inner part(box/peanut)

The properties of the bar affects dynamics : spiral arm location, resonances, gas inflow, etc.

*Bars themselves can evolve secularly through angular momentum transport, producing different boxy/peanut and X-shaped bulges

Clarification of the Galactic bar/bulge and its origin Very important for studies of the formation and evolution of disk- galaxies

high-quality observational data( both kinematical and chemical) to testthe theories regarding the origin and subsequent history of the bulges

★Surveys of the bulge of the MW are necessary and important!

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VVV survey: ZYJHKs Photometry ＋ 100 epochs in Ks Bulge 300 sq deg. VISTA 4.1m telescope at ESO sensitivity:0.84 to 2.5 micronsAPOGEE survey: High-resolution H-band spectroscopic survey2.5m telescope at the Apache Point ObservatoryAPOGEE-1(SDSS-III):100,000 giants to magnitude H=12.5Bulge stars:7000R~20000- 30000, S/N~100Wavelength1.52-1.69mvelocity error 0.5 km/s15 elements error of 0.1 dex

APOGEE-2(S) (SDSS-IV) has been proposed to NSFThe same instrument as that of APOGEE-1will be set at Las Canpanas Observatory

~90,000stars in the bulgeMission period: 2014-2019

★VVV, APOGEE, BRAVA, ARGOS, ・・・

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Photometry, radial velocities and elemental abundances of stars in the bulge of the MW

Furthermore we need astrometric parameter:

・ annual parallax

・ proper motion

3-dimensional positions and velocities of stars

will be provided.

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Trace of a star :Trace of a star : Helical motionHelical motionannual parallatic ellipseannual parallatic ellipse 　＋　　＋　 proper motion(straight line)proper motion(straight line)

Astrometry: Fundamental task of measuring stellar positions

Helical motion of a star

§3. Astrometry and Upcoming space astrometry missions

Repeated measurements 2D-positions of stars in space

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1. Apparent annual elliptical motion *Parallactic Ellipse (annual parallax) 　　　　　　 Distances of stars

2. Systematic displacement of stellar positions Proper motion *Proper motion + Distance 　　　　 　　 Tangential velocities of stars　　

　

Helical motions of stars

Astrometry ＝＞important information of distances and tangential velocities of stars

Residual motions from the helical motion

C

α

M＊ G Mp

a

Periodic residual motions

Physical characters such as mass of binary stars, mass of planets etc.

Very important information !!Binary systems, Planetary systems,Gravitational lens effects, effects of starspot, etc.

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Space Astrometry Projects 　　　　　　　　Mission Agency ethod Launch #of Stars Mag.limit AccuracyM

Hipparcos ESA teles. 1989 120000 12 1mas@V=10

Gaia ESA teles. 2013 1 billion 20 7-300 as@6 G 20 < <

（ ）(all sky survey) 9-26 as@V=15

Nano- z=7.5NAOJ teles 2015 0.5 million 9 3mas@

( )JASMINE (all sky survey) for only N-J data

0 .1mas /year wi th(

)Hipparcos catalogue

Small- Hw 11.5NAOJ teles. ~2019 12 10-70 as@one hundred <

( )JASMINE Hw-band&JAXA of thousands

Remark: Infrared astrometry mission (Small-JASMINE) has advantage in observing stars in the Galactic bulge, hidden by interstellar dustin optical bands. 　　　　　　　

★Gaia(ESA’s mission)

　　 *Gaia will be launched at 19*Gaia will be launched at 19thth Dec. ,2013. Dec. ,2013.

　　 　　 *The final catalogue will be released in 2021.*The final catalogue will be released in 2021.

*all sky survey in an optical band*all sky survey in an optical band

　　 *G-band*G-band （（ 0.33-1.0 micron0.33-1.0 micron ）、　）、　 6mag6mag ＜＜ G<20magG<20mag

　　　　　　　　　　 *accuracies of parallax: *accuracies of parallax: as(6<G<20mag)

　　

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G = V - 0.0257 - 0.0924 · (V-IC) - 0.1623 · (V-IC)2 + 0.0090 · (V-IC)3 (fit error of 0.05mag)

The predicted errors vary over the sky

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§4. Small-JASMINE project Astrometric Measurement in Hw-band(1.1m~1.7m)Infrared astrometry missions have advantage in surveying theGalactic bulge, hidden by interstellar dust in optical bands!Accuracy: parallax: 10 as ~70 as for Hw<11.5mag *10 as distance accuracy:~640pc@8kpc　　 proper motion: 10as/yr ~70 as/yr for Hw<11.5mag *tangential velocity accuracy: 0.4~2.8km/s @8kpc (if the distance is accurately determined) position: 8 as ~40 as for Hw<11.5mag photometry(Hw-band) <0.01 magSurvey Area:

Near the Galactic center+ some directions toward interesting target objects(e.g CygX-1, planeray systems, browndwarfs. star-forming regions besides the area near the center)

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The Number of Objects: toward the Galactic bulge ： <10kpc: ~120,000 　　 (6kpc<d<10kpc: 88,000)

　　　　 （ highest accuracy region 　　　　　 : <10kpc :10,000, 6kpc<d<10kpc: 6,700)

Multi color photometry: J, H and Hw(astrometry)

The target launch date is around ~2019

　

＊ Proposal of SJ mission to small science-satellite missions executed by JAXA in Feb.2014.

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Hw<11.5mag

Mission life: ~3 years

Orbits: sun synchronized orbit ~550km

Launcher: Epsilon launch vehicle(solid rocket) provided

by JAXA

Small JASMINE

Development effort of NAOJ with JAXA (Japan Aerospace eXploration Agency)

and universities in Japan

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Advantage of Small-JASMINE Small-JASMINE is a unique space astrometric measurement in Hw-

band to get the accurate astrometric data for many stars in our Galactic bulge.

/

Small-JASMINE: ~ a few 103 stars of the bulge in its small survey area (with <0.1)Gaia: ~a few stars of the bulge in the same area as that in Small-JASMINE (with <0.1)

/

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Survey area of Small-JASMINE

★Another advantage: High time resolution!!Small-JASMINE will measure the same target every 100 minutes if the target is located towards the Galactic bulge .If a target is located toward other direction and Small-JASMINE can measure itin summer or winter season, Small-JASMINE measure it frequently as needed.*Gaia can measure the same target every one or two months.

Scientific targets of Small-JASMINE

1. The origin and evolution of the Galactic bulge　　＊ 3D-distributions of stellar positions and velocities in the inner part

of the bulge 　　　　 its origin and relation to

galaxy formations and evolutions

　　＊ star formation history in the Galactic bulge

2. Astrophysics around the Galactic center

　　＊ Formation of Super massive black hole at the Galactic center

Effect on stellar velocity distribution

　　＊ Motion of star clusters the origins of star clusters,

the gravitational potential field around the Galactic center

　　＊ existence of an inner bar structure effect on star formation around the center

　　

＊ Frequent and long-period monitor of Sg ｒ A* existence of QPO

Informtion of spin of SM-BH

　　　　　　　　　　　　

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Scientific targets of Small-JASMINE3. Compact celestial objects

＊ Determination of orbit element of X-ray binaries and -ray binaries

Big revolution! physics of accretion disk and jets, etc.

　　　 *a good candidate of X-ray bursts ： Cyg X-1:(l=71°, b=+3°)

period:5.6 days( unmeasurable by Gaia)

companion star: mv~9mag , change of the position: 40~50μas measurable

by Small-JASMINE

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*the Galactic ridge X-ray dim point sources

CVs(cataclysmic variables, symbiotic star) or late-type stars

4. Extra-planets

＊ detection of planets by astrometric method

(e.:g. primary star low-mass star(late M-dwarf, brawn dwarf): H-10mag,V=16-18mag)

5. Gravitational lens: Search of Wormholes!?

6. Stellar physics, Star formation

＊ 3-Ddistribution of inter -stellar dust

＊ annual parallax and proper motions of Mira-type variable stars in the bulge

　　　　　　　　　　　　

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Good candidates of -ray bursts: LS5039, J1018, LSI+61

Information of radial velocities , chemical composition and photometry (in other bands) is

complementary to

Small-JASMINE for these scientific targets

in the Galaxy.

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Cooperation with APOGEE-S and VVV is very strong synergy for studies of the Galactic bulge.

MOU for powerful scientific collaboration between APOGEE-2(S), SDSS-IV collaboration and Small-JASMINE has been concluded.

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Design of Small-JASMINE instrument• Optics design: Modified Korsch System (3mirrors) • Material: Synthetic Silica • Aperture size: 0.3m• Focal length: 3.9m• Field of view: 0.6 degree 0.6 degree

• Detector: Hw-band: HgCdTe(H4RG), Number of detectors: 1

pixel size:10m the number of pixels:4096 4096 potential well:100,000 read-out noise :30e

Structure model of the mission system (JAXA)

J, H-bands for photometry

第 53 回 宇宙科学技術連合講演会 20

Integration SystemDesign task of the integration system

• Satellite system -Compatibility of the bus system

-Control system of the pointing of the telescope

-Thermal structure

Small-JASMINE 　Ｓａｔｅｌｌｉｔｅ　ｓｙｓｙｔｅｍ

Ｍｉｓｓｉｏｎ　system

Ｂｕｓ　 system Ｔｈｅｒｍａｌ　ｃｏｎｔｒｏｌ

Ｓｔｒｕｃｔｕｒｅ

Ｔｅ l ｅｍｅｔｒｙ

Ｄａｔａ　ｈａｎｄｌｉｎｇ

Electronic power

Attitude control

2nd propulsion

commission the task to companies prospects are almost good

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We need astrometric measurements forthe Galactic bulge survey with larger areawhich overs the whole region of the bulgethan the survey area of the Small-JASMINE.

★Small-JASMINE will provide many interesting results in wide fields of astronomy and astrophysics.

however

§5 . WISH as an infrared space astrometry mission

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WISH：wide survey with accurate measurements in infrared bandsWISH has high possibility to play a role as an infrared astrometry mission for the Galactic bulge

astrometric measurements with achievement of ~10as accuracy

Pointing stability （ 70mas/3sec) of the telescope and thermal stability(~0.1K/30h) of the instruments are required in the design of the WISH satellite.

Required stability of the pointing of the telescope for WISH (70mas/300sec) is sufficient enough to achieve 10μas precisions of asttrometric measurements.

*The Galactic bulge survey with area of 6°(b)×16°(l)*Precisions of ~10μas （ K<11mag)

*necessary observation time: 0.6years/5years(1.4months/1year: 20days in spring and 20days in autumn)*option: survey area of 3°(b)×16°(l)0.3years/5years

WISH

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Our JASMINE team is willing to contribute to the WISH mission for the resolution of technical issues, the developmentof the satellite, and data analysis if WISH will play a role as an infrared astrometry mission for the Galactic bulge!!

We hope that the WISH mission will be successful.

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Jasmine

Thank you for your attention.