Hu Zhan

National Astronomical Observatories Chinese Academy of Sciences

Future Sky Survey and Big Data

KASI, 2016.4.25-29

1. NAOC & projects under construction

2. Large-area optical survey under China’s

Manned Space Program

• Research Groups: Stellar Astrophysics, Star Cluster and Nearby Galaxies, etc.

• Main facilities: LAMOST, 2.16m reflector, 2.4m reflector

• CAS Key Laboratory of Optical Astronomy, Structure and Evolution of Celestial Objects, Astronomical Optics & Technologies

Optical Astronomy

• Research Group: FAST, Lab of Radio Astronomy, Pulsars, Compact Objects and Diffuse Medium, KOSMA, ISM

• Main Facilities: FAST, 50/40/25m Radio Telescope, 3m KOSMA

• Key laboratory jointly operated with PMO and SHAO

Radio Astronomy

• 9 Research Groups

• Main Facilities:

• Key Laboratory of Computational Astrophysics, CAS Galaxy & Cosmology

• 9 Research Groups

• Main Facilities: Lunar Ultraviolet Telescope, GWAC

• Key Laboratory of Space Astronomy and Technology, CAS Space Science

• 5 Research Groups

• Main Facilities: Miyun station, Fuxian solar obs.

• Key Laboratory of Solar Activities, CAS Solar Physics

• 4 Research Groups

• Main Facilities: 50/40/25m Antenna & GRAS

• Key Laboratory of Lunar and Deep Space Exploration, CAS

Lunar and Deep Space Exploration

• Site Survey, Navigation & Space Debris

• Main Facilities: SLR network, CAPS and Site Monitoring Equipments

• Key Lab development in schedule Applied Astronomy

First light: Sept. 2016

Nov 2015

• Radius of curvature: 300m

• Effective Aperture: 300m

• Pointing: zenith angle ≤40°

• Frequency: 70MHz－3GHz

Science: HI 21cm survey, ISM,

IGM, pulsars, molecular lines,

masers, radio continuum

• Tianlai: a 21cm intensity mapping experiment to study dark energy with z

2015 2020 2025 2030

rad

io

IR/O

X

-ray

γ

-ray

e

/CR

/G

RW

Cosmic Web

DAMPE

SVOM HXMT XTP EP

mmVLBI 21cm SULFRO

21cm COME

cLISA

STEP

JEEEDIS

NEarth

UV

2015

2017 missions

To be carried out by a 2m-class telescope that can dock with the Chinese space station for maintenance and repair.

Announced at the 66th International

Astronautical Congress (Oct, 2015)

March 9, 2016

• Science case: 2009, suggestion of a telescope for astronomy on the Chinese space station (CSS); 4/2010, 1st meeting about astronomy with a large-aperture telescope on the CSS; 12/2010, 1st version of science goals; concept of a large-scale multiband imaging & slitless spectroscopy survey was well received by the CSS Space Application System and by China Manned Space Agency;

• Telescope: 2011, feasibility study; 2012, CSS applications selection; 2013, down-selection of design and budget review; 2014, man-tended free flyer concept; 2015-, preliminary design & technology development;

• Camera: 2015, NAOC & IOE selected to lead construction; preliminary design & technology development.

2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

2.5m

10000□°spect

Dark Energy Survey，4m 5000□°imaging

1.8m

30000 □°imaging

HETDEX，9.2m 420□°spect

Subaru，8.2m 1400□°imaging 1400□°spect

DESI，4m 14000□°spect

4MOST，4m 15000□°spect

Euclid，1.2m 15000□°imaging & spect

WFIRST，2.4m 2400□° imaging &

spect

Opportunity for a high-resolution

multiband NUV-optical survey.

LSST，8.4m 18000 □° imaging

• 17500□°imaging : 255-1000nm, ≥6 filters, ≥25.5m (5σ, point source, AB mag);

• 17500□°spect: 255-1000nm, R≥200, ≥22-23m;

• 400□°deep imaging & spect: at least 1m deeper.

Science Cosmology: dark energy, dark matter, gravity,

large-scale structure, neutrinos, primordial non-

Gaussianity…

AGNs: high-z AGNs, clustering, dual AGNs,

variability, UV excess, host galaxies…

Galaxies: formation & evolution, mergers, high-zs,

dwarfs, LSBs, near field, halos properties…

Milky Way: structure, satellites, dust, extinction…

Stellar science: formation, dwarfs, metal poor…

Solar system (high inclination): TNO、NEA…

Astrometry: reference frame, star clusters…

Ecliptic Coord.

Project Site/ orbit

Launch/op

FoV REE80 Num

pixels Area Wavelength Num

Filters Spect

deg2 ″ 109 deg2 nm

Space Station

LEO ~2022 1.1

0.002 0.15 0.25

2.5 0.002

17500 -

255—1000 900—1700

7 2

yes yes

Euclid L2 2020 0.56 0.55

>0.2 0.6

0.6 0.07

15000 550—920

1000—2000 1 3

no yes

WFIRST GEO ≥2024 0.28 >0.2 0.3 2400 927—2000 4 yes

LSST Chile 2022 9.6 >0.7 3.2 18000 320—1050 6 no

REE80: radius encircling 80% energy

Space Station

HST/ACS WFC

Euclid WFIRST

REE50 0.1" 0.06" 0.13" 0.12"

REE80 0.15" 0.12" ~0.23" ~0.24" Space

Station HST Euclid

Best imaging quality among surveys!

The Chinese space station optical survey is very competitive.

Its capability, especially high-resolution near-UV imaging and

slitless spectroscopy in the optical, is unique and highly

complementary to other surveys.

Euclid Definition Study

LSST does not fully overlap w/ Euclid.

Euclid CSS optical survey

Ecliptic Coord

• Field of View: 1.1 □° • Number of Pixels: 2.5×109

• Wavelength: 0.25-1μm, 0.9-1.7μm • Optical Resolution: 0.15″ • Spectral Resolution: R≥200

CSS Optical Survey

• 84 5k×6k CCD

• 8 4k×6k CMOS GS

• 8 2k×2k CMOS WFS

• 2.5B+0.2B pixels

(detector format subject

to change but same FoV)

LSST

• 189 4k×4k CCD

• 8 4k×4k CCD GS

• 4 4k×4k CCD WFS

• 3.2B pixels

Euclid

• 36 4k×4k CCD

• 16 2k×2k NIR FPA

• 0.64B pixels

HST

NUV &

optical

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

200 300 400 500 600 700 800 900 1000 1100

T (%

)

Wavelength (nm)

NUV

u

g

r

i

z

y

Exp. NUV u g r i z y

17500□° 2×150s 25.5 25.5 26.3 26.0 25.9 25.3 24.7

400□° 8×250s 26.8 26.7 27.5 27.2 27.1 26.5 26.0

0.000

0.200

0.400

0.600

0.800

1.000

250 350 450 550 650 750 850 950 1050

QE

Wavelength (nm)

NUV:u:g:r:i:z:y=2:1:1:1:1:1:2

1st order

R~250

Exp. GU

(res)

GV

(res)

GI

(res)

GU

(tot)

GV

(tot)

GI

(tot)

17500□° 4×150s 20.6 21.1 21.1 23.2 23.4 23.9

400□° 16×250s 21.8 22.3 22.3 24.4 24.5 25.0

Factors considered: Sun, Moon, Earth limb, SAA, solar panels, field

tiling, scheduled maintenance, unexpected down time... Roughly 60% of

the time is usable, and the total exposure time is ~34% of the time (HST:

40%). Can be increased considerably if allowing higher background.

The Galactic plane & eclliptic plane can be observed!

g, 150s×2 r, 150s×2

i, 150s×2, 26/□′ g+r+i, 38/□′

400-650nm, 6000×4800pix (45 □′, CCD size) 2/□′ with brightest 4 pixels S/N5 4.7/□′ with whole spectrum S/N10

620-1000nm, 6000×4800pix (45 □′) 3.9/□′ with brightest 4 pixels S/N5 8.5/□′ with whole spectrum S/N10

Amounts to several hundred million low-resolution galaxy spectra!

400-650 nm Brightest 4 pixels S/N5

Whole spectrum S/N10

620-1000 nm Brightest 4 pixels

S/N5 Whole spectrum

S/N10

120/□′ ，550-1050nm，R≃69-131，iAB≲28m

CSS: ≳2/□′ ELGs

Ultra-luminous quasar at z=5.363, i = 18 mag

i=23 mag

i=22 mag

Even higher: z=7.08, i = 20.3 mag, 21.3mag

Metal-Poor Stars

NUV-g color appears to be useful for selecting metal-poor

star candidates.

=21m

e2v CCD203-82 4096×4096 12μm 3D profiler scanning the focal plane

Flatness better than 25μm (req. ≤50μm), not much difference between the result at room temperature and that at -100℃

• The Chinese space-station optical survey has

unique capabilities and great potential for

discovery.

• Collaboration is crucial both for future projects

and scientists. Although we don’t have an

official policy yet, CMSA is very much open to

international collaborations. I think it will be

sorted out in a year or so and am looking

forward to working with you in the future!