Optical Surveys of Galaxies

サーベイの科学的インパクト
－可視光での銀河サーベイを例に－
岡村定矩
法政大学理工学部創生科学科
HSC研究会 国立天文台
2012年9月26日（水）
Ⅰ はじめに（釈迦に説法）
Ⅱ Early Surveys and Their Impacts
Ⅲ Modern Surveys and Their Impacts
Ⅳ Future Surveys
サーベイ観測
天体カタログ
（測光カタログ）
空の画像
主
10年くらい前まで
分光カタログ
従
画像の大部分は天体のない「のっぺりした」空だった
極めて暗い天体まで写るようになると、空はびっしり
と天体で覆われていた (confusion limit)。
従
最近・今後
主
ハッブルディープフィールド（1995)の例
・天体の性質を
記述するデータ
・莫大な数の天
体の分光データ
地上望遠鏡による写真
ハッブル望遠鏡による写真
約3000個の天体（銀河）
地上望遠鏡による写真
満月
暗い天体まで見えれば
数はどんどん増える
各波長帯での代表的な広視野サーベイ
天体の数
可視光
108 - 109
最も長い歴史。他波長観測の
準拠データ。
赤外線
108 - 109
電波
紫外線
X線
ガンマ線
http://ned.ipac.caltech.edu/level5/March12/Djorgovski/Djorgovski1.html
105 - 106
107 - 108
~105
~103
第XXVIII回国際天文学連合(IAU)総会
SpS15: Data Intensive Astronomy
SOC Chair Masatoshi Ohishi
SpS15: Data Intensive Astronomy
SOC Chair Masatoshi Ohishi
天文学
Data-starving Science
(Tony Tyson）
2005年頃まで
現在は移行期
Data-mining Science
2015年頃から
(Understanding/Interpretation-starving science)
Ⅰ はじめに（釈迦に説法）
Ⅱ Early Surveys and Their Impacts
Ⅲ Modern Surveys and Their Impacts
Ⅳ Future Surveys
Shapley-Ames Catalog (1932)
Shapley, H. and Ames, A. 1932, Harvard College Observatory Bulletin No. 887, pp.1-6
Annals of Harvard College Observatory, vol. 88, pp.41-76
The Local Supercluster
天球面全体を
モルワイデ図法
で表現した図
完全性
均質性（一様性）
広い天域
局所超銀河団
As a contribution to the study
of the structure of the
metagalactic system, we have
completed a photometric
catalogue, appearing later in
annals, of more than a
thousand extragalactic objects
brighter than the thirteenth
magnitude. The primary
virtues of the survey are its
essential completeness and the
fair homogeneity of the
magnitudes over the whole sky.
Compilation of 1249 mostly
known ‘Extragalactic Nebulae’
Mag. Res.
α (1950) δ
(NGC)
(IC I+II)
λ β
First magnitude-limited catalog based on
more or less uniform photographic plates
一定の（見かけの）明るさ
まですべて拾う
Des.
Not naked eye!
Large efforts to give
calibrated magnitudes
Diams. Type
Aut.
A Revised Shapley-Ames Catalog (1981)
~50年後
Sandage, A. and Tammann, G., Carnegie Institution of Washington
The present catalog is, then, a compilation of available data on
redshifts, morphological types, and magnitudes for Shapley-Ames
galaxies, using literature sources to summer 1980. (1246 galaxies)
Study of the Local Supercluster and Field Luminosity Function
Redshift distribution
z
z
x
天の北半球
Luminosity Function
フィールド
y
個数の対数
個数
天の南半球
Spatial Structure
銀河団
y
x
距離
Yahil et al. 1980, ApJ, 242, 448
明
暗
Binggeli et al. 1988, ARA&A, 26, 509
Shane-Wirtanen (Lick) Count (1954)
Shane and Wirtanen 1954, AJ, 59, 285
Counts of extragalactic nebulae
( m<18.4) in 10’x10’ cells over
12h<α<18h, -23°<δ<20°
Plates taken with 20-inch Carnegie
Astrograph of the Lick Observatory
New analysis by Seldner et al.
1977, AJ, 82, 249
First measurement of two-point
correlation function of galaxy
distribution
210,980 nebulae
Totsuji & Kihara 1969, PASJ, 21, 221 ξ(r) ~ r -1.8
Peebles 2012, ARA&A, 50, 1
World’ Major Schmidt Telescopes
LAMOST
(2010; 400cm)
Palomar Schmidt
(1949; 122cm)
Kiso Schmidt
(1974; 105cm)
シュミット望遠鏡： 広視野の写真撮影専用の望遠鏡
鏡筒の中央に焦点があり、そこに
大型写真乾板をセットして写真を撮る。
ESO Schmidt
(1973-98;100cm)
UK Schmidt
(1973; 122cm)
Tautenburg Schmidt
(1960；134cm)
写真乳剤＋
フィルター
Major Surveys with Schmidt Telescopes
Designation
Survey Area
名称
サーベイ天域
Northern Sky
Palomar Schmidt
Emulsion+
Filter
# of plates
year
乾板枚数
西暦年
(POSS=Palomar Observatory Sky Survey)
7年を費やした歴史的
サーベイ
1999
(* as of April 1999)
写真乳剤＋
Designation Survey Area
フィルター
名称
サーベイ天域
Emulsion+ # of plates
Filter
乾板枚数
year
西暦年
Southern Sky
UK Schmidt (SERC=Science and Engineering Research Council)
2000?
ESO Schmidt
(* as of April 1999)
Eye Inspection of Survey Plates or Printed Charts
Scale: 67.1”/mm
満月の
大きさ
Palomar Charts
パロマ－チャート
13個分
Major galaxy catalogs made from Schmidt surveys
Eye Inspection
・Morphological Catalogue of Galaxies (MCG): 4 volumes
Northern Sky
Vorontsov-Velyaminov et al. 1962-68 (Moscow State Univ.)
~29,000 galaxies from POSS-I
・Catalogue of Galaxies and Clusters of Galaxies (CGCG): 6 volumes
Zwicky et al. 1961-68 (California Institute of Technology)
~28,000 galaxies from POSS-I complete down to mZ =15.5 mag and
~9700 clusters of galaxies
Zwicky mag.
・Uppsala General Catalogue of Galaxies (UGC)
Nilson 1973, Acta Uppsala Univ., Ser. V, A, Vol.1
Southern Sky
12,921 galaxies from POSS-I with δ>-2.5 down to 14.5 mag
・The ESO/Uppsala Survey of ESO(B) Atlas
Lauberts 1982 (ESO)
~16,000 galaxies from ESO quick B survey with D>1’
10,000-30,000 galaxies
Man-power limit of a single
person or a few people
Catalogue of Galaxies and Clusters of Galaxies (CGCG)
CLUSTERS OF GALAXIES
Palomar Chart
(Virgo Cluster)
GALAXIES
6.6 deg
These galaxy catalogs had been an important and
indispensable basis of galaxy studies and observational
cosmology until recently.
CGCG (Zwicky et al. 1961-68)
UGC (Nilson 1973)
as of Aug. 5, 2012
# of papers whose abstracts
# of papers whose abstracts
include ‘Zwicky catalog’ is about
include ‘Uppsala catalog’ is about
270 (except IAUC and CBET)
150 (except IAUC and CBET)
Total citation: 905
Total citation: 1584
Digitization of Schmidt Plates (1980s-90s)
Plate Scanning Machines
COSMOS: Co-ordinates, Sizes,
Magnitudes, Orientations, Shape
PDS microdensitometer
(PDS 2020 GMS)
Automated Photographic
Measuring System (APM)
The Minnesota Automated
Plate Scanner (APS)
APM Galaxy Survey
~3 million galaxies from UK Schmidt plates
down to bJ=22 over 7000 square degrees.
185 UK Schmidt Fields
UK Schmidt Field
SGP 南銀極
天球面上の300万個
の銀河の分布
http://vo.iucaa.ernet.in/2df/Survey/apm.html
Input catalog of 2dFGRS (2dF Galaxy Redshift Survey)
ハッブル分類（音叉図）
改訂ハッブル分類
（三次元分類）
Reference Catalogue of Bright Galaxies
Morphological type, magnitude, diameter, ….
Not complete in any sense
E S0 Sa Sb Sc Irr
(1) Reference Catalogue of
Bright Galaxies (RC1)
G. & A. de Vaucouleurs 1964, University
of Texas Press
2599 galaxies
RC1
Revised Hubble
Classification
(2) Second Reference Catalogue
of Bright Galaxies (RC2)
G. & A. de Vaucouleurs, H.G.Corwin 1976,
University of Texas Press
4364 galaxies
(3) Third Reference Catalogue
of Bright Galaxies (RC3)
RC2
G. de Vaucouleurs et al. 1991, New York: Springer
23,024 galaxies
Exponential
increase!
RC3
Era of Redshift Surveys (1980’s- 90’s)
宇宙の大規模構造
First hint of large-scale structure
Importance of completeness!
Wedge diagram
260 sq. deg
238 galaxies
(m<15.0)
(only) 44 new redshifts
toward completeness
Gregory & Thompson 1978, ApJ, 222, 784
CfA Survey
(CfA: Harvard-Smithsonian Center for Astrophysics)
m<15.5 mag
7031 galaxies
CGCG+UGC
CfA-II (1984-1995)
~18000 galaxies (m<15.5)
over 9700 deg^2
Motivation for wider
and deeper surveys
m<14.5 mag
188 galaxies
Complete
sample
CfA-I (1977-1982)
2401 galaxies (m<14.5)
over 8700 deg^2 (b>40, δ>0)
First CfA Slice
m<15.5 mag
1769 galaxies
Geller et al. 1987, IAUS, 124, 301
IRASz: IARS Point Source Catalog Redshift Survey
SPS: Supergalactic Plane Survey
SAPM: Stromlo-APM Redshift Survey
SSRS2: Southern Sky Redshift Survey II
CFRS: Canada-France Redshift Survey
ORS: Optical Redshift Survey
LCRS: Las Campanas Redshift Survey
ESP: ESO Slice Project
CNOC2: Canadian Network for Obs.’l Cosmology
Field Galaxy Redshift Survey
~ 1990
wide survey
mB<~16 mag
~ 2000
mB<~16 mag
deep pencil-beam survey
150 h-1 Mpc
mB<~22 mag
south
wide survey
our Galaxy
north
redshift
different
sample
Periodic structure = Picket Fence
redshift
Broadhurst et al. 1990, Nature, 343, 726
150 h-1 Mpc
Ⅰ はじめに（釈迦に説法）
Ⅱ Early Surveys and Their Impacts
Ⅲ Modern Surveys and Their Impacts
Ⅳ Future Surveys
写真からCCDへ（1980s-90s）
14インチシュミット乾板
木曽の初代CCDカメラで
ある高遠カメラ (1988年)
写真乾板データ
高遠CCDカメラによるデータ
感度が写真より約100倍高い
面積はシュミット写真乾板
の約1000分の1
パロマーサーベイは7年
広い空の観測は無理
CCDをたくさん並べる
モザイクCCDカメラ
スローンディジタルスカイサーベイのメインカメラ
Physics today
アパッチポイント天文台
(アメリカ、ニューメキシコ州)
関口真木氏とSDSS main camera
2k x 2k 素子を 30素子並べた
世界最大のCCDカメラ
2010年に退役。スミソニアン自然誌
博物館に展示予定。
Modern Wide Surveys
Imaging Survey + Spectroscopic (Redshift) Survey
Input catalog
Photometric Catalog
mB<~19 mag
測光カタログ
mB<~16 mag
2dF Galaxy Redshift Survey (2dFGRS) Sloan Digital Sky Survey (SDSS)
(photographic photometry and)
redshifts of 220,000 galaxies
Southern Hemisphere
5-band Photometry: 3.57x108 objects
redshifts: 930,000 galaxies, ~100,000
quasars, and 460,000 stars.
z=0.15
z=0.1
z=0.05
3.9-m AAT
Started in 1997, completed in 2001
Final Data Release - 30 June 2003
APM (photographic) Galaxy Survey
was used as the input catalog
2.5-m
dedicated tel.
Equatrial stripe
Started in 2000, completed in 2008
7th Data Release 2009, ApJS, 182, 543
Sloan Digital Sky Survey (SDSS) Legacy Survey (2000-2008)
5 bands
Quantum Efficiency
Apache Point Observatory
(2800m; New Mexico, USA)
Wavelength (Å）
Two 320-channel
spectrographs
Survey Volume
Proceeded in parallel
Spectroscopic Survey
640+ holes
z=0.2
Plug plates
our Galaxy
Our
Imaging survey
Camera
Fiber cartridge
Impacts of a large survey (1)
absolute r magnitude
Tanaka, SO et al. 2004, AJ, 128, 2677
- 21.4
bright complete sample
(volume-limited)
- 19.4
below the
mag. limit
redshift
color index
complete sample
critical density for
faint galaxies
local number density
faint complete sample
(volume-limited)
・Galaxies living in higher density
regions are redder.
・However, the relation between
local density and color is
different for galaxies of
different luminosities.
・The relation is more
pronounced for faint galaxies
than for bright galaxies.
Impacts of a large survey (2)
・Small statistical error
・Accurate estimate of intrinsic dispersion
Large sample
金属量
Luminosity (Mass) ー Metallicity Relation
光度（質量） － 金属量関係
53,000 star forming
galaxies in the SDSS sample
Elliptical galaxies
Metallicity
Local Group dE
E (Bender et al.)
E (Brodie & Huchra)
Spiral galaxies
Intrinsic
dispersion
giant S
Irr
before SDSS
after SDSS
MB (Absolute Magnitude)
明るさ
Zaritsky et al. 1994, ApJ, 420, 87
Log M* (Stellar Mass)
Tremonti et al. 2005, ApJ, 613, 898
Impacts of a large survey (3)
Global trend
at a glance
Absolute
magnitude
Sersic
index
Large sample
Surface
brightness
144,609 galaxies
Color indices
銀河の性質の
大局的な相関
を鳥瞰出来る
Blanton et al. 2003,
ApJ, 594, 186
銀河の性質のさまざまな指標
Impacts of a large survey (4)
anticipated
Discoveries!
before SDSS
quasars
<~15,000
High-z (z>5)
quasars
None
(zmax=4.897)
L and T dwarfs
after SDSS
~>80,000
~60 (DR5 catalog)
+ 13 z>6 quasars
71 (new from
SDSS, 2006)
~20 (mostly from
2MASS, 1999)
Lensed QSOs
serendipitous
36 (25 new)
Actively star forming E galaxies
Green Peas
Actively star forming compact dwarf galaxies
Cardamone, C. 2009, MNRAS, 399, 1191
Fukugita et al. 2004, ApJ, 601, L127
etc., etc.
明るい
真の明るさ
Absolute Magnitude
77,429 quasars
(DR5 Catalog)
Known quasars
(open circles)
暗い
SDSS以前は約15,000個
（すべてz<5）
0
1
距離
発見から理解へ
2
3
Redshift
4
5
Impacts of a large survey (5)
Detection of Weak Signals!
Stacking of 683
clusters of galaxies
at 0.2<z<0.3
Two-point correlation function
Zibetti et al. 2005,
MNRAS, 358, 949
弱い信号の検出
Detection of
diffuse
intracluster light
銀河間空間に広
がる淡い光
Detection of
the Baryon Acoustic Peak
バリオン音響振動のピーク波長
誤差が小さい
46,748 luminous red galaxies in
0.72 h-3 Gpc over 3816 deg2
at 0.16 <z< 0.47
Eisenstein et al. 2005, ApJ, 633, 560
Comoving separation (h-1 Mpc)
Impacts of a large survey (6): Virgo Cluster
Las Campanas Survey: VCC (Virgo Cluster Catalog)
Binggeli et al. 1984, AJ, 89, 64 ;
1987, AJ, 94, 251
2.5m du Pont Tel.
+ 50-cm pg. plates
67 plates (1.5 deg FoV)
Study of dwarf
galaxies beyond
the Local Group
Giant galaxies
巨大銀河
Virgo Cluster Catalog: VCC
2096 galaxies down to B~18 mag
declination
20 degrees
Dwarf galaxies
15 degrees
right ascension
矮小銀河
1277 certain members
574 possible members
245 background galaxies
Ichikawa, Wakamatsu, SO 1986, ApJS, 60, 475
Next Generation Virgo Cluster Survey (NGVS)
Ferrarese et al. 2012, ApJS, 200, 4
five SDSS bands
CFHT/MegaPrime,
~140 nights (2009-2012)
104 deg^2
5個の波長帯
(point source)
u* = 25.9 AB mag
g’ = 25.7 AB mag
r’ = 25.2 AB mag
i’ = 24.9 AB mag
z’ = 24.6 AB mag
VCC1104
VCC1129
-7
平均表面輝度
average surface brightness
明
-11
absolute magnitude MB (mag)
8 mag.!
NGVS
limit
-15
VCC
limit
-19
-23
Palomar Chart
limit (1960s)
giant early-type
galaxies
Virgo dwarf
LG dwarf at
Virgo distance
VCC limit
(1985)
NGVS limit (2012)
apparent magnitude B (mag)
見かけの明るさ
明
Ⅰ はじめに（釈迦に説法）
Ⅱ Early Surveys and Their Impacts
Ⅲ Modern Surveys and Their Impacts
Ⅳ Future Surveys
北京のIAU総会 SpS15で話したことの報告
Major Existing, Upcoming , and Future Surveys
SXDS: The Subaru/XMM-Newton Deep Survey
COSMOS: Cosmic Evolution Survey
CFHTLS: Canada-France-Hawaii Telescope Legacy Survey
NDWFS: The NOAO Deep Wide-Field Survey
BCS: Blanco Cosmology Survey
Black: Existing
Magenta: Upcoming
Stripe82: SDSS Legacy Survey Stripe82
+ Red
RCS2: Red Sequence Cluster Survey 2
VST-ATLAS: VLT Survey Telescope (2.6m tel) Blue: Future
PS1/PS2: Pan-STARRS 1&2 Telescopes
KIDS: Kilo degree Survey (VST)
HSC: Hyper Suprime-Cam Survey
DES: Dark Energy Survey (DECam+Blanco 4m)
Skymapper: Skymapper Southern Sky Survey
Euclid: Euclid Satellite
LSST: Large Synoptic Survey Telescope
(Credit: M.Takada, HSC survey team)
暗い
Major Existing, Upcoming , and Future Surveys
全天の面積
限界等級
HSC=Hyper Sprime-Cam
on Subaru Telescope
明るい
Black: Existing
Magenta: Upcoming
+ Red
Blue: Future
カバーする空の面積 （平方度）
(Credit: M.Takada, HSC survey team)
Hyper Suprime-Cam (HSC) on Subaru Telescope
Japan/Princeton/Taiwan Collaboration
with Mitsubishi/Canon/Hamamatsu
Suprime-Cam
Hyper Suprime-Cam
1.7 m
840 mm φ
1.5 deg
すばる望遠鏡
0.05 deg
HST/ACS
0.5 deg
Suprime-Cam
1.77 sq. deg
HSC
Comparison of Field of View
116 2Kx4K CCDs
LSST: 9.6 sq. deg
暗い
Major Existing, Upcoming , and Future Surveys
全天の面積
限界等級
0.2 TB
100 PB
Data Amount
and
Data Rate
30 TB/night
(10 years)
300 TB
0.5 TB/night
20 TB
明るい
Black: Existing
Magenta: Upcoming
+ Red
Blue: Future
65 TB
カバーする空の面積 （平方度）
(Credit: M.Takada, HSC survey team)
HSC Survey will explore
new frontier in survey
parameter space
Coming soon (2013- )
Stay tuned!!
0.2 TB/night
max. data rate
データ公開
DSS http://stdatu.stsci.edu/dss/index.html
可視光
SDSS http://www.sdss.org/
2MASS http://www.ipac.caltech.edu/2mass/
赤外線
UKIDSS http://www.ukidss.org/
IRAS http://irsa.ipac.caltech.edu/IRASdocs/iras.html
NVSS http://www.cv.nrao.edu/nvss/
電波
紫外線
X線
FIRST http://sundog.stsci.edu,
PMN http://www.parkes.atnf.csiro.au/observing/
databases/pmn/pmn.html
GALEX http://www.galex.caltech.edu/
ROSAT http://heasarc.gsfc.nasa.gov/docs/rosat/rass.html
ガンマ線 Fermi http://fermi.gsfc.nasa.gov/
'Sky Surveys', Djorgovski et al. 2012, in Astronomical Techniques, Software, and
Data (ed. H. Bond), Vol.2 of Planets, Stars, and Stellar Systems (Springer)
LSST: Large Synoptic Survey Telescope
サーベイ専用の8.4m望遠鏡（次世代「シュミット望遠鏡」）
2020年より10年間南天のサーベイ観測を行う
LSST
サンチャゴ
・LSST=Integrated Survey System
・no PI-programs
・All science will be done by the community
(not by the project)
・口径 8.4m
・3.2 Giga-pixel Cameara
(視野9.6平方度）
・6 バンド（0.3-1.1μm）
・18,000 平方度の空を3日毎に撮影（10年間）
宇宙の姿は残せるか？
ロゼッタストーンは
2000年以上生き延び
て記録を伝えている
ロゼッタストーンも真っ青！？
2012年9月25日朝日新聞朝刊
私の心配は
杞憂であった（？）