SLIDE 1
Gong-Bo Zhao National Astronomical Observatories, China (NAOC) http://icosmology.info gbzhao@nao.cas.cn
Oct 17, 2017 CSSOS workshop
CMB SNe Redshift surveys (BAO,RSD)
17/10/2017 2 CSSOS workshop
CSSOS and dark energy Gong-Bo Zhao National Astronomical - - PowerPoint PPT Presentation
CSSOS and dark energy Gong-Bo Zhao National Astronomical - - PowerPoint PPT Presentation
CSSOS and dark energy Gong-Bo Zhao National Astronomical Observatories, China (NAOC) http://icosmology.info gbzhao@nao.cas.cn Oct 17, 2017 CSSOS workshop CMB SNe CSSOS workshop 17/10/2017 2 Redshift surveys (BAO,RSD) 100+ Nobel Prizes
SLIDE 2
SLIDE 3
NASA
100+ Nobel Prizes since 1901!
17/10/2017 3 CSSOS workshop
SLIDE 4
NASA
100+ Nobel Prizes since 1901!
Huge discovery space in the dark sector!
CMB (1978; 2006) Cosmic Acceleration (2011) Gravitational Waves (2017)
17/10/2017 4 CSSOS workshop
SLIDE 5
17/10/2017
The expansion of the Universe can accelerate if
Dark Energy In GR, to add new ‘repulsive matter’, which contributes 70% total energy Modified Gravity To modify General Relativity
NASA/Jim Campbell/Aero-News Network
5 CSSOS workshop
SLIDE 6
17/10/2017
The expansion of the Universe can accelerate if
Dark Energy In GR, to add new ‘repulsive matter’, which contributes 70% total energy Modified Gravity To modify General Relativity
NASA/Jim Campbell/Aero-News Network
LSS surveys can help break the degeneracy
6 CSSOS workshop
SLIDE 7
17/10/2017
credit: Jean-Paul KNEIB
(2014-2020) DESI, PFS
7 CSSOS workshop
SLIDE 8
17/10/2017
credit: Jean-Paul KNEIB
(2014-2020) DESI, PFS
9, 376 deg2 1, 372, 737 galaxies 294, 153 quasars
8 CSSOS workshop
SLIDE 9
17/10/2017
What do redshift surveys measure?
q, , j, , z
A 3D galaxy map in z-space
9 CSSOS workshop
SLIDE 10
17/10/2017
P(k) BOSS (Beutler et al, 2014) x(s) BOSS (Samushia et al, 2014)
A 3D galaxy map in z-space
Feldman et al, 1994 Landy & Szalay, 1993 10 CSSOS workshop
SLIDE 11
Baryonic Acoustic Oscillations (BAO)
The standard Ruler
17/10/2017 CSSOS workshop 11
SLIDE 12
17/10/2017 CSSOS workshop
Baryonic Acoustic Oscillations (BAO)
A bump at ≈ 150 Mpc formed on density profile.
The BAO scale is cosmology- dependent!
source: Daniel Eisenstein’s web
12
SLIDE 13
17/10/2017
BOSS (Alam et al), 2016, 1607.03155 Fourier space Configuration space
Latest BAO measurements
13 CSSOS workshop
SLIDE 14
17/10/2017
BOSS (Alam et al), 2016, 1607.03155
14 CSSOS workshop
SLIDE 15
17/10/2017
Tomographic BAO measurements from BOSS DR12
GBZ, Wang, et al, (BOSS team), MNRAS 2017, 1607.03153 Wang, GBZ, et al, (BOSS team), MNRAS 2017, 1607.03154
15 CSSOS workshop
SLIDE 16
17/10/2017
BOSS (Wang, GBZ et al), 2016
Tomographic galaxy correlation function measurement
16 CSSOS workshop
SLIDE 17
BOSS (Yuting Wang, GBZ et al), 2016, 1607.03154
17/10/2017 17 CSSOS workshop
SLIDE 18
BOSS (GBZ, Yuting Wang et al), 2016, 1607.03153
Latest BOSS tomographic BAO measurements
17/10/2017 18 CSSOS workshop
SLIDE 19
17/10/2017
BOSS (GBZ, Yuting Wang et al), 2016, 1607.03153
19 CSSOS workshop
SLIDE 20
17/10/2017
BAO is key to Dark Energy
- Negative
pressure:
a / a = − 4πG 3 (ρ +3p) > 0 ⇒ w ≡ p / ρ < −1/ 3
- Candidates: Vacuum energy :
w = -1 Dynamical fields:
Quintessence (Ratra & Peebles, 1988): w (a)>-1 Phantom (Caldwell, 2002): w (a)<-1 Quintom (Feng, Wang and Zhang 2004): w (a) across -1
GBZ & Zhang, 2010
20 CSSOS workshop
SLIDE 21
17/10/2017
eBOSS forecast (GBZ et al, 2015)
21 CSSOS workshop
w(a) = w0+wa(1-a)
SLIDE 22
17/10/2017
eBOSS forecast (GBZ et al, 2015)
22 CSSOS workshop
w(a) = w0+wa(1-a)
SLIDE 23
17/10/2017
+ PFS, FoM=79
23 CSSOS workshop
w(a) = w0+wa(1-a)
SLIDE 24
Today 9 billion years ago GBZ et al，Phys. Rev. Lett. 2012.
24
17/10/2017 CSSOS workshop
SLIDE 25
17/10/2017 CSSOS workshop 25
LCDM dynamical DE
Zhao et al., (BOSS collaboration), 2017 Nature Astronomy, 2017
SLIDE 26
26 17/10/2017 CSSOS workshop
SLIDE 27
17/10/2017
Reconstruct w(a) non-parametrically
27 CSSOS workshop
Zhao et al., (BOSS collaboration), 2017 Nature Astronomy, 2017
SLIDE 28
17/10/2017 CSSOS workshop 28
SLIDE 29
17/10/2017
We use redshift z to infer distance d in redshift surveys!
The Redshift Space Distortion (RSD)
29 CSSOS workshop
SLIDE 30
17/10/2017
Galaxies have peculiar motions due to the local overdensity
- n top of the Hubble velocity
30 CSSOS workshop
SLIDE 31
17/10/2017
OVERDENSITY
31 CSSOS workshop
SLIDE 32
17/10/2017
Kaiser, 1987
32 CSSOS workshop
SLIDE 33
17/10/2017
Latest BOSS DR12 RSD measurements
BOSS (Alam et al), 2017, MNRAS, 1607.03155
33 CSSOS workshop
SLIDE 34
17/10/2017 CSSOS workshop 34
Yuting Wang, GBZ et al (BOSS), 1709.05173
SLIDE 35
eBOSS Survey (started summer 2014)
17/10/2017
http://www.sdss.org
² Dark-time observations ² Fall 2014 – Spring 2020 ² 1000 fibers per 7 deg2 plate ² Wavelength: 360-1000 nm, resolution R~2000 ² 1–2% distance measurements from baryon acoustic oscillations between 0.6 < z < 2.5
35 CSSOS workshop
SLIDE 36
17/10/2017 CSSOS workshop 36
Ata et al (eBOSS team including GBZ), MNRAS, 2017
SLIDE 37
17/10/2017 CSSOS workshop 37
Ata et al (eBOSS team including GBZ), MNRAS, 2017
SLIDE 38
17/10/2017 CSSOS workshop 38
Ata et al (eBOSS team including GBZ), MNRAS, 2017
SLIDE 39
17/10/2017 CSSOS workshop 39
Ata et al (eBOSS team including GBZ), MNRAS, 2017
SLIDE 40
17/10/2017
eBOSS ability to constrain MG
40 CSSOS workshop
SLIDE 41
17/10/2017
PFS ability to constrain MG
41 CSSOS workshop
SLIDE 42
17/10/2017 CSSOS workshop
Get some sense…
42
SLIDE 43
17/10/2017 CSSOS workshop
GR
43
SLIDE 44
17/10/2017 CSSOS workshop
f(R)
44
SLIDE 45
R > Gpc Reconstructing w(z) using BAO, SN Mpc < R < Gpc
Galaxy clustering, WL
R < Mpc Cluster profiles
Observational tests on multi-scales
0.01 0.1 0.1 0.2 0.3 0.4 ADEPT+LSST SKA 1.3<z<1.7 0.01
Pengjie Zhang et al., 2007, PRL
EG = Ω0 f Geff GNewton
GBZ et al., 2011, PRL
GBZ et al., 2009, PRL
Terukina et al., 2014, JCAP
GBZ et al., 2012, PRL 17/10/2017 45 CSSOS workshop
SLIDE 46
R > Gpc Reconstructing w(z) using BAO, SN Mpc < R < Gpc
Galaxy clustering, WL
R < Mpc Cluster profiles
Current surveys
BOSS z<0.6
740 SNe from SNLS
Planck ~50 clusters
17/10/2017 46 CSSOS workshop
SLIDE 47
R > Gpc Reconstructing w(z) using BAO, SN Mpc < R < Gpc
Galaxy clustering, WL
R < Mpc Cluster profiles
Surveys in 5 years
DES ~1000 SNe 5000 deg2
eBOSS 0.6<z<2.5 ~2000 clusters IFU ~10000 spectra
17/10/2017 47 CSSOS workshop
SLIDE 48
R > Gpc Reconstructing w(z) using BAO, SN Mpc < R < Gpc
Galaxy clustering, WL
R < Mpc Cluster profiles
Surveys in 10 years
TMT: 30 meter imaging ~20000 clusters
DESIRE (Euclid)+LSST ~18k SNe LSST: 8.4 m，20000 deg2 imaging Euclid: 15000 deg2 imaging + spectroscopic DESI: 4 m，14000 deg2 spectroscopic PFS：8 m spectroscopic SKA：full sky radio
17/10/2017 48 CSSOS workshop
SLIDE 49
R > Gpc Reconstructing w(z) using BAO, SN Mpc < R < Gpc
Galaxy clustering, WL
R < Mpc Cluster profiles
Surveys in 10 years
TMT: 30 meter imaging ~20000 clusters
CSSOS!!
17/10/2017 49 CSSOS workshop
SLIDE 50
Summary
17/10/2017
Ø Galaxy surveys can provide key information for cosmology, and tomographic BAO/RSD analyses are crucial for DE and MG; Ø BOSS DR12 data (combined with others) show a hint of DE dynamics at 3.5 sigma level. The next step is to approve/falsify this signal at 5 sigma level, which is the threshold for a detection. CSST gives us the opportunity!! Ø CSST offers key information on the structure growth history of the Universe, which is essential for gravity tests.
50 CSSOS workshop
SLIDE 51
China built excellent instruments!!
17/10/2017 51 CSSOS workshop
SLIDE 52
CSSOS makes China GREAT again in astronomy!!
17/10/2017 52 CSSOS workshop