Instrumentation and
Controls Group
Universal expansion
INAF-OATs
Recesssion velo
ocity
The original Hubble diagram (Hubble 1929):
Distance
All distant galaxies are found to recede from us.
Hubble's Law: v = H0 a
→ The universe expands!
Congresso SAIt 2011 - Paolo Di Marcantonio
1
Dynamics
Instrumentation and
Controls Group
INAF-OATs
Can we measure the history of the expansion directly?
a(t)
()
H0
a(t0 + Δt0)
a(t
(t0)
H(z)
a(te + Δte)
a(t
(te)
te te + Δte
z(t0 + Δt0) - z(t0)
Δt0
t0 t0 + Δt0
z
t0
t
dz
dt 0
Congresso SAIt 2011 - Paolo Di Marcantonio
1 z H
0
H z
2
Instrumentation and
Controls Group
Cosmic signal
INAF-OATs
H = H 0 [Ω M (1 + z ) + Ω R (1 + z ) + Ω Λ + (1 − Ω tot )(1 + z )
where Ω tot = Ω M + Ω R + Ω Λ ≈ 1
3
4
Plotted are values and
errors of the “measured”
velocity drift v˙, expected
for a total experiment
p
duration of Δt0 = 30 yr, a
total integration time of
4000 h and for standard
cosmological
g
parameters
p
(h70 = 1, ΩM = 0.3, ΩΛ =
0.7).
Liske et al., 2008
Congresso SAIt 2011 - Paolo Di Marcantonio
3
]
1
2 2
Instrumentation and
Controls Group
Direct dynamical measurements
INAF-OATs
Sandage 1962 ApJ 136,319
“It should be possible to choose between various models of the
expanding universe if the deceleration of a given galaxy could be
predictions of the expected
p
change
g in z=dl/l0 for
measured. Precise p
reasonable observing times (say 100 years) is exceedingly small.
Nevertheless, the predictions are interesting, since they form part of
the available theory for the evolution of the universe”
Since then:
McVittie (1965), Weinberg (1972), Ebert & Trümper (1975), Davis & May
(1978), Rüdiger (1980), Lake (1981), Rüdiger (1982), Phillipps (1982),
Lake (1982), Partovi & Mashhoon (1984), Teuber (1986), Loeb (1998),
Nakamura & Chiba (1999), Gudmundsson & Björnsson (2002), Freedman
(2002), Zhu & Fujimoto (2004), Davis & Lineweaver (2004), Seto &
Cooray (2006).
(2006)
Congresso SAIt 2011 - Paolo Di Marcantonio
4
Instrumentation and
Controls Group
How to measure this signal?
INAF-OATs
The Lyman Forest
Today and …
… years after
Congresso SAIt 2011 - Paolo Di Marcantonio
5
Instrumentation and
Controls Group
Observing dz/
dz/dt in the Ly
Ly--α forest
INAF-OATs
Congresso SAIt 2011 - Paolo Di Marcantonio
6
Instrumentation and
Controls Group
Observing dz/
dz/dt in the Ly
Ly--α forest
INAF-OATs
Congresso SAIt 2011 - Paolo Di Marcantonio
7
Instrumentation and
Controls Group
Observing dz/
dz/dt in the Ly
Ly--α forest
INAF-OATs
Δt = 106 years!
Congresso SAIt 2011 - Paolo Di Marcantonio
8
The instrument
Instrumentation and
Controls Group
INAF-OATs
COsmic
Dynamics &
E
Exo-earth
th
experiment
Congresso SAIt 2011 - Paolo Di Marcantonio
9
Exciting science cases …
Instrumentation and
Controls Group
INAF-OATs
1. Dynamical measurement Universal
expansion
2. Extrasolar Twin Earths
3 Variability of Physical Constants
3.
4. Metallicity of the low density IGM
5 Nucleochronometry
5.
Congresso SAIt 2011 - Paolo Di Marcantonio
10
Instrumentation and
Controls Group
Some history …
INAF-OATs
• CODEX was first
fi t born
b
as a conceptt for
f OWL (2005)
• FP6 - small instrument studyy ((2006))
• Proposal of ESPRESSO at VLT (2007)
• E-ELT Phase A study (2008-2009)
Congresso SAIt 2011 - Paolo Di Marcantonio
11
Consortium
Instrumentation and
Controls Group
INAF-OATs
• IoA Cambridge (Martin Haehnelt)
• IAC ((Ramon Garcia-Lopez)
p )
• INAF (Ts and Brera) (Stefano Cristiani)
• Observatoire de Genève (Michel Mayor)
• ESO (L. Pasquini)
Jochen Liske, Bob Carswell, George Becker, Stephane Udry, Francesco Pepe, Christophe
Lovis, Dominique Naef, Miroslava Dessauges, Denis Mégevand, Rafael Rebolo, Garik
Israelian, Artemio Herrero, María Rosa Zapatero, Valentina D'Odorico, Paolo Molaro,
Matteo Viel, Eros Vanzella, Piercarlo Bonifacio, Antonio Manescau, Gerardo Ávila, Hans
Dekker, Olaf Iwert, Bernard Delabre, Gaspare Lo Curto, Michel Fleury, Ian Hughes, Fabio
Tenegi Paolo Di Marcantonio,
Tenegi,
Marcantonio Paolo Santin,
Santin Maurizio Comari,
Comari Roberto Cirami,
Cirami Igor
Coretti, Filippo Maria Zerbi, Paolo Spanò, Marco Riva.
page:
g
http://www.iac.es/proyecto/codex/
p
p y
CODEX web p
Congresso SAIt 2011 - Paolo Di Marcantonio
12
Instrumentation and
Controls Group
Top--level requirements
Top
INAF-OATs
Congresso SAIt 2011 - Paolo Di Marcantonio
13
Instrumentation and
Controls Group
Functional diagram
INAF-OATs
Congresso SAIt 2011 - Paolo Di Marcantonio
14
Instrumentation and
Controls Group
Front--end
Front
INAF-OATs
ADC
Focusing lens, X-Y correction
stage, Focus linear stage
Intermediate focal plane for
Calibration injection
Guiding and Stabilization
system
Congresso SAIt 2011 - Paolo Di Marcantonio
15
Instrumentation and
Controls Group
Optical design
INAF-OATs
Congresso SAIt 2011 - Paolo Di Marcantonio
16
Instrumentation and
Controls Group
Spectrograph layout
INAF-OATs
Congresso SAIt 2011 - Paolo Di Marcantonio
17
Instrumentation and
Controls Group
Thermo--cryoThermo
cryo-mechanics
INAF-OATs
Congresso SAIt 2011 - Paolo Di Marcantonio
18
Instrumentation and
Controls Group
R&D: Laser Frequency comb
INAF-OATs
Congresso SAIt 2011 - Paolo Di Marcantonio
19
Instrumentation and
Controls Group
Expertise
INAF-OATs
Consortium members participated and had leading roles in most optical
H-R and Radial Velocity spectrographs built in the last 20 yrs in Europe
((Elodie,, Coralie,, Sophie,
p , FEROS,, UVES,, FLAMES ...))
HARPS and ESPRESSO
which have (and will have) a special role for its scientific and its technical heritage
S also:
See
l
htt //
http://www.oact.inaf.it/exoit/EXO-IT/Home.html
t i f it/
it/EXO IT/H
ht l
Congresso SAIt 2011 - Paolo Di Marcantonio
20