El Gran Telescopio Milimétrico

El Gran Telescopio Milimétrico:
David Hughes (INAOE)
Director Científico del GTM
(LMT Project Scientist)
El Gran Telescopio Milimétrico:
• LMT & site characteristics
• project status
• first-light & 2nd generation
instrumentation
• examples of key-projects
during early-science
Primary Science with the LMT
The formation & evolution of structure in the Universe
Large Millimeter Telescope
(LMT/GTM) www.lmtgtm.org
• Bi-national project: INAOE (Mexico) & UMASS (USA)
• 50-m main reflector (180 panel segments)
• active surface (compensates gravity
& thermal deformations) to achieve
surface r.m.s. of ~70 microns
• operational wavelengths 0.85 - 4 mm
beam resolution (FWHM) 4 -18 arcsec
• FOV ~ 4 arcmin diameter
• site: Sierra Negra (4600m); Lat. +19;
tau(225)~0.1 (winter); wind 4m/s; temp -0.3C
• First-light instruments already in operation;
commissioning & science starting early 2010
(with inner 32-m diameter)
Volcán Sierra La Negra (97o 18’ 53” W, +18o 59’ 06”)
altitude 4600m
Monthy-averaged opacity (225 GHZ) above LMT site
8mm PWV = 60% transmission
at elevation 45 degs
2mm PWV = 90% transmission
at elevation 45 degs
Effective area of (5-ring) 50m LMT
3mm
2mm
1.4mm 1.1mm
0.85mm
Inner 32-m surface-segments installed
LMT panel segments
• 180 segments (~5 x 3m)
in 5 concentric rings
• 8 sub-panels (<7 microns)
electro-formed Nickel
• thermal insulation
• 45 adjusters (segments set
to 20-30 microns in lab)
• aluminium base plate
• stainless steel sub-frame
& axial bars
• 4 actuators
Installation of holography receiver
at prime focus (July 2008)
LMT 12GHz holography map
(inner 32-m) 0.9 m resolution
Effective area of (3-ring) 32m LMT
3mm
2mm
1.4mm 1.1mm
0.85mm
LMT receiver & control rooms
Receiver front-end/back-end
& control rooms
2nd Floor
3rd Floor
AzTEC and Future
Continuum
Instruments
10-m
SEQUOIA
BACKENDS
Future 1mm
Array
Elevation
Axis
M3 Mirror
Cassegrain
Focus Instruments:
Redshift/1mm RX
First-light Instrumentation Overview
Commissioned
• AzTEC (JCMT 15-m, ASTE 10-m)
144-pixel 1.1mm (or 2.1mm) continuum camera
• SEQUOIA (FCRAO 14-m)
32-pixel dual-polarization spectrometer at 85-116 GHz
with 15 GHz instantaneous bandwidth
• 90 GHz Redshift Receiver (FCRAO 14-m)
2 pixel, dual-polarization, ultra-wideband analog
autocorrelation spectrometer (instantaneous bandwidth
~35 GHz) at 75-111GHz
First-light LMT instrumentation
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AzTEC (P.I. Grant Wilson - UMASS)
1.1mm camera (144 pixels)
0.23 sq. deg/hr/mJy2 (SCUBA-2, ALMA)
wide-field & confusion-limited continuum
mapping of Galactic & extragalactic fields.
Faster multi-frequency larger-format
camera planned.
operational JCMT(2005), ASTE (2007-2008)
Redshift Seach Receiver
(P.I. Neal Erickson - UMASS)
75 – 111 GHz instantaneous bandwidth;
~100 km/s resolution; 2 pixel (2 pol).
Receiver temp ~ 60K; stable baselines
detect multiple molecular-lines without
prior information on galaxy redshifts
operational FCRAO-14m (2007-2008)
Effective area of (3-ring) 32m LMT
3mm
2mm
1.4mm 1.1mm
0.85mm
RSR
molecular line
spectroscopy
AzTEC continuum
imaging camera
First-light Instrumentation Overview
Under development
• SPEED
4 pixel (FSB) prototype continuum camera. Each pixel
operates simultaneously at 0.85, 1.1, 1.4, 2.1 mm
• 1.3mm SIS receiver
1 pixel dual-polarization spectrometer 210-275 GHz
• LMT wideband spectrometer
versatile digital autocorrelator e.g. Redshift searches BW > 10000 km/s, dnu~100 km/s
quiescent Dark Clouds BW ~20km/s, dnu~0.01km/s
SPEED
P.I. Grant Wilson UMASS
Ch.4
1.5THz FSB
1.1THz FSB
Ch.3
Ch.2
Ch.1
FSB
Detector
SQUID multiplexor
• designed to measure mm-wave SED
of previously detected objects
• simultaneous multi-frequency measurements
• matched beams in all bands
• high per-pixel sensitivity
• takes advantage of new bolometer technologies
• TES detectors (thermistor) +SQUIDs
• Frequency Selective Bolometers
FSB
Backshort
Future Instrument Development
• CIX (Cluster Imaging eXperiment)
256-pixel 4-band multi-frequency camera based on SPEED
prototype
• OMAR
16-pixel receiver (210-275 GHz) based on
single-pixel 1.3mm SIS development
• TolTEC
Large-format continuum camera (~6400 pixels),
full-sampled array filling available FOV based on
successful TES development (e.g. SCUBA2,
MUSTANG, MBAC, … ) or other new technologies
Commissioning to “early-science” schedule
• November 2009 – March 2010
– Begin commissioning (drive systems; control software; reflector
surface alignment; installation of M2 & receiver room coupling optics
(M3-M6) for AzTEC & RSR; optical camera & initla pointing model;
determine initial system efficiencies & performance of LMT)
• January 2010 – March 2010
– Installation of first-light receivers (AzTEC & RSR); test software &
hardware interfaces; generate mm- calibration & pointing models;
test all basic observing modes (pointing; photometry; map)
• March 2010 – mid / late 2010
– Science-verification tests. Observe known targets to prove LMT
works. Transition to “First-light” science with AzTEC & RSR
• > late 2010
– early-science “shared-risk” proposals
LMT Key-science: Evolution of large-scale structure
need larger samples of massive galaxies at high–z
i.e. wider & deeper (sub-)mm surveys
COSMOS
2sq. degs
Discovery first & basic characterisation
of population – N(>S,z), followed by
understanding of physical properties &
nature
(sub-)mm Extragalactic Background Light (EBL)
• EBL (0.24 nW/m2/sr) at 1100 microns due to z >> 1 SMGs (~ 20 – 25 Jy/deg2)
1.1mm source-counts
LFIR = 1012 L
SFR ~ 100 M/yr
redshift
(Austermann et al. 2009)
age (Myr)
Mstars ~ 1e10 M
or MH2 > 5e8 M in SF
SFR (M/yr)
LFIR (L)
1.1mm flux
5 < z < 15
900
> 10
>1e11
> 0.1 mJy
10 < z < 15
210
> 50
>5e11
> 0.5 mJy
Mapping speeds of current and
next-generation continuum cameras
CCAT 850 microns
TolTEC
AzTEC on LMT comparable
mapping speed to SCUBA-2
(0.5 sq. degs/hr/mJy^2)
Large-format camera (TolTEC)
with 6400 pixels at 1.1mm we
expect (10 sq. degs/hr/mJy^2)
• TolTEC more than 100x faster
than ALMA detection rate for
sources > 0.5mJy sources at 1.1mm
adapted from CCAT Feasibility/Concept Study Review
Tracing obscured starformation in LSS environments
LMT +TolTEC
5 sq. deg
COSMOS
2sq. degs
• LMT Key Project: 5 sq. degs sample (TolTEC 10 sq. deg/hr/mJy^2)
• > 50,000 galaxies in 800 hr confusion-limited survey
(>0.1mJy; SFR >20 Msun/yr ; or resolving 100% of the
extragalactic mm-background or 60% of FIR background)
SCUBA survey of the Hubble Deep Field
Hughes etal. 1998, Nature, 394, 241
HST optical
SCUBA 850 microns
HDF850.1 bright SMG
8 mJy at 850 microns
ALMA + ELT 0.1 arcsec
SCUBA on 15-m JCMT
14 arcsec FWHM beam
IDs
redshift
luminosity
SFR
Advantage of intermediate resolution
AND high mapping-speeds
Radio-FIR photometric –z
Spectroscopic –z
Radio-detected +
radio-dim SMGs
Radio-detected
SMG
(Aretxaga et al. 2007)
AzTEC/SMA
ACS
IRAC 3.6um
(Chapman et al. 2005
MIPS 24um
VLA
1.1mm/0.87mm
(Younger et al. 2007)
Photometric redshifts support AzTEC 1.1mm sources at z > 3-4 (Younger etal 2009).
LABOCA 870um sub-mm selected (SMG) at z=4.76 (optical redshift).
dnu ~ 0.6 GHz at 95 GHz
Weiss et al. 2005, A&A, 440, L45
LMT 90 GHz Redshift Receiver – Rx-z
Strongest spectral lines from CO and CI (492, 810 GHz). More than one line
needed; search the maximum possible bandwidth. CO lines (separated by 115
GHz in rest-frame) are expected to be quite weak, search in best 3 mm
(75 -111 GHz) window.
System noise temp (TRx = 60 K)
& 2 and 5 mm PWV
Redshift coverage in 3mm atmospheric window
red - no CO line;
yellow – one CO line;
green - two CO lines.
Direct measurement of molecular gas (CO) and
spectroscopic-redshifts with the LMT “redshift-receiver”
LMT
• perform efficient measurements of CO spectroscopic redshifts
without the prior necessity to have accurate X-ray, optical, IR or
radio positions.
(Yun et al. 2006)
Large Millimeter Telescope
early-science >2010
• Valuable complement to multifrequency science in next 3
decades with ELT’s, JWST,
ALMA, SKA, …..
• Spain has access to LMT:
scientific collaboration with
ALMA, IRAM 30-m, IRAM PdBI,
Yebes 40-m, Herschel, SKA, …
Redshift Search Receiver