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Istituto Nazionale di Astrofisica Sardinia Radio Telescope
Super-risoluzione in Radioastronomia, 12 Ottobre 2017, Villa Galileo, Firenze
Status attuale e prospettive future del
Sardinia Radio Telescope (SRT)
A. Navarrini a nome del team SRT
INAF (Istituto Nazionale di Astrofisica)
Osservatorio Astronomico di Cagliari
Istituto Nazionale di Astrofisica Sardinia Radio Telescope
Super-risoluzione in Radioastronomia, 12 Ottobre 2017, Villa Galileo, Firenze
SRT Project
Collaboration among three Research Structures of INAF:
• INAF Astronomical Observatory of Cagliari, Cagliari
• INAF Institute of Radio Astronomy, Bologna
• INAF Arcetri Astrophysical Observatory, Florence
Main Funding Institutions:
• MIUR (Italian Ministry of Education and Scientific Research)
• ASI (Italian Space Agency)
• RAS (Sardinia Regional Government)
Cost 60 MEuro
64 m diameter fully steerable radiotelescope to cover 0.3-116 GHz:- Single dish operation
- Part of VLBI network
- Radioastronomy, geodynamical studies, Deep Space Network
Istituto Nazionale di Astrofisica Sardinia Radio Telescope
Super-risoluzione in Radioastronomia, 12 Ottobre 2017, Villa Galileo, Firenze
SRT site
Altitude a.s.l. ≈600 m
Latitude +390 29m 50s
Istituto Nazionale di Astrofisica Sardinia Radio Telescope
Super-risoluzione in Radioastronomia, 12 Ottobre 2017, Villa Galileo, Firenze
SRT technical specificationsPrimary mirror D=64 m; Secondary mirror D=7.9 m
Gregorian configuration with shaped surfaces
Six focal positions: Primary,
Gregorian, & four Beam Wave Guide
Primary surf. accuracy:150 m RMS
Frequency agility
Pointing accuracy (RMS): 2 ÷ 5 arcsec
Can host up to 20 dual polarization
receivers: mono feed, dual frequency,
multibeam, phased array feeds
0.3-116 GHz frequency coverage
Active Surface: Primary mirror adjustable with 1116 actuators to compensate gravitational
deformation of the BKS; also used to convert shaped surface to parabolic for primary focus
operation
Optical Configuration and Ray Tracing of SRT
Primary Focus
F1/D =0.33
300MHz < f < 20GHz
Beam Wave Guide Foci
F3/D=1.37
F4/D = 2.81 (not shown)
1.4GHz < f < 35GHz
Gregorian Focus
F2/D =2.35
7.5GHz < f < 116GHz
Active surface: shape of primary mirror controlled with actuators
Compensate deformations of the primary mirror Convert shaped profile to a true-parabola (for primary focus) Compensate deformations of the secondary mirror
Active surface: the actuators
0.015mm/30mm
0.36mm/s
Weight: 12kg
-10° +60oC
Active surface: the actuators
actuators
1116 actuators
Istituto Nazionale di Astrofisica Sardinia Radio Telescope
Super-risoluzione in Radioastronomia, 12 Ottobre 2017, Villa Galileo, Firenze
Six-month Early Science Program completed by Aug. 2016
12 large programs allocated for a total
of ≈2000 hours observing time
Front-EndFreq. range
[GHz]
Focal
position,
F/D
N. Pixels
× pols
Measured/
Expected*
receiv. noise
temp. [K]
Status
L- and P- band
coaxial feed
P: 0.305-0.410 Primary
0.33
1 × 2 17-22 Commissioned
L: 1.3-1.8 1 × 2 10-13 Commissioned
High C-band 5.7-7.7BWG I
1.371 × 2 6.5-9 Commissioned
K-band 18-26.5Gregorian
2.357 × 2 20-40 Commissioned
S-band 3.0-4.5Primary
0.337 × 2 15*
Under
construction
Low C-band 4.2-5.6BWG II
2.811 × 2 8*
Under
construction
Q-band 33-50Gregorian
2.3519 × 2 25*
Under
construction
W-band 84-116Gregorian
2.351 × 1 30-45
Under
construction
X-band (ASI) 8.2-8.6BWG II
2.811 × 2 15 Commissioned
SRT Front-Ends built and under construction at INAF
Commissioned SRT Front-Ends developed by INAFL-P band coaxial feed
P: 305-410 MHz
L: 1.3-1.8 GHz
K-band multibeam18-26.5 GHz
High-C-band monofeed5.7-7.7 GHz
Istituto Nazionale di Astrofisica Sardinia Radio Telescope
Super-risoluzione in Radioastronomia, 12 Ottobre 2017, Villa Galileo, Firenze
Front-Ends installed at the SRT primary focus
L-P band
receiver
Holographic
receiver
(11 GHz)
X-Ka band
receiver
7.9 m diameter
secondary mirror
S band 7-beam receiver forthcoming
Istituto Nazionale di Astrofisica Sardinia Radio Telescope
Super-risoluzione in Radioastronomia, 12 Ottobre 2017, Villa Galileo, Firenze
High-C band, installedLow-C-Band,
forthcoming
Movable
M3
K band multibeam,
installedSecondary focus
positioner
(rotating turrett)
Front-Ends at the Gregorian and BeamWaveGuide (BWG) foci
Q band & 3 mm band,
forthcoming
Secondary
focus
Istituto Nazionale di Astrofisica Sardinia Radio Telescope
Super-risoluzione in Radioastronomia, 12 Ottobre 2017, Villa Galileo, Firenze
K-band multibeam receiver installed on SRT
July 2012
Istituto Nazionale di Astrofisica Sardinia Radio Telescope
Super-risoluzione in Radioastronomia, 12 Ottobre 2017, Villa Galileo, Firenze
SRT backends
• DFB (Digital Filter Bank): 1 GHz BW full-Stokes; up to 2048 ch.,
folding and search mode (Pulsars);
• Roach1: 512 MHz BW, sw correlation - CPU cluster (Pulsars);
• XARCOS: 62.5 MHz, 7 beams dual pol., 2048 ch., freq. res. down
to 0.25 KHz (spectroscopy);
• Total Power: up to 7 beams dual pol., 2 GHz BW;
• Sardara, Roach2: 2.3 GHz BW, 7 beams full-Stokes, up to 16 kch.,
(pulsars, spectroscopy, continuum, spectropolarimetry).
Zoom modes (< 0.25 kHz res).
• VLBI backend: DBBC + MK-V recorder; RFI monitoring;
Istituto Nazionale di Astrofisica Sardinia Radio Telescope
Super-risoluzione in Radioastronomia, 12 Ottobre 2017, Villa Galileo, Firenze
W3(OH) at 6.7 GHz with SRT: OTF continuum imaging and
spectroscopy of methanol maser line at increasing spectral resolutions
=30 kHz
=3.8 kHz
=1 kHz
=0.25 kHz
2 deg
Backends:
- Total power for mapping;
- XARCOS for spectra;
Credit: SRT Astronomical
Validation Team (AV)
Methanol maser
Istituto Nazionale di Astrofisica Sardinia Radio Telescope
Super-risoluzione in Radioastronomia, 12 Ottobre 2017, Villa Galileo, Firenze
• Egron et al., Single-dish and VLBI observations of Cygnus X-3 during the 2016
giant flare episode, MNRAS, 2017, accepted;
See also http://www.srt.inaf.it
Science with SRT, published papers:
• Egron et al., Imaging of SNR IC443 and W44 with the Sardinia Radio Telescope
at 1.5 GHz and 7 GHz, MNRAS, Vol. 470, Issue 2, p.1329-1341, 2017;
• Govoni et al., Sardinia Radio Telescope observations of Abell 194 the intra-
cluster magnetic field power spectrum, A&A, 2017, 603, A122;
• Sanna et al, Planar infall of CH3OH gas around Cepheus A HW2, A&A, 2017,
in press;
• Murgia et al, Sardinia Radio Telescope wide-band spectral polarimetric
observations of the galaxy cluster 3C129, MNRAS, Vol. 461, 4, p.3516-3532, 2016;
• Prandoni et al, The Sardinia Radio Telescope: From a Technological Project to a
Radio Observatory, A&A, 2017, in press;
Istituto Nazionale di Astrofisica Sardinia Radio Telescope
Super-risoluzione in Radioastronomia, 12 Ottobre 2017, Villa Galileo, Firenze
Status and perspectives of SRT project
• Six-month Early Science Program as single dish completed in Aug. 2016 with:
- L-P Band, C-Band and K-Band multibeam receivers;
- Backends: Roach2-based (2 GHz BW, 7 beams full-Stokes), VLBI,
total power, XARCOS (spectroscopy), DFB and Roach1 for pulsars;
• VLBI observations (part of EVN and RadioAstron);
• First scientific results being published;
• Refurbishment of the primary dish active surface completed in August 2017;
• Moving to new site infrastructures: control room, equip. room, visitor center, etc.
• Developing new Front-Ends, Back-ends and annexed hardware/software;
• ASI observed the grand finale of Cassini mission with X-band receiver in Sept. 2017;
• Technical and scientific recommissioning started end of Sep. 2017;
• New early science program in Autumn 2018 (stress test);
• Opening observation to international community in guest observer mode: early 2019;
Istituto Nazionale di Astrofisica Sardinia Radio Telescope
Super-risoluzione in Radioastronomia, 12 Ottobre 2017, Villa Galileo, Firenze
Two multibeam receivers under development:
Q-Band (33-50 GHz) 19-beam
receiver for Gregorian focus
S-Band (3.0-4.5 GHz) 7-beam
receiver for primary focus
Istituto Nazionale di Astrofisica Sardinia Radio Telescope
Super-risoluzione in Radioastronomia, 12 Ottobre 2017, Villa Galileo, Firenze
Vivaldi arrayPHAROS2: Demostrator of cryogenic C-band (4-8 GHz) Phased Array
Feed (PAF) of Vivaldi antennas with digital beamformer
Upgrade of PHAROS PAF, which was based on
analog beamformer;
Under development in the framework of the
PAF Advanced Instrumentation Program for
SKA;
Technology demonstrator project cooperated by
an international collaboration that includes
INAF, UMAN, ASTRON, OSO, UMalta;
To be mounted at Lovell telescope, Jodrell
Bank Observatory, UK;
INAF is developing the Warm Section, the IFoF
signal transportation and iTPM digital
beamforming of PHAROS2;
- 220 elements Vivaldi array;
- 24 Low Noise Amplifiers;
- 20 K cooling;
- 24 elements form four beams; Building up experience on system hardware and
software to allow developing a PAF for SRT;
Istituto Nazionale di Astrofisica Sardinia Radio Telescope
Super-risoluzione in Radioastronomia, 12 Ottobre 2017, Villa Galileo, Firenze
Thank you !
http://www.srt.inaf.it