Russian Space-VLBI missions: results and prospects
Sergey Likhachev (On behalf of Astro Space Center, Lebedev Physical Institute Russian Academy of Sciences), and Alexangr Alferov (Scientific Secretary of RAS Space Council) *Horsehead image captured by Herschel telescope
Radioastron Mission
“Radioastron” is the largest space radio telescope in the world, forming the largest ever space-ground interferometer.
The aim of the mission is to use the space telescope to investigate the Universe with the extraordinary high angular resolution up to 8 micro arc seconds at the shortest wavelength 1.35 cm. Tests in Lavockin Assotiation, Summer, 2011 July 18, 2011 6:31 Moscow time, Baykanoor.
Launch of the observatory. Radioastron Orbit
Antenna diameter [m] 10
Apogee height [km] 350,000 Orbital period 9.5 days Polarization LC/RC Data downlink 128 Mbit/s Observing 0.2 -- 22 frequencies [Ghz] Highest resolution 8 [microarcsec] Ground tracking stations
Puschino, Russia Green Bank, USA 22 m 43 m Scientific Data Transferring from Ground Telescopes
Badary Russia Parks Australia Tidbinbilla Australia ATCA Australia Urumqi China Shanghai China Noto Italy
Robledo Spain Onsala Sweden Jodrell Bank UK Hart Africa Torun Poland Arecibo Puerto Rico Zelenchuk Russia
GBT USA Usuda Japan Westerbork Netherlands Yebes Spain Effelsberg Germany Medicina Italy Svetloe Russia Structure of Data Processing Center
Server for checking node 1 information node 2
node 3 On-line storage for collection Computer of node 4 and checking operator information 600TB
node 5 Gb Archive on HDD
0 2000 TB
Computer cluster 1 Storage for data processing 80 TB node 6 Server Switch node 7 Storage for results of Tape library node 8 processing 120 TB node 9 Archive on tape node 10 2000 TB Main Pulsar Results in Radioastron Mission
With "Radioastron" was obtained the spatial distribution of the interstellar medium inhomogeneities in the direction of the pulsars: B1919 + 21, B0950 + 08, B0329 + 54, B0531 + 21. For the first time with ultra-high resolution, was discovered a sub- structure in scattering disk of these pulsars. Published статья Astrophysical Journal, 2014
Scattering disk for PSR 0329+54 was resolved by direct observations at long baselines with angular diameter of 5 mas Published Astrophysical Journal, 2016
Giant pulses from Crab pulsar First time Space-VLBI observations of giant pulses from B0531+21 pulsar. Observed significant change in CCF shape for space-ground baselines. At 92 cm scattering disk is being resolved on ground-ground baselines. Rudnitskiy A.G., Popov M.V., Soglasnov V.A., “Preliminary results of giant pulse investigations from Crab pulsar with Radioastron.”, Proceedings of Science, EVN 2014 (065) Rudnitskiy A.G., Popov M.V., Soglasnov V.A., Karuppusamy R., Astronomy Reports, 2016, 93 Radioastron mission main results. Pulsar 1641-45
An image of pulsar B1641-46 scattered by interstellar medium. Radioastron mission main results. NGC4258 galaxy
• For the first time in the history of radio astronomy space-ground interferometer detected water in extragalactic mega maser (18.12.2014.). • Baseline projection Radioastron – Green Bank (USA) - 2 Earth diameters. • Galaxy NGC4258, z = 0.00149, distance 24 millions of light years. Mega maser is located in the accretion disk gas around the black hole. Radioastron Angular Super-Resolution
Baseline projections: L-band: 27.1xED, (345 000 km), Source: 0048-097 С-band: 23.1xED, (295 000 km), Source: 0716+714 K-band: 15.5xED, (190 000 km), Source: 0851+202 Comparison with Ground VLBI (3C84, 5 GHz)
without “Radioastron” with “Radioastron” 13 Current Radioastron Correlation Results
• Data from 2130 sessions have been successfully correlated. Fringes on Space-Ground baselines were found in 703 observations.
• For now, data processing rate in "Radioastron" mission is about 160 sessions per month, observation rate is 80-120 experiments per month. Thus, ASC correlator performance is enough to correlate all the data in "Radioastron" project. Millimetron Mission
The first 10-m space telescope
for the FIR, submm and mm range (diffraction limited 80µm) for cosmology and astrophysics deployable and adjustable on orbit mechanically cooled (<10K) with post-cryo life orbit around L2 Lagrange point lifetime: 10 years; at cryo >3 years dual operation modes: • S-VLBI for 0.3 – 17 mm • Single dish for 0.02 – 3 mm
Mission has been approved and supported by RSA Spacecraft in Phase-B Science payload in Phase-A Launch date : 2025 Evolution of the FIR/Submm/Mm Instruments for Space Science
The satellites addressed to measure CMB 2001 2009 1989
COB WMAP Planck Hersch E el Mmtron 2025 JWST + 2018
Sky Spectrum SPICA All Sky Survey 2009 2025 SurveySurve SOFI SPICA y ISO Spitzer A 2025 2003 AKARI IRAS 1995 2006 2011
WIS 1983 E 2009 2014
Odi 2001 SWAS 1998 n Millimetron Orbit
• Orbit period – 365 days (L2). • Baseline – 1 500 000 km, max. • Time of oscillation around L2 is about half of a year. • MM antenna view angle opening is+/- 75 deg in ecliptic latitude and longitude. Capabilities of the Millimetron unprecedented high angular resolution in observing mode as S-VLBI element
1.0E+00
0235+164 1.0E-01 EHT
1.0E-02 (arcsec)
1.0E-03 Mmtron Millimetron 1.0E-04 1.0E-04 4.8E-05 ALMA 1.0E-05 1.4Е-6 ALMA 1.0E-06 VSOP VSOP2
1.0E-07 1.0E-07
Angular Resolution Radioastron Millimetron
1.0E-08 Antenna Mock-Up (ISS-Reshetnev, Russia, 2014)
19 Conclusions
• The Russian Federation has the technology create unfolding space antennas of large diameter ("Radioastron" and "Millimetron“ missions).
• The Russian Federation has the technology of space-ground interferometer scientific data processing and analysis.
• Mission "Radioastron" yielded scientific results that are unique in modern radio astronomy.
20 Thank you for your attention!