Updates Radioastron (Spektr-R) updates

[Notebook]

Dear colleagues,

Lavochkin association has prepared a couple of nice Radioastron related
movies.
The first one will be most appreciated by Russians since it has Russian
comments. It discusses different aspects of the mission:
ftp://ftp.asc.rssi.ru/Spektr-R/movies/1.mpg 209MB download

The second one shows the space radio telescope deployment.
Almost like it has happened on July 22-23 in space.
ftp://ftp.asc.rssi.ru/Spektr-R/movies/2.mpg 215MB fownload

Enjoy.

Yuri Kovalev

 

[Wishbone]

RIA Novosti cites Alexander Kovalenko from Puschino radioobservatory that the first attempt to test telemetry and command channel failed today because the craft was too cold (-20 deg C instead of -15 deg C). The next attempt to get TTC working from Puschino is scheduled for August 13.

 

[Wishbone]

High-bandwidth channel tested, all systems nominal.

 

[Wishbone]

Update from Roskosmos: http://www.roscosmos.ru/main.php?id=2&nid=17773&lang=ru

NPO after S.A.Aizikovich ehhrm, sorry Lavochkin, is debugging "Plazma-F", and has rotated the spacecraft to do away with unexpected thermal problems (uneven heating, or so they say).

В НПО им. С.А.Лавочкина специалисты объединения продолжают летные испытания космического радиотелескопа (КРТ) «Спектр-Р» в соответствии с запланированной программой. Бортовые системы функционируют штатно, наземный комплекс управления осуществляет связь с КА в обычном режиме.

При прохождении очередного перигея в зоне возможной связи станции слежения в Пущино с космическим аппаратом был успешно осуществлен прием тестового сигнала передатчиков двух каналов ВИРК (передача научной информации и синхронизация работы борта и Земли).

Кроме того, продолжаются работы по отладке режима работы комплекса «Плазма-Ф», плановые проверки режимов функционирования бортового комплекса управления.

В целях изучения влияния положения Солнца относительно осей космического аппарата на распределение температур по поверхности «Спектра» осуществлена переориентация спутника.

Продолжается работа по проверке режимов функционирования КРТ и подготовке к его работе в очередном перицентре.

 

[N_Molson]

This is dramatic:

Wow, nice vid ! Since when Roscosmos is doing movies like that ?

The Antonov landing with the light music behind was especially fun

 

[Notebook]

======================
RadioAstron Newsletter
Number 5
September 16, 2011
======================
Russian version of the Newsletter can be found here:
http://www.asc.rssi.ru/radioastron/newsletter/newsl_rus.pdf



Spectr-R in-orbit tests continue


Many things have happened since the previous Newsletter
which reported on the space radio telescope deployment.
Science payload and survice systems of Spectr-R were
successfully turned on. Technical details can be found here:
http://www.asc.rssi.ru/radioastron/news/news.html
In particular:
- The H-maser (atomic clock) was turned on and internal test
has shown that the clock works properly, its stability
is reported to be within the specs.
- Tests of "VIRK", the system which includes high-gain 1.5-m
diameter antennae and is used to contact with the tracking station
in Pushchino, continue. The so-called "open loop", the tone signal
at 8 GHz, was successfully detected in Pushchino and is being used
to perform Doppler measurements of the orbit parameters.
The 15 GHz tone signal was also successfully detected.
- Today, the first system temperature measurements were
performed for the Australian-made 18 cm astronomical receiver
while the space telescope was pointed on a cold sky;
the system temperature is estimated to be about 42 K
which is close to receiver's specifications.


Plans for the near future:
- VIRK pointing correction measurements and 15 GHz data link tests,
- performance measurements for all the other astronomical receivers
of the 92, 6, and 1.3 cm bands,
- Cassiopea A first light single-dish radio astronomical observations
including space radio telescope efficiency measurements.


With best regards,
Nikolai Kardashev ([email protected])
Yuri Kovalev ([email protected])

N.

 

[Notebook]

======================
Astro Space Center
RadioAstron Newsletter
Number 8
November 3, 2011
======================
Russian version of the Newsletter can be found here:
http://www.asc.rssi.ru/radioastron/news/news_ru.pdf


Space radio telescope tests in 6 and 1.35 cm bands

Many observations of space objects have happened by Spektr-R in October 2011 in 6 and 1.35 cm bands. Cassiopeia A, Moon, Jupiter, as well as the Crab nebulae were observed in a scanning mode of a single radio telescopes. Radio signals from all these objects were successfully detected. The space radio telescope pointing has proven to be very good and stable. Tests at these two bands continue in order to achieve high quality telescope calibration information.


First maser observations by the space radio telescope

First single dish observations of a space object have happened on October 29 and 30 when scientific and telemetry data were transmitted to the ground through the wide band 15 GHz data link between Spektr-R and Pushchino tracking station. This mode of observations and recording is similar to the one which will be used for interferometric experiments. A maser source W3(OH) was observed in the OH (1665 MHz) and H20 (22232 MHz) lines. They correspond to 18 and 1.35 cm RadioAstron bands. The measurememnts have happened at the Spektr-R separation from the Earth by 60 and 200 thousand kilometers.
See attached figure with the spectra produced by the RadioAstron in-orbit checkout team of Astro Space Center.

W3(OH) is located about two kiloparsec away from the Earth in our Galaxy in a proto-stellar region. Radio emission from the object was collected by the 10-m space radio dish, digitized and formatted on-board, sent by the high-gain 1.5-m antenna to the Pushchino tracking station, decoded and recorded on the RadioAstron data recorder at the tracking station. Recorded data were transmitted to Astro Space Center over a dedicated Internet line. Data analysis in Astro Space Center confirmed the maser lines in both bands in left and right circular polarizations at expected frequencies, with expected amplitude and shape. As a result, this experiment has confirmed the full functionality of the space segment of interferometer.


First RadioAstron experiments in a mode of Space-Earth interferometer, so called fringe search, are planned to start in the second half of November 2011.


With best regards,
Nikolai Kardashev ([email protected])
Yuri Kovalev ([email protected])

There is also a pdf file in this newsletter, can't attach here, this relates to the axis.

October 30, 2011, 10:44 UTC
In-orbit Radioastron 1.35 cm receiver spectral response on the W3(OH) maser, water vapor (H2O) line component at -50 km/sec: right (top) and left (bottom) circular polarization. Amplitude is shown in arbitrary units.

N.

 

[SiberianTiger]

The RadioAstron Newsletter # 9, November 24, 2011.

======================
Astro Space Center
RadioAstron Newsletter
Number 9
November 24, 2011
======================
Russian version of the Newsletter can be found here:
http://www.asc.rssi.ru/radioastron/news/news_ru.pdf

RadioAstron fringe search has started

First fringe search observations of the ground-space interferometer RadioAstron have started on November 15 and 23, 2011. Both sessions have happened successfuly, observations were made on the 18 cm band. Scientific data from the space radio telescope were successfully transmitted to and recorded by the Pushchino tracking station. The observations were supported by the following ground VLBI stations: three 32-m telescopes of the Russian VLBI network Kvazar in Svetloe, Zelenchukskaya, Badary, 70-m radio telescope in Evpatoria (Ukraine), 64-m Usuda (Japan), 100-m Effelsberg (Germany), 100-m GBT (USA). Quick data quality check has confirmed that the data are suitable for the fringe search. The data analysis center in Astro Space Center of Lebedev has started the interferometric fringe search.

The first RadioAstron fringe test on November 15 had been also supported by two EVN telescopes, Metsahovi 14 m (Finland) and Onsala 20 m (Sweden) as a part of the JIVE-led Planetary Radio Interferometry and Doppler Experiment (PRIDE). These PRIDE observations of the Spektr-R tone signal at 8.4 GHz will provide additional Doppler measurements for orbit determination feed
into the data correlation process.

The RadioAstron team plans first fringe search experiments at the 6 cm band to happen in December 2011. First successful distance measurements with a laser ranger Laser ranging is one of several methods being used to reconstruct the Spektr-R orbit with high accuracy required for a proper functioning of the ground-space radio interferometer.

First successful laser ranging of Spektr-R has happened on November 15, 2011, from 5:30 to 6:30 Moscow time. The ranging was performed by the Observatoire de la Cote d'Azur (Grasse, France) as part of the International Laser Ranging Service. The distance measurements were done continuously during 35 minutes resulting in 875 independent measurements. The distance to the space craft has changed during this period of time from 65 to 70
thousand kilometers. Refelected signal was of a very high quality. The error of measurements is about or less than 10 cm.

Results are available from:
ftp://cddis.gsfc.nasa.gov/slr/data/npt_crd/radioastro/2011/

Pulsar PSR0329+54 and water maser Orion KL As part of the ongoing in-orbit checkout activities, the bright pulsar PSR0329+54 was observed on November 7 at 316 MHz while the water maser in the Orion KL region -- on November 8, 2011, at 22 GHz. The space radio telescope scientific data were
transmitted to the ground using the wide band data link to the Pushschino tracking station. Positive data processing results can be found on the attached plots indicating a good overall performance of the system.

With best regards,
Nikolai Kardashev ([email protected])
Yuri Kovalev ([email protected])
To subscribe or un-subscribe to the Newsletter, use:
http://asc-lebedev.ru/index2.php?engdep=22

Results of RadioAstron space radio telescope observations of the water maser in Orion KL
region, right circular polarization, 22 GHz. The high narrow peaks correspond to the pulse-
calibration signal. The amplitude is shown in arbitrary units.

Results of RadioAstron space radio telescope observations of the bright pulsar PSR0329+54 at
316 MHz. The pulsar pro le is generated by averaging 90 minutes of data. The amplitude is
shown in arbitrary units.

 

[Notebook]

======================
Astro Space Center
RadioAstron Newsletter
Number 10
December 8, 2011
======================
Russian version of the Newsletter can be found here: http://www.asc.rssi.ru/radioastron/news/news_ru.pdf


RadioAstron finds first interference fringes


We are delighted to report a successful detection of the first interference fringes -- a correlated signal on ground-to-space baselines -- by the RadioAstron team at the Astro Space Center of the Lebedev Physical Institure, Russian Academy of Sciences. The fringes were found between the space radio telescope, Spektr-R, and the following ground based radio telescopes: The 32-m Russian "Quasar" antennas at Svetloe, Zelenchukskaya, and Badary of the Institute of Applied Astronomy, Russian Academy of Sciences, the 64-m Ukranian antenna at Evpatoria, the State Space Agency of Ukraine, and the Max-Planck-Institute for Radio Astronomy 100-m antenna at Effelsberg, Germany. The observations of the quasar 0212+735 were made on November 15, 2011 at 18 cm wavelength. The attached picture shows the clear detection of the interference fringes on the baseline between Effelsberg and the space radio telescope on a delay-fringe frequency plot.

http://i89.photobucket.com/albums/k207/Notebook_04/Astron_1.jpg


The quasar 0212+735 was selected as a target by the Radioastron team on the basis of a preliminary determination of its very compact structure and high surface brightness by recent observations using the NRAO Very Long Baseline Array in the U.S.

The successful detection of interference fringes demonstrates the overall excellent status of the complex system and reflects the birth of the new international ground-to-space very long baseline interferometer, RadioAstron.

A search for fringes at other frequency bands and at longer interferometer baselines will continue until the end of January 2012, and will be followed by an "Early Science" program on quasars, AGN, pulsars, and cosmic masers. The Astro Space Center will also continue to perform in-orbit tests together with the Lavochkin Association including an effort to improve the quality of scientific data link from the space radio telescope to the ground through the Pushchino tracking station.

On behalf of the Astro Space Center, we would like to congratulate and thank the Lavochkin Association as well as the many other institutions in Russia, Ukraine, and other countries on their long lasting effort which resulted in this milestone result!


With best regards,
Nikolai Kardashev ([email protected])
Yuri Kovalev ([email protected])

N.

 

[SiberianTiger]

http://ria.ru/science/20111213/515799083.html

Radioastron observatory has begun its scientific program one and half months ahead of the expected time, said a Yuri Kovalev, researcher from Lebedev Physical Institute (PhIAN).

Having gained a success with observations in ground-to-space correlation mode at 6 and 18 centimetres wavelengths, we have saved much time. We are launching an initial scientific observations at the already tried wavelengths.

According to him, the first real target will be [ame="http://en.wikipedia.org/wiki/BL_Lacertae"]BL Lacertae[/ame] extragalactical source, discovered in 1929 by German astronomer Cuno Hoffmeister who believed it was an unusual variable star.

We have picked observations time in such a way that we'll have 5-days long slot, from 10th to 14th of December. This will help us to study this object in different resolutions and get very detailed information on its radiation.

Kovalev also announced, that in the next year, applicants from any country will have a chance to submit proposals of their observations to be done with Radioastron, given they pass a necessary set of requirements.

 

[SiberianTiger]

http://english.ruvr.ru/2011/12/22/62689654.html

Russian astrophysicist receives 2012 Grote Reber Medal
Dec 22, 2011 14:55 Moscow Time

Russian astrophysicist Nikolai Kardashev has been awarded the 2012 Grote Reber Medal for his significant contribution into radio astronomy.

Kardashev heads the Division of General Physics and Astronomy at the Lebedev Physics Institute.

He was the head of the scientific group, which designed and launched into space the Radioastron telescope in July 2011. This telescope enables astronomers to obtain images with the resolution 1,000 times better than those of the world known Hubble telescope.

The Grote Reber medal was established in honor of the US astronomer Grote Reber, who in 1937 built the world’s first radio telescope and conducted the first sky survey in the radio frequencies.

(RIAN)

Great news, although comparing incomparable (Radioastron to the Hubble) is not good.

 

[Notebook]

======================
Astro Space Center
RadioAstron Newsletter
Number 12
March 20, 2012
======================
Russian version of the Newsletter can be found here:
http://www.asc.rssi.ru/radioastron/news/news_ru.pdf


First 92 cm RadioAstron interference fringe at the 220,000 km baseline
projection!

On January 25, 2012, RadioAstron has successfully detected the first
interferometric signal at 92 cm from individual pulses of the pulsar
B0950+08 from the longest distance to the space craft - 300,000 km.
Projected interferometer baseline was 220,000 km which provided the
highest ever achieved resolution at this wave length of about 1/1000
arcsecond. The ground VLBI stations which participated in this
experiment are Arecibo (USA), Westerbork (the Netherlands), and
Effelsberg (Germany). The interference fringes were found between the
space radio telescope and all thee ground telescopes. See some result on
the two attached figures.

The observed variations of the correlated signal from the pulsar is due
to the propagation effects - pulsar emission scintillation on the
inhomogeneous interstellar plasma. Such effect is only seen for emission
of very compact objects. Thus, astronomers have got a tool to study
characteristics of the interstellar medium and the pulsar itself, to
localize the pulsar radiation zone in the magnetosphere of the neutron
star - either above the polar cap or near the light cylinder. The
conducted experiment has both confirmed RadioAstron capabilities at 92
cm and provided first important scientific data in this band. About 10
brightest radio pulsars of our Galaxy are planned to be studied in the
RadioAstron early science program.


Tests of the closed-loop mode of Spektr-R synchronization

A test in a special closed-loop mode of Spektr-R synchronization was
successfully performed on January 22, 2012. This mode of operation
utilizes the ground based maser clock located at the Pushchino tracking
station to synchronize the space radio telescope observations through a
special up-down phase link at 7.2 and 8.4 GHz. As a result of these
observations at 18 cm, an interference fringe was found by the
RadioAstron correlator from the quasar 0212+735 at the projected
distance of about 16,000 km.

Successful Spektr-R orbit correction

In order to correct the orbit of Spektr-R, two injections were done on
February 22 and March 1, 2012, with a total momentum of about 3 m/sec.
The correction was performed successfully. As a result, the perigee of
the space craft orbit has increased to about 55,000 km, the ballistic
life time of the orbit has increased to 10 years.


The RadioAstron early science program and final steps of the fringe
search

Regular experiments within the RadioAstron early science program (ESP)
have started in February 2012. Hydroxyl and water masers in our Galaxy
(W3OH, Orion KL, etc.), the Crab pulsar as well as bright active
galactic nuclei were observed since then. These experiments were
supported from the ground by more than ten different VLBI stations: the
European VLBI Network telescopes including the Russian ones, the
Ukrainian Eupatoria, the Japanese Usuda. The international RadioAstron
ESP working groups are reducing and analyzing the data together with the
Astro Space Center correlator.
The fringe search experiments are finishing. First segments of 1.3 cm
observations have failed due to very bad weather conditions on the
ground (GBT, Effelsberg). The search for 1.3 cm fringes continues.
Additionally, first test experiments with the Australian VLBI network
LBA were performed on March 11, 2012, to prepare for science
observations with LBA preliminary planned for May.


With best regards,
Nikolai Kardashev ([email protected])
Yuri Kovalev ([email protected])

 

[Notebook]

======================
Astro Space Center
RadioAstron Newsletter
Number 13
June 14, 2012
======================
Russian version of the Newsletter can be found attached and here:
http://www.asc.rssi.ru/radioastron/news/news_ru.pdf


First RadioAstron 1.3 cm fringes!

Along with conducting the RadioAstron Early Science Program, the
RadioAstron fringe search team continued interferometric tests at 1.3 cm
(K-band) -- the shortest RadioAstron wave length. We are happy to report
that the first K-band fringes were successfully detected on a baseline
Spektr-R -- Effelsberg (MPIfR, Germany) from the compact quasar
2013+370. Moreover, these observations were organized in a dual-band
mode. Simultaneous measurements at 6 cm were carried out on the baseline
Spektr-R -- Westerbork (WSRT, the Netherlands). The 6 cm fringes were
found on this baseline with delay and rate values which agree to the 1.3
cm results. The attached Figure shows the 6 and 1.3 cm fringes. The
baseline projection was 1/4 of the Earth diameter.
This positive result marks the successful end of in-orbit tests of the
ground-space radio interferometer RadioAstron.


RadioAstron coherence time

Coherence time in radio interferometry is the maximum time interval for
which the interferometric signal can be coherently (without loses)
integrated. Sensitivity of interferometric measurements is proportional
to the square-root of this value. Typical coherence time of
ground-ground very long baseline interferometric experiments is 1 to 15
minutes for centimeter wave lengths; it is determined by characteristics
of the turbulent atmosphere, ionosphere, troposphere. Coherence time
analysis is extremely important since it characterizes the overall
sensitivity as well as stability of the system, including atomic clock.

We have performed an analysis of the RadioAstron coherence time at the
shortest wave lengths, 6 and 1.3 cm, using observations from March 15
and May 12, 2012, consequently, on the baseline Spektr-R -- Effelsberg.
Results are shown on the Figure attached. The signal-to-noise ratio
increases as a square-root of integration time (fringe fitting interval)
up to about 10 minutes at 6 cm and up to 2 minutes at 1.3 cm. This first
estimate of the coherence time demonstrates high stability of the space
element of the RadioAstron interferometer.


RadioAstron International Science Council meeting 2012

The RadioAstron International Science Council (RISC) will meet for
several days in Pushchino, Moscow region, starting from June 18, 2012.
The main goal of the meeting is to discuss the current status of the
mission and plans for organization of future RadioAstron experiments.
The meeting will unite representatives of Russian and International
institutions including many major radio observatories of the world.


With best regards,
Nikolai Kardashev ([email protected])
Yuri Kovalev ([email protected])

 

[Notebook]

======================
Astro Space Center
RadioAstron Newsletter
Number 16
October 9, 2012
======================
Find Russian version attached to this e-mail


One year has passed since the birth of the Spektr-R 10-meter orbiting
radio telescope

About one year ago, on September 27, 2012, the space radio telescope
Spektr-R has registered the first light from the supernova remnant
Cassiopeia A. Congratulations to all involved! We are pleased to note
that since than the RadioAstron radio interferometer has proven its
stability and operability at all four available wave bands of 92, 18, 6,
and 1.3 cm. New science results were obtained within the three main
areas of the RadioAstron Early Science program: pulsars, galactic
masers, and active galactic nuclei. Interferometric signals were
successfully detected for the interferometer baselines up to 20 Earth
diameters for pulsar observations and up to 7 Earth diameters for
quasars.


First RadioAstron-EVN image of the active galaxy 0716+714!

The international RadioAstron AGN early science program team of
researchers has produced the first RadioAstron-EVN image of the rapidly
variable active galaxy 0716+714 at 6.2 cm (see Figure attached). Data of
about 24 hours of observations from about 10 largest ground radio
telescopes from Europe, Russia, and China together with the 10-meter
space Spektr-R were used in the analysis. Correlated emission of
0716+714 was detected up to 5.2 Earth diameters. Apparent parameters of
the core were estimated. The jet base width is measured to be about 70
microarcseconds or 0.3 parsec, its brightness temperature - about
2x10^12 K which agrees with the model of incoherent synchrotron emission
of relativistic electrons with Doppler boosting. We note that these
parameters were measured at an epoch of low activity state of the BL
Lacertae object 0716+714.


With best regards,
Nikolai Kardashev ([email protected])
Yuri Kovalev ([email protected])


--------------------------------------------------------------------------------

As always, there is more stuff from this, best you look out for the interweb material!

 

[SiberianTiger]

The picture:

The area surrounding the blazar pictured is 1.5 billion parsec away from us.

 

[Notebook]

======================
Astro Space Center
RadioAstron Newsletter
Number 17
October 26, 2012
======================
Russian version can be found attached to this e-mail


The process to select projects for the open RadioAstron observing time
within the AO-1 period (July 2013 - June 2014) has started

From the middle of 2013 RadioAstron will move to the open sky phase of
its science operations. Any scientist in the world can apply for the
RadioAstron observing time. RadioAstron proposals will be reviewed by
the international RadioAstron program evaluation committee. Applying for
time is a three-stage process. An initial Letter of Intent (LoI) should
have been directed to the Mission by 17 October 2012. Each team
submitting an LoI is expected to participate in the key science program
(KSP) consortia organization workshop that will be held at the
Max-Planck-Institute for Radio Astronomy in Bonn on 3-4 December 2012.
Based on the positive feedback from the Mission and discussions with
other potential KSP proposers during the December meeting, the resulting
KSP consortia will prepare full KSP proposals to be submitted by 1
February 2013 to the Mission and to the respective ground radio
telescopes required for the specific observations. While submitting an
LoI and taking part in the workshop is expected to provide significant
advantages to the teams in preparing their full proposals, this is not a
mandatory requirement. Details can be found at
http://www.asc.rssi.ru/radioastron/ao-1/ao1.html

We are happy to report that the international community has actively
participated in the first phase of the process. We have received 31
Letters of Intent with the total observing time request about 4.5
thousand hours which is about 4 times larger than our estimate of
available observing time during the AO-1 period. Some more statistics
follows. These LoIs were submitted by about 160 co-authors from 18
countries, about 50 of them plan to participate in the consortia
organization workshop in December. The highest number of authors are
from Russia (34) being followed by Australia, Germany, and USA (about 20
each). Science areas covered by the LoIs include active galactic nuclei
(the highest number of Letters), masers, pulsars, interstellar medium,
transients, astrometry, gravity, and cosmology.


With best regards,
Nikolai Kardashev ([email protected])
Yuri Kovalev ([email protected])

 

[Notebook]

======================
Astro Space Center
RadioAstron Newsletter
Number 21
August 15, 2013
======================
Find full Russian and English pdf versions attached to this e-mail


Green Bank Earth station (GBES)

A group of engineers from Astro Space Center has visited the National
Radio Astronomy Observatory, Green Bank, to work together with local
NRAO staff on the installation of the tracking station equipment. The
instrumentation which has been installed on the 140-ft telescope was
manufactured in Russia and is similar to that which has been in
operation now for two years at Puschino. We are happy to report that
the equipment was delivered to Green Bank and installed and tested
without problems and is now operational. The tests of the GBES went very
well. On 1 August 2013, science data from the RadioAstron space radio
telescope was successfully recorded and sent to Moscow for evaluation.
Due to the high gain of the 140-ft antenna, the detected signal power
level was found to be well above operational requirements, and the bit
error rate satisfactorily low. The results of Doppler measurements of
the satellite velocity agreed well with measurements made sequentially
by the Green Bank and Pushchino stations.

Active observations of the RadioAstron AO1 Key Science Program will
start in late August 2013 with a reduced duty cycle in order to fully
develop a detailed operating model. Starting in early October, we
expect RadioAstron scientific observations to be fully supported by the
GBES.

We congratulate everyone involved in this achievement, thank the NRAO-GB
staff for their traditionally very high level of support and wish all of
us happy observing with two available RadioAstron tracking stations
during the execution of AO1.

The NRAO press release can be found here:
http://www.nrao.edu/pr/2013/RadioAstron/


Nikolai Kardashev ([email protected])
Yuri Kovalev ([email protected])


The RadioAstron project is led by the Astro Space Center of the Lebedev
Physical Institute of the Russian Academy of Sciences and the Lavochkin
Scientific and Production Association under a contract with the Russian
Federal Space Agency, in collaboration with partner organizations in
Russia and other countries.

 

[Notebook]

======================
Astro Space Center
RadioAstron Newsletter
Number 28
28 May 2015
======================
The RadioAstron AO-3 open science program starts in July 2015
We are happy to report that RadioAstron operations are extended by Roscosmos until the end of
2016.
The second year of the RadioAstron open science program AO-2 is coming to its end in June
2015. Astro Space Center and its Russian and international partners have successfuly performed
science experiments within approved AO-2 projects (see the list of projects in the RadioAstron
Newsletter No. 24).
Starting from July 2015, the RadioAstron mission will move into the third year of its open
program, AO-3 observations will continue until June 2016. The third RadioAstron Announcement
of Opportunity has invited proposals of the following two types: the “Key Science Program” (KSP)
and “General Observing Time” (GOT). See for details the full set of announcement documents in
http://www.asc.rssi.ru/radioastron/ao-3/ao3.html.
All proposal were evaluated by the RadioAstron Program Evaluation Committee (RPEC) which
was appointed by the RadioAstron International Science Council (RISC). Results of the evaluation
were approved by the RadioAstron project director Nikolai Kardashev. RPEC members for AO-3
are Jason Hessels (U. Amsterdam, the Netherlands), David Jauncey (CSIRO, Australia), Matthew
Lister (Purdue U., USA), Mikhail Popov (ASC Lebedev, Russia), Richard Porcas (chair, MPIfR,
Germany), Wouter Vlemmings (Chalmers U., Sweden). Below we list 9 accepted projects which
have requested observations with RadioAstron during the AO-3 period in their submission order:
• GOT: “Tracing micro-structures of H2O masers with ultimate angular resolution”, PIs: Hiroshi
Imai (Kagoshima U., Japan), Alexey Alakoz (ASC Lebedev, Russia);
• GOT: “Second-epoch Space VLBI visit into core-jet laboratories in the distant Universe”, PI:
Leonid Gurvits (JIVE and TU Delft, the Netherlands);
• KSP: “Space VLBI Survey of AGN at the Highest Angular Resolutions”, PI: Yuri Kovalev (ASC
Lebedev, Russia);
• KSP: “Probing the innermost regions of AGN jets and their magnetic fields”, PI: Jose-Luis
Gomez (IAA, Spain);
• KSP: “Gravitational redshift experiment with RadioAstron”, PI: Valentin Rudenko (SAI MSU,
Russia);
• GOT: “Resolving the milli-parsec jet in the nearby spiral galaxy M81”, PI: Michael Bietenholz
(HartRAO, South Africa; York U., Canada);
• GOT: “Substructure in Pulsar Scattering Disks”, PI: Carl Gwinn (UCSB, USA);
• GOT: “Core shifts with no blending”, PI: Mikhail Lisakov (ASC Lebedev, Russia);
• GOT: “H2O megamasers at high resolution”, PI: Willem Baan (ASTRON, the Netherlans;
ShAO, China).
Among the approved projects, four got rank ‘A’ (the highest priority), two — rank ‘B’, and
three — rank ‘C’. A total of about 160 co-investigators represent 20 countries. The largest
number of co-Is are from Russia, other countries with a high number of co-investigators are the
USA, Germany, Spain, the Netherlands, Australia, Italy, UK, etc.
Nikolai Kardashev ([email protected])
Yuri Kovalev ([email protected])
The RadioAstron project is led by the Astro Space Center of the Lebedev
Physical Institute of the Russian Academy of Sciences and the Lavochkin
Scientific and Production Association under a contract with the Russian
Federal Space Agency, in collaboration with partner organizations in
Russia and other countries.

 

[Notebook]

======================
Astro Space Center
RadioAstron Newsletter
Number 29
18 July 2015
======================
See full Russian and English versions attached to this e-mail as pdf files


** Four years since the launch **

Today is the fourth year birth day of the RadioAstron Space Radio Telescope Spektr-R! We would like to express our congratulations and deep thanks to all the institutions and individuals involved in the mission's operations and science.
Several weeks ago AO3 observations have started.

** Ultra-high spatial resolution image of nearby radio galaxy 3C84 at 22 GHz **

The RadioAstron Key Science Program on imaging nearby active galactic nuclei has successfully produced an ultra-high spatial resolution space-VLBI image of 3C84, a radio source located in the giant elliptical galaxy NGC1275 in the Perseus Cluster at a distance of
75 Mpc. At this distance, an angular size of 1 milliarcsecond corresponds only to about 0.3 parsec linear size. Because of its proximity and bright, relatively compact radio emission, 3C84 is one of the best candidates for studying the inner jet at very high spatial resolution and it was selected as an ideal target for space-VLBI imaging with RadioAstron. The ultra-high resolution images of 3C84 will help us to understand the AGN jet formation and evolution within the innermost parsec from the central engine.

The 22-hour long imaging experiment was carried out on 21-22 September 2013. Observations were obtained at the same time at 5 and 22 GHz using the dual-band observing mode of the Space Radio Telescope. The ground array data comes from 25 telescopes including the European VLBI Network together with the Russian Kvazar network, the Korean VLBI Network, Kalyazin and the NRAO telescopes Very Long Baseline Array, the Green Bank Telescope, and the phased Very Large Array. Part of the ground array observed at 5 GHz and a part at 22 GHz with Effelsberg switching between the two. The data presented here were correlated at the Max-Planck-Institut fuer Radioastronomie, Bonn. Space-to-ground fringes were detected from 0.2 Earth Diameters (ED) up to ~7 ED at both frequencies. The Figure 1 shows the resulting 22 GHz space-VLBI image after the full data calibration and deconvolution.



At sub-mas scale, the central region of 3C84 is resolved in a complex structure. The most prominent features are the core at the northern end of the jet and a bright component South of the core, which moves at sub-luminal speed along a curved trajectory connected to the core by a limb-brightened jet. The RadioAstron image shows substructure in these features at an unprecedented detail. For the first time a counter-jet is clearly visible at sub-parsec scale. The core is elongated in East-West direction implying a resolved structure at the angular resolution of about 50 microarcsec, corresponding to about 500 Schwarzschild radii.
The limb-brightened, well-resolved jet and counter-jet can be seen right from the beginning. The bright spot inside the southern component is identified with the end of the limb-brightened jet. Its compactness indicates a very high brightness which is unusual for sub-luminal jets being observed at a large angle.

** Probing the cosmic plasma with a pulsar's radio pulses and an "interstellar interferometer" **

Radio pulsars provide a powerful tool for studying the ionized interstellar medium. Pulsar B1933+16 was observed with RadioAstron on 1 August 2013 for 1.5 hours at two wavelengths simultaneously: 92 and 18 cm. This was the first experiment to use Green Bank tracking station, the 45-m antenna of NRAO (USA). The observations were supported by several ground radio telescopes: the 300-m telescope in Arecibo, the array of 14 telescopes in Westerbork (WSRT), the 32-m radio telescope in Torun, one 25-m dish of the VLBA system in Saint-Croix (USA), and one telescope of the Russian system QUASAR in Svetloe. The pulsar is located in the Sagittarius Arm at a distance from 3 to 10 kpc, with the most probable value of 3.7 kpc. The direction to the pulsar goes along this spiral arm, and such circumstances provide possibility of complex structure of interstellar medium on the light of sight.

We measured angular diameter of the scattering disk at 92 cm from the decrease of amplitude of interferometric visibility with the increasing baseline. Figure 2 illustrates the method. The diameter of the scattering disk was found to be equal to 17 mas at 92 cm. A scattering disk size is proportional to lambda squared, and at wavelength of 18 cm we expect scattering disk to be about 0.7 mas in diameter. This value can be measured at the maximum RadioAstron baselines, but not in the August 2013 configuration. Scattering of radio waves on the inhomogeneties of interstellar plasma causes the mutual interference of scattered waves at the observer position, thus forming an "interstellar interferometer" with a baseline equal to the distance between scattering rays at the effective screen. This can reach values of several astronomical units. In figure 3 we present an interferogram (delay-fringe rate diagram) of these scattered rays obtained for pulsar
B1933+16 using data recorded with the Arecibo radio telescope for our
observing session. The diagram is also called a secondary spectrum, since it is obtained as a 2-d Fourier transform of the dynamic spectrum.
One can see parabolic features in the diagram. Such features were discovered by Stinebring in 2001 and they are called scintillation arcs.
Each scintillation arc corresponds to separate scattering screen, and the curvature of the arc is related to the distance of the given screen.
Dashed white lines going through arcs in the figure represent our approximations, that give us values for the two screen position as 0.27 and 0.73 of the distance to the pulsar. Comparing these values with the large scale structure of the spiral arm, we can in principle improve the estimate of the pulsar distance as well.

** RadioAstron study of galactic water masers with ultimate angular resolution **

Recent observations of the most luminous water maser source in the Galaxy, star-forming region W49N, resulted in a successful detection updating the RadioAstron record in angular resolution achieved in observations of cosmic masers. W49N is located at a distance of about
11 kpc from the Sun in a distant part of the Perseus arm near the Solar circle. A correlated signal was obtained on 27 April 2015 between the space antenna and the two sensitive European ground facilities taking part in the experiment: the 100-m radio telescope in Effelsberg
(Germany) and the 43-m radio telescope in Yebes (Spain). Projected baselines of the space-ground interferometer in the experiment reached up to about 9.7 Earth diameters, achieving a fringe-spacing resolution of about 23 microarcsec.
The collected data on water masers are used to study structure and physical characteristics of the star forming regions in our Galaxy, impose tight limits on the sizes of individual maser spots, estimate brightness temperatures and provide the necessary input for the studies of their pumping mechanisms.


Nikolai Kardashev ([email protected]) Yuri Kovalev ([email protected])

The RadioAstron project is led by the Astro Space Center of the Lebedev Physical Institute of the Russian Academy of Sciences and the Lavochkin Scientific and Production Association under a contract with the Russian Federal Space Agency, in collaboration with partner organizations in Russia and other countries.

For more info:
http://www.asc.rssi.ru/radioastron/index.html

N.

 

[Notebook]

Well, its Happy Fifth Birthday now.

http://www.asc.rssi.ru/radioastron/index.html

====================== Astro Space Center RadioAstron Newsletter Number 30 20 June 2016 ======================

The RadioAstron extension and AO-4 open science program start in July 2016
We are happy to report that RadioAstron operations are extended by Roscosmos until the end of 2018.
The third year of the RadioAstron open science program AO-3 is coming to its end in July 2016. Astro Space Center and its russian and international partners have successfuly performed science experiments within approved AO-3 projects (see the list of projects in the RadioAstron Newsletter No. 28).

Starting from July 2016, the RadioAstron mission will move into the fourth year of its open program, AO-4 observations will continue until June 2017. The fourth RadioAstron Announcement of Opportunity has invited proposals of the following two types: the “Key Science Program” (KSP) and “General Observing Time” (GOT). See for details the full set of announcement documents in http://www.asc.rssi.ru/radioastron/ao-4/ao4.html. All proposal were evaluated by the RadioAstron Program Evaluation Committee (RPEC) which was appointed by the RadioAstron International Science Council (RISC). Results of the evaluation were approved by the RadioAstron project director Nikolai Kardashev. RPEC members for AO-4 are Jason Hessels (U. Amsterdam, the Netherlands), David Jauncey (CSIRO, Australia), Matthew Lister (Purdue U., USA), Mikhail Popov (ASC Lebedev, Russia), Richard Porcas (chair, MPIfR, Germany), Wouter Vlemmings (Chalmers U., Sweden).

Below we list 11 accepted projects which have requested observations with RadioAstron during the AO-4 period in their submission order:
• GOT: “Mapping and monitoring of cores of H2O masers with ultimate angular resolution”, PIs: Hiroshi Imai (Kagoshima U., Japan), Alexey Alakoz (ASC Lebedev, Russia);
• GOT: “Angular diameters of pulsar scattering disks and the distribution of interstellar plasma fluctuations”, PI: Mikhail Popov (ASC Lebedev, Russia); • GOT: “Second-epoch Space VLBI visit into core-jet laboratories in the distant Universe (continued)”, PI: Leonid Gurvits (JIVE and TU Delft, the Netherlands);
• GOT: “The nuclear structure of 3C84 with Space VLBI – II epoch”, PI: Gabriele Giovannini (Bologona U. and INAF, Italy);
• GOT: “H2O megamaser sources at high resolution”, PI: Willem Baan (ASTRON, the Netherlans; ShAO, China).
• KSP: “Probing the innermost regions of AGN jets and their magnetic fields”, PI: Jose-Luis Gomez (IAA, Spain);
• KSP: “Monitoring of the brightest AGN cores with RadioAstron”, PI: Yuri Kovalev (ASC Lebedev, Russia);
• GOT: “A milli-arcsecond gravitational lens in S5 B0615+820?”, PI: Eduardo Ros (MPIfR, Germany; U. Valencia, Spain);
• GOT: “Resolving the Jet-Collimation Region of the NGC1052 Twin-Jet System”, PI: AnneKathrin Baczko (MPIfR, Germany);
• KSP: “Gravitational redshift experiment with RadioAstron”, PI: Valentin Rudenko (SAI MSU, Russia);
• GOT: “Joint Pulsar – AGN Ground-Space VLBI”, PI: Vladimir Soglasnov (ASC Lebedev, Russia).
Among the approved projects, four got rank ‘A’ (the highest priority), three — rank ‘B’, and four — rank ‘C’. A total of about 155 co-investigators represent 19 countries. The largest number of co-Is are from Russia, other countries with a high number of co-investigators are the USA, Germany, Spain, the Netherlands, Australia, Italy, etc.

RadioAstron science results
We are happy to note the growing number of RadioAstron publications (http://www.asc.rssi. ru/radioastron/publications/publ.html) as well as many reports on science meetings including the recent “Dissecting the Universe” workshop in Bonn (https://events.mpifr-bonn. mpg.de/indico/event/4/timetable/) and “Blazars through Sharp Multi-Wavelength Eyes” in Malaga (http://jets2016.iaa.es/content/program).
On June 20-22, 2016, many colleagues gather in Moscow to celebrate the 100 years anniversary of Iosif Shklovsky at the Shklovsky-100 symposium (http://shklovsky100.asc.rssi.ru/index. php/en/programm).
Nikolai Kardashev ([email protected]) Yuri Kovalev ([email protected])

The RadioAstron project is led by the Astro Space Center of the Lebedev Physical Institute of the Russian Academy of Sciences and the Lavochkin Scientific and Production Association under a contract with the Russian Federal Space Agency, in collaboration with partner organizations in Russia and other countries.

Don't know how the Kerbals got in there...