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September 2019 Newsletter Edition 54 Call for Proposals - September 2019 Deadline: 01 October 2019, 23:59:59 UTC

Science Highlights Technical Highlights Network Highlights

An ‘orphan’ gamma-ray A CASA-based fully Dwingeloo fringes using burst afterglow automated Very Long the Westerbork H-maser page 4 Baseline page 10 calibration and imaging New jet-maser in the pipeline Enabling new Very Long nucleus of the Seyfert 2 page 7 Baseline Interferometry galaxy IRAS15480-0344 equipment at the Arecibo revealed EVN Technical Operation page 5 Meeting at Jodrell Bank page 12 Observatory Origin of the off-pulse page 9 Integration of e-MERLIN emission from pulsars telescopes into the page 6 European VLBI Network page 14

Meetings University of Tasmania and JIVE sign a Memorandum SKA-VLBI Key Science Projects and Operations Workshop of Understanding 14-17 October 2019, Jodrell Bank, page 14

The Eighth International VLBI Technology Workshop 18-20 November 2019, ATNF headquarters, Sydney, Australia

Astronomical Data Analysis Software and Systems (ADASS) Con- JUMPING JIVE ference Series update 6-10 October 2019, Groningen, The page 16 are compelling and the prospects arrays. At the CBD, we are for the future of the array are drawing up an initial proposal to outstanding. A new EVN Science constitute a global astro-VLBI Vision document, compiling the coordinating group (the ‘Global formidable science to be produced VLBI Alliance’) which will by the EVN in the future, is being work on setting future standards finalised right now. for calibration, observing Rafael Bachiller, bands, other issues affecting Chairman, EVN Consortium The technical activities aimed to interoperability, and mechanisms Board of Directors upgrade the performance of the for easy access to a future ‘World EVN are also very successful. Array’. It is an honour to have been The e-MERLIN array in the UK selected to serve as Chairman and the three KVAZAR stations We at the EVN continue to be of the European VLBI Network in joined the e-VLBI very active promoting scientific (EVN) Consortium Board of network a few months ago, meetings and schools. The Directors (CBD) for the period leading to a record of 15 stations ERIS2019 school will be hosted July 2019-July 2021. It is also an operating at a total data rate of 24 by , honour and a pleasure to share Gbps during an e-VLBI session 7-11 October 2019. The this responsibility with Tiziana on May 14. The frequency YERAC2020 will be hosted by Venturi, new CBD vice-chair, coverage is also improving very IRAM in Granada, , by and Pablo de Vicente, new CBD fast. We have now 7 mm receivers summer 2020, and finally, the Secretary, during the two years available at the Yebes, Tianma, 15th EVN Symposium, the great ahead. and Effelsberg stations. Together scientific gathering of all EVN with the previously equipped friends, will take place in Cork, I would like to thank the outgoing stations (Korean VLBI Network, Ireland on 6-10 July, 2020 under CBD Chair, John Conway, and the Metsähovi, , Onsala), nine the very appropriate lemma outgoing CBD Secretary, Michael dishes are now able to observe “Providing the sharpest view of Lindqvist, for their outstanding in Q-band, to which Sardinia, the universe”. job guiding the CBD over the last Medicina, and Robledo will be two years. Also thanks to all CBD added soon. members for thinking of me to perform this exciting task. The EVN maintains excellent The scientific results of the EVN relationships with other VLBI

The EVN newsletter has always on the capacity of the network, been a great opportunity to share attract new and diverse users VLBI news and updates across and push scientific and technical the network. It is with pleasure boundaries across the globe. that JIVE has accepted the responsibility of compiling and We hope that all members and distributing future editions, led users of the network will continue by our Support Scientists. to share their news, views and Paco Colomer, insights over time by emailing Director of the Joint Institute for VLBI-ERIC This is indeed an exciting time for them across to communications@ the EVN as we continue to build jive.eu.

2 Call for Proposals

Deadline: 01 October 2019, 23:59:59 UTC

The details of the call can be found here: https://www.evlbi.org/call-proposals

Observing proposals are invited for the European VLBI Network (EVN). The EVN facility is open to all astronomers. Astronomers with limited or no VLBI experience are particularly encouraged to apply for observing time. Student proposals are judged favorably.

Support with proposal preparation, scheduling, correlation, data reduction and analysis can be requested from Image by Paul Boven ([email protected]). Satellite image: Blue Marble the Joint Institute for VLBI-ERIC Next Generation, courtesy of Nasa Visible Earth (visibleearth.. (JIVE). gov).

The EVN is a Very Long Baseline size to arcsecond scales. Further cm. e-VLBI observations can be Interferometry (VLBI) network improvement of the uv-coverage performed at 18/21, 6, 5, and 1.3 of radio telescopes operated by may be achieved in global VLBI cm. e-MERLIN can be combined an international consortium of observations when the EVN with the EVN in both standard institutes. It is located primarily observes jointly with National and e-VLBI observations. Global in and Asia, with Observatory/ observations are performed only additional antennas in South with standard observations. Every Africa and Puerto Rico. The EVN telescopes or with the Long year standard EVN observations provides very high sensitivity Baseline Array. occur during three sessions of images at angular scales of (sub-) approximately 21 days each and milliarcseconds in the radio EVN observations may be ten days of e-VLBI mode. domain. EVN proposals may conducted with disk recording also request joint e-MERLIN (standard) or in real-time More information regarding and EVN observations for an (e-VLBI) correlation. Standard the EVN capabilities, observing improved uv-coverage at short EVN observations are available sessions, proposal guidelines, and spacings, significantly increasing on wavelengths of 92, 50, 30, user support can be found at the largest detectable angular 18/21, 13, 6, 5, 3.6, 1.3 and 0.7 www.evlbi.org.

3 Science Highlights

An ‘orphan’ gamma-ray burst afterglow

Benito Marcote, Kenzie Nimmo, Om Salafia, Zsolt Paragi, Jason Hessels, ASTRON/JIVE, The Netherlands

A radio source that has been decaying for the last 30 years, known as FIRST J1419+3940, is potentially linked to fast radio bursts and/or long gamma-ray bursts. The source is actually located in an environment that resembles FRB 121102. European VLBI Network (EVN) observations of the source have revealed an expansion, which suggests that the source is the orphan afterglow of a long gamma-ray burst.

When the biggest stars in the Artist’s impression of the time evolution of the observed event: from Universe reach the end of their the original massive star, and the explosion during its death that lives, they collapse due to their own produced a hidden gamma-ray burst, to the afterglow that was finally gravity and produce a observed. Credit: Benito Marcote (JIVE). explosion. In some cases, they also emit a long gamma-ray far there were no solid detections size of 3.9 ± 0.7 mas (1.6 ± 0.3 burst (GRB) lasting seconds or of such objects. pc given the angular diameter minutes. This GRB is only visible distance of 83 Mpc). These results if pointing directly towards the The team conducted observations confirm that the radio emission is Earth. There is, however, a long- of FIRST J1419+3940 with the nonthermal and imply an average lived afterglow that expands at EVN in September 2018 to study expansion velocity of (0.10 ± relativistic velocities and, after the source on milliarcsecond 0.02)c, which is consistent with a isotropization, can be visible scales and search for Fast Radio GRB jet expansion. Although no at radio frequencies even if the Bursts (FRBs) with the Effelsberg FRBs were detected during these gamma-ray emission was not single-dish telescope. They observations, FIRST J1419+3940 observed. This is termed an detected FIRST J1419+3940 as could still be a potential source of ‘orphan’ GRB afterglow, but so a compact radio source with a this kind of bursts.

Published in: Marcote et al. (2019, ApJL, 876, L14)

4 New jet-maser in the nucleus of the Seyfert 2 galaxy IRAS15480-0344 revealed

Paola Castangia, Osservatorio Astronomico di Cagliari,

The study of the physical properties, the structure, and the kinematics of the gas surrounding super-massive black holes (SMBHs) is essential in building detailed models of active galactic nuclei (AGN) and in shedding light on the impact of nuclear activity on galaxy evolution. The radio emission from luminous

H2O masers, the so-called “megamasers”, constitutes the only way to directly map the molecular gas at sub-parsec distance from the SMBH. Studies of megamaser sources not only allow us to constrain accretion disk geometry but also to improve our understanding of the jet (or outflows) interaction with the interstellar medium (ISM) of the host galaxies.

With the aim of finding new maser Radio continuum emission in the nucleus of IRAS 15480-0344 sources, suitable for Very Long mapped with the EVN at 1.7 and 5 GHz. The color scale represents Baseline Interferometry (VLBI) emission at L-band, ranging from −0.7 to 4.6 mJy beam−1, while the follow-ups, we searched for 22 overlaid contours delineate the C-band emission convolved with the GHz water maser emission in a L-band beam (contour levels are −1, 1, 2, 4, 8, 16, 32, 64 × 0.45 mJy well defined sample of 36 heavily beam−1). The positions of the water maser spots detected with the 23 −2 VLBA are also indicated. The star and the cross mark the location absorbed AGN (NH > 10 cm ), including Compton-thick sources. of the narrow (M1) and the broad blueshifted line emission (M2), respectively. A new luminous H2O maser (L ~ 200 L ) was detected H2O Sun in the mid-IR-bright Seyfert 2 continuum emission from IRAS (SRT), we galaxy IRAS 15480−0344. We 15480−0344 with the European resolved the radio continuum mapped the distribution of the VLBI Network (EVN). emission from the innermost maser emission with the Very regions of IRAS 15480-0344 into Long Baseline Array (VLBA). Indeed, employing a sensitive two bright components (labeled More recently, we performed array of EVN antennas, which SW and NE). The properties of deep images of the nuclear radio included the new 64-m Sardinia these sources (spectral indices, 5 brightness temperatures, them. Hence, it might trace the adding a new source to the few dimensions, and radio power) position of the core (not visible in confirmed jet-masers reported so indicate that their radio emission the radio continuum images) and far. In addition, the combination is synchrotron radiation, most be associated with the accretion of VLBI radio continuum and likely produced by two weak disk or a nuclear outflow. The maser observations unveiled the knots, which are part of a compact position of the broad maser presence of a compact radio jet radio jet. Both components show feature, M2, instead, coincides and strong interactions of the evidence for strong interaction with source NE, suggesting that latter with the dense interstellar with a dense interstellar medium. the maser emission might be medium in the nucleus of a produced by the interaction of the relatively radio quiet galaxy. This VLBI observations allowed us to jet with the interstellar medium, highlights the potential of maser locate the masers positions w.r.t. as it was proposed for the maser studies to shed light on the parsec the main nuclear components. in NGC 1068 and Mrk 348. scale environment around AGN The position of the narrow maser and, possibly, on the role of low line, M1, is along the imaginary Hence, the fundamental power jets on galaxy evolution. line connecting the two radio contribution of the EVN maps continuum sources, SW and NE, made it possible to determine and is nearly equidistant from the nature of the water maser,

Published in: Castangia et al. 2019, A&A, 629, A25

Origin of the off-pulse emission from pulsars

Benito Marcote, Yogesh Maan (ASTRON/JIVE, The Netherlands

Pulsars typically exhibit radio emission in the form of narrow, periodic pulses originating from confined regions in their magnetospheres. A potential presence of magnetospherically originated emission outside these regions, the so-called off- pulse emission, would challenge existing emission theories.

Detection of significant off- EVN images of B0525+21 showing the pulsed emission (left) and pulse emission has been reported the off-pulse region (right). The color-scale starts above the 3-σ rms from only two pulsars so far, noise level of each image, and gray-scale covers the range -3 to 3-σ. B0525+21 and B2045−16, at 325 and 610 MHz, with the Giant emission remains unclear. radio observations of B0525+21 Metrewave Radio Telescope and B2045−16 with the European (GMRT). However, the nature of To probe its origin the team VLBI Network (EVN) at 1.39 this newly uncovered off-pulse conducted very high resolution GHz. Whereas the pulsed emission

6 was detected at an expected level, sensitive to extremely compact two pulsars are accompanied by there was an reported absence of angular scales, our results suggest compact bow-shock pulsar wind any off-pulse emission above 42 a non-magnetospheric origin nebulae. and 96 μJy beam-1 (three times the for the previously reported off- rms noise levels) for B0525+21 pulse emission. The presence of The previously claimed and B2045−16, respectively. extended emission that is resolved detections were at slightly lower The stringent upper limits imply out on these milliarcsecond scales frequencies (325 and 610 MHz). the off-pulse emission to be less still remains plausible. In this Consequently, a meagre and than 0.4 and 0.3% of the period- case, the emission is constrained perhaps unlikely possibility is that averaged pulsed flux density, i.e., to arise from structures with the off-pulse emission somehow much fainter than the previously sizes of ~(0.61–19) × 103 au abruptly ceases between 610 MHz suggested values of 1–10%. for B0525+21 and ~ (0.48–8.3) and 1.4 GHz. Future observations × 103 au for B2045−16. These will clarify these possibilities. Since the EVN data are most constraints might indicate that the

Published in: Marcote et al. 2019, A&A, 627L, 2

Technical Highlights

A CASA-based fully automated Very Long Baseline Interferometry calibration and imaging pipeline

Michael Janssen, Radboud University, The Netherlands

The Common Astronomy CASA was missing a few crucial has led to the augmentation of the Software Applications (CASA) calibration capabilities and its CASA package with all required package has become the primary precursor, the Astronomical Image VLBI functionalities (e.g., a software tool for the reduction of Processing System (AIPS), has fringe-fitting task), making it radio interferometric data sets, been the standard calibration tool possible to reduce both connected most prominently for connected so far. Recently, a joint effort from element interferometer and VLBI element interferometers like the Joint Institute for VLBI-ERIC observations with the same Atacama Large Millimeter/ (JIVE) and Radboud University software package. CASA has the (ALMA) supported by the BlackHoleCam advantages of an intuitive IPython and the Very Large Arrau and RadioNet projects in user interface resulting in a low (VLA). For Very Long Baseline collaboration with National learning curve for new generations Interferometry (VLBI) data, Radio Astronomy Observatory of radio astronomers, an active

7 Results from the rPICARD pipeline. The left panel shows how rPICARD optimizes the fringe-fit solution interval for a baseline between the KP and NL antennas for 86 GHz data. The data is segmented with different intervals, which results in the ranges of SNR shown in blue. Increasingly longer intervals are tried until the median SNR is above the threshold of 5.5 for a 120s solution interval, which yields robust fringe detections within narrow delay and rate search windows. The right panel shows an image reconstruction of the 7mm jet of M87 based on VLBA data calibrated and imaged with rPICARD. software development and of VLBI data, but it can also be adjusted parameters as needed support, a built-in MPI standard used to reconstruct images with for severe data issues. The satisfying the need for hardware the CASA multi-scale multi- pipeline is able to reduce data scalability of future observations, frequency synthesis tclean task. from any standard VLBI array, and batch processing for Using self-tuning parameters, including the European VLBI science reproducibility is easily rPICARD is able to deliver high Network, Very Long Baseline facilitated. quality calibrated data without Array, High-Sensitivity Array, human interaction. On the other Global mm VLBI Array, and Based on the recent VLBI hand, many parameters can the Telescope. It upgrades, a CASA-based VLBI be manually adjusted. Every was used by a team at Radboud data reduction pipeline called step of the pipeline can be re- University Nijmegen and IRA- the Radboud PIpeline for the run effortlessly and verbose INAF Bologna as one of three Calibration of high Angular diagnostics are created so users independent calibration pipelines Resolution Data (rPICARD) can quickly review how well the that lead to the EHT results has been developed. The code calibration worked. The idea is published earlier this year, is publicly available here and that users blindly calibrate their revealing the first image of a is published by Janssen et al. data in a first step, check if the black hole. (2019). The primary purpose science goals can be reached, of the pipeline is the calibration and re-run specific steps with

Published in: Janssen et al. 2019, A&A, 626A, 75

8 EVN Technical Operation Meeting at

Uwe Bach, Max-Planck-Institut für Radioastronomie,

This year’s European VLBI Network (EVN) Technical Operations Group (TOG) meeting took place at Jodrell Bank Observatory (JBO), UK on June 26, 2019. The TOG meetings aim to discuss topics that arose from past Very Long Baseline Interferometry (VLBI) sessions and to plan future developments. In total, 27 participants from 11 countries and 13 different institutes met in the new Headquarters building at JBO. The meeting was supported by RadioNet. Meeting group picture taken in front of the new SKA Headquarter Common topics of the meetings building and the Lovell antenna. are the feedback from the Joint Institute for VLBI-ERIC (JIVE) With this, a project started many the number of available antennas correlator about the performance years ago, will finally reach its for real-time eVLBI. During the of the EVN stations during completion and should improve eVLBI session in May 2019, 18 the last sessions, reports from the amplitude calibration within stations observed together at 5 stations, and VLBI relevant hard- the EVN. GHz at a total bit rate of 27 Gbps and software developments. demonstrating that eVLBI can Faster internet connections at now provide a comparable uv- A few achievements from the last many sites have allowed to coverage and sensitivity as the years include the implementation replace Mark5 disk recorders by disk recording based sessions. of continuous calibration so called Flexbuffs. Flexbuffs capabilities for VLBI receivers are storage disk raids that are not A subject for the next months will at many of the central European being shipped physically, but the be to find and test common modes EVN stations, which allows to data is e-transferred to a second for data rates of up to 4 Gbps measure the system temperature raid at the correlator at JIVE. The (corresponding to 2 x 512 MHz not only in gaps between scans, available space allows to record of bandwidth) within the EVN, but continuously during the more and more observations at 2 but also for global observations whole scan to, e.g., better trace Gbps recording rates. The faster with the upgraded Very Long changing weather conditions. connections have also increased Baseline Array.

9 Network Highlights

Dwingeloo fringes using the Westerbork H-maser

Paul Boven, JIVE, The Netherlands

The ASTERICS H2020 project aimed to address common challenges shared by the various astronomy European Strategy Forum on Research Infrastructures facilities. Within its Cleopatra work package, we studied the distribution of very stable and accurate time and frequency references over fiber, using the open White Rabbit (WR) standard. Our goal was to show that with Diagram of the fiber connections between Dwingeloo, Westerbork some modifications, WR offers and Groningen. sufficient frequency stability to obtain good coherence in Very Long Baseline Interferometry (VLBI) observations.

To make this both more relevant, and more challenging, we decided to include the use of WR over an existing production fiber network in our demonstration, where the WR wavelengths would co-exist with other traffic on the same fibers.

The Westerbork (WSRT) and our VLBI signal processing flowchart. Dwingeloo offices are connected by 35 km of dark fiber, and networking provider. Their both locations, taking a detour via both host a networking point participation in this project the city of Groningen. of presence for SURFnet, our allowed us to also build a much national research and education longer (169 km) link between Although WR was not originally

10 designed with the high frequency stability requirements of VLBI in mind, recent advances (especially a ‘low-jitter daughter board’) result in much lower phase noise. To further improve the frequency stability, a high quality clean-up oscillator was added at the output of the WR switch in the telescope.

The Dwingeloo radio telescope participated in the first European VLBI tests in 1978 (Schilizzi et al. 1979, A&A 77, 1) but this task soon passed to the then new WSRT. These days, the Dwingeloo telescope is a national monument, and is being run by the volunteers of the CAMRAS foundation. They use it regularly to observe e.g. pulsars and the hydrogen line, making the telescope an ideal candidate for testing our remote clock system. ADEV measurement on the WSRT-DW baseline, observing 3C84. Since the Dwingeloo telescope Purple: using 35km WR link. Green: using 169km link. Black line: does not have a VLBI formatter, directly measured link performance on a long fiber. I decided to make one from a commercial off-the-shelf and the telescope. The CAMRAS does indeed provide a suitable Software Defined Radio (SDR), volunteers undertook the ground reference. No significant using the open source GNU Radio works and fiber installation with difference in performance SDR software to re-sample and enthusiasm, and in February between the 35 km and 169 km timestamp the recorded samples. 2019, we finally had the clock links could be detected. The flowchart shows the actual signal present in the telescope. signal processing blocks used to Our research was subdivided generate VDIF data, including The Dwingeloo telescope into several deliverables, each one custom block that I wrote participated unofficially in reported separately. The links which supplies the actual VDIF the N19L1 18cm Network to each of the reports are below, header with timestamps. First Monitoring Experiment, and which contain a much more fringes (since 40 years) were we obtained fringes to the detailed description of the work obtained in August last year using other stations. As the current and results. a Rb timebase. This result was receivers in Dwingeloo are better presented as a poster at the 2018 suited for 21 cm, subsequent * The design of the improved WR EVN symposium. observations with a smaller hardware (D5.4) number of telescopes (WSRT, * Design rules for integration Actually connecting the Toruń and Jodrell Bank) allowed in optical networks, and timing Dwingeloo telescope to the us to measure the performance calibration (D5.7) WSRT maser required running of the frequency transfer link. * VLBI demonstration and about 300 m of fiber between the The results show that at L-band, LOFAR link (D5.14) office buildings in Dwingeloo likely up to C-band, the system

11 Enabling new Very Long Baseline Interferometry equipment at the

Harro Verkouter, JIVE, The Netherlands

The Arecibo Observatory (AO) FieldSystem (FS). in order to generate the correct has been part of the e-European procedures for the RDBEs. VLBI Network (EVN), AO, under its new management Together, these pieces of software participating in real-time Very of University of Central Florida, form the basis of the AO RDBE + Long Baseline Interferometry Universidad Ana G. Méndez and Mark6 support. (VLBI) observations since as Yang Enterprises Inc., had funds early as 2004. During a real-time available to enable an external The three key components in the observation somewhere in 2017 expert to visit and work on the new system, a new, upgraded, FS it was noted that the equipment VLBI equipment. Thanks to computer (9.13.0), the RDBEs being used was still the same the persistence of Kristen Jones and the Mark6 recorder, needed as then: a VLBA4 analog rack (postdoc at the AO at the time) I reviewing. All bootup procedures with the original 1Gbps Mark5A was invited to spend two weeks and system configurations were recorder - a PentiumIII based(!) on-site at AO in the second half checked and updated to come single-core 1.26 GHz CPU of June 2019. up in operational state after a equipped with 256 MB of RAM. reboot. The new FS and the At the Effelsberg (Ef) radio upgrades were readily verified. As Linux dropped support for telescope in Germany, an Then, communication between the PentiumIII CPU, upgrading RDBE + Mark5C combination the local telescope control system the Mark5A’s O/S and recording is used for High Sensitivity (CIMA) and the FS needed to application became impossible. Array observations - under FS be reinstated. This was more Consequently, AO missed out control. The FS is very versatile precarious as the RDBE-specific on bug fixes and new features in certain dimensions: it is parts of the control code had to enabled by Joint Institute for possible to implement new SNAP be extracted from the Effelsberg VLBI-ERIC’s (JIVE) own commands by handling those specific station control code recorder software, e.g. to start in the station specific control and transplanted into Arecibo’s. participating in e-shipping VLBI module. Dave Graham altered the The FS interface to CIMA and data. Ef station module code, adding its configuration had to be well command and query support for understood in order to get the Besides running the oldest RDBEs. This is not enough; the new FS computer to drive the equipment in the EVN, the AO DRUDG program, part of the FS telescope. owns four NRAO/MIT Haystack suite, is needed to transform a Roach Digital Back End digital VLBI schedule in VEX format to Bob Campbell of JIVE had receivers (RDBE) and a 16 Gbps SNAP commands and procedures prepared an observing schedule 10-core Intel Xeon with 64 GB for a station’s hardware setup. in the three anticipated observing RAM Mark6 ethernet recorder. DRUDG also has no knowledge modes: DDC4 (4x tunable 32 The reason this new equipment of the RDBE and its specific MHz, 512 Mbps), DDC8 (8x was not used so far is because commands. Therefore, Dave tunable 32 MHz, 1 Gbps) and the combination RDBE + Mark6 wrote a simplified DRUDG PFB (16x32 MHz untunable, is not officially supported by the replacement too - vex2snap.pl - 2 Gbps). Using the rewritten 12 vex2snap program (in Python), With that fix in place, schedules project clearly demonstrated the these VEX files were converted now can be started and recordings international and cooperational into FS procedure- (.prc) and reliably made. The PFB data nature of VLBI. Without valuable SNAP (.snp) files. - a stream of Mark5B frames - input from experts around the seems to be working. The VDIF world, Walter Brisken and Matt An essential part of the upgrade headers of the frames output by Luce (NRAO, USA), Uwe plan was to use jive5ab on the the DDC firmware contained the Bach (MPIfR, Germany), Chet Mark6 as recording software, wrong number of channels and Ruszczyk (MIT Haystack, USA), requiring that Mark6 module bits-per-sample values. Also the Ed Himwich and Dave Horsley mounting/unmounting issues TSYS broadcast did not switch (NVI Inc., USA) and the AO needed to be addressed; from PFB to DDC format if the staff - Arun Venkatamaran, normally, this is handled through firmware was changed. After Luis Quintero, Kristen Jones the Massachusetts Institute of NRAO sent the rdbe_server and Anish Roshi with their in- Technology (MIT) Haystack source code, the latter issue was depth knowledge of not just the cplane software. Jan Wagner’s readily fixed (the problem was a telescope but of VLBI, networks standalone m6sg_mount script case sensitive string compare). and electronics in general, this was used as basis and an updated The VDIF header issue was not visit would not have been half as version now allows flexible (un) fixed until after returning home useful. mounting of one or more modules and following this up further with from the command line. NRAO. Currently, it is possible to reliably record RDBE data to Mark6 disk The RDBEs output their UDP Another advantage of the RDBEs packs at Arecibo, establishing a frames (Mark5B if PFB firmware is that the firmwares support solid basis for the future, whether loaded, VDIF if DDC) to a hard- measuring continuous calibration disk modules will be shipped coded port 625. This is a UNIX information. Unfortunately, the or the data e-transferred. There privileged port and requires connector on the NRAO RDBEs was not enough time to try to root privilege to capture data used at AO, where the 80 Hz achieve fringes - although with from. Because running with continuous calibration signal the broken VDIF frames that root privilege is an unacceptable for the noise diode control can would have been very difficult security risk, jive5ab never be tapped, is not wired due to to begin with, if not impossible. allows this. A solution was to a slightly different hardware The commissioning of the allow jive5ab to run with SUID design. AO staff is working on a new system is ongoing and the privilege and support this mode solution to generate the linked-to- upgraded system will be released properly. To this effect jive5ab the-1PPS 80 Hz signal external to the astronomy community gained a command line argument: to the RDBEs. Once this system after successfully completing --allow-root. The alternative, is in place, it should be possible commissioning observations. running as root, “works”, but has to get continuous calibration the effect that all recorded scans information for the AO as well. on the disk pack are owned by It is safe to say that a lot of root, which is unacceptable for work was done before, during production. and after those two weeks. The

13 Integration of e-MERLIN telescopes into the European VLBI Network

Kazi Rygl, INAF-Istituto di Radioastronomia, Italy

Integrated e-MERLIN + it is essential that a clear For e-MERLIN outstations European VLBI Network (EVN) scientific/technical justification correlated within the EVN, the observations are now available for the inclusion of e-MERLIN maximum bitrate available for using up to five e-MERLIN outstation telescopes is provided, each outstation correlation at outstations at 512 Mbps; in including why e-MERLIN JIVE (both disk and e-VLBI) addition to the selected Jodrell outstation antennas are required is 512 Mbps – equivalent to Bank home station. This additional for the delivery of the scientific two polarizations at 64 MHz capability provides short-spacing goal. This is because in addition bandwidth. Thus, the PI may coverage between 11 and 220 km to EVN Programme Committee request up to five outstation within e-MERLIN, together with (PC) approval, the e-MERLIN telescopes in dual polarization intermediate and long baselines outstation contribution has to mode with a bandwidth of 64 between e-MERLIN and EVN be approved by the e-MERLIN MHz per polarization in addition antennas in both disk-recording Time Allocation Group (TAG). to the e-MERLIN home station and e-VLBI mode. Principal For e-MERLIN TAG approved antenna at up to 1 Gbps depending Investigators (PIs) can request projects, e-MERLIN outstation on the observing wavelength multiple e-MERLIN outstation data will then be available for (two polarizations at 128 MHz antennas (all, or a subset of full correlation with other EVN bandwidth). Pickmere, Darnhall, Knockin, antennas at the Joint Institute for Defford, Cambridge) in addition VLBI-ERIC (JIVE). Note that For further enquiries regarding to an EVN home station antenna EVN proposals requesting only e-MERLIN + EVN observations at Jodrell Bank Observatory the Lovell or Mark II telescopes please see the e-MERLIN Contact (Lovell, Mark II). are still considered as standard Webpage, or alternatively email: EVN proposals and will only [email protected]. For eMERLIN+EVN proposals, require approval by the EVN PC.

University of Tasmania and JIVE sign a Memorandum of Understanding to boost spacecraft tracking activities

Guifré Molera Calvés, University of Tasmania, Australia

Last July, the University of of Understanding (MoU) to Experiment (PRIDE) project Tasmania (UTas) and the formalise the collaboration of lead by Prof. Leonid Gurvits Joint Institute for VLBI-ERIC UTas in the Planetary Radio from JIVE. The purpose of (JIVE) signed a Memorandum Interferometry and Doppler this agreement is to provide a

14 framework to support the role that PRIDE is taking in the Jupiter Icy moons Explorer (JUICE) mission by the European Space Agency (ESA), as well as, investigating opportunities for further potential collaboration in areas of mutual interest.

UTas will provide access to its network of radio telescopes to support ground-based spacecraft VLBI tracking observations of the JUICE mission. The JUICE mission will be launched in 2022 and its arrival on Jupiter is expected by 2029. Prior to this mission, a number of test University of Tasmania Hobart-26 m radio telescope (Credit: Jim experiments with current ESA Lovell). missions will be conducted to improve the observations and to optimise the processing pipeline.

Even though the UTas radio telescopes are not members of the EVN, they have already participated in several of the past experiments to demonstrate the Very Long Baseline Interferometry (VLBI) near- field technique in recent years. UTas is currently operating five radio telescopes located around the Australian continent: an ex-NASA 26-m station together with a 12-m dish in Hobart (Tasmania), an old data communications 30-m antenna Illustration of the JUICE mission and its environment (Credit:ESA) in Ceduna (South Australia), and two 12-m telescopes in in the sessions arranged by the they are currently being Yarragadee (Western Australia) Australian Large Baseline Array upgraded to the new VGOS-type and Katherine (Northern (LBA), in a broad frequency recommendations. The Hobart-12 Territory). All these antennas range of operations. telescope has already a broadband are operated from the AUscope receiver (from Callisto) installed Operations Centre in Hobart. The three small dishes (12-m) with a frequency of operations The radio telescopes take part are primarily used for geodetic between 2-14 GHz. Katherine is regularly in the geodetic VLBI purposes. They were initially undergoing the upgrade process session (in coordination with the equipped with a standard S- right now and it is expected that International VLBI Service) and and X-band receiver. However, Yarragadee will be upgraded

15 at the beginning of next year. star forming regions only visible and mapping of different maser In addition, a new dedicated from the southern hemisphere. transitions. The UTas radio tracking station with uplink and The main goal is to construct a astronomy and geodetic VLBI downlink capabilities is currently three-dimensional picture of the research group currently hosts under design for construction in spiral structure of the about a dozen doctoral and 2020 in Tasmania in collaboration and determine its fundamental postdoctoral researchers working with the Australia Space Agency parameters. on these topics. (ASA). The new broadband receivers UTas is currently seeking for There is also an active research also allow for novel methods 2-3 new doctoral candidates to atmosphere at UTas that is centred of data calibration and flexible work in a variety of spacecraft, around the aforementioned frequency setups to take part near-field, space ties related network of radio telescopes. in monitoring and VLBI activities and geodetic data The largest undertaking is an experiments with a number of series. Check the UTas website ongoing Australian Research unique telescope arrays; some for available projects and do not Council Discovery Project that of the research topics utilising hesitate to contact us at: guifre. aims to provide accurate distance these arrays include structure [email protected]. estimates via trigonometric studies of active galactic nuclei parallax to a large number of and the simultaneous monitoring

JUMPING JIVE Update

Giuseppe Cimò, JIVE, The Netherlands

During the summer, the work for Astronomical Society (EAS): the travelled to Lyon to take care of Joining up Users for Maximizing European Week of Astronomy the JIVE booth. The idea behind the Profile, the Innovation and and Space Science (EWASS). JIVE’s presence at the EWASS Necessary Globalization of JIVE The event has grown year after was to showcase the scientific (JUMPING JIVE) continued to year into a big multi-disciplinary applications of Very Long produce great results by engaging conference. This year, from the Baseline Interferometry (VLBI) with prospective new users and 24th to the 28th of June 2019, about to an audience of astronomers expanding the capabilities of the 1200 participants enjoyed the 55 of different fields. Four roll- Joint Institute for VLBI-ERIC parallel sessions and the many up banners were designed to (JIVE) and the European VLBI plenary talks in the heatwave that highlight a number of scientific Network (EVN). scorched Lyon. results by EVN users in the fields of transient astrophysics, A very suitable setting for Giuseppe Cimò, JUMPING jet physics, space science, and promoting the exciting science JIVE project manager, together formation, evolution and death with the EVN is the annual with Gina Maffey, JIVE’s of stars. Furthermore, a set of meeting of the European science communication officer, postcards, which were both funny 16 and relevant to VLBI, were very popular among the conference attendees and other exhibitors. The booth was also covered by a tablecloth showing the map of the EVN telescopes. Laminated figurines of all EVN telescopes completed the booth.

The JIVE booth was popular and aroused the curiosity of prospective new users. Besides the compliments on the layout by many people, other exhibitors came to get inspiration and took pictures of our booth. Attracting people at such a dispersive meeting is fundamental. We were Gina Maffey and Giuseppe Cimò at the JIVE booth (Credit: EAS, busy explaining what EVN and taken from EAS Facebook page). VLBI are, and many astronomers (from optical to high energy, but also a number of planetary scientists) were interested in possible applications of VLBI for their research. The JIVE-EVN brochure helped to highlight the support that JIVE provides.

Gina Maffey also gave a talk about how to communicate radio astronomy in a visual world. It was an interactive presentation that showed how it is possible to overcome the difficulties of competing with the beautiful pictures of optical astronomers (before the black hole ‘photo’, of course).

On the technological side, an important advance is the work in Bordeaux and JIVE to improve the geodetic capabilities (work package 6) of JIVE and the EVN. A typical 24-hour International VLBI Service (IVS) session, R1872, that took place in December 2018 with eight HOPS Fourfit output plot obtained from data of IVS-R1872 session stations, was selected for testing correlated at JIVE.

17 the newly-implemented Mark4 data interface and compare the results from the EVN software correlator at JIVE (SFXC) and from the DiFX correlator in Bonn, where the session was originally correlated and post-processed. The session R1872 has been fully processed with SFXC using as much as possible the same Comparison of the total multiband delay (TOTMBD) and signal-to- noise ratio (SNR) between the JIVE and Bonn correlators at X band. parameters as those employed in The plots show the total multiband delay differences (left) and ratios Bonn. The results of the SFXC SNR(JIVE)/SNR(Bonn) (right). correlation were then converted to Mk4 format, post-processed agreement at the 5 ps level, tools. This novel result will with HOPS and exported into which is the level of consistency appear in the proceedings of the vgosDB format, following the expected. Now, any geodetic- European VLBI for Geodesy and standard geodetic path. style session can be correlated Astrometry (EGVA) meeting held with SFXC, post-processed on 18-20 March in Las Palmas Comparison of those results and exported into standard (Gran Canaria). with the results from the DiFX geodetic format for analysis correlator in Bonn indicates with the most common geodetic

Next Newsletter: January 2020 Contributions can be submitted to [email protected] until 10 December 2019.

Newsletter edited by Katharina Immer, Support Scientist at JIVE ([email protected]).

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