Status for 2025APR

All ATNF Telescope Applications for 2025APR must be submitted using OPAL.

The deadline for all proposals is 06:00 UT (17:00 Sydney local time) on Monday, 16 December 2024.

Summary of major changes and important notes for 2025APR:

  • ATNF long-term proposals are invited for the 2025APR semester. These proposals are accepted once per year (at the December deadline) and can combine observations from multiple ATNF facilities. More information can be found in the OPAL Users Guide under “3.5 Long Term Projects”.
  • We carried out an initial installation of the Cryogenically Cooled Phased Array Feed (CryoPAF) on Murriyang, the 64-m Parkes radio telescope, during Q4 2024.  It will be reinstalled in Q1 2025. Details for applying for time using the CryoPAF are given below in the section for Parkes.
  • We expect to replace CABB with the BIGCAT upgrade by April 2025. Observers should expect that only BIGCAT will be available during the 2025APR semester, although it may still be in the commissioning stage in April.
  • ATNF proposals are fully anonymised. Proposals that reveal applicant identities will be penalised by a reduction of scores or outright rejection for blatant breaches of anonymity (e.g. self-citations where the first author is listed by name). Please check under “Proposal Guidance” below.
  • We strongly encourage proposers to use this LaTeX template for ATNF scientific justifications (with appropriate BibTeX setup to support anonymisation).

We encourage OPAL users to report any issues via email (atnf-datasup@csiro.au). The file format for cover sheets and observations tables changed from 2022OCT onward. If you have files (in OXML format) from 2022APR and previous semesters please reload them into the OPAL editors, carefully re-check and update them, and save them in the new JSON format.

Telescope availability

For 2025APR, ATNF proposals will be accepted for the:

Commonwealth sanctions

As a Commonwealth agency, CSIRO is required to comply with Australia’s foreign policy settings and sanctions laws. Accordingly, CSIRO will not accept proposals for observing time on our Australia Telescope National Facility instruments from teams that include researchers at Russian or Belarussian state-owned or controlled institutions. CSIRO will continue to monitor and act in accordance with Australia’s evolving foreign policy settings and our assessment of the sanctions law compliance risks.

Proposal guidance

  • ATNF has moved to full anonymisation during the TAC review process. Proposers must not list their team members in the justification. Past projects should be referred to by proposal code rather than by the name of the PI. We also encourage proposers to consider using numbered references particularly when self-citations are included. A LaTeX template that uses this approach can be obtained here. Further guidance is given below under “Dual-anonymous Peer Review”.
     
  • Note that Large Proposals (>400 hours over the lifetime of the project) and ATNF Long-Term Projects are required to include in their justifications a section describing team roles/contributions (see the OPAL Users Guide, Section 3.4). To do this, and avoid listing team members in the justification, proposers can state the various skills required to conduct the project and refer to the size and composition of the proposing team. For example, “Our team comprises n members, and possesses x people with expertise in planning and conducting these observations, y people with experience in reducing the data, and z members able to interpret the data within the theoretical modelling described earlier.”

Dual-anonymous Peer Review:

In line with many other leading observatories, the ATNF TAC follows a dual-anonymous peer review process. This means that names and affiliations are redacted from the cover sheets when reviewed by the TAC and proposals should not identify any team member within the proposal.

Since this has been in place for several semesters, the TAC now has discretion to penalise proposals that identify authors, either through outright rejection of the proposal (for blatant breaches of anonymity), or by a reduction of the final grade. Below we list some examples of what could be penalized and provide some alternatives that adhere to dual-anonymous peer review practices.

Examples that could warrant a reduction in score:

  • Self-citations or inclusions that could lead the TAC to identify the proposal authors.
    • e.g. “In observations from another of our projects (C1234) …”
    • “We have previously shown that x=y [1]” (using numbered citations, but identifying it as the teams previous work.)
    • Using initials to describe team contributions.

Examples that could lead to outright rejection by the TAC:

  • Listing PI or author names within the scientific justification
  • Self-citations that identify the proposal authors,
    • e.g. “In [NAME] (2018), we showed x,y,z”,
    • “In our previous observations (C1234, PI: Smith)”

Instead, the following examples demonstrate ways authors could provide this information in line with ATNF’s anonymity guidelines:

  • “Data from C1234 shows that…”
  • “It has been shown in [1] that x=y”
  • To support these observations, we have compiled a team of XX people. In our team there are 3 members who are experience observers and 5 who have contributed to our data reduction pipeline and are expert [telescope] users. The remaining YY members will contribute to the scientific analysis.

Further guidance on the dual anonymous peer review system, and more examples on how to avoid identifying authorship, can be found on other observatory websites such as HST, ESO:

https://hst-docs.stsci.edu/hsp/hubble-space-telescope-call-for-proposals-for-cycle-32/hst-anonymous-proposal-reviews

https://www.eso.org/sci/observing/phase1/dual-anonymous-guidelines.html

Impact of instrument upgrades for 2025APR

Upgrades are underway for several instruments, and the associated project timescales mean we need flexibility in ATNF scheduling during 2025APR. Specific details for individual telescopes are provided below.

  • ATCA: It is anticipated that BIGCAT will be installed during the 2024OCT semester and will be offered in a shared-risk observing mode after a period of commissioning and verification. BIGCAT will initially support the same observing modes as currently offered by CABB and will be limited to the existing IF setup of 2×2 GHz. Proposers requesting ATCA observations in this semester should prepare observations tables using the current CABB configuration with any technical requirements not captured in the observations table clearly stated in the proposal text. It is anticipated that additional BIGCAT observing modes, including pulsar binning mode and increased bandwidth of 4×2 GHz, will be made available later in the semester.
  • ATCA: The observing schedule for 2025APR will be released once we are confident that BIGCAT is working as intended.
  • ATCA: We welcome NAPA proposals for rapid response observations (within ~10 minutes of an alert). A rapid response mode for the ATCA is now in operation. Proposers seeking to use this mode must contact Jamie Stevens (Jamie.Stevens [at] csiro.au) and demonstrate a working triggering mechanism before being allowed to send triggers to the telescope.
  • Murriyang: Scheduling for the semester is likely to be impacted by activities related to CryoPAF, long-term maintenance and spacecraft tracking efforts. We may choose to release the schedule in parts.
  • LBA: It may be some months following the BIGCAT upgrade before the ATCA is able to participate in VLBI observing. Additionally, the CryoPAF installation at Parkes will result in limited availability of Parkes at frequencies above 4 GHz.

General Information

Observing support, training, and remote observing qualification requirements have recently been updated and are described on the ATNF Observing Support and Training page.

Observations with ASKAP are automated, and all other ATNF telescopes are remotely user-operated. Observations from the Marsfield or Perth Science Operations Centres are supported but not required.

Telescope time that is unallocated when the observing schedules for the semester are released can be requested as Director’s Discretionary Time (sometimes referred to as “green time”, as that’s how it appears in the graphical version of the schedules). Additional information and guidance can be found in slides presented by Jamie Stevens at the April 2024 ATUC Open Session.

Target of Opportunity proposals can be submitted at any time. This is intended for observations which are time critical. Proposals that are not time critical should be submitted through the regular TAC process when possible, rather than relying on applications for Director’s time or Target of Opportunity time.

Large Projects are projects that require a total of more than 400 hours of observing time over the lifetime of the project. Please read the Large Projects page in addition to the information on this page. Large Proposals are required to include in their justifications a section describing team roles/contributions (see the OPAL Users Guide, Section 4.3 for more details).

Long-Term Projects are designed to maximise the scientific outputs from ATNF facilities by building on experience gained during ATCA Legacy projects, including the incorporation of feedback from Legacy project principal investigators. By design, Long-Term Projects are able to combine allocations on: ATCA; Murriyang, the 64-m Parkes radio telescope; ASKAP; and LBA. More details of the scheme including policy and guidelines are available in the OPAL Users Guide under “3.5 Long Term Projects”. Long-Term Proposals will be considered for 2025APR.

A document outlining Time Assignment Committee procedures is available on the Time Assignment Committee page.

For further information contact George Hobbs (George.Hobbs [at] csiro.au).

ASKAP radio telescope

ASKAP is designed for autonomous operations in pre-defined modes with high efficiency. Guest Science Project (GSP) observations, like Survey Science Project (SSP) observations, will be fully specified in advance, then scheduled autonomously and dynamically by the automated scheduler SAURON based on the identified constraints. This means that users should carefully consider requests for narrow scheduling windows or long sequences of repeated observations with specific cadence. Doing so will impact the technical feasibility of the proposal and should be well-motivated by the science justification.

The data will be calibrated, processed, and archived according to a pre-defined processing template. Proposers will be notified when their data products are available in the science data archive CASDA, accessible through the Data Access Portal/CASDA. Recipients of data will be required to submit a short validation report after being granted access and before the data can be released and used for science.

Examples of well-tested observing and processing strategies include continuum observations with 10” resolution at a sky frequency of 944 MHz, bandwidth of 288 MHz. and a typical integration time of 10 hours (EMU-mode), or spectral line observations with 18.5 kHz spectral channels and 30” resolution at a sky frequency of 1368 MHz with 144 MHz of bandwidth and a typical integration time of 8 hours (WALLABY-mode). Various combinations of these modes are possible and the ASKAP Operations team will work with guest science teams to define a specific configuration for each project. ASKAP generates Stokes I data products by default but is capable of producing full polarisation products if needed. Further examples of well-tested modes include the following: 

  • POSSUM mode extends the EMU or WALLABY mode by adding full Stokes parameters, additionally with a “continuum cube” containing 1 MHz frequency resolution for spectral index or rotation measure studies. 
  • VAST mode differs from EMU continuum mode by providing Stokes I & V data and is optimised for snapshot observations of 12 minutes, for covering wide areas or searching for transients with multiple epoch-based observations of the same field(s). It uses a slightly different sky frequency of 888 MHz. 
  • FLASH mode is a form of spectral line observing designed for absorption-line science, with some adjustments to the beamforming to ensure broad lines are well characterised, and a sky frequency of 856 MHz optimised for high-redshift HI. 

We are currently working with the CRAFT team to integrate a new high-time-resolution visibility system and offer it as a National Facility observing mode. The current implementation allows for nominal scheduling and temporary non-archival data storage, but with minimal visibility of the status of the CRACO instrument, making the mode high-risk compared with other ASKAP data products. Users who accept this risk and would be willing to trial the new mode can indicate their desire for CRACO data products. These will take the form of Stokes I visibilities with 110ms time resolution, 288×1 MHz channels in UVFITS format, recorded for up to 2 hours at a time, for a total of less than 10 hours per month. Users can also elect to receive a list of single pulse search candidates in a csv file. More information on data access procedures will be made available to successful proposers and will minimally require access to the Pawsey Acacia storage system.

ASKAP’s continuum sensitivity yields an RMS noise level of about 200 μJy/beam at 900 MHz in 15 minutes of observing time. With longer 10-hour observations the RMS noise level drops to about 20 μJy/beam.

ASKAP GSPs should address how ASKAP’s unique capabilities (e.g. wide field of view) benefit the proposed science outcomes. GSPs should avoid direct competition with the existing Survey Science Projects and describe how their goals differ from existing plans. 

ASKAP can be included in Large and Long-term projects, within the constraints of the total time available for allocation via GSPs (currently, 150 hours per semester). Users may request all this time for a single project if they have a compelling science case and the number of hours may be increased up to 300 in future if we become oversubscribed with good quality proposals.

Detailed system information can be found in the following locations: 

  1. Australian square kilometre array pathfinder 1: system description. Hotan et al.  https://ui.adsabs.harvard.edu/abs/2021PASA…38….9H/abstract 
  2. The ASKAP Guest Science user guide and observation guide via this resource kit (in development): https://research.csiro.au/askap-guide

Please use this form to request Target of Opportunity time for ASKAP.

Being a survey telescope, ASKAP generates a rich amount of data for potential follow-up by other telescopes in radio and other wavelengths. A few other observatories have expressed an interest in shadowing ASKAP observations in real-time to maximise the chances of simultaneously detecting any interesting event. Although we do not yet officially support such activities with a metadata service, ASKAP’s current pointing direction is visible on public web pages and other observatories may choose to shadow your observations without our knowledge. As with source coordinates that may be sensitive in nature, ASKAP’s wide field of view affords the opportunity to displace the field centre and observe your object of interest off-axis if reasonable justification is provided.

Australia Telescope Compact Array (ATCA)

ATCA Observing

Remote observing with the ATCA is the default mode of observing, but it is also possible to observe from the Marsfield Science Operations Centre (SOC) or the Perth SOC. Observing at the Narrabri site is encouraged for observers who wish to visit the observatory, or for observers wanting to become familiar with BIGCAT, and for complex or non-standard observations, or in other circumstances where this is the more sensible option.

The Narrabri observatory is considered a remote observing site with regard to support levels for normal observations. New observers are able to be trained remotely, but are encouraged to travel to the SOC if they prefer.

Array configurations

At least one 6km configuration, a 1.5 km configuration, a 750 m configuration and all the H168, H214 and H75 hybrid configurations will be offered during the semester. Configurations will only be scheduled if there is sufficient proposal demand for them.

Anticipated BIGCAT modes

The BIGCAT modes that will be available for 2025APR semester, along with the coversheet selection that should be used to indicate which one you would like to use, are:

  1. CFB 1M: A bandwidth of 2 GHz with 1920 x 1 MHz channels split over 15 subbands, with no “zoom” bands. There will be 2 of these windows for a total of 4 GHz of bandwidth.
  2. CFB 1M-0.5k: A bandwidth of 2 GHz with 1920 x 1 MHz channels split over 15 subbands, and (optionally) several finer resolution zoom bands in any or all subbands. There will be 2 of these windows, for a total of 4 GHz of bandwidth. Each zoom’s bandwidth and spectral resolution will be configurable, but you will need to describe your requirements in your proposal. Standard zooms will include: 2 MHz bandwidth with 0.5 kHz resolution, 4 MHz bandwidth with 0.24 kHz resolution, and 2 MHz bandwidth with 0.06 kHz resolution.
  3. CFB 64M-32k: A bandwidth of 2 GHz with a configurable of number of channels across the 15 continuum subbands, for very wide spectral line windows. Standard modes will include 74 kHz resolution (1728 channels per subband), 37 kHz (3456 channels), 18.5 kHz (6912 channels) and 9 kHz (13824 channels). There will be 2 of these windows for a total of 4 GHz of bandwidth. No zooms will be available in this mode. If you need some other spectral resolution, please describe this in your proposal, along with a science justification.
  4. VLBI backend tied-array mode: The exact features of the BIGCAT tied-array voltage capture mode have not yet been finalised, but please select this if you are interested in using it. You must include in your proposal a short description of how you will process the data and data transport logistics.

Compact Array receivers and frequency ranges

The 16-cm band receivers provide an instantaneous frequency coverage from 1.1 to 3.1 GHz (although the usable bandwidth is reduced by typically 30% by Radio Frequency Interference [RFI] — the impact of RFI on the 16cm band can be seen at this webpage.). The 16-cm band receivers have an improved sensitivity over the original 20- and 13-cm receivers, and include new ortho-mode-transducers, significantly improving the polarisation performance toward the top end of the band.

The 4-cm band receivers cover the band from 4 GHz to 12 GHz. These receivers provide significantly improved system temperatures over the original 6- and 3-cm receivers. The focus positions for the antennas in the 4cm band differ from those of other bands, which should be borne in mind if changing between bands during an observation. It takes about 2 minutes to refocus the antennas.

In the 15-mm (16–25 GHz), 7-mm (30–50 GHz) and 3-mm (83.5–106 GHz) bands, two 2GHz-wide intermediate frequency bands may be selected within an 8 GHz bandwidth. In the 7-mm band, both band centres must be either greater than 41 GHz (the point at which the conversion changes from lower side-band to upper side-band) or both less than 41 GHz.

Observing is possible with the standard 15-mm and 7-mm systems on all six antennas, and 3-mm systems on five antennas: there is no 3mm receiver on CA06. Note that the 3mm receivers are ageing and that, as spare parts are limited, or non-existent, component failure in a receiver may not be able to be repaired in a timely manner, or at all.

The ATCA sensitivity calculator provides a means of determining the sensitivity characteristics of observations, and can include the reduction in bandwidth expected due to RFI in the 16cm band.

Millimetre observing

Observing at 3 mm generally starts in May and ends in mid-October. Proposers are reminded that the primary flux density calibrator at 3 mm is Uranus, which in April 2025 will be near a R.A. of 3h28m and declination of +18d39m. Proposals for 3-mm observations that require accurate flux calibration should request time for observations of Uranus (if the array configuration allows). For 7-mm observations with CABB, PKS 1934-638 has sufficient flux density to be used as a primary flux density calibrator, and should be preferred over Uranus for all projects.

Proposers requiring their own observations of Uranus (at special frequencies, or at a time when their main target has set, for example), should make this clear in the observations table and justification of their proposal. For secondary calibration at 3- and 7-mm, Observatory staff will calibrate a number of bright AGN, spread over the full range of R.A., against Uranus (at 3mm) and 1934-638 (at 7mm) at the standard continuum observing frequencies throughout the semester.

The array is outfitted with Water Vapour Radiometers (WVRs) provided by the University of New South Wales. Experience to date indicates that these units will, in some conditions, allow corrections to the measured phases on longer baselines to be made, improving phase stability and sensitivity. Interested mm-wavelength observers will be able to use of this capability during 2024OCT. Details of the system are available at the WVR webpage.

Further information

Murriyang, our Parkes radio telescope

Receiver availability

The default receiver pairing will be Ultra-Wideband Low (UWL) receiver along with the Cryogenically Cooled Phased Array Feed (CryoPAF). High-frequency receivers such as 13mm and MARS will replace the UWL when required.

There will be a three-week maintenance period in the month of May 2025 for critical gear box maintenance. Exact dates are yet to be finalised but the telescope will not be available to observe in any capacity during this time.

Subject to the continued commissioning of the CryoPAF, we anticipate to offer “shared-risk” CryoPAF observing for the remainder of the 2025APR semester, with limited modes and features. At present, we expect to offer up to 72 beams for “pulsar search” and “spectrometer” modes and 8 beams for “pulsar fold” mode. A complete description of the CryoPAF modes and features are described in this CryoPAF specification document.

We welcome expressions of interest in this proposal round, with the following conditions:

  • Shared-risk proposals should represent reasonably short requests for time during the 2025APR semester, perhaps framed as a pilot or feasibility study for an anticipated survey or project requiring a larger time request in future semesters;
  • Teams that wish to work with ATNF to help develop calibration techniques for the CryoPAF are particularly encouraged;
  • Some aspects of the beam forming and data processing software are expected to be only partially implemented, so shared-risk observers will be requested to contribute to development and testing, as well as providing feedback to the observatory team;
  • Shared-risk time will be allocated subject to evidence of awareness of, and capacity to manage, the large data rates produced by CryoPAF – particularly for pulsar search mode;
  • Shared-risk observers will be strongly encouraged to visit ATNF at Marsfield and/or Parkes to work with staff on setting instrument configuration, determining the state of the system and initialising observing. 

If you submitted a proposal to use CryoPAF for the 2024OCT and/or 2024APR semesters, you have the option of pre-graded status for 2025APRS. For pre-graded proposals you will need to submit the cover sheet and observations table in OPAL, but do not need to attach the scientific justification. Your grade from 2024OCTS or 2024APRS (whichever is later) will be carried over for 2025APRS. If you would like to take up this option, please send a short email to the TAC Executive Officer (elizabeth.mahony [at] csiro.au) noting that you are requesting pre-graded status for CryoPAF shared-risk observations.

The key contact for CryoPAF installation and commissioning plans, as well as information about associated visits and travel support is Simon Johnston (Simon.Johnston [at] csiro.au), CryoPAF Project Scientist.

Backend Availability

DFB4 is not available. Please request MEDUSA or other backend as below.

MEDUSA is a GPU based backend and details of the available modes can be found in the User’s Guide here (with other modes driven by proposals, acknowledging shared risk development). Whilst we await the Ultra-Wideband High frequency receiver, UWH (a 4-32GHz receiver), MEDUSA can be used with the UWL, plus the Mars and 13mm high frequency legacy receivers. For those intending to use MEDUSA please include details of the backend capabilities required.

Other available backends:

  • Breakthrough Listen backend is available for scientific use up to 50hrs per semester, please see this webpage for details and contact Danny Price to enquire as to availability.
  • VLBI backends Multiple VLBI backends (LBADR, MEDUSA) are available for non-LBA VLBI and single dish voltage capture. The LBADR system allows you to capture up to 2 x 64 MHz (1 Gbps) or 8×16 MHz (512 Mbps) dual polarisation bands with 2-bit sampled raw voltage output, or 2×16 MHz dual polarisation bands with 8-bit sampled voltage. The MEDUSA GPU is now capable of a VLBI voltage capture mode. Data recording up to 8 Gbps should be available (2 GHz bandwidth with 2bit sampling). A bit depth of 2,4 or 8 bits/sample is supported. If you choose to use Parkes in this mode, without requesting any other LBA station or VLBI correlation by ATNF, you only need to write a Parkes proposal. These modes have restrictions: proposers who are interested in using this must contact Chris Phillips to discuss what is possible. You must include in your proposal a short description of how you will process the data and data transport logistics.

Data Rates and Volumes

Data from Parkes observations are archived in ATOA (the Australia Telescope Online Archive) or the Data Access Portal (DAP). Given the high data rate of the receivers, we need to know the expected data requirements to manage data access, archiving and scheduling. We cannot guarantee availability of all recorded data products if your observations exceed the proposed data rates.

The cover sheet for Parkes proposals specifically requests the following information for all projects:

  • State your expected data rate in TB per hour
  • Are you recording more than 10TB in total for this semester [yes/no]? (if yes, data may not be archived in DAP for pulsar data or ATOA for spectral line/continuum data after 10TB have been taken)
  • Identify your data endpoint [options are ATNF bookable disk space, CSIRO HPC, other]
  • Have you requested adequate storage on your data endpoint [yes/no]? 
  • There is a checkbox confirming the user has read and agree to the following terms: Data rates from Parkes receivers can be as high as 10TB per hour – it takes time to transfer these volumes, so please be mindful that your observations may have adverse effects on the next set of observations. For scheduling and archiving purposes, it is essential that we know the maximum data rates and volumes that your project will produce, and that you have planned adequate storage for your data. If you exceed your stated data rate/volume, then we may need to delete the data before you are able to access them, and they will not be archived.

To assist in determining your data rate an equation is provided below, and the DHAGU? interface will also calculate your data rate when generating a parameter set. An email notification to our data management team will be triggered if the data rate from a parameter set exceeds 1TB per hour.

The following can be used to calculate data rates per beam (single beam for the UWL, maximum 72 beams for the Cryo-PAF):

  • Pulsar Search: File size [bytes] = Nchan x Npol x Nbit/8 x Tobs/Tsamp
  • Pulsar Fold: File size [bytes] = Nchan x Npol x Nbin x 16/8 x Nsub
  • Spectral line mode: File size [bytes] = Nc_sb x Nsb x Npol x Ndump x 32/8
  • Voltage Capture (non-standard): File size per zoom band [bytes] = Nbit/8 x BW x 1e6 x 2 x Tobs x 2

where:

  • Nc_sb = number of channels per subband

  • Nsb = number of subbands (normally 26 for the UWL)
  • Nsub = number of subintegrations in pulsar fold mode
  • Nchan = total number of channels = Nc_sb * Nsb
  • Npol = number of polarisation states (1, 2 or 4)
  • Nbit = number of bits/sample (1, 2, 8, 16 or 32)
  • Tobs = observation time (seconds)
  • Tsamp = sampling time (seconds)
  • Ndump = number of spectral dumps (the total integration divided by the spectral dump time (seconds))
  • BW = bandwidth in MHz

Noting that the total data volume will be a few percent larger than that given by the equation because of the need to store meta-data information.

Contracted telescope usage

Breakthrough Listen will be allocated of the order of 150 hrs of Murriyang observing time in the 2025APR semester. The Breakthrough Foundation is not guaranteed any more than 30% of time at any given local sidereal time (LST) range (hour) each month. Commensal use of Breakthrough Listen data is possible (the data is not proprietary) and does not require a proposal to be submitted for consideration by the ATNF Time Assignment Committee. Data is obtained for the P595 project (PULSE at Parkes) and PX600 (a Galactic Centre search) commensally and can be found on the DAP.

In addition to Breakthrough Listen there are also agreements with an NAOC FAST collaboration for 144 hrs per semester; Intuitive Machines (lunar lander tracking) for approximately 140hrs; and other spacecraft tracking industry partners for approximately 40 hours.

Spacecraft tracking is treated like a NAPA trigger and may override scheduled astronomy observations. Observatory staff will contact affected observers and work with projects to reschedule any lost time as promptly as possible.

Observing Information

Remote observing with the Murriyang telescope is the default mode of observing. It is also possible to observe from the Marsfield Science Operations Centre (SOC), the Perth SOC, or Parkes itself (for complex or non-standard observations, or in other circumstances where this is the more sensible option). Although observing onsite at Parkes is not fully supported, we do encourage site visits during working hours for those interested.

Remote assistance can be sought during working hours through the PORTAL. Local Parkes Observatory staff will continue to provide the first point of contact for matters relating to safety of the telescope, and equipment.

Further information

Proposers intending to start a new project are advised to contact the Parkes Observatory Senior System Scientist, Shi Dai (Shi.Dai[at] csiro.au), to discuss their requirements and availability of configurations before proposal submission. For further information on all Parkes capabilities please refer to the Parkes Radio Telescope Users Guide.

Tidbinbilla

In the 2025APR semester the 70-m and 34-m antennas at Tidbinbilla will have some availability for single-dish use. Access to Tidbinbilla antennas is provided through the host country agreement, which usually provides approximately 220 hours in total each semester.

This is used for both single dish (typically 180 hours per semester) and LBA (typically 40 hours per semester) use. Tidbinbilla proposals remain active for one year. All observations are taken in a service mode when scheduling permits (i.e., the proposer does not need to be present and is not involved in the actual observing). Successful proposals require the submission of a source list with accurate target and calibrator positions.

The Pulsar Backend and the Radio Astronomy Spectrometer are available for successful merit-based proposals. The new Radio Astronomy Users Guide provides a basic outline of the capabilities of both backends. The spectrometer is capable of up to 16 IF products, with up to 32,768 spectral channels, each with 1GHz bandwidth. More detailed documentation about these backends, including details of configuration files, can be found in Virkler et al. 2020, ApJS, 251, 1 (preprint here).

The 70-m antenna is equipped with 2.3, 8.4 and 22 GHz receivers and 34-m antennas are equipped with 2.3, 8.4, 26 and 32 GHz receivers. The 1.6 GHz receiver on the 70-m antenna is unlikely to be fully commissioned until after the 2025APR semester. The pointing performance of the 70-m is adequate for observations at the three lowest frequencies (1.6, 2.3 and 8.4 GHz) with no additional calibration, but observations at 22-GHz require a small overhead (~10% of observing time) for determining pointing corrections using bright AGN near the target of interest.

It should be noted that the 22 GHz system is the most sensitive in the southern hemisphere, covering 18.0 to 26.5 GHz with a system temperature of 60 Jy. The 34-m antennas are equipped with 2.3, 8.4, 26 and 32 GHz receivers. The 8.4 GHz and 22 GHz systems are well-suited for radio recombination line observations. For large area spectral line mapping projects an On-the-Fly mapping mode is available.

Full details of available frequency coverage and other technical information are available from the Tidbinbilla Information page. (See also the NASA Deep Space Communication Complex web pages.) An on-line sensitivity calculator is available to assist in proposal preparation.

For the latest information of availability please refer to the Tidbinbilla website, or contact Shinji Horiuchi (Shinji.Horiuchi [at] csiro.au).

Long Baseline Array

In the 2025APR semester, the Long Baseline Array (LBA) will use the Australia Telescope Compact Array and the Parkes and Mopra radio telescopes, together with the Hobart and Ceduna and the AuScope Yarragadee and Katherine 12-m antennas operated by the University of Tasmania. Use of the Warkworth Observatory 12m and 30m antennas, now operated by SpaceOps NZ, may be possible around their other commitments.

The Warkworth 12m can observe at 13 and 3cm, and the Warkworth 30-m telescope can observe at 6.7 and on a best-efforts basis at 4.8 and 8.4 GHz: these can be requested but their availability cannot be guaranteed. The Hartebeesthoek 26-m or 15-m telescopes may also be available. All telescope availability is subject to other commitments – scheduling is done on a best efforts basis.

A limited amount of time may be available with the Tidbinbilla 70-m antenna (although, as noted above, the 1.6 GHz capability of the 70m is unlikely to be reinstated until after the 2025APR semester) or one of the 34-m antennas.

For the 2025APR, ASKAP will not be available for VLBI. The AuScope antenna have undergone a receiver upgrade from their original S/X (2/8 GHz) receivers and now have wideband 2–14 GHz receivers. Commissioning of the BIGCAT backend at the ATCA, and the CryoPAF receiver at Parkes, is likely to limit the availability, or capability, of these telescopes for some months. This in turn, may reduce the number of LBA blocks to be scheduled in 2024OCTS. It may be some months following the BIGCAT upgrade before the ATCA is able to participate in VLBI observing.

During the 2025APR semester, some LBA time may be scheduled at the same time as a European VLBI Network (EVN) session, opening the possibility of joint LBA/EVN observations. The easternmost stations of the EVN are in a similar longitude range to the LBA telescopes, and for sources in equatorial regions, baselines to western European stations are also achievable. Proposals for joint LBA/EVN observations must be submitted separately to both the LBA and EVN at their respective deadlines. Similarly, co-observing with the East Asian VLBI Network is possible, via proposals to both networks.

The BIGCAT upgrade for the ATCA will mean that during observations with the VLBI tied array it will be possible to record data in the standard ATCA continuum mode at the same time (a feature that was only available in a limited capacity with CABB). 

Constraints on Parkes receiver changes impose limits on the frequency of LBA observations with Parkes. Once the CryoPAF (700–1950 MHz) is installed alongside the UWL (700 MHz–4 GHz) receiver, observations at higher frequencies will entail removing one or other of these large receiver packages. This is unlikely to be done more than once per semester. Observations with Parkes at 8.4 and 22 GHz may be possible: other frequencies may be requested but are less likely, and will be available less frequently.

The Parkes UWL and AuScope Katherine, Hobart and Yarragadee telescopes produce linear polarisations, which are converted to circular polarisations post-correlation, usually with reasonable results.

LBA proposers are reminded that a member (or members) of the proposal team will be required to assist with the VLBI observing on the ATNF telescopes. Please ensure that a member of the proposal team will be able to help. Note that due to logistical constraints the VLBI schedule usually is released only a few weeks before observing, so the observer will need to be qualified for remote observing with Parkes and ATCA. New observers are able to be trained remotely prior to the LBA session.

Telescopes outside the core LBA may be also requested for special observations. Specific system availability may be dependent on availability at individual antennas. Sources close to the equator may benefit from including telescopes from Asia. No formal mechanism is currently available for requesting time and all such telescopes need to be negotiated on a case-by-base basis. Phil Edwards can assist with this process.

For more details, please refer to the Long Baseline Array and pages thereunder.

Potential first-time users have a Novices Guide available to them from the VLBI webpage.

Proposers can use the EVN planning tool, which includes the LBA telescopes. Proposers may also contact Phil Edwards (details below) with any questions related to sensitivity calculations for LBA observations.

The current capabilities of the LBA are briefly outlined below:

  • The disk-based recording system is used for all recorded VLBI observations and data rates (up to 1 Gbps) can be achieved at most stations.
  • All recorded observations will be correlated with the DiFX software correlator. The software correlator is capable of correlating the high data rate observations at high spectral resolution with arbitrary correlator integration times.

User support is available, including assistance with proposal preparation, scheduling, observer training and data reduction.

A bit rate of 256 Mbps (2x16MHz bandwidth in 2 polarisations, with 2 bit digitisation and Nyquist sampling) can be sustained at all LBA telescopes and is the standard observing mode. Observations requesting higher bit rates will need to include a clear justification for the requested rate. Potential users must consult the VLBI National Facility Upgrade capabilities.

For more information contact the LBA System Scientist, Phil Edwards (Philip.Edwards [at] csiro.au).