SOuthern Astrometry Project (SOAP)

• Objectives of the campaign
• Preliminary results
• People
• Proposed Observations
• Source lists
• Current status
• Raw data
• Mailing list

The project proposal document is available here.

Phases of the program:

• Exploratory phase SOAP-E1. Includes all sources brighter 250 mJy at declinations <-45° except 38 objects observed in LBA v561a experiment. The number of target sources: 219. Each source is observed in two scans of 4 minutes long. Two twenty-four hour experiments are required. The objectives of this campaign are
  • to determine the correlated flux density at the medium length baselines (Au-Au: 1000–3000 km and long baselines, Hh-Au: 8000–10000~km)
  • improve source position by a factor of 2 to 0.8~mas level. Observing with two scans reduces of false negative when a wrong decision about source suitability may be made due to an unnoticed failure in observations. The outcome of this phase will be the source list for SOAP-A1 phase.

  The outcome of this phase will be the source list for SOAP-A1 phase.
• Astrometry phase SOAP-A1. Includes all the sources brighter 250 mJy at declinations <-45° that were detected in SOAP-E1, even those that were observed before with IVS and have position error better 0.3 mas but still do not have images. The total number of target sources will be known after analysis of SOAP-E1 observations and is expected to be close to 200. Each source on average is observed in eight to ten scans of 5~minutes long. The trial SOAP-A1-01 schedule had 16 sources with 8--10 scans per source. The scan length is reduced to 2 minutes for strong sources and extended to 8 minutes for weak sources. Considering data losses at a rate of 15%, fifteen 24-hour experiments are required. The objectives of this campaign are
  • to improve source position by a factor of 5 down to 0.3~mas level};
  • generate images at X and S-band;
  • determine jet direction;
  • evaluate kiloparsec scale flux density simultaneously with parsec-scale images, which allows us to determine the source compactness.

  The images will be derived from 80 observations per source, which is approximately equivalent to 2 scans at the VLBA. We expect jet directions will be determined for 50–70% sources. Including SOAP-E1 observations, the source position will be derived from 10–12 scans, 100–120 observations.
• Exploratory phase SOAP-E2. Includes all sources in a range [120, 250]~mJy at declinations <-45°, except those observed in v561a experiment. The number of target sources: 123. Each source is observed in two scans of 8 minutes long. Two 24-hour hour experiments are required. The objectives of this campaign are the sama as for SIAP-E1. The outcome of this phase will be the source list for SOAP-A2 phase.
• Astrometry phase SOAP-A2. Includes all sources in a range [120, 250]~mJy at declinations <-45° that were detected in SOAP-E2. The number of sources is expected in a range of 200--250. Each source is observed in ten scans of 10~minutes long. Twenty eight 24 hour experiments are required. The objectives of this campaign are the same as for SOAP-A1. The source images will be derived from 40--100 observations. We expect jet directions will be determined for 50% sources. Including SOAP-E2 observations, the source position will be derived from 12~scans, 40–100 observations.

Preliminary results

1. Interim resport on the results obtained by 2019.01.01 is prepared on 2019.02.14.
2. Catalogue of 144 sources with improved positions due to SOAP program including observations provessed by 2019.01.01 is avialable here.
3. Preliminary results of SOAP-E1 from processing SOAP-E1-01 (aua025, 20170822_q) and SOAP_E1-02 (aua026, 20170913_p).
4. Preliminary results of SOAP-A1 campaign.

People

The list of sources from the SOAP-E1 observed so far can found here.

Preliminary target source list SOAP-A1 can be found here.

Current status

• Program SOAP A1 is running.

• Program SOAP E1 is completed.

VLBI correlator output

Mailing list is for discussing issues related to the SOAP experiments. Only

This web page was prepared by Leonid Petrov ()
Last update: 2019.02.18_03:06:49