East Asian VLBI Network (EAVN)

Overview

We invite proposals for open-use observations with the East Asian VLBI Network (EAVN), which is the international collaborative VLBI array between China, Korea, and Japan. In the 2021A semester, 14 telescopes (VERA 4 x 20 m, KVN 3 x 21 m, Tianma 65 m, Sheshan 25 m, Nanshan 26 m, Nobeyama 45 m, Takahagi 32 m, Hitach 32 m, and Yamaguchi 32 m) participate in the EAVN open-use program.

Observing mode

EAVN provides an opportunity of a VLBI observation with a data recording rate of 1 Gbps (total bandwidth of 256 MHz and with single polarization at 6.7, 22, and 43 GHz. Dual-frequency (22 and 43 GHz) simultaneous observation system can be used for EAVN observations at KaVA and Nobeyama, while the session will be set in which the system is available. Details of available observing mode can be found in the EAVN Status Report on the EAVN website.

Telescope time and array configuration

The total available observation time for EAVN is up to 500 hours in the 2021A semester, while the available observing time for individual EAVN telescopes are different. All EAVN observations will be allocated between 2021 January 16 and June 15. Please refer to the EAVN status report on the EAVN website for more details.

EAVN accepts a request for usage of sub-array configuration (KaVA 7 telescopes and additional telescopes from non-KaVA stations). There are several conditions of the antenna combination depending on the observing frequency. Further details about the sub-array configuration are shown in the EAVN status report.

The maximum request time for a single EAVN proposal is limited to 100 hours in case of usage of only KaVA, while one can request for the maximum total observation time of 36 hours for non-KaVA telescopes (except Nobeyama) for a single proposal, and that of 24 hours for Nobeyama. Proposers can request their project to be allocated over a year until the end of the 2021B semester(2022 January 15), while the total request time of the proposal is still limited as shown above.

Target of opportunity

EAVN accepts target of opportunity (ToO) proposals. Note that Nobeyama cannot be included for ToO proposals. It is strongly recommended that ToO proposals (especially expected ToO) are submitted during the regular CfP, while unexpected or urgent ToO can be submitted as Director's Discretionary Time (DDT) proposals at any time. ToO proposals must include clear triggering criteria to initiate an observation. ToOs are valid for one year after it is approved. ToO proposals for DDT should follow the same way of regular call and should be submitted via the EAVN website.

Proposal submission

Proposals should be submitted via EAVN website. Proposal submission deadline is 2020 November 2 (Mon.), 8:00 UT. Please refer to the EAVN status report for detailed information about the proposal format. The designated cover sheet form can be downloaded from the EAVN websites.

Acknowledgment

All EAVN users are asked to specify the acknowledgment to EAVN in their publications. A template for the acknowledgment can be found in the EAVN status report.

Sincerely,