Scientific Goals and Missions - Japanese VLBI Network (JVN)

Purpose

The Japanese VLBI Network (JVN) project is to establish the observation network consisting of 30-meter-class radio telescopes located in Japan, aiming to develop the time-domain VLBI astronomy for high-mass protostars and high energy events.

Missions

The missions of this project are:

1. to compile and deliver time-domain VLBI data catalogs to the scientific community utilizing large radio telescopes that have been operated and maintained by the respective university in Japan; and
2. to nurture highly-skilled youths by offering opportunities for undergraduate/master/Ph.D. students to engage in not only extensive science activities but also productive educational programs including on-site observation experience.

Primary Scientific Goals

The primary scientific goals of this project are:

1. to create the world's largest flux variation monitor catalog for 450 methanol maser sources, covering four transitions (6.668, 12.178, 19.967, 23.121 GHz), and clarify the time variations in flux density and structure using JVN telescopes;
2. to measure the annual parallaxes of five OH/IR stars obscured in thick dust by VLBI observations, and also aim to identify about five new objects from the candidate list of non-variables OH/IR stars;
3. to observe 10 star-forming regions associated with supernova remnants using the JVN, and to make a catalog of water maser sources that can be used for annual parallax measurements; and
4. to carry out total of 50 monitoring observations on five X-ray binaries including simultaneous observations in other wavelength bands and publish two papers on the results.

Target Date

End of March 2028