Parkes observations for project P1372 semester 2025OCTS_01

The gamma-ray source, 4GFL J1646.5-4406, has recently been identified as a new spider pulsar binary, and potentially a redback system due to its longer eclipse. With only ~30 redback systems known so far, a detailed analysis of such a new system is needed to further understand this population. We requested simultaneous 6x2-hour Murriyang UWL and 6x3-hour ATCA L-band observations on this newly identified pulsar, PSR J1646-4406, covering its ingress and/or egress to further constrain its orbital parameters, investigate the eclipse mechanism and intrabinary shocks, and understand its evolutionary pathways.伽马射线源4GFL J1646.5-4406近期被认证为一颗新型蜘蛛脉冲星双星系统，因其更长的食延时长，被初步归类为红背系统（redback system）。截至目前，已知的红背系统仅约30个，对该新型系统开展详细分析，有助于进一步解析该天体族群的特性。我们针对这颗新发现的脉冲星PSR J1646-4406，申请了同步观测计划：6次单次时长2小时的Murriyang UWL观测，以及6次单次时长3小时的ATCA L波段观测，覆盖其食入和/或食出过程，以进一步约束其轨道参数，探究食相机制与双星内激波现象，并阐明其演化路径。