论文标题
使用Lofar搜索与极化点源相关的脉冲星:Tulipp Project中的初始发现
Searching for pulsars associated with polarised point sources using LOFAR: Initial discoveries from the TULIPP project
论文作者
论文摘要
发现无线电脉冲星,尤其是毫秒脉冲星(MSP),对于一系列天体物理应用很重要,例如测试重力理论或探测磁极的星际介质。我们的目的是通过利用低频阵列(Lofar)两米高的Sky Survey(Lotss)的敏感,低频无线电图像中的PULSAR可观察物(主要是极化)来发现可能错过的PULSAR,并开始使用靶标图像(tulipp)(Tulipp)调查。在这项调查中,我们在中心频率为144 MHz的中心频率和48 MHz带宽的中心频率下,线性和圆形极化点源具有比2 MJY亮的磁通密度明亮。超过40多个已知的脉冲星,其中一半是MSP,被检测为地段图像中的极化源,并被排除在调查之外。我们已经获得了30个候选物的梁形成的洛法观测,这些观察是使用相干解散搜索脉冲的。在这里,我们介绍了Tulipp调查第一年的结果。我们发现了两个脉冲星,PSRS J1049+5822和J1602+3901,旋转周期分别为p = 0.73 s和3.7 ms。我们还检测到了另外五个已知的脉冲星(两个缓慢旋转的脉冲星和三个MSP),无法为其准确的天空位置,以允许与大量源的独特的交叉匹配。这项针对性的调查提出了一种相对有效的方法,使用脉冲星(尤其是MSP)可以使用柔性观察模式的敏感射电望远镜(例如平方公里阵列及其探路者/前体)的柔性观察模式,尤其是因为当前使用相干性降级的宽区域全天候调查是当前计算的。
Discovering radio pulsars, particularly millisecond pulsars (MSPs), is important for a range of astrophysical applications, such as testing theories of gravity or probing the magneto-ionic interstellar medium. We aim to discover pulsars that may have been missed in previous pulsar searches by leveraging known pulsar observables (primarily polarisation) in the sensitive, low-frequency radio images from the Low-Frequency Array (LOFAR) Two-metre Sky Survey (LoTSS), and have commenced the Targeted search, using LoTSS images, for polarised pulsars (TULIPP) survey. For this survey, we identified linearly and circularly polarised point sources with flux densities brighter than 2 mJy in LoTSS images at a centre frequency of 144 MHz with a 48 MHz bandwidth. Over 40 known pulsars, half of which are MSPs, were detected as polarised sources in the LoTSS images and excluded from the survey. We have obtained beam-formed LOFAR observations of 30 candidates, which were searched for pulsations using coherent de-dispersion. Here, we present the results of the first year of the TULIPP survey. We discovered two pulsars, PSRs J1049+5822 and J1602+3901, with rotational periods of P=0.73 s and 3.7 ms, respectively. We also detected a further five known pulsars (two slowly-rotating pulsars and three MSPs) for which accurate sky positions were not available to allow a unique cross-match with LoTSS sources. This targeted survey presents a relatively efficient method by which pulsars, particularly MSPs, may be discovered using the flexible observing modes of sensitive radio telescopes such as the Square Kilometre Array and its pathfinders/precursors, particularly since wide-area all-sky surveys using coherent de-dispersion are currently computationally infeasible.