标题： 引力波事件后续研究中星系目录的有效性 显示英文标题

标题： Efficacy of Galaxy Catalogues for following up gravitational wave events

摘要： 引力波（GW）由LIGO-Virgo-KAGRA（LVK）网络检测到，这开启了天体物理学的新时代。 GW源的电磁对应物的识别对于多信使天文学至关重要，其中一种方法是使用星系目录来指导光学后续观测。 在本文中，我们测试了针对星系的方法在正在进行的LIGO O4运行中的效用，该方法对星系进行质量优先排序。 我们使用了预期的LIGO O4事件的模拟结果和NED-LVS星系目录，并以小视场望远镜为研究对象，特别是GROWTH-印度望远镜（GIT）。 随着LIGO/Virgo在正在进行的O4观测运行中灵敏度的提高，预计的总检测数量已增加，但这些检测大多数现在定位得也很差。 我们显示，在相同视场（FoV）上覆盖更大的体积会导致每个FoV中的星系总数显著增加。 在按质量排序的星系列表中观察到了明显的顶部偏重现象，通常这些星系的数量仍为几千个。 在更远的距离上，这种大量的深度后续观测在大多数情况下是不可行的，使得星系目录在有限的情况下才有用，但在LVK探测器当前敏感且星系完整性较高的较低距离下仍然有用。 我们还探讨了质量填充的影响，以考虑在远距离处的星系目录不完整性。 如果将质量填充的概率视为排名和覆盖的指标，我们发现，在超过300 Mpc的距离（NED-LVS在此距离内约为70%完整），传统的二维概率搜索优于基于三维星系目录（无质量填充）的搜索；而在较近的事件中，使用每个瓦片中的三维质量乘以概率表现更好。 显示英文摘要

摘要： The detection of gravitational waves (GW) by the LIGO-Virgo-KAGRA (LVK) network has opened up a new era in astrophysics. The identification of the electromagnetic counterparts of GW sources is crucial for multi-messenger astronomy, one way of which is to use galaxy catalogues to guide optical follow-up observations. In this paper, we test the utility of galaxy-targeted approach with mass prioritised galaxy ranking for the ongoing LIGO O4 run. We have used the simulated results for the expected LIGO O4 events and the NED-LVS galaxy catalogue and based our study for small field of view telescopes, specifically the GROWTH-India Telescope (GIT). With the increase in sensitivity of LIGO/Virgo in the ongoing observing run O4, the expected number of total detections have gone up but most of these are also now poorly localised. We show that a larger volume covered in the same field-of-view (FoV) on the sky results in a large increase in the total number of galaxies in each FoV. A significant top-heaviness is observed in the mass-ranked list of galaxies, which still number to a few thousand in most cases. At larger distances, such high numbers of deep follow-up observations are infeasible in most cases rendering galaxy catalogues useful in limited cases, but these are still useful at lower distances where LVK detectors are currently sensitive and where galaxy completeness is higher. We also explore the effect of mass-filling to account for galaxy catalogue incompleteness at large distances. If mass-filled probabilities are considered as the metric for ranking and coverage, we find that the conventional 2D probability search performs better than a 3D galaxy catalogue (without mass-filling) based search at distances larger than 300 Mpc (upto which NED-LVS is ~70% complete), and using 3D mass times probability in each tile performs better for nearby events.