The TRAPUM Large Magellanic Cloud pulsar survey with MeerKAT I: Survey setup and first seven pulsar discoveries
V. Prayag, L. Levin, M. Geyer, B. W. Stappers, E. Carli, E. D. Barr, R. P. Breton, S. Buchner, M. Burgay, M. Kramer, A. Possenti, V. Venkatraman Krishnan, C. Ve… 展开作者
V. Prayag, L. Levin, M. Geyer, B. W. Stappers, E. Carli, E. D. Barr, R. P. Breton, S. Buchner, M. Burgay, M. Kramer, A. Possenti, V. Venkatraman Krishnan, C. Venter, J. Behrend, W. Chen, D. M. Horn, P. V. Padmanabh, A. Ridolfi
备注：
12 pages, 4 figures, 4 tables. Accepted for publication in Monthly Notices of the Royal Astronomical Society
本文介绍 TRAPUM 利用 MeerKAT 在 L 波段对大麦哲伦云开展的高灵敏度脉冲星巡天，基于前四个指向发现七颗新脉冲星，并对 SN 1987A 脉冲辐射给出流量上限。
摘要：
大麦哲伦云（Large Magellanic Cloud，LMC）因其独特的恒星形成特征以及与银河系的邻近性，为脉冲星族群研究提供了独特环境。作为 TRAPUM（TRAnsients and PUlsars with MeerKAT，即利用 MeerKAT 研究暂现源和脉冲星）大型巡天项目的一部分，我们正在使用 MeerKAT 射电望远镜（MeerKAT）的核心阵列，在 L 波段频率 856–1712 MHz 上对 LMC 开展射电脉冲星定向搜索。MeerKAT 出色的灵敏度，加上 2 小时的积分时间，使该巡天的灵敏度达到以往 LMC 射电脉冲星巡天的 3 倍。我们报告了最初四个巡天指向的结果，这些观测发现了七颗新的射电脉冲星，使 LMC 射电脉冲星族群增加了 30%。这些新脉冲星的脉冲周期范围为 278 至 1690 ms，最高色散量为 254.20 pc cm⁻³。我们还在以 SN 1987A 遗迹为中心的波束中搜索了显著脉冲射电辐射，但没有发现，从而在 1400 MHz 下对其最小流量密度设定了 6.3 μJy 的上限。
英文摘要：
The Large Magellanic Cloud (LMC) presents a unique environment for pulsar population studies due to its distinct star formation characteristics and proximity to the Milky Way. As part of the TRAPUM (TRAnsients and PUlsars with MeerKAT) Large Survey Project, we are using the core array of the MeerKAT radio telescope (MeerKAT) to conduct a targeted search of the LMC for radio pulsars at L-band frequencies, 856-1712$\,$MHz. The excellent sensitivity of MeerKAT, coupled with a 2-hour integration time, makes the survey 3 times more sensitive than previous LMC radio pulsar surveys. We report the results from the initial four survey pointings which has resulted in the discovery of seven new radio pulsars, increasing the LMC radio pulsar population by 30 per cent. The pulse periods of these new pulsars range from 278 to 1690$\,$ms, and the highest dispersion measure is 254.20$\,$pc$\,$cm$^{-3}$. We searched for, but did not find any significant pulsed radio emission in a beam centred on the SN$\,$1987A remnant, establishing an upper limit of 6.3$\,μ$Jy on its minimum flux density at 1400$\,$MHz.
We report the discovery of 13 new pulsars in the globular cluster NGC 1851 by the TRAPUM Large Survey Project using the MeerKAT radio telescope. The discoveries consist of six isolated millisecond pulsars (MSPs) and seven binary pulsars, of which six are MSPs and one is mildly recycled. For all the pulsars, we present the basic kinematic, astrometric, and orbital parameters, where applicable, as well as their polarimetric properties, when these are measurable. Two of the binary MSPs (PSR J0514-4002D and PSR J0514-4002E) are in wide and extremely eccentric (e > 0.7) orbits with a heavy white dw…
We report 4 new pulsars discovered in the core-collapsed globular cluster (GC) NGC 6624 by the TRAPUM Large Survey Project with the MeerKAT telescope. All of the new pulsars found are isolated. PSR J1823$-$3021I and PSR J1823$-$3021K are millisecond pulsars with period of respectively 4.319 ms and 2.768 ms. PSR J1823$-$3021J is mildly recycled with a period of 20.899 ms, and PSR J1823$-$3022 is a long period pulsar with a period of 2.497 s. The pulsars J1823$-$3021I, J1823$-$3021J, and J1823$-$3021K have position and dispersion measure (DM) compatible with being members of the GC and are there…
The TRAPUM collaboration has used the MeerKAT telescope to conduct a search for pulsed radio emission from the young Small Magellanic Cloud pulsar J0058-7218 located in the supernova remnant IKT 16, following its discovery in X-rays with XMM-Newton. We report no significant detection of dispersed, pulsed radio emission from this source in three 2-hour L-band observations using the core dishes of MeerKAT, setting an upper limit of 7.0 μJy on its mean flux density at 1284 MHz. This is nearly 7 times deeper than previous radio searches for this pulsar in Parkes L-band observations. This suggests …
Pulsar Discoveries from the TRAPUM UHF Survey of Fermi-LAT Sources
The University of Manchester（曼彻斯特大学）；National Astronomical Research Institute of Thailand（泰国国家天文研究所）；Max Planck Institute for Gravitational Physics (Albert Einstein Institute)（马克斯·普朗克引力物理研究所（爱因斯坦研究所））；Leibniz Universität Hannover（汉诺威莱布尼茨大学）；INAF – Osservatorio Astronomico di Cagliari（意大利国家天体物理研究所卡利亚里天文台）
More than 100 millisecond pulsars (MSPs) have been discovered in radio observations of gamma-ray sources detected by the Fermi Large Area Telescope (LAT), but hundreds of pulsar-like sources remain unidentified. Here we present the first results from the targeted survey of Fermi-LAT sources being performed by the Transients and Pulsars with MeerKAT (TRAPUM) Large Survey Project. We observed 79 sources identified as possible gamma-ray pulsar candidates by a Random Forest classification of unassociated sources from the 4FGL catalogue. Each source was observed for 10 minutes on two separate epoch…
A joint MeerKAT and Parkes view of Omega Centauri: New TRAPUM Searches and Pulsar Timing
INAF – Osservatorio Astronomico di Cagliari（意大利国家天体物理研究所卡利亚里天文台）；Max-Planck-Institut für Radioastronomie（马克斯·普朗克射电天文研究所）；Australia Telescope National Facility, CSIRO（CSIRO澳大利亚望远镜国家设施）；School of Science, Western Sydney University（西悉尼大学理学院）；Space Science Division, Naval Research Laboratory（海军研究实验室空间科学部）；South African Radio Astronomy Observatory（南非射电天文观测站）
Globular clusters are known to host an unusually large population of millisecond pulsar when compared to the Galactic disk. This is thanks to the high rate of dynamical encounters occurring in the clusters that can create the conditions to efficiently recycle neutron stars into millisecond pulsars. The result is a rich population of pulsars with properties and companions difficult or impossible to replicate in the Galactic disk. For these reasons, globular clusters have been and still are a prime target of searches for new and exciting pulsars. Because of their large distances, the limiting fa…
We report the discovery of two Black Widow millisecond pulsars in the globular cluster M28 with the MeerKAT telescope. PSR J1824$-$2452M (M28M) is a 4.78-ms pulsar in a $5.82\,$hour orbit and PSR J1824$-$2452N (M28N) is a 3.35-ms pulsar in a $4.76\,$hour orbit. Both pulsars have dispersion measures near $119.30\,$pc$\,$cm$^{-3}$ and have low mass companion stars ($\sim$$0.01-0.03\,$M$_\odot$), which do not cause strong radio eclipses or orbital variations. Including these systems, there are now five known black widow pulsars in M28. The pulsar searches were conducted as a part of an initial ph…
We have used the central 44 antennas of the new 64-dish MeerKAT radio telescope array to conduct a deep search for new pulsars in the core of nine globular clusters. This has led to the discovery of eight new millisecond pulsars in six different clusters. Two new binaries, 47 Tuc ac and 47 Tuc ad, are eclipsing "spiders", featuring compact orbits ($\lesssim 0.32$ days), very low-mass companions and regular occultations of their pulsed emission. The other three new binary pulsars (NGC 6624G, M62G, and Ter 5 an) are in wider ($> 0.7$ days) orbits, with companions that are likely to be white dwar…
Discovery of Millisecond Pulsars toward the Galactic Bulge in an Image-based Survey with MeerKAT
Max Planck Institute for Gravitational Physics (Albert Einstein Institute)（马克斯·普朗克引力物理研究所（爱因斯坦研究所））；Leibniz Universität Hannover（汉诺威莱布尼茨大学）；Center for Gravitation, Cosmology, and Astrophysics, Department of Physics and Astronomy, University of Wisconsin-Milwaukee（威斯康星大学密尔沃基分校物理与天文学系引力、宇宙学与天体物理中心）；Department of Physics and Astronomy, University of North Carolina at Chapel Hill（北卡罗来纳大学教堂山分校物理与天文学系）；National Radio Astronomy Observatory（国家射电天文台）；Department of Engineering and Physics, Sweet Briar College（斯威特布莱尔学院工程与物理系）；U.S. Naval Research Laboratory（美国海军研究实验室）
We report on the discovery and localization of fast radio bursts (FRBs) from the MeerTRAP project, a commensal fast radio transient-detection programme at MeerKAT in South Africa. Our hybrid approach combines a coherent search with an average field-of-view of 0.4 $\rm deg^{2}$ with an incoherent search utilizing a field-of-view of $\sim$1.27 $\rm deg^{2}$ (both at 1284~MHz). Here, we present results on the first three FRBs: FRB 20200413A (DM=1990.05 pc cm$^{-3}$), FRB 20200915A (DM=740.65 pc cm$^{-3}$), and FRB 20201123A (DM=433.55 pc cm$^{-3}$). FRB 20200413A was discovered only in the incohe…
PSR J2140$-$2311B is a 13-ms pulsar discovered in 2001 in a 7.8-hour Green Bank Telescope (GBT) observation of the core-collapsed globular cluster M30 and predicted to be in a highly eccentric binary orbit. This pulsar has eluded detection since then, therefore its precise orbital parameters have remained a mystery until now. In this work, we present the confirmation of this pulsar using observations taken with the UHF receivers of the MeerKAT telescope as part of the TRAPUM Large Survey Project. Taking advantage of the beamforming capability of our backends, we have localized it, placing it $…
We present the polarization profiles of 22 pulsars in the globular cluster 47 Tucanae using observations from the MeerKAT radio telescope at UHF-band (544-1088 MHz) and report precise values of dispersion measure (DM) and rotation measure (RM). We use these measurements to investigate the presence of turbulence in electron density and magnetic fields. The structure function of DM shows a break at $\sim 30$ arcsec ($\sim 0.6$ pc at the distance of 47 Tucanae) that suggests the presence of turbulence in the gas in the cluster driven by the motion of wind-shedding stars. On the other hand, the st…
The most massive globular cluster in our Galaxy, Omega Centauri, is an interesting target for pulsar searches, because of its multiple stellar populations and the intriguing possibility that it was once the nucleus of a galaxy that was absorbed into the Milky Way. The recent discoveries of pulsars in this globular cluster and their association with known X-ray sources was a hint that, given the large number of known X-ray sources, there is a much larger undiscovered pulsar population. We used the superior sensitivity of the MeerKAT radio telescope to search for pulsars in Omega Centauri. In th…
Max-Planck-Institut für Radioastronomie（马克斯·普朗克射电天文研究所）；Fakultät für Physik, Universität Bielefeld（比勒费尔德大学物理学院）；Rheinische Friedrich-Wilhelms-Universität Bonn（波恩大学）；South African Radio Astronomy Observatory（南非射电天文观测站）；INAF – Osservatorio Astronomico di Cagliari（意大利国家天体物理研究所卡利亚里天文台）
Radio and Gamma-Ray Timing of a Newly Discovered Millisecond Pulsar
University of Wisconsin-Milwaukee（密尔沃基威斯康星大学）；Max Planck Institute for Gravitational Physics (Albert Einstein Institute)（马克斯·普朗克引力物理研究所（爱因斯坦研究所））；Leibniz Universität Hannover（汉诺威莱布尼茨大学）；University of North Carolina at Chapel Hill（北卡罗来纳大学教堂山分校）
Using the MeerKAT radio telescope, a series of observations have been conducted to time the known pulsars and search for new pulsars in the globular cluster NGC 6440. As a result, two pulsars have been discovered, NGC 6440G and NGC 6440H, one of which is isolated and the other a non-eclipsing (at frequencies above 962 MHz) "Black Widow", with a very low mass companion (M$_{\rm c}$ > 0.006 M$_{\odot}$). It joins the other binary pulsars discovered so far in this cluster which all have low companion masses (M$_{\rm c}$ < 0.30 M$_{\odot}$). We present the results of long-term timing solutions obt…
Multi-element interferometers such as MeerKAT, which observe with high time resolution and have a wide field-of-view, provide an ideal opportunity to perform real-time, untargeted transient and pulsar searches. However, because of data storage limitations, it is not always feasible to store the baseband data required to image the field of a discovered transient or pulsar. This limits the ability of surveys to effectively localise their discoveries and may restrict opportunities for follow-up science, especially of one-off events like some Fast Radio Bursts (FRBs). Here we present a novel maxim…
Discovery of two new millisecond pulsars towards the Galactic bulge
NASA Goddard Space Flight Center（美国宇航局戈达德太空飞行中心）；University of Maryland（马里兰大学）；LAPTh, CNRS, USMB（拉普特实验室，法国国家科学研究中心，萨瓦大学）；Université Grenoble Alpes, CNRS, IPAG（格勒诺布尔阿尔卑斯大学，法国国家科学研究中心，天体物理学与行星学研究所）；Australia Telescope National Facility, CSIRO, Space and Astronomy（澳大利亚望远镜国家设施，CSIRO空间与天文部门）；Western Sydney University（西悉尼大学）；George Mason University（乔治梅森大学）；Naval Research Laboratory（海军研究实验室）；Department of Engineering and Physics, Sweet Briar College（斯威特布莱尔学院工程与物理系）；National Radio Astronomy Observatory（美国国家射电天文台）；Fakultät für Physik, Universität Bielefeld（比勒费尔德大学物理学院）；INAF – Osservatorio Astronomico di Cagliari（意大利国家天体物理研究所卡利亚里天文台）；Max-Planck-Institut für Radioastronomie（马克斯·普朗克射电天文研究所）；Max Planck Institute for Gravitational Physics (Albert Einstein Institute)（马克斯·普朗克引力物理研究所（阿尔伯特·爱因斯坦研究所））；Leibniz Universität Hannover（汉诺威莱布尼茨大学）
Radio pulsars provide some of the most important constraints for our understanding of matter at supranuclear densities. So far, these constraints are mostly given by precision mass measurements of neutron stars (NS). By combining single measurements of the two most massive pulsars, J0348$+$0432 and J0740$+$6620, the resulting lower limit of 1.98 $M_\odot$ (99% confidence) of the maximum NS mass, excludes a large number of equations of state (EOSs). Further EOS constraints, complementary to other methods, are likely to come from the measurement of the moment of inertia (MOI) of binary pulsars i…
