FAST early pulsar discoveries: Effelsberg follow-up
M. Cruces, D. J. Champion, D. Li, M. Kramer, W. W. Zhu, P. Wang, A. D. Cameron, Y. T. Chen, G. Hobbs, P. C. C. Freire, E. Graikou, M. Krco, Z. J. Liu, C. C. Mia… 展开作者
M. Cruces, D. J. Champion, D. Li, M. Kramer, W. W. Zhu, P. Wang, A. D. Cameron, Y. T. Chen, G. Hobbs, P. C. C. Freire, E. Graikou, M. Krco, Z. J. Liu, C. C. Miao, J. Niu, Z. C. Pan, L. Qian, M. Y. Xue, X. Y. Xie, S. P. You, X. H. Yu, M. Yuan, Y. L. Yue, Y. Zhu
We report the follow-up of 10 pulsars discovered by the Five-hundred-meter Aperture Spherical radio-Telescope (FAST) during its commissioning. The pulsars were discovered at a frequency of 500-MHz using the ultra-wide-band (UWB) receiver in drift-scan mode, as part of the Commensal Radio Astronomy FAST Survey (CRAFTS). We carried out the timing campaign with the 100-m Effelsberg radio-telescope at L-band around 1.36 GHz. Along with 11 FAST pulsars previously reported, FAST seems to be uncovering a population of older pulsars, bordering and/or even across the pulsar death-lines. We report here two sources with notable characteristics. PSR J1951$+$4724 is a young and energetic pulsar with nearly 100% of linearly polarized flux density and visible up to an observing frequency of 8 GHz. PSR J2338+4818, a mildly recycled pulsar in a 95.2-d orbit with a Carbon-Oxygen white dwarf (WD) companion of $\gtrsim 1\rm{M}_{\odot}$, based on estimates from the mass function. This system is the widest WD binary with the most massive companion known to-date. Conspicuous discrepancy was found between estimations based on NE2001 and YMW16 electron density models, which can be attributed to under-representation of pulsars in the sky region between Galactic longitudes $70^o<l<100^o$. This work represents one of the early CRAFTS results, which start to show potential to substantially enrich the pulsar sample and refine the Galactic electron density model.
We have been conducting the GMRT High Resolution Southern Sky (GHRSS) survey for the last four years and have discovered 18 pulsars to date. The GHRSS survey is an off-Galactic-plane survey at 322 MHz in a region of the sky (declination range -40 degrees to -54 degrees) complementary to other ongoing low-frequency surveys. In this paper we report the discovery of three pulsars, PSRs J1239-48, J1516-43 and J1726-52. We also present timing solutions for three pulsars previously discovered with the GHRSS survey: PSR J2144-5237, a millisecond pulsar with a period P=5 ms in a 10 day orbit around a …
The SUrvey for Pulsars and Extragalactic Radio Bursts ran from 2014 April to 2019 August, covering a large fraction of the southern hemisphere at mid- to high-galactic latitudes, and consisting of 9-minute pointings taken with the 20-cm multibeam receiver on the Parkes Radio Telescope. Data up to 2017 September 21 have been searched using standard Fourier techniques, single-pulse searches, and Fast Folding Algorithm searches. We present 19 new discoveries, bringing the total to 27 discoveries in the programme, and we report the results of follow-up timing observations at Parkes for 26 of these…
The LOFAR Tied-Array All-Sky Survey (LOTAAS) is the most sensitive untargeted radio pulsar survey performed at low radio frequencies (119--151\,MHz) to date and has discovered 76 new radio pulsars, among which the 23.5-s pulsar J0250+5854, up until recently the slowest-spinning radio pulsar known. Here, we report on the timing solutions of 35 pulsars discovered by LOTAAS, which include a nulling pulsar and a mildly recycled pulsar, and thereby complete the full timing analysis of the LOTAAS pulsar discoveries. We give an overview of the findings from the full LOTAAS sample of 76 pulsars, discu…
Imaging without visibilities: FAST-Effelsberg scintillometry of PSR B1508+55
Max-Planck-Institut für Radioastronomie（马克斯·普朗克射电天文研究所）；South-Western Institute for Astronomy Research (SWIFAR), Yunnan University（西南天文学研究所（SWIFAR），云南大学）；McGill University（麦吉尔大学）
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…
New Discoveries from the Arecibo 327 MHz Drift Pulsar Survey Radio Transient Search
我们提出了一个新的算法，用于识别分散的天体物理脉冲的martterrank。这样的脉冲通常从银河系恒星和旋转射电瞬变（RRAT）中检测到，它们是具有零星射电发射的中子星。最近，被称为快速射电暴（FRB）的孤立的、高度分散的脉冲已被确定为河外激变射电源的潜在特征，与射电星和RRAT不同。Arecterrank帮助我们在Arecibo 327 MHz漂移脉冲星巡天（AO327）的数据中发现了14颗Arecibo和8颗RRAT。新的RRAT具有范围为$23.5 - 86.6$ pc cm $^{-3}$的DM和范围为$0.172 - 3.901$ s的周期。新的调制器具有范围$23.6 - 133.3$ pc cm $^{-3}$中的DM和范围$1.249 - 5.012$ s中的周期，并且包括两个零器和一个模式切换对象。我们估计的全天空FRB率$10^5$天$^{-1}$的爆发宽度为10毫秒和流量密度$\gtrsim 83$毫焦耳的上限。所有新发现的DM都与银河系起源一致。在比较新的RRAT的统计数据与来自RRAT的来源时，我们发现这两组数据都来自同一时期的分布。与此相反，我们发现，新的恒星的周期分布是不同的周期分布的规范恒星的ATNF目录或AO327数据中发现的恒星的周期搜索。这表明集群排名是周期性搜索的有力补充，并发现了迄今为止在调查结果中代表性不足的脉冲星种群子集，因此在银河系脉…
We report on a search for pulsars at the positions of eight low-mass white dwarfs and one higher-mass white dwarf with the 100-m Effelsberg Radio Telescope. These systems have orbital parameters suggesting that their unseen companions are either massive white dwarfs or neutron stars. Our observations were performed at 1.36 GHz, reaching sensitivities of 0.1-0.2 mJy. We searched our data accounting for the possible acceleration and jerk of the pulsar signals due to orbital motion, but found no significant pulsar signals. Considering our result jointly with 20 non-detections of similar systems w…
We present the results of a timing analysis undertaken with the goal of obtaining an improved mass measurement of the recycled pulsar J2045+3633. Using regular high-cadence observations with the Effelsberg, Nançay, and Lovell radio telescopes, together with targeted campaigns with the Arecibo Telescope and Effelsberg, we have assembled a 6-yr timing data set for this pulsar. We measure highly significant values for the proper motion and the related rate of change of orbital semi-major axis ($\dot{x}$), and have obtained high precision values of the rate of advance of periastron time ($\dotω$),…
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…
We are using the LOw-Frequency ARray (LOFAR) to perform the LOFAR Tied-Array All-Sky (LOTAAS) survey for pulsars and fast transients. Here we present the astrometric and rotational parameters of 20 pulsars discovered as part of LOTAAS. These pulsars have regularly been observed with LOFAR at 149 MHz and the Lovell telescope at 1532 MHz, supplemented by some observations with the Lovell telescope at 334 MHz and the Nancay Radio Telescope at 1484 MHz. Timing models are calculated for the 20 pulsars, some of which are among the slowest-spinning pulsars known. PSR J1236-0159 rotates with a period …
Flux-density spectral analysis for several pulsars and two newly-identified gigahertz-peaked spectra
在本文中，我们提出的结果通量密度测量的21个恒星在一个很宽的频率范围内，使用巨型米波射电望远镜（GMRT）和Effelsberg望远镜。我们的样本是一组大多是新发现的恒星星，这些恒星星是从千兆赫兹峰值光谱（GPS）恒星星的候选者中挑选出来的。利用我们的观测结果以及以前公布的数据，我们确定了两个新的GPS卫星。PSR J 1740 +1000是第一颗DM值很低的脉冲星，其色散量为24 pc cm $^{-3}$，我们还选择了几个光谱变化频率很高的候选天体，这些天体需要进一步的研究，我们还重新讨论了我们的源选择标准，以便将来寻找GPS脉冲星。
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 lin…
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）
We present an overview of the LOFAR Tied-Array All-Sky Survey (LOTAAS) for radio pulsars and fast transients. The survey uses the high-band antennas of the LOFAR Superterp, the dense inner part of the LOFAR core, to survey the northern sky (dec > 0 deg) at a central observing frequency of 135 MHz. A total of 219 tied-array beams (coherent summation of station signals, covering 12 square degrees), as well as three incoherent beams (covering 67 square degrees) are formed in each survey pointing. For each ofthe 222 beams, total intensity is recorded at 491.52 us time resolution. Each observation …
Survey of compact sources for pulsars and exotic objects -- I. Overview and initial discoveries
National Centre for Radio Astrophysics (NCRA - TIFR)（国家射电天体物理中心（NCRA-TIFR））；ASTRON, the Netherlands Institute for Radio Astronomy（荷兰射电天文研究所（ASTRON））；International Centre for Radio Astronomy Research, Curtin University（科廷大学国际射电天文研究中心）；Inter-University Centre for Astronomy and Astrophysics（大学间天文学与天体物理学中心）；Department of Astrophysics/IMAPP, Radboud University（拉德堡德大学天体物理学系/IMAPP）
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…
Discovery of pulsars is one of the main goals for large radio telescopes. The Five-hundred-meter Aperture Spherical radio Telescope (FAST), that incorporates an L-band 19-beam receiver with a system temperature of about 20~K, is the most sensitive radio telescope utilized for discovering pulsars. We designed the {\it snapshot} observation mode for a FAST key science project, the Galactic Plane Pulsar Snapshot (GPPS) survey, in which every four nearby pointings can observe {\it a cover} of a sky patch of 0.1575 square degrees through beam-switching of the L-band 19-beam receiver. The integratio…
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 latest six pulsars discovered through our standard pipeline in the intermediate-latitude region (|b| < 15 deg) of the Parkes High Time Resolution Universe Survey (HTRU). We also present timing solutions for the new discoveries and for 19 further pulsars for which only discovery parameters were previously published. Highlights of the presented sample include the isolated millisecond pulsar J1826-2415, the long-period binary pulsar J1837-0822 in a mildly eccentric 98-day orbit with a > 0.27 M_sun companion, and the nulling pulsar J1638-4233, detected only 10% of the time. Other …
We present the discovery of 24 pulsars in 15 Globular Clusters (GCs) using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). These include the first pulsar discoveries in M2, M10, and M14. Most of the new systems are either confirmed or likely members of binary systems. M53C, NGC6517H and I are the only three pulsars confirmed to be isolated. M14A is a black widow pulsar with an orbital period of 5.5 hours and a minimum companion mass of 0.016 \Ms. M14E is an eclipsing binary pulsar with an orbital period of 20.3 hours. With the other 8 discoveries that have been reported elsew…
The repeating FRB source, FRB 20201124A, was found to be highly active in March and April 2021. We observed the source with the Effelsberg 100-m radio telescope at 1.36 GHz on 9 April 2021 and detected 20 bursts. A downward drift in frequency over time is clearly seen from the majority of bursts in our sample. A structure-maximizing dispersion measure (DM) search on the multi-component bursts in our sample yields a DM of 411.6$\pm$0.6 pc/cm$^3$. We find that the rotation measure (RM) of the bursts varies around their mean value of -605 rad/m$^2$ with a standard deviation of 11.1 rad/m$^2$. Thi…
Timing and statistical analysis of single-pulse search pulsar discoveries from the PALFA survey
West Virginia University（西弗吉尼亚大学）；Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut)（马克斯·普朗克引力物理学研究所（爱因斯坦研究所））；University of Wisconsin - Milwaukee（威斯康星大学密尔沃基分校）；Cornell Center for Astrophysics and Planetary Science（康奈尔天体物理学与行星科学中心）；South African Radio Astronomy Observatory（南非射电天文观测站）；Franklin and Marshall College（富兰克林和马歇尔学院）
Gamma-ray Orbital Modulation in Spider Pulsars: Three Discoveries and a Universal Modulated Fraction
Norwegian University of Science and Technology（挪威科技大学）；Universitat Politècnica de Catalunya（加泰罗尼亚理工大学）；Shanghai Jiao Tong University（上海交通大学）；INAF Osservatorio Astrofisico di Arcetri（意大利国家天体物理研究所阿切尔蒂天文台）
We report the discovery of three new pulsars in the Globular Cluster (GC) NGC6517, namely NGC 6517 E, F, and G, made with the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The spin periods of NGC 6517 E, F, and G are 7.60~ms, 24.89~ms, and 51.59~ms, respectively. Their dispersion measures are 183.29, 183.713, and 185.3~pc~cm$^{-3}$, respectively, all slightly larger than those of the previously known pulsars in this cluster. The spin period derivatives are at the level of 1$\times$10$^{-18}$~s~s$^{-1}$, which suggests these are recycled pulsars. In addition to the discovery of …
We present new discoveries and results from long-term timing of 72 pulsars discovered in the Arecibo PALFA survey, including precise determination of astrometric and spin parameters, and flux density and scatter broadening measurements at 1.4 GHz. Notable discoveries include two young pulsars (characteristic ages $\sim$30 kyr) with no apparent supernova remnant associations, three mode changing, 12 nulling and two intermittent pulsars. We detected eight glitches in five pulsars. Among them is PSR J1939+2609, an apparently old pulsar (characteristic age $\sim$1 Gy), and PSR J1954+2529, which li…
New VLA detections of the variable radio continuum source VLA J181335.1$-$174957, associated with the energetic X-ray pulsar PSR~J1813$-$1749 and the TeV source HESS J1813-178, are presented. The radio source has a right circular polarization of $\sim50\%$, and a negative spectral index of $-1.3\pm0.1$, which show that it is non-thermal. The radio pulses of the pulsar are not detected from additional Effelsberg observations at 1.4~GHz made within one week of a VLA detection. This result would appear to support the idea that the continuum radio emission detected with the VLA does not trace the …
The Large European Array for Pulsars (LEAP) is a European Pulsar Timing Array project that combines the Lovell, Effelsberg, Nançay, Sardinia, and Westerbork radio telescopes into a single tied-array, and makes monthly observations of a set of millisecond pulsars (MSPs). The overview of our experiment is presented in Bassa et al. (2016). Baseband data are recorded at a central frequency of 1396 MHz and a bandwidth of 128 MHz at each telescope, and are correlated offline on a cluster at Jodrell Bank Observatory using a purpose-built correlator, detailed in Smits et al. (2017). LEAP offers a subs…
We report the discovery of four Fast Radio Bursts (FRBs) in the ongoing SUrvey for Pulsars and Extragalactic Radio Bursts (SUPERB) at the Parkes Radio Telescope: FRBs 150610, 151206, 151230 and 160102. Our real-time discoveries have enabled us to conduct extensive, rapid multi-messenger follow-up at 12 major facilities sensitive to radio, optical, X-ray, gamma-ray photons and neutrinos on time scales ranging from an hour to a few months post-burst. No counterparts to the FRBs were found and we provide upper limits on afterglow luminosities. None of the FRBs were seen to repeat. Formal fits to …
A survey for radio pulsars and transients in the 10 pc region around Sgr A*
Max-Planck-Institut für Radioastronomie（马克斯·普朗克射电天文研究所）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；INAF – Osservatorio Astronomico di Cagliari（意大利国家天体物理研究院卡利亚里天文台）；Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, The University of Manchester（曼彻斯特大学物理学与天文学系乔德雷尔银行天体物理学中心）；Shanghai Astronomical Observatory, Chinese Academy of Sciences（中国科学院上海天文台）；State Key Laboratory of Radio Astronomy and Technology（射电天文与技术国家重点实验室）
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 present timing solutions and analyses of 11 pulsars discovered by the Five-hundred-meter Aperture Spherical radio Telescope (FAST). These pulsars were discovered using an ultra-wide bandwidth receiver in drift-scan observations made during the commissioning phase of FAST, and were then confirmed and timed using the 64-m Parkes Radio Telescope. Each pulsar has been observed over a span of at least one year. Highlighted discoveries include PSR J0344-0901, which displays mode-changing behaviour and may belong to the class of so-called `swooshing' pulsars (alongside PSRs B0919+06 and B1859+07);…
Milagro and HAWC have detected extended TeV gamma-ray emission around nearby pulsar wind nebulae (PWNe). Building on these discoveries, Linden et al. [1] identified a new source class -- TeV halos -- powered by the interactions of high-energy electrons and positrons that have escaped from the PWN, but which remain trapped in a larger region where diffusion is inhibited compared to the interstellar medium. Many theoretical properties of TeV halos remain mysterious, but empirical arguments suggest that they are ubiquitous. The key to progress is finding more halos. We outline prospects for new d…
