PSR J1227$-$6208 and its massive white dwarf companion: pulsar emission analysis, timing update and mass measurements
Miquel Colom i Bernadich, Vivek Venkatraman Krishnan, David J. Champion, Paulo C. C. Freire, Michael Kramer, Thomas M. Tauris, Matthew Bailes, Alessandro Ridolfi, Maciej Serylak
备注：
Paper accepted for publication at Astronomy & Astrophysics. Main text: 17 pages, 8 figures. Appendices: 3 pages, 5 figures
PSR J1227$-$6208 is a 34.53-ms recycled pulsar with a massive companion. This system has long been suspected to belong to the emerging class of massive recycled pulsar-ONeMg white dwarf systems such as PSR J2222$-$0137, PSR J1528$-$3146 and J1439$-$5501. Here we present an updated emission and timing analysis with more than 11 years of combined Parkes and MeerKAT data, including 19 hours of high-frequency data from the newly installed MeerKAT S-band receivers. We measure a scattering timescale of 1.22 ms at 1 GHz with a flat scattering index 3.33<$β$<3.62, and a mean flux density of 0.53-0.62 mJy at 1 GHz with a steep spectral index 2.06<$α$<2.35. Around 15% of the emission is linearly and circularly polarised, but the polarisation angle does not follow the rotating vector model. Thanks to the sensitivity of MeerKAT, we successfully measure a rate of periastron advance of 0.0171(11) deg/yr, and a Shapiro delay with an orthometric amplitude of 3.6$\pm$0.5 $μ$s and an orthometric shape of 0.85$\pm$0.05. The main source of uncertainty in our timing analysis is chromatic correlated dispersion measure noise, which we model as a power law in the Fourier space thanks to the large frequency coverage provided by the Parkes UWL receiver. Assuming general relativity and accounting for the measurements across all the implemented timing noise models, the total mass, companion mass, pulsar mass and inclination angle are constrained at 2.3<Mt/$M_\odot$<3.2, 1.21<Mc/$M_\odot$<1.47, 1.16<Mp/$M_\odot$<1.69 and 77.5<i/deg<80.3. We also constrain the longitude of ascending node to either 266$\pm$78 deg or 86$\pm$78 deg. We argue against a neutron star nature of the companion based on the very low orbital eccentric of the system (e=1.15e-3), and instead classify the companion of PSR J1227-6208 as a rare, massive ONeMg white dwarf close to the Chandrasekhar limit.
On the variable timing behavior of PSR B0540-69: an almost excellent example to study pulsar braking mechanism
PSR B 0540 -69在其持续状态下具有制动指数测量值：n=2.129 \pm 0.012。最近，据报道，它的自旋下降状态发生了变化：自旋下降速率突然增加了36%。结合持续状态制动指数测量和不同的自旋下降状态，PSR B 0540 -69在约束脉冲星自旋下降模型方面比间歇性脉冲星更强大。脉冲星风模型被用来解释PSR B 0540 -69的变时行为。PSR B 0540 -69的持续状态制动指数是磁偶极子辐射和粒子风的综合效应。粒子密度实时反映了磁层的活动，并可能是导致自旋下降行为变化的原因。对应于PSR B 0540 -69的自旋下降速率增加36%，在真空间隙模型中颗粒密度的相对增加为88%。模型计算出新状态下的制动指数为n=1.79。PSR B 0540 -69在新的自旋下降状态下的未来制动指数观测将非常有力地区分不同的脉冲星自旋下降模型和不同的粒子加速模型。PSR J1846-0258的可变定时行为在脉冲星风模型中也是可以理解的。
We present timing solutions of PSR B0950+08, using 14 years of observations at Nanshan 26-m Radio Telescope of Xinjiang Astronomical Observatory. The braking index of PSR B0950+08 varies from --367 392 to 168 883, which shows an oscillation with large amplitude ($\sim 10^5$) and uncertainty. Considering the variation of braking indices and the most probable kinematic age of PSR B0950+08, a model withe long-term magnetic field decay modulated by short-term oscillations is proposed to explain the timing data. With this magnetic field decay model, we discuss the spin and thermal evolution of PSR …
Face changing companion of the redback millisecond pulsar PSR J1048+2339
我们提出的红背毫秒脉冲星PSR J1048+2339，这是一个4.66毫秒的射电脉冲星在一个紧凑的二进制与轨道周期为6小时的光学观测。我们用鹿林1米望远镜获得了PSR J1048+2339的高质量光变曲线。该系统显示出两个不同的六小时轨道调制，其中椭球调制在不到14天的时间内变成正弦曲线。除了这种变化，伴星的亮度增加了一个星等，这表明后一种调制是由伴星的脉冲星风加热引起的，并且加热在系统中占主导地位。虽然这些变化并不意外，但这样的时间表是类似系统中最短的。我们进行建模分析，以提取系统的属性。我们得到该系统的脉冲星质量为2.1 M $_{\odot }$，伴星质量为0.4 M $_{\odot }$。辐射功率增加了6倍，在此期间，脉冲星风加热占主导地位。我们还报告了两个档案钱德拉X射线观测，并讨论了几种可能性，可能会导致不同的加热的同伴。
PSR J1311-3430: A Heavyweight Neutron Star with a Flyweight Helium Companion
我们获得了新发现的Pb= 94 min γ射线黑寡妇脉冲星PSR J1311-3430的初步光谱观测和补充测光结果。凯克光谱显示出一个以氦为主，几乎不含氢的光球层和一个609.5+/-7.5km/s的大径向速度振幅。同时七色GROND测光进一步探测了这颗伴星的加热，并显示了存在的红外线过剩。我们已经模拟了静态光变曲线，限制了轨道倾角和质量。简单的加热光变曲线拟合得到M_NS=2.7Msun，但显示出系统的光变曲线差异。添加额外的组件允许拟合更大的质量范围，但所有可行的解决方案都具有M_NS>2.1Msun。如果得到证实，那么这样大的M_NS将在很大程度上限制物质在超核密度下的物态方程。
We performed deep observations to search for radio pulsations in the directions of 375 unassociated Fermi Large Area Telescope (LAT) gamma-ray sources using the Giant Metrewave Radio Telescope (GMRT) at 322 and 607 MHz. In this paper we report the discovery of three millisecond pulsars (MSPs), PSR J0248+4230, PSR J1207$-$5050 and PSR J1536$-$4948. We conducted follow up timing observations for around 5 years with the GMRT and derived phase coherent timing models for these MSPs. PSR J0248$+$4230 and J1207$-$5050 are isolated MSPs having periodicities of 2.60 ms and 4.84 ms. PSR J1536-4948 is a …
The double pulsar (PSR J0737-3039A/B) provides some of the most stringent tests of general relativity (GR) and its alternatives. The success of this system in tests of GR is largely due to the high-precision, long-term timing of its recycled-pulsar member, pulsar A. On the other hand, pulsar B is a young pulsar that exhibits significant short-term and long-term timing variations due to the electromagnetic-wind interaction with its companion and geodetic precession. Improving pulsar B's timing precision is a key step towards improving the precision in a number of GR tests with PSR J0737-3039A/B…
Keck-telescope spectrophotometry of the companion of PSR J1810+1744 shows a flat, but asymmetric light-curve maximum and a deep, narrow minimum. The maximum indicates strong gravity darkening near the L_1 point, along with a heated pole and surface winds. The minimum indicates a low underlying temperature and substantial limb darkening. The gravity darkening is a consequence of extreme pulsar heating and the near-filling of the Roche lobe. Light-curve modeling gives a binary inclination i=65.7+/-0.4deg. With the Keck-measured radial-velocity amplitude K_c=462.3+/-2.2km/s, this gives an accurat…
In a multi-orbit (100 ks) $\mathrm{\it XMM-Newton}$ exposure of the original black widow pulsar, PSR J1959+2048, we measure the strong orbital modulation caused by intrabinary shock (IBS) emission. The IBS light curve peak appears asymmetric, which we attribute to sweep-back effects in the companion wind. We also see evidence for an X-ray eclipse by the companion and its wind. Together with the IBS fit, this supports an edge-on $i\sim 90^\circ$ view of the system and a modest $\sim 1.8M_\odot$ mass for the recycled pulsar. Our IBS fit parameters imply a wind flux that, if persistent, would eva…
We present radio observation of a millisecond pulsar PSR J0621+1002 using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The pulsar shows periodic pulse intensity modulations for both the first and the third pulse components. The fluctuation spectrum of the first pulse component has one peak of 3.0$\pm$0.1 pulse periods, while that of the third pulse component has two diffused peaks of 3.0$\pm$0.1 and 200$\pm$1 pulse periods. The single pulse timing analysis is carried out for this pulsar and the single pulses can be divided into two classes based on the post-fit timing resi…
We report on radio timing observations of the black widow binary pulsar J0610$-$2100 and optical observations of its binary companion. The radio timing observations extend the timing baseline to 16yr and reveal a marginal detection of the orbital period derivative, but they show no significant evidence of orbital variations such as those seen in other black widow pulsars. Furthermore, no eclipses are seen in the observations at observing frequencies ranging from 310 to 2700MHz. The optical VRI light curves were modulated with the orbital period, reaching maximum brightness of $V=26.8$, $R=25.4…
We analyze photometry and spectra of the "redback" millisecond pulsar binary J2339$-$0533. These observations include new measurements from Keck and GROND, as well as archival measurements from the OISTER, WIYN, SOAR, and HET telescopes. The parameters derived from GROND, our primary photometric data, describe well the rest of the datasets, raising our confidence in our fitted binary properties. Our fit requires hot-spots (likely magnetic poles) on the surface of the companion star, and we see evidence that these spots move over the 8 yr span of our photometry. The derived binary inclination $…
We present analysis of the timing noise in PSR J1733-3716, which combines data from Parkes 64-m radio telescope and nearly 15 years of timing data obtained from the Nanshan 25-m radio telescope. The variations in the spin frequency and frequency derivative are determined. The fluctuation in the spin frequency is obvious with an amplitude of 1.94(7)*10 -9 Hz. Variations of the integrated profile at 1369 MHz are detected with the changes occur in the relative peak intensity from the right profile component. From analysis of the single pulse data at 1382 MHz, we detect weak emission states that a…
New and updated timing models for seven young energetic X-ray pulsars, including the Big Glitcher PSR J0537-6910
Haverford College（哈弗福德学院）；Space Research Organisation Netherlands（荷兰空间研究组织）；Universidad de Santiago de Chile (USACH)（智利圣地亚哥大学）；Center for Interdisciplinary Research in Astrophysics and Space Sciences (CIRAS), Universidad de Santiago de Chile（智利圣地亚哥大学天体物理与空间科学跨学科研究中心）；IRAP, CNRS（法国国家科学研究中心天体物理学研究所）；Université de Toulouse, CNES, UPS-OMP（图卢兹大学、法国国家空间研究中心、 ups-omp）；X-Ray Astrophysics Laboratory, NASA Goddard Space Flight Center（NASA戈达德太空飞行中心X射线天体物理实验室）；Theoretical Division, Los Alamos National Laboratory（洛斯阿拉莫斯国家实验室理论部）；Columbia Astrophysics Laboratory, Columbia University（哥伦比亚大学天体物理实验室）
The 559 Hz black-widow pulsar PSR J1555-2908, originally discovered in radio, is also a bright gamma-ray pulsar. Timing its pulsations using 12 yr of Fermi-LAT gamma-ray data reveals long-term variations in its spin frequency that are much larger than is observed from other millisecond pulsars. While this variability in the pulsar rotation rate could be intrinsic "timing noise", here we consider an alternative explanation: the variations arise from the presence of a very-low-mass third object in a wide multi-year orbit around the neutron star and its low-mass companion. With current data, this…
Generalized Non-linear Bayesian Pulsar Timing with Enterprise
West Virginia University（西弗吉尼亚大学）；Oregon State University（俄勒冈州立大学）；Cornell University（康奈尔大学）；University of Colorado, Boulder（科罗拉多大学博尔德分校）；Vanderbilt University（范德堡大学）；Jet Propulsion Laboratory, California Institute of Technology（加州理工学院喷气推进实验室）
Improving timing sensitivity in the microhertz frequency regime: limits from PSR J1713$+$0747 on gravitational waves produced by super-massive black-hole binaries
We report the discovery of PSR J1555-2908, a 1.79 ms radio and gamma-ray pulsar in a 5.6 hr binary system with a minimum companion mass of 0.052 $M_\odot$. This fast and energetic ($\dot E = 3 \times 10^{35}$ erg/s) millisecond pulsar was first detected as a gamma-ray point source in Fermi LAT sky survey observations. Guided by a steep spectrum radio point source in the Fermi error region, we performed a search at 820 MHz with the Green Bank Telescope that first discovered the pulsations. The initial radio pulse timing observations provided enough information to seed a search for gamma-ray pul…
Measuring a pulsar's rotational evolution is crucial to understanding the nature of the pulsar. Here we provide updated timing models for the rotational evolution of six pulsars, five of which are rotation phase-connected using primarily NICER X-ray data. For the newly-discovered fast energetic young pulsar, PSR J0058-7218, we increase the baseline of its timing model from 1.4 days to 8 months and not only measure more precisely its spin-down rate nudot = (-6.2324+/-0.0001)x10^-11 Hz s^-1 but also for the first time the second time derivative of spin rate nuddot = (4.2+/-0.2)x10^-21 Hz s^-2. F…
We present a timing analysis of the transitional millisecond pulsar PSR J1023+0038 using observations taken between January 2018 and January 2020 with the high time resolution photon counter Aqueye+ mounted at the 1.82 m Copernicus telescope in Asiago. We report the first measurement of the timing solution and the frequency derivative of PSR J1023+0038 based entirely on optical data. The spin-down rate of the pulsar is $(-2.53 \pm 0.04) \times 10^{-15}$ Hz$^2$, which is $\sim$20% slower than that measured from the X-ray observations taken in 2013-2016 and $\sim$5% faster than that measured in …
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…
In this paper we introduce a new Python package, the Pulsar Signal Simulator, or PsrSigSim, which is designed to simulate a pulsar signal from emission at the pulsar, through the interstellar medium, to observation by a radio telescope, and digitization in a standard data format. We use the PsrSigSim to simulate observations of three millisecond pulsars, PSRs J1744--1134, B1855+09, and B1953+29, to explore the covariances between frequency-dependent parameters, such as variations in the dispersion measure (DM), pulse profile evolution with frequency, and pulse scatter broadening. We show that …
Constraints on Einstein-aether gravity from the precision timing of PSR J1738+0333
SISSA（国际高等研究院）；INFN Sezione di Trieste（意大利国家核物理研究所的里雅斯特分部）；IFPU - Institute for Fundamental Physics of the Universe（宇宙基础物理研究所）；INAF - Osservatorio Astronomico di Cagliari（意大利国家天体物理研究所卡利亚里天文台）；School of Physics, Indian Institute of Science Education and Research Thiruvananthapuram（印度科学教育与研究学院特里凡得琅物理学院）；Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut), Leibniz Universität Hannover（马克斯·普朗克引力物理研究所（爱因斯坦研究所），汉诺威莱布尼茨大学）；Fakulät für Physik, Universität Bielefeld（比勒费尔德大学物理学院）；Max-Planck-Institut für Radioastronomie（马克斯·普朗克射电天文研究所）
