- ID:
- ivo://CDS.VizieR/J/MNRAS/458/3341
- Title:
- 42 millisecond pulsars high-precision timing
- Short Name:
- J/MNRAS/458/3341
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the high-precision timing of 42 radio millisecond pulsars (MSPs) observed by the European Pulsar Timing Array (EPTA). This EPTA Data Release 1.0 extends up to mid-2014 and baselines range from 7-18yr. It forms the basis for the stochastic gravitational-wave background, anisotropic background, and continuous-wave limits recently presented by the EPTA elsewhere. The Bayesian timing analysis performed with TEMPONEST yields the detection of several new parameters: seven parallaxes, nine proper motions and, in the case of six binary pulsars, an apparent change of the semimajor axis. We find the NE2001 Galactic electron density model to be a better match to our parallax distances (after correction from the Lutz-Kelker bias) than the M2 and M3 models by Schnitzeler. However, we measure an average uncertainty of 80 per cent (fractional) for NE2001, three times larger than what is typically assumed in the literature. We revisit the transverse velocity distribution for a set of 19 isolated and 57 binary MSPs and find no statistical difference between these two populations. We detect Shapiro delay in the timing residuals of PSRs J1600-3053 and J1918-0642, implying pulsar and companion masses mp=1.22^+0.5^_-0.35_M_{sun}_, mc=0.21^+0.06^_-0.04_M_{sun}_ and mp=1.25^+0.6^_-0.4_M_{sun}}, mc=0.23^+0.07^_-0.05_M_{sun}_, respectively. Finally, we use the measurement of the orbital period derivative to set a stringent constraint on the distance to PSRs J1012+5307 and J1909-3744, and set limits on the longitude of ascending node through the search of the annual-orbital parallax for PSRs J1600-3053 and J1909-3744.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/605/759
- Title:
- Multifrequency obs. of radio pulse broadening
- Short Name:
- J/ApJ/605/759
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have made observations of 98 low Galactic latitude pulsars to measure pulse broadening caused by multipath propagation through the interstellar medium. Data were collected with the 305m Arecibo telescope at four radio frequencies between 430 and 2380MHz. We used a CLEAN-based algorithm to deconvolve interstellar pulse broadening from the measured pulse shapes. We employed two distinct pulse-broadening functions (PBFs): PBF_1_ is appropriate for a thin screen of scattering material between the Earth and a pulsar, while PBF_2_ is appropriate for scattering material uniformly distributed along the line of sight from the Earth to a pulsar. We found that some observations were better fitted by PBF_1_ and some by PBF_2_. Pulse-broadening times ({tau}_d_) are derived from fits of PBFs to the data and are compared with the predictions of a smoothed model of the Galactic electron distribution. Several lines of sight show excess broadening, which we model as clumps of high-density scattering material.
- ID:
- ivo://CDS.VizieR/J/MNRAS/301/235
- Title:
- Multifrequency polarimetry of 300 pulsars
- Short Name:
- J/MNRAS/301/235
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Polarimetric observations of 300 pulsars have been conducted with the 76-m Lovell telescope at Jodrell Bank at radio frequencies centred around 230, 400, 600, 920, 1400 and 1600MHz. More than half of the pulsars have no previously published polarization profiles and this compilation represents about three times the sum of all previously published pulsar polarization data. A selection of integrated polarization profiles is provided. Tables of pulse widths and the degree of both linear and circular polarization are given for all pulsars, and these act as an index for all the data, which are available by anonymous ftp in numerical and graphical form.
- ID:
- ivo://CDS.VizieR/J/MNRAS/449/1570
- Title:
- Multifrequency pulsar scatter time sample
- Short Name:
- J/MNRAS/449/1570
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present our results of pulse broadening time estimates and the study of the frequency scaling of this quantity for 60 pulsars based on actual multifrequency scattering estimates. This research was based on our own measurements, performed on the observational data and the profiles from various pulsar profile data bases, as well as the scatter time measurements that were found in the literature. We were able to construct a data base of over 60 pulsars with true multifrequency {alpha} measurements, which allowed us to revise the previously proposed relations between the scatter time spectral slope and the dispersion measure (DM). We found that the deviations from theoretical predictions of the value of {alpha} appear for pulsars regardless of their DM, however, the DM-averaged value of the scaling index is almost constant except for pulsars with very high DMs. Based on the obtained slopes we were also able to estimate the amount of scattering at the standard frequency of 1GHz. We found that while the estimated standardized pulse broadening time increases with DM the relation seems to be much flatter than it was previously proposed, which suggests higher values of the scatter time for mid-DM pulsars, and lower values of expected pulse broadening for highly dispersed sources.
- ID:
- ivo://CDS.VizieR/J/ApJS/208/17
- Title:
- 2nd Fermi LAT cat. of gamma-ray pulsars (2PC)
- Short Name:
- J/ApJS/208/17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog summarizes 117 high-confidence >= 0.1 GeV gamma-ray pulsar detections using three years of data acquired by the Large Area Telescope (LAT) on the Fermi satellite. Half are neutron stars discovered using LAT data through periodicity searches in gamma-ray and radio data around LAT unassociated source positions. The 117 pulsars are evenly divided into three groups: millisecond pulsars, young radio-loud pulsars, and young radio-quiet pulsars. We characterize the pulse profiles and energy spectra and derive luminosities when distance information exists. Spectral analysis of the off-peak phase intervals indicates probable pulsar wind nebula emission for four pulsars, and off-peak magnetospheric emission for several young and millisecond pulsars. We compare the gamma-ray properties with those in the radio, optical, and X-ray bands. We provide flux limits for pulsars with no observed gamma-ray emission, highlighting a small number of gamma-faint, radio-loud pulsars. The large, varied gamma-ray pulsar sample constrains emission models. Fermi's selection biases complement those of radio surveys, enhancing comparisons with predicted population distributions.
- ID:
- ivo://CDS.VizieR/J/ApJ/578/405
- Title:
- Neutron stars in NGC 5139
- Short Name:
- J/ApJ/578/405
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Chandra/ACIS-I detectors observed NGC 5139 in imaging mode for two continuous periods (2000 January 24 02:15-09:46 and January 25 04:33-17:24 TT) for a total exposure of ~68.6ks. We combined the two observations and analyzed them as one. We searched for point sources using CELLDETECT, using only the 0.1-2.5keV energy range, excluding regions less than 16 pixels from the detector edges and keeping only sources with signal-to-noise ratio (S/N)>5.0. We find 40 X-ray point sources over the four ACIS-I chips and chip S2 of ACIS-S, which are numbered in order of decreasing S/N in Table 1.
- ID:
- ivo://CDS.VizieR/J/MNRAS/386/1881
- Title:
- New pulsar rotation measures
- Short Name:
- J/MNRAS/386/1881
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We measured a sample of 150 pulsar rotation measures (RMs) using the 20-cm receiver of the Parkes 64-m radio telescope. 46 of the pulsars in our sample have not had their RM values previously published, whereas 104 pulsar RMs have been revised. We used a novel quadratic fitting algorithm to obtain an accurate RM from the calibrated polarization profiles recorded across 256MHz of receiver bandwidth. The new data are used in conjunction with previously known dispersion measures and the NE2001 electron-density model to study models of the direction and magnitude of the Galactic magnetic field.
- ID:
- ivo://CDS.VizieR/J/MNRAS/359/1524
- Title:
- 10 new pulsars in Arecibo drift-scan survey
- Short Name:
- J/MNRAS/359/1524
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a 430-MHz survey for pulsars conducted during the upgrade to the 305-m Arecibo radio telescope. Our survey covered a total of 1147deg^2^ of sky using a drift-scan technique. We detected 33 pulsars, 10 of which were not known prior to the survey observations. The highlight of the new discoveries is PSR J0407+1607, which has a spin period of 25.7ms, a characteristic age of 1.5Gyr and is in a 1.8-yr orbit about a low-mass (>0.2M) companion. The long orbital period and small eccentricity (e=0.0009) make the binary system an important new addition to the ensemble of binary pulsars suitable to test for violations of the strong equivalence principle. We also report on our initially unsuccessful attempts to detect optically the companion to J0407+1607, which imply that its absolute visual magnitude is >12.1. If, as expected on evolutionary grounds, the companion is an He white dwarf, our non-detection implies a cooling age of least 1Gyr.
- ID:
- ivo://CDS.VizieR/J/ApJS/253/48
- Title:
- New rotation measures from the CGPS
- Short Name:
- J/ApJS/253/48
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Faraday rotation provides a valuable tracer of magnetic fields in the interstellar medium; catalogs of Faraday rotation measures provide key observations for studies of the Galactic magnetic field. We present a new catalog of rotation measures derived from the Canadian Galactic Plane Survey, covering a large region of the Galactic plane spanning 52{deg}<l<192{deg}, -3{deg}<b<5{deg}, along with northern and southern latitude extensions around l~105{deg}. We have derived rotation measures for 2234 sources (4 of which are known pulsars), 75% of which have no previous measurements, over an area of approximately 1300deg^2^. These new rotation measures increase the measurement density for this region of the Galactic plane by a factor of 2.
- ID:
- ivo://CDS.VizieR/J/A+A/644/A73
- Title:
- Nulling of 20 pulsars
- Short Name:
- J/A+A/644/A73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Most of pulsar nulling observations were conducted at frequencies lower than 1400MHz. We aim to understand the nulling behaviors of pulsars at relatively high frequency, and to check if nulling is caused by a global change of pulsar magnetosphere. 20 bright pulsars are observed at 2250MHz with unprecedented lengths of time by using Jiamusi 66m telescope. Nulling fractions of these pulsars are estimated, and the null and emission states of pulses are identified. Nulling degrees and scales of the emission-null pairs are calculated to describe the distributions of emission and null lengths. Three pulsars, PSRs J0248+6021, J0543+2329 and J1844+00, are found to null for the first time. The details of null-to-emission and emission-to-null transitions within pulse window are first observed for PSR J1509+5531, which is a small probability event. A complete cycle of long nulls for hours is observed for PSR J1709-1640. For most of these pulsars, the K-S tests of nulling degrees and nulling scales reject the hypothesis that null and emission are of random processes at high significance levels. Emission-null sequences of some pulsars exhibit quasi-periodic, low-frequency or featureless modulations, which might be related to different origins. During transitions between emission and null states, pulse intensities have diverse tendencies for variations. Significant correlations are found for nulling fraction, nulling cadence and nulling scales with the energy loss rate of the pulsars. Combined with the nulling fractions reported in literatures for 146 nulling pulsars, we found that statistically large nulling fractions are more tightly related to pulsar period than to characteristic age or energy loss rate.
