- 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.
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- ID:
- ivo://CDS.VizieR/J/ApJ/901/L7
- Title:
- NIR obs. of the Gal. magnetar SGR 1935+215 with PGIR
- Short Name:
- J/ApJ/901/L7
- Date:
- 23 Feb 2022 09:05:54
- Publisher:
- CDS
- Description:
- The Galactic magnetar SGR 1935+2154 has been reported to produce the first example of a bright millisecond-duration radio burst (FRB200428) similar to the cosmological population of fast radio bursts (FRBs). The detection of a coincident bright X-ray burst represents the first observed multiwavelength counterpart of an FRB. However, the search for similar emission at optical wavelengths has been hampered by the high inferred extinction on the line of sight. Here, we present results from the first search for second-timescale emission from the source at near-infrared (NIR) wavelengths using the Palomar Gattini-IR observing system in the J band, enabled by a novel detector readout mode that allows short exposure times of ~0.84s with 99.9% observing efficiency. With a total observing time of ~12hr (~47728 images) during its 2020 outburst, we place median 3{sigma} limits on the second-timescale NIR fluence of <~18Jy.ms (13.1 AB mag). The corresponding extinction-corrected limit is <~125Jy.ms for an estimated extinction of A_J_=2.0mag. Our observations were sensitive enough to easily detect an NIR counterpart of FRB 200428 if the NIR emission falls on the same power law as observed across its radio to X-ray spectrum. We report nondetection limits from epochs of four simultaneous X-ray bursts detected by the Insight-HXMT and NuSTAR telescopes during our observations. These limits provide the most stringent constraints to date on fluence of flares at ~10^14^Hz, and constrain the fluence ratio of the NIR emission to coincident X-ray bursts to R_NIR_<~0.025 (fluence index >~0.35).
- 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.
- ID:
- ivo://CDS.VizieR/J/ApJ/810/85
- Title:
- Observation of first Fermi-LAT sources at Parkes
- Short Name:
- J/ApJ/810/85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In a search with the Parkes radio telescope of 56 unidentified Fermi-Large Area Telescope (LAT) gamma-ray sources, we have detected 11 millisecond pulsars (MSPs), 10 of them discoveries, of which five were reported by Kerr et al (2012ApJ...748L...2K). We did not detect radio pulsations from six other pulsars now known in these sources. We describe the completed survey, which included multiple observations of many targets conducted to minimize the impact of interstellar scintillation, acceleration effects in binary systems, and eclipses. We consider that 23 of the 39 remaining sources may still be viable pulsar candidates. We present timing solutions and polarimetry for five of the MSPs and gamma-ray pulsations for PSR J1903-7051 (pulsations for five others were reported in the second Fermi-LAT catalog of gamma-ray pulsars). Two of the new MSPs are isolated and five are in >1 day circular orbits with 0.2-0.3 M_{sun}_ presumed white dwarf companions. PSR J0955-6150, in a 24 day orbit with a 0.2-0.3 M_{sun}_ companion but eccentricity of 0.11, belongs to a recently identified class of eccentric MSPs. PSR J1036-8317 is in an 8 hr binary with a>0.14 M_{sun}_ companion that is probably a white dwarf. PSR J1946-5403 is in a 3 hr orbit with a>0.02 M_{sun}_ companion with no evidence of radio eclipses.
- ID:
- ivo://CDS.VizieR/J/A+A/458/245
- Title:
- Obs. of 2 Unidentified Gamma-ray Sources
- Short Name:
- J/A+A/458/245
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The systematic X-ray and optical coverage of low-latitude unidentified gamma-ray sources, aiming at sources with high X-ray/optical flux ratio, seems one of the most promising ways to spot INS candidate counterparts. We have focussed on two middle-latitude, probably galactic, EGRET sources: 3EG J0616-3310 and 3EG J1249-8330. Here we report on X-ray observations of the two gamma-ray error boxes performed with XMM-Newton and on their optical follow-up carried on with the Wide Field Imager at the ESO/MPG 2.2m telescope. Less than half of the ~300 sources detected by the X-ray coverage have no optical counterparts. Among those, we have selected few interesting sources with f_X_/f_opt_>100, which we consider promising INS candidates.
- ID:
- ivo://CDS.VizieR/J/ApJ/769/108
- Title:
- Optical photometry of 4 millisecond pulsars
- Short Name:
- J/ApJ/769/108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the last few years, over 43 millisecond radio pulsars have been discovered by targeted searches of unidentified {gamma}-ray sources found by the Fermi Gamma-Ray Space Telescope. A large fraction of these millisecond pulsars are in compact binaries with low-mass companions. These systems often show eclipses of the pulsar signal and are commonly known as black widows and redbacks because the pulsar is gradually destroying its companion. In this paper, we report on the optical discovery of four strongly irradiated millisecond pulsar companions. All four sources show modulations of their color and luminosity at the known orbital periods from radio timing. Light curve modeling of our exploratory data shows that the equilibrium temperature reached on the companion's dayside with respect to their nightside is consistent with about 10%-30% of the available spin-down energy from the pulsar being reprocessed to increase the companion's dayside temperature. This value compares well with the range observed in other irradiated pulsar binaries and offers insights about the energetics of the pulsar wind and the production of {gamma}-ray emission. In addition, this provides a simple way of estimating the brightness of irradiated pulsar companions given the pulsar spin-down luminosity. Our analysis also suggests that two of the four new irradiated pulsar companions are only partially filling their Roche lobe. Some of these sources are relatively bright and represent good targets for spectroscopic follow-up.
- ID:
- ivo://CDS.VizieR/J/ApJ/866/83
- Title:
- Opt/NIR obs. of 1FGLJ1417.7-4407 neutron star bin.
- Short Name:
- J/ApJ/866/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Fermi {gamma}-ray source 1FGL J1417.7-4407 (J1417) is a compact X-ray binary with a neutron star primary and a red giant companion in a ~5.4 days orbit. This initial conclusion, based on optical and X-ray data, was confirmed when a 2.66ms radio pulsar was found at the same location (and with the same orbital properties) as the optical/X-ray source. However, these initial studies found conflicting evidence about the accretion state and other properties of the binary. We present new optical, radio, and X-ray observations of J1417 that allow us to better understand this unusual system. We show that one of the main pieces of evidence previously put forward for an accretion disk-the complex morphology of the persistent H{alpha} emission line-can be better explained by the presence of a strong, magnetically driven stellar wind from the secondary and its interaction with the pulsar wind. The radio spectral index derived from VLA/ATCA observations is broadly consistent with that expected from a millisecond pulsar, further disfavoring an accretion disk scenario. X-ray observations show evidence for a double-peaked orbital light curve, similar to that observed in some redback millisecond pulsar binaries and likely due to an intrabinary shock. Refined optical light-curve fitting gives a distance of 3.1+/-0.6kpc, confirmed by a Gaia DR2 parallax measurement. At this distance the X-ray luminosity of J1417 is (1.0_-0.3_^+0.4^)x10^33^erg/s, which is more luminous than all known redback systems in the rotational-powered pulsar state, perhaps due to the wind from the giant companion. The unusual phenomenology of this system and its differing evolutionary path from redback millisecond pulsar binaries points to a new eclipsing pulsar "spider" subclass that is a possible progenitor of normal field millisecond pulsar binaries.
- ID:
- ivo://CDS.VizieR/J/ApJ/872/42
- Title:
- Opt. spectroscopy of redback ms pulsar binaries
- Short Name:
- J/ApJ/872/42
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first optical spectroscopy of five confirmed (or strong candidate) redback millisecond pulsar binaries, obtaining complete radial velocity curves for each companion star. The properties of these millisecond pulsar binaries with low-mass, hydrogen-rich companions are discussed in the context of the 14 confirmed and 10 candidate field redbacks. We find that the neutron stars in redbacks have a median mass of 1.78+/-0.09M_{sun}_ with a dispersion of {sigma}=0.21+/-0.09. Neutron stars with masses in excess of 2M_{sun}_ are consistent with, but not firmly demanded by, current observations. Redback companions have median masses of 0.36+/-0.04M_{sun}_ with a scatter of {sigma}=0.15+/-0.04M_{sun}_, and a tail possibly extending up to 0.7-0.9M_{sun}_. Candidate redbacks tend to have higher companion masses than confirmed redbacks, suggesting a possible selection bias against the detection of radio pulsations in these more massive candidate systems. The distribution of companion masses between redbacks and the less massive black widows continues to be strongly bimodal, which is an important constraint on evolutionary models for these systems. Among redbacks, the median efficiency of converting the pulsar spin-down energy to {gamma}-ray luminosity is ~10%.
- ID:
- ivo://CDS.VizieR/J/MNRAS/328/17
- Title:
- Parkes Multi-Beam Pulsar Survey
- Short Name:
- J/MNRAS/328/17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Parkes multi-beam pulsar survey is a sensitive survey of a strip along the Galactic plane with |b|<5{deg} and l=260{deg} to l=50{deg}. It uses a 13-beam receiver on the 64-m Parkes radio telescope, receiving two polarizations per beam over a 288-MHz bandwidth centred on 1374MHz. The receiver and data acquisition systems are described in some detail. For pulsar periods in the range 0.1-2s and dispersion measures of less than 300cm^-3^pc, the nominal limiting flux density of the survey is about 0.2mJy. At shorter or longer periods or higher dispersions, the sensitivity is reduced. Timing observations are carried out for pulsars discovered in the survey for 12-18 months after confirmation to obtain accurate positions, spin parameters, dispersion measures, pulse shapes and mean flux densities. The survey is proving to be extremely successful, with more than 600 pulsars discovered so far. We expect that, when complete, this one survey will come close to finding as many pulsars as all previous pulsar surveys put together. The newly discovered pulsars tend to be young, distant and of high radio luminosity. They will form a valuable sample for studies of pulsar emission properties, the Galactic distribution and evolution of pulsars, and as probes of interstellar medium properties. This paper reports the timing and pulse shape parameters for the first 100 pulsars timed at Parkes, including three pulsars with periods of less than 100ms which are members of binary systems. These results are briefly compared with the parameters of the previously known population.
- ID:
- ivo://CDS.VizieR/J/MNRAS/342/1299
- Title:
- Parkes Multi-Beam Pulsar Survey. III.
- Short Name:
- J/MNRAS/342/1299
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Parkes Multibeam Pulsar Survey has unlocked vast areas of the Galactic plane, which were previously invisible to earlier low-frequency and less-sensitive surveys. The survey has discovered more than 600 new pulsars so far, including many that are young and exotic. In this paper we report the discovery of 200 pulsars for which we present positional and spin-down parameters, dispersion measures, flux densities and pulse profiles. A large number of these new pulsars are young and energetic, and we review possible associations of {gamma}-ray sources with the sample of about 1300 pulsars for which timing solutions are known. Based on a statistical analysis, we estimate that about 19+/-6 associations are genuine. The survey has also discovered 12 pulsars with spin properties similar to those of the Vela pulsar, nearly doubling the known population of such neutron stars. Studying the properties of all known 'Vela-like' pulsars, we find their radio luminosities to be similar to normal pulsars, implying that they are very inefficient radio sources. Finally, we review the use of the newly discovered pulsars as Galactic probes and discuss the implications of the new NE2001 Galactic electron density model for the determination of pulsar distances and luminosities.
