- ID:
- ivo://CDS.VizieR/J/A+A/545/L2
- Title:
- PSR J0537-6910 gamma-ray emission
- Short Name:
- J/A+A/545/L2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the significant detection of the first extragalactic pulsar wind nebula (PWN) detected in gamma rays, N157B, located in the large Magellanic Cloud (LMC). Pulsars with high spin-down luminosity are found to power energised nebulae that emit gamma rays up to energies of several tens of TeV. N157B is associated with PSRJ0537-6910, which is the pulsar with the highest known spin-down luminosity. The High Energy Stereoscopic System telescope array observed this nebula on a yearly basis from 2004 to 2009 with a dead-time corrected exposure of 46h. The gamma-ray spectrum between 600GeV and 12TeV is well-described by a pure power-law with a photon index of 2.8+/-0.2stat+/-0.3syst and a normalisation at 1TeV of (8.2+/-0.8stat+/-2.5syst)x10^-13^/cm^2^/s/TeV. A leptonic multi-wavelength model shows that an energy of about 4x10^49^erg is stored in electrons and positrons. The apparent efficiency, which is the ratio of the TeV gamma-ray luminosity to the pulsar's spin-down luminosity, 0.08%+/-0.01%, is comparable to those of PWNe found in the Milky Way. The detection of a PWN at such a large distance is possible due to the pulsar's favourable spin-down luminosity and a bright infrared photon-field serving as an inverse-Compton-scattering target for accelerated leptons. By applying a calorimetric technique to these observations, the pulsar's birth period is estimated to be shorter than 10ms.
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- ID:
- ivo://CDS.VizieR/J/A+A/552/A127
- Title:
- PSR J1048-5832 V and R images
- Short Name:
- J/A+A/552/A127
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- PSR J1048-5832 is a young radio-pulsar that has recently been detected in {gamma}-rays with Fermi, and also in X-rays with Chandra and XMM-Newton. It powers a compact pulsar wind nebula visible in X-rays and is in many ways similar to the Vela pulsar. We present deep optical observations made with the ESO Very Large Telescope to search for optical counterparts of the pulsar and its nebula and to explore their multi-wavelength emission properties. The data were obtained in the V and R bands and were compared with archival data in other spectral domains.
- ID:
- ivo://CDS.VizieR/J/A+A/631/A104
- Title:
- PSR J1023+0038 VLT, XM and Swift observations
- Short Name:
- J/A+A/631/A104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on a simultaneous near-infrared, optical, and X-ray campaign performed in 2017 with the XMM-Newton and Swift satellites and the HAWK-I instrument mounted on the Very Large Telescope (VLT) on the transitional millisecond pulsar PSR J1023+0038. Near-infrared observations were performed in fast-photometric mode (0.5s exposure time) in order to detect any fast variation of the flux and correlate this with the optical and X-ray light curves. The optical light curve shows the typical sinusoidal modulation at the system orbital period (4.75hr). No significant flaring or flickering is found in the optical, nor any signs of transitions between active and passive states. On the contrary, the near-infrared light curve displays a bimodal behaviour, showing strong flares in the first part of the curve, and an almost flat trend in the rest. The X-ray light curves instead show a few low-high mode transitions, but no flaring activity is detected. Interestingly, one of the low-high mode transitions occurs at the same time as the emission of an infrared flare. This can be interpreted in terms of the emission of an outflow or a jet: the infrared flare could be due to the evolving spectrum of the jet, which possesses a break frequency that moves from higher (near-infrared) to lower (radio) frequencies after the launching, which has to occur at the low-high mode transition. We also present the cross-correlation function between the optical and near-infrared curves. The near.infrared curve is bimodal, therefore we divided it into two parts (flaring and quiet). While the cross-correlation function of the quiet part is found to be flat, the function that refers to the flaring part shows a narrow peak at 10s, which indicates a delay of the near-infrared emission with respect to the optical. This lag can be interpreted as reprocessing of the optical emission at the light cylinder radius with a stream of matter spiraling around the system due to a phase of radio ejection. This strongly supports a different origin of the infrared flares that are observed for PSR J1023+0038 with respect to the optical and X-ray flaring activity that has been reported in other works on the same source.
- ID:
- ivo://CDS.VizieR/J/A+A/591/A101
- Title:
- PSR J1023+0038 & XSS J12270-4859 VRi polarimetry
- Short Name:
- J/A+A/591/A101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first optical polarimetric study of the two transitional pulsars PSR J1023+0038 and XSS J12270-4859. This work is focused on the search for intrinsically linearly polarised optical emission from the two systems. To this aim, we carried out multiband optical (BVRi) and near-infrared (JHK) photo-polarimetric observations of the two systems using the ESO New Technology Telescope (NTT) at La Silla (Chile), equipped with the EFOSC2 and the SOFI instruments.
105. Pulsar glitches
- ID:
- ivo://CDS.VizieR/J/MNRAS/269/849
- Title:
- Pulsar glitches
- Short Name:
- J/MNRAS/269/849
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the expectancy of large glitches ({Delta}{Omega}/{Omega}>10^-7) from a sample of 430 pulsars other than the Vela pulsar. The pulsars in this sample have exhibited 19 large glitches. We assume that all pulsars experience such glitches, with rates that depend on the pulsar's rotation rate omega and spin-down rate omega, and on the glitch model. We use the core-quake model, and two variants of the superfluid vortex unpinning model, and choose model parameters such that the observed number of glitches is matched by the theoretically expected number. Among the models investigated, one of the superfluid vortex unpinning models gives good agreement with the observed distribution of glitches and with the parameter values deduced for the Vela pulsar glitches.
- ID:
- ivo://CDS.VizieR/J/ApJS/234/11
- Title:
- Pulsar rotation measures
- Short Name:
- J/ApJS/234/11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the measurements of Faraday rotation for 477 pulsars observed by the Parkes 64m radio telescope and the Green Bank 100m radio telescope. Using these results, along with previous measurements for pulsars and extragalactic sources, we analyze the structure of the large-scale magnetic field in the Galactic disk. Comparisons of rotation measures of pulsars in the disk at different distances, as well as with rotation measures of background radio sources beyond the disk, reveal large-scale reversals of the field directions between the spiral arms and interarm regions. We develop a model for the disk magnetic field, which can reproduce not only these reversals but also the distribution of the observed rotation measures of background sources.
- ID:
- ivo://CDS.VizieR/J/A+AS/136/571
- Title:
- Pulsars identified from the NRAO VLA Sky Survey
- Short Name:
- J/A+AS/136/571
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Table1 gives the NVSS radio sources around the positions of all known pulsars. This table was generated by searching NVSS catalog, and each row gives the closest source around one pulsar. However, not all of them are pulsars, as we discussed in our paper. If there is "?" in the Notes, we had more considerations to identify the source as a pulsar. If there is nothing or just "*" in Notes, the source is believed to be the pulsar. Table 2 lists 14 strong pulsars not detected by the NVSS, or more exactly saying, not listed in the NVSS catalog. By the courtesy of Jim Condon, we found some of these pulsars are confused by nearby strong radio sources, and most of them were really scintillating during the NVSS.
- ID:
- ivo://CDS.VizieR/J/MNRAS/424/2832
- Title:
- Pulsars in {gamma}-ray sources
- Short Name:
- J/MNRAS/424/2832
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Machine learning, algorithms designed to extract empirical knowledge from data, can be used to classify data, which is one of the most common tasks in observational astronomy. In this paper, we focus on Bayesian data classification algorithms using the Gaussian mixture model and show two applications in pulsar astronomy. After reviewing the Gaussian mixture model and the related expectation-maximization algorithm, we present a data classification method using the Neyman-Pearson test. To demonstrate the method, we apply the algorithm to two classification problems. First, it is applied to the well-known period-period derivative diagram. Our second example is to calculate the likelihood of unidentified Fermi point sources being pulsars.
- ID:
- ivo://CDS.VizieR/J/A+AS/147/195
- Title:
- Pulsar spectra of radio emission
- Short Name:
- J/A+AS/147/195
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have collected pulsar flux density observations and compiled spectra of 281 objects. The database of Lorimer et al. (1995, Cat. <J/MNRAS/273/411>) has been extended to frequencies higher than 1.4GHz and lower than 300MHz. Our results show that above 100 MHz the spectra of the majority of pulsars can be described by a simple power law with average value of spectral index <{alpha}>=-1.8+/-0.2. A rigorous analysis of spectral fitting revealed only about 10% of spectra which can be modelled by the two power law. Thus, it seems that single power law is a rule and the two power law spectrum is a rather rare exception, of an unknown origin, to this rule. We have recognized a small number of pulsars with almost flat spectrum ({alpha}>=-1.0) in the wide frequency range (from 300MHz to 20GHz) as well as few pulsars with a turn-over at unusually high frequency (~1GHz).
- ID:
- ivo://CDS.VizieR/J/A+A/469/607
- Title:
- Pulsar subpulse modulation properties at 92cm
- Short Name:
- J/A+A/469/607
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A large sample of pulsars has been observed to study their subpulse modulation at an observing wavelength (when achievable) of both 21 and 92 cm using the Westerbork Synthesis Radio Telescope. In this paper we present the 92-cm data and a comparison is made with the already published 21-cm results. The main goals are to determine what fraction of the pulsars have drifting subpulses, whether those pulsars share some physical properties and to find out if subpulse modulation properties are frequency dependent. We analysed 191 pulsars at 92-cm searching for subpulse modulation using fluctuation spectra. The sample of pulsars is as unbiased as possible towards any particular pulsar characteristics.
