Search

The recycling model argues the existence of an evolutionary connection between low mass X-ray binaries and radio millisecond pulsars. The main difficulties which this model finds in predict the parameters of the fully recycled millisecond pulsars, as mass and spin period, can be overcome by the onset of the so-called radio-ejection mechanism. This work is to provide observational support to the radio-ejection mechanism by inspecting the orbital and spin parameters of the known population of fully recycled radio pulsars and compare these with the expectation for the occurrence of this mechanism.

The High Time Resolution Universe survey for pulsars and fast transients has yielded the discovery of a slow radio pulsar, PSR J1622−4950, that despite its high dispersion measure exhibited a highly variable flux density and integrated pulse profile. The pulsar shares many properties with the two previously known magnetars that emit radio pulsations, including a similarly high inferred magnetic field strength. In contrast to other magnetars, PSR J1622−4950 shows no observed variations in X‐ray emission.

We present the evolution of the radio emission from the 2.8‐s pulsar of the double pulsar system PSR J0737−3039A/B. We describe the changes in the pulse profile and flux density over five years of observations, culminating in the B pulsar’s radio disappearance in 2008 March. Over this time, the flux density decreased by 0.177 mJy yr−1 at the brightest orbital phases and the pulse profile evolved from a single to a double peak. Relativistic spin precession, coupled with an elliptical beam, can model the pulse profile evolution well and the reappearance is expected to happen in ∼2035 with the same part of the beam or in ∼2014 if we assume a symmetric beam shape.

The High Time Resolution Universe survey for radio pulsars and transients is the largest such survey yet undertaken with the Parkes radio telescope. We use the 13‐beam multibeam receiver centred at 1352 MHz, connected to BPSR, our new all‐digital backend. This system provides us with 340 MHz of usable band split into 870 channels, each sampled with two bits every 64 μs. The factor of eight improvement in frequency resolution over previous Parkes multibeam surveys allows us to probe further into the galactic plane for short duration signals, such as those from fast transients and millisecond pulsars. The survey is split into low, mid and high Galactic latitude regions, each covered with integration times of 4300, 540 and 270 s respectively. To date we have almost completed the mid latitude survey, discovering 65 previously unknown pulsars, including 15 millisecond pulsars. Upon completion we expect to discover some 400 pulsars, of which 75 will be millisecond pulsars.

A number of observations hints for the presence of an intermediate mass black hole (IMBH) in the core of three globular clusters: M15 and NGC 6752 in the Milky Way, and G1, in M31. However the existence of these IMBHs is far form being conclusive. In this paper, we review their main formation channels and explore possible observational signs that a single or binary IMBH can imprint on cluster stars. In particular we explore the role played by a binary IMBH in transferring angular momentum and energy to stars flying by., Comment: 8 pages,6 figures,Invited review in: "Interacting binaries", July 4-10 Cefalu, eds. Antonelli et al., to be published with AIP

We present the status of the Sardinia Radio Telescope (SRT) project, a new general purpose, fully steerable 64 m diameter parabolic radio telescope under construction in Sardinia. The instrument is funded by Italian Ministry of University and Research (MIUR), by the Sardinia Regional Government (RAS), and by the Italian Space Agency (ASI), and it is charge to three research structures of the National Institute for Astrophysics (INAF): the Institute of Radio Astronomy of Bologna, the Cagliari Astronomical Observatory (in Sardinia), and the Arcetri Astrophysical Observatory in Florence. The radio telescope has a shaped Gregorian optical configuration with a 8 m diameter secondary mirror and additional Beam‐Wave Guide (BWG) mirrors. One of the most challenging feature of SRT is the active surface of the primary reflector which provides good efficiency up to about 100 GHz. This paper reports on the most recent advances of the construction.

The Square‐Kilometre‐Array (SKA) represents the future of radio astronomy and will have a profound impact on a wide range of science. In particular, it will completely change the field of pulsar astronomy, providing not only a vast number of sources that can be studied but will also deliver an unprecedented sensitivity and timing precision for such studies. The result will be applications impossible with current technology, for example, in the field of gravitational physics. With the SKA we will study the nHz‐gravitational wave sky, will probe the properties of gravitational waves and will also establish the properties of black holes.

The last few years have seen a revolution in very high γ‐ray astronomy (VHE; E>100 GeV) driven largely by a new generation of Cherenkov telescopes. These new facilities, namely H.E.S.S. (High Energy Stereoscopic System), MAGIC (Major Atmospheric Gamma Imaging Cherenkov Telescope) and its upgrade MAGIC 2, Veritas (Very Energetic Radiation Imaging Telescope Array System) and CANGAROO (Collaboration of Australia and Nippon for a Gamma Ray Observatory in the Outback) were designed to increase the flux sensitivity in the energy regime of hundreds of GeV, expanding the observed energy range from 100 (50) GeV to multi‐TeV, and fostered as a result a period of rapid growth in our understanding of the Non‐Thermal Universe. As a result of this fast development the number of pulsar wind nebulae (PWNe) detected has increased from a few in the early 90’s to more than two dozen of firm candidates nowadays. A review of the most relevant VHE results concerning pulsars and their relativistic winds is discussed here in the...

In this project single pulse energy histograms of five pulsars in three different wavelengths—2.8 cm, 6 cm, 21 cm‐were constructed. Not only have we constructed the ON‐pulse histograms, but also the histograms of individual components. Furthermore we have estimated the fraction of null pulses for the ON‐pulse window and for each component individually.

Observations of twelve newly discovered pulsars were performed at 610 MHz using GMRT. We have found some candidates for pulsars with Gigahertz‐Peaked Spectra (GPS) with PSR J1705−3950 and PSR J1852−0635 being the most promising.

Pulsars, and more in general rotating neutron stars, are expected to permanently emit gravitational waves, mainly at the double of the rotational frequency. This type of signals requires long observation times in order to distinguish the peak at the emission frequency in the antenna signal spectrum from the incoherent noise floor. The energy of the signal spectral peak is smeared by the Doppler phase modulation due to the antenna motion with respect to the source and by the phase shift induced by the source rotational frequency slowing because of energy losses due to emissions. The correction to these effects requires, in general, the knowledge of the source emission frequency, of the spin‐down and of the source sky position. We propose a very effective method to compensate for Doppler and spin‐down. The technique is particularly useful for semi‐targeted searches. It consists in a fast resampling of the antenna signal aimed to synchronize with a large accuracy the detector time with the source one. The ap...

γ‐ray telescopes cannot focus incident high‐energy radiation, and the background emission from sources nearby in projection can obscure the periodic emission from pulsars, making unambiguous detection of pulsations difficult. In the context of the Fermi Large Area Telescope (LAT), we present modified statistical tests for periodicity in which each photon is weighted by its probability to have originated from the candidate pulsar. Since the probabilities are calculated using the instrument response function and a full spectral model, they provide powerful background rejection. With Monte Carlo methods, we demonstrate that the new tests increase the sensitivity to pulsars by more than 50% under a wide range of conditions.

The ∼800 yr‐old pulsar PSR J1846‐0258 in the supernova remnant Kes 75 is a unique transition object between rotation‐powered pulsars and magnetars. While it typically behaves as a rotation‐powered pulsar, in 2006 it exhibited a distinctly magnetar‐like outburst accompanied by a large glitch with an unusual over‐recovery. We present X‐ray timing observations taken with the Rossi X‐ray Timing Explorer after the X‐ray outburst and accompanying glitch had recovered. We observe that the braking index of the pulsar, previously measured to be n = 2.65±0.01 has decreased by 18±5%. We also note a persistent increase in the timing noise relative to the pre‐outburst level, reminiscent of behavior previously observed from some magnetars.

An intriguing paper has recently been published claiming that the long‐sought Rosetta Stone needed to decipher the nature of pulsar radio emission has been finally identified as the bifurcated features in averaged pulsar profiles. The authors argued that highly symmetric bifurcated features observed in PSR J1012+5307 and other pulsars are produced by a split‐fan beams of extraordinary‐mode curvature radiation emitted by thin streams of sources conducted by a very narrow bundles of magnetic field lines. We examined the arguments leading to such a profound conclusion and found at least one fatal flaw. Using an elementary pulsar physics we showed that there is not enough energy to power the bifurcated feature in J1012+5307 within a split‐fan beams model. If the source streams are indeed so thin that their emission can reveal the signatures of elementary radiation mechanism, then the energy deficit reaches several orders of magnitude.

“Tsubame” is a university‐built small satellite mission that measures polarization of hard X‐ray photons (30–100 keV) from gamma‐ray bursts (GRB) using azimuthal angle anisotropy of Compton scattering. The satellite is intended for a piggy‐back launch on the H‐IIA rocket. It uses Control moment gyros to quickly orient itself to GRBs within 15 seconds from triggers. We are now developing the engineering model of the two detector systems on Tsubame, the polarimeter and the bust monitor. In this paper, we present an overview of the Tsubame mission, and detail of development of engineering model of our polarimeter and burst monitor.

Terzan5 is the globular cluster (GC)-like stellar system harboring the largest known population of MSPs. Using the Multi-Conjugate Adaptive Optics demonstrator MAD at the ESO - VLT, we recently obtained a superb (K, J - K) color-magnitude diagram, which has revealed the existence of two horizontal branches (HBs) well separated in magnitude and colour (Ferraro et al. 2009, Nature,462, 483). A prompt spectroscopic follow-up with NIRSPEC@Keck has shown that the two populations have (1) significantly different iron content ([Fe/H]= -0.2 and +0.3 for the faint and the bright HB, respectively), (2) distinct [alpha/Fe] abundance patterns and (3) no evidence of the Al-O anti-correlation commonly observed in GCs. All these properties suggest that Ter 5 is far from being a genuine globular. Instead it has experienced the explosion of a huge number of supernovae (SNe), thus accounting for its high metal content and it should have been much more massive in the past than today, thus to retain the SN ejecta within its potential well. The many type II SNe should have also produced a large number of neutron stars (NSs), which could finally explain its exceptionally large population of MSPs., Comment: Contributed Talk at the conference "Radio Pulsars: a key to unlock the secrets of the Universe", Baia Chia, Sardinia, Italy, 11-15 Oct. 2010, 4 pages, 2 figures

Don Backer was a true founding father of pulsar astronomy, a dedicated and passionate scientist who, alongside a career of tremendous and varied scientific accomplishment, was friendly, easy‐going, dignified, and kind. This tribute summarizes Don’s work, highlighting his many contributions to pulsar astronomy and other fields.

Observational evidences of erratic 1(st) harmonic pulse phase shifts in accreting millisecond X-ray pulsars pulse phase evolution was reported by several authors. This effect always go together with much more stable 2(nd) harmonics pulse phase delays. Different possible explanations of these phase shifts have been given in literature. But all these interpretations do not explain why the 2(nd) harmonic are more stable than the 1(st) harmonic. The explanation of such a behaviour is of fundamental importance in order to gain an insight on the NS rotational behaviour and to remove the still present interpretative ambiguity on the results of timing analysis. We propose a simple toy-model to interpret these phenomena as effect of small variations of the ratio between the fluxes from the two hot-spots. We show how it affects the phase of the overall pulse profile, when the two amplitudes are similar and the two hot-spots are not perfectly antipodal. Using this model, we give a detailed explanation of the phase jump observed in the 2002 outburst of SAX J1808.4-3658.

We report a discovery of a phase‐related subpulse drift pattern in the relatively less studied pulsar, B1039−19, using high sensitivity GMRT observations at 325 MHz. We observe simultaneous occurrence of four/three drift regions—evident subpulse drifting under the leading and the trailing peaks, less evident subpulse drifting under the small peak near to the leading peak and under the inner saddle region. Subpulse drifting in all the four regions appear to be locked in phase.

To search for extragalactic pulsars we carried out observations of six nearby galaxies at 820 MHz with the 100‐m Robert C. Byrd Green Bank radio telescope. All target galaxies of the Local Group are at high galactic latitudes |b|>30°, that provides much less Galactic contribution to dispersion measures of extragalactic pulsars, and is crucial to detect them. In the present work we report about our preliminary results.

We describe our studies of the radio and high-energy properties of Rotating Radio Transients (RRATs). We find that the radio pulse intensity distributions are log-normal, with power-law tails evident in two cases. For the three RRATs with coverage over a wide range of frequency, the mean spectral index is -1.7\pm0.1, roughly in the range of normal pulsars. We do not observe anomalous magnetar-like spectra for any RRATs. Our 94-ks XMM-Newton observation of the high magnetic field RRAT J1819-1458 reveals a blackbody spectrum (kT ~130 eV) with an unusual absorption feature at ~1 keV. We find no evidence for X-ray bursts or other X-ray variability. We performed a correlation analysis of the X-ray photons with radio pulses detected in concurrent observations with the Green Bank, Effelsberg, and Parkes telescopes. We find no evidence for any correlations between radio pulse emission and X-ray photons, perhaps suggesting that sporadicity is not due to variations in magnetospheric particle density but to changes in beaming or coherence., 4 pages, 2 figures, to appear in AIP Conference Proceedings of Pulsar Conference 2010 "Radio Pulsars: a key to unlock the secrets of the Universe", Sardinia, October 2010

We have built two single photon very high speed photometers (AquEYE for the Asiago 1.8 m telescope and IquEYE for the 3.5 m ESO NTT) as prototypes of a quantum photometer for the 42 m European Extremely Large Telescope (E‐ELT). The two photometers are the most accurate time machines available to optical astronomy. The arrival time of each detected photon is referenced to UTC with a precision better than 500 picoseconds, continuously for hours of data acquisition. We report timing results for three optical pulsars.

We report on a new 3D fully relativistic, modular, parallel and scalable Particle‐In‐Cell (PIC) code currently being developed at the Computational Astrophysics Laboratory in the National University of Ireland, Galway and its initial test applications to the plasma distribution in the vicinity of a rapidly rotating neutron star. We find that Plasma remains confined by trapping surfaces close to the star as opposed to propagating to a significant portion of the light‐cylinder distance as predicted in this early work. We discuss planned future modifications and applications of the developed code.

When the line of sight of a pulsar is close to the Sun, the electron density and magnetic field from the solar wind will strongly affect the dispersion and rotation measure of the pulsar. Here we present the effect from pulsar observations and describe our model of the solar wind.

Mildly recyled pulsars (MRP), conventionally defined as neutron star having spin period in the 20–100 ms range and surface magnetic field

We have applied a cross correlation analysis to timing observations of 20 pulsars to study the isotropic, stochastic gravitational‐wave background signal. No gravitational‐wave signal was detected. We showed that, because of the variable data spans and noise levels across the 20 time series, only a few pulsars contribute to estimating the gravitational‐wave signal. This prohibits the calculation of a 95% confidence upper bound on the amplitude of the gravitational‐wave background.

We present results of electron‐positron pair cascade simulations in a dipole magnetic field whose polar cap is offset from the dipole axis. In such a field geometry, the polar cap is displaced a small fraction of the neutron star radius from the star symmetry axis and the field line radius of curvature is modified. Using the modified parallel electric field near the offset polar cap, we simulate pair cascades to determine the pair deathlines and pair multiplicities as a function of the offset. We find that the pair multiplicity can change dramatically with a modest offset, with a significant increase on one side of the polar cap. Lower pair deathlines allow a larger fraction of the pulsar population, that include old and millisecond pulsars, to produce cascades with high multiplicity. The results have some important implications for pulsar particle production, high‐energy emission and cosmic‐ray contribution.

We demonstrate that the high‐magnetic field pulsar J1119−6127 exhibits three different types of behaviour in the radio band. Trailing the “normal” profile peak there is an “intermittent” peak and these components are flanked by two additional components showing very erratic “RRAT‐like” emission. Both the intermittent and RRAT‐like events are extremely rare and are preceded by a large amplitude glitch in the spin‐down parameters. The post‐glitch spin‐down rate is smaller than the pre‐glitch rate, which is very unusual for the pulsar population as a whole, but is observed in the glitch recovery of a RRAT. If the abnormal radiative behaviour in PSR J1119−6127 is indeed glitch induced then there might exist a population of neutron stars which only become visible in the radio band for a short duration in the immediate aftermath of glitch activity. These neutron stars will be visible in the radio band as sources that only emit some clustered pulses every so many years.

Several models have been proposed for the description of anomalous X‐ray pulsars (AXPs) and soft gamma‐ray repeaters (SGRs). The most widely discussed is the magnetar model, which involves a neutron stars with a surface magnetic field of the order of 1014÷1015 G [1]. Some other models put forward to explain the observed peculiarities of AXPs and SGRs. There is currently no model that can satisfactorily describe all the observational properties of these objects. We develope the drift model. Here, we discuss the applicability of the magnetar model and consider the feasibility of the drift model.Several models have been proposed for the description of anomalous X‐ray pulsars (AXPs) and soft gamma‐ray repeaters (SGRs). The most widely discussed is the magnetar model, which involves a neutron stars with a surface magnetic field of the order of 1014÷1015 G [1]. Some other models put forward to explain the observed peculiarities of AXPs and SGRs. There is currently no model that can satisfactorily describe all the observational properties of these objects. We develope the drift model. Here, we discuss the applicability of the magnetar model and consider the feasibility of the drift model.

High‐precision pulsar timing relies on a solar system ephemeris in order to convert times of arrival (TOAs) of pulses measured at an observatory to the solar system barycenter. Any error in the conversion to the barycentric TOAs leads to a systematic variation in the observed timing residuals; specifically, an incorrect planetary mass leads to a predominantly sinusoidal variation having a period and phase associated with the planet’s orbital motion about the Sun. By using an array of pulsars (PSRs J0437−4715, J1744−1134, J1857+0943, J1909−3744), the masses of the planetary systems from Mercury to Saturn have been determined. These masses are consistent with the best‐known masses determined by spacecraft observations, with the mass of the Jovian system, 9.547921(2)×10−4M⊙, being significantly more accurate than the mass determined from the Pioneer and Voyager spacecraft, and consistent with but less accurate than the value from the Galileo spacecraft. While spacecraft are likely to produce the most accurat...

The results of radio emission observations from AXP 1E 2259+586 and 4U 0142+61 are reported. The observations were carried out on two sensitive transit radio telescopes at two frequencies 111 and 62 MHz. New data of pulse profiles and dynamic spectra are presented. Comparison with X‐ray data shows large differences in the mean pulse widths and the flux variations.

Fermi‐LAT and AGILE have already detected more than 70 rotation‐powered pulsars at GeV energies, opening a new era of pulsar physics. In particular, Fermi has unveiled the existence of a large population of Geminga‐like pulsars, γ‐ray bright but radio‐silent. We used XMM‐Newton, Chandra and Swift to study such new, γ‐ray selected, pulsar population and to compare its X‐ray behaviour with that of the radio pulsars. While radio‐loud and radio‐quiet pulsars need not to be different objects, their different viewing geometry with respect to the observer does influence the ratio between γ and X‐ray emissions. When plotting the distance‐indipendent γ to X‐ray flux ratios as a function of the pulsars’ rotational energy losses, one immediately sees that pulsars with similar energetics have Fγ/FX spanning 3 decades. Such spread, most probably stemming from vastly different geometrical configurations of the X and γ‐ray emitting regions, defies any straightforward interpretation of the plot. We find that, on average,...

The Double Pulsar (J0737‐3039) is an exceptional physical laboratory. It allows us to probe pulsar emission mechanisms, physical processes related to pulsars and General Relativity tests. In this poster we examine a mechanism where spin‐down is caused by the field lines which are open with respect to the magnetosphere. The orbital variation of the magnetosphere adds a periodic imprint to the derivative of the spin frequency of pulsar B which will be observed as a higher order correction on the phase. This modulation can be used to provide information for clearing the signal received from Pulsar B from the noise which is essential for high precision General Relativity tests. We also evaluate the magnetic field of Pulsar B and the shape of the boundary.

We consider the radiative transfer problem in a plane‐parallel slab of thermal electrons in presence of an ultra‐strong magnetic field (B≳4.4×1013 G). Under such conditions, the magnetic field behaves as a birefringent medium for the propagating photons, and the electromagnetic radiation is splitted into two polarization modes, ordinary and extraordinary, having different cross‐sections. When the optical depth of the slab is large, the ordinary‐mode photons are significantly more Comptonized and the photon field is dominated by the isotropic component. For sub‐relativistic electron temperatures, it is possible to treat the full kinetic Boltzmann equation for such photons using the Fokker‐Planck approximation. The full solution is then obtained by the method of variable separation. We report the numerical solution obtained for eigenvalues and eigenfunctions of the space operator, and consider the emerging Comptonization spectrum of the ordinary‐mode photons for energies significantly less than the cyclotro...

We investigate the unique nulling properties PSR B0818−41 with the GMRT at 325 and 610 MHz. A strong trend in the intensity fluctuations of the individual pulses just before and after the nulls is observed by us for this pulsar. In addition, we report a possible connection between the intensity fluctuations and the drift rate of subpulses just before and after the nulls. We find some very specific and well correlated changes in the radio emission properties of PSR B0818−41 when the emission restarts after a null. These could imply that the phenomenon of nulling is associated with some kind of a “reset” of the pulsar radio emission engine.

The Vela pulsar has been monitored almost daily since 1985 using the HartRAO 26 m antenna. During this time ten large glitches have been observed. In 1994 the Vela pulsar experienced two large glitches (Δν/ν = 8.61×10−7 and Δν/ν = 1.99×10−7) separated by only 32 days. The event is accompanied by typical transients in rotation frequency derivative (ν) although all of the long‐term offset occurs at the first event and the rapidly‐decaying transient is only seen with the second spin‐up. We discuss the unique features of these glitches and show that they do not seem to fit in with the widely accepted creep theory of post‐glitch recovery.

We present the results from a sensitive targeted search campaign at the GMRT to find young pulsars in Galactic SNRs. A sample of 12 SNRs with “filled‐center”, “composite” and “shell” type morphologies were searched using a single pixel phased array beam of the GMRT at 610 MHz. No new pulsars were detected in this survey. Known pulsars within field of view of the pointings are seen with expected sensitivity. The achieved search sensitivity of better than 100 mJy, makes this one of the most sensitive searches for pulsars in SNRs.Single pixel searches with phased array beams of interferometers are ideal for compact SNRs. They are not efficient for searching in extended remnants where the pulsar could have moved a significant distance from the centroid. We describe plans and current status of a new phased array search with the GMRT, that forms multiple simultaneous beams from a single recording of raw voltage data from all the antennae, using the new GMRT Software Back‐end (GSB). This new search technique wil...

In rotating neutron stars the existence of the Coriolis force allows the presence of the so‐called Rossby oscillations (r‐modes) which are known to be unstable to emission of gravitational waves. Here we show that r‐modes can generate very strong toroidal fields in the core of accreting millisecond pulsars by inducing differential rotation. The generated magnetic field modify the r‐mode instability window and it stabilizes the star at higher spin frequencies.

We present the radio observations of two isolated neutron stars: XDINS 1RXS J1308.6+212708 and 1RXS J214303.7+065419. The observations were carried out on two sensitive transit radio telescopes at a few low frequencies with using new digital receiver. We have obtained pulse profiles and dynamic spectra and have estimated the main parameters of radio emission for two objects. Results of the correlation analysis of data, allowing to define a dispersion measure by independent method, are given as well. Comparison with X‐ray data shows large differences in the mean pulse widths and luminosities.

The Parkes multi‐beam pulsar survey (PMPS) [1] is the most successful pulsar survey ever undertaken, discovering 786 pulsars (including those from this work) and 30 RRATs (e.g. [2] and references therein). Previous analyses of the survey have not been fully sensitive to relativistic binary systems, where the spin period of the pulsar varies significantly over the duration of the 35 minute observations because of the Doppler effect. The aim of this latest re‐analysis was to partially combat such selection effects and to find any relativistic binary systems that were missed in previous searches. In total 16 pulsars have been discovered including one MSP binary and a possible intermittent pulsar.

Millisecond pulsar B1744−24A (Ter5A) in globular cluster Terzan 5 belongs to the one of the few “windy” binary systems, with unbound material escaping from the companion star and interacting with the pulsar’s magnetosphere. In this work we used two decades of timing data to trace the evolution of the pulsar’s spin and orbital parameters. Also, Ter5A appears to emit strong wide single pulses, with energies 30 or more times the mean pulse energy, with widths comparable to that of the average profile. These pulses occur preferentially shortly before and after the pulsar is obscured by the unbound material from the companion star.

Recently, Vink & Bamba (2009) detected extended emission around the magnetar 1E 1547.0–5408 in quiescence and characterized it as the result of a pulsar wind nebula (PWN). From analysis of a February 2010 XMM‐Newton observation of the source, as well as three archival XMM‐Newton observations, we confirm the detection of extended emission. However, we find that its X‐ray flux is highly variable and tightly correlated with the X‐ray flux of the magnetar itself. We conclude that it is most likely due to a dust‐scattering halo and not a PWN as previously claimed.

The extreme conditions found in and around pulsars make them a fantastic natural laboratory through which many aspects of fundamental physics and astronomy can be probed. Whether it is an exotic pulsar which pushes the limits of the equation‐of‐state, a precisely timed millisecond pulsar (MSP) that can be used as part of an array to detect gravitational waves or a normal pulsar that will, for example, help to map the interstellar medium, the discovery of new pulsars inevitably leads to an improvement in our understanding of the Universe we live in. We therefore perform an all‐sky survey for pulsars using the Effelsberg and Parkes telescopes. This work will concentrate only on the Northern half of the High Time Resolution Universe (HTRU) survey collaboration’s work.

We report on simulations of different methods to estimate the number of pulsars for which the parallax can be measured with the SKA and to what distance a parallax can be measured.

As the rotation of a neutron star slows down, its density increases, pushing the matter inside the star out of beta equilibrium. The beta decays restoring this equilibrium dissipate energy, which heats the star, making it emit thermal ultraviolet radiation for much longer than the standard cooling times. This effect might have been observed in the nearest millisecond pulsar, J0437‐4715, by Kargaltsev and collaborators. We show how it operates if the nucleons in the star are superfluid. The steady‐state chemical imbalances and temperature increase with the energy gaps, making it possible to constrain the energy gaps from observations. In certain cases, strong oscillations of the temperature can occur. We also analyze competing heating mechanisms, such as vortex friction, and suggest observations that might distinguish between them.

A comprehensive CCD survey of the optical emission from Fermi pulsars is currently being performed using the WHT, TNG and INT telescopes. Candidate targets have been identified for follow‐up time‐resolved observations with instruments such as GASP, ULTRACAM and OPTIMA.

We devise an accurate method to compute the emission profile corresponding to a given set of pulsar emission parameters, for eg. inclination angle α, impact angle β, frequency of emission ω, Lorentz factor γ, and pulsar spin‐period P. The intensity of emission is simulated, and compared with the observed profiles.