The association of PSR B1757–24 and the supernova remnant (SNR) G5.4–1.2 was recently questioned by Thorsett et al. (2002) on the basis of proper motion measurements of the pulsar and the “incorrect” orientation of the vector of pulsar transverse velocity (inferred from the orientation of the cometary-shaped pulsar wind nebula). We show, however, that the association could be real if both objects are the remnants of an off-centered cavity supernova explosion.

The Cygnus Loop is one of the nearest supernova remnants (440 pc) and has been studied extensively in radio through X-ray wavelengths. An unusual bright “V”-shaped region on the south-western limb (near RA 20h46m and Decl. +30°) was revealed in ROSAT PSPC observations of the Cygnus Loop. The left side of the “V” has one of the highest hardness ratios (0.9–2 keV / 0.1–0.4 keV) in the Cygnus Loop whereas the right side has one of the lowest. Images and spatially resolved spectra were obtained using Chandra ACIS observations. Some results of analysis of the images and spectra are presented here.

We have used the Parkes-MIT-NRAO (PMN) radio survey, at a common frequency of 4.85 GHz (λ=6 cm), to study the distribution of Galactic shell supernova remnants (SNRs). We estimate distances and distribution of the Galactic shell SNRs and find the peak of distances to be between 4 and 6 kpc. Our two-dimensional model of the distribution of Galactic shell SNRs shows a concentration between the Sagittarius and the Scutum arms.

We briefly summarize the survey of HI 21 cm emission lines to search for shocked atomic gas associated with Galactic supernova remnants (SNRs) in the southern sky. For G347.3–0.5, we discuss the distance to the SNR and the implications of the HI results.

A study of the nature and the spatial distribution of over 250 discrete radio sources (HII regions and SNRs) in the Magellanic Clouds (MCs) is underway. A multi-frequency comparison of these sources involves the latest radio, IR, optical and X-ray surveys with angular resolution of <1′. Special emphasis is given to the MC SNRs. Their morphology, birth rate and overall properties are investigated and compared with Galactic SNRs and SNRs from other nearby galaxies. Also, we are investigating the radio source distribution throughout both MCs.

We propose a new model of distinct thin circular disk shells to analyze Gaussian fits to spectral features of OH emission at 1720 MHz toward supernova remnants. We have inferred that the OH(1720 MHz) maser features toward G348.5+0.1 are radiated from three distinct thin circular disk shells, and have obtained the parameters of the shells.

In the radio band, supernova remnants (SNRs) and pulsars are best identified at low frequencies due to their steep spectrA. Motivated by this fact, we have carried out a deep 330-MHz observation of M31 using the VLA. Achieving a sensitivity of 0.6 mJy at 6″ resolution over the entire optical disk of M31, we identified 405 distinct radio sources. While most of these are unresolved background radio galaxies, we found five SNR candidates, three pulsar wind nebula (PWN) candidates, and three pulsar candidates in our source list. The properties of these sources are discussed.

We show some examples from a WWW-based catalog, containing Chandra archive data, that is now under construction. Many remnants show manifestations of internal neutron stars, which are of particular interest to this conference.

I review the results of radio and X-ray searches for pulsations from young neutron stars, emphasizing work accomplished in the last five years. I cover undirected searches, as well as directed searches of pulsar wind nebulae, EGRET γ-ray sources, and also the search for pulsations from “isolated neutron stars” and “central compact objects”.

We review current understanding of the underlying, as opposed to the observed, pulsar population. The observed sample is heavily biased by selection effects, so that surveys see less than 10% of all potentially observable pulsars. We compare various techniques used to correct the sample for these biases. By far the most significant recent development has been the discovery of over 700 pulsars in the Parkes Multibeam (PM) survey. This new sample is far less affected by selection effects and we use it to make a preliminary analysis of the Galactic pulsar distribution, finding further evidence for a deficit of pulsars in the inner Galaxy.

In a throwback to the early days in radio astronomy, new concepts for radio telescopes are being considered as next-generation facilities. The Low-Frequency Array (LOFAR) and the Square-Kilometer Array (SKA) are two particular projects that will incorporate innovations in hardware and software. Along the way to these projects, major surveys for pulsars and transients and/or follow-up pulsar timing observations will be conducted with the ALFA multibeam system at Arecibo, the Allen Telescope Array (ATA), the Extended VLA (EVLA) and with SKA prototype systems that include the European MBRACE project (Multibeam Radio Astronomy Concept Experiment) and China's FAST (500m Aperture Spherical Telescope). These projects are discussed here in the context of anticipated science drivers.

We report on calculations of the pulsar birth rate based on the results of the Parkes multibeam survey. Prom the observed sample of more than 800 pulsars, we compute the pulsar current, accounting as accurately as possible for all known selection effects. The main goal of this work is to understand the pulsar birth rate as a function of the surface dipole magnetic field strength. We show that pulsars with magnetic fields greater than 1012.5 G account for about half of the total birth rate.

Most astronomers now accept that stars more massive than about 9 M⊙ explode as supernovae and leave stellar remnants, either neutron stars or black holes. However, less than half of the SNRs within 5 kpc have identified central sources. Here, we discuss a systematic effort to search for compact central sources in the remaining 23 SNRs of this distance-limited sample. As the first part of this survey, we are able to state with some confidence that there are no associated central sources down to a level of one tenth of that of the Cas A central source, LX ≲ 1031 ergs s−1, in four SNRs (G093.3+6.9, G315.4−2.3, G084.2+0.8, and G127.1+0.5). We compare our limits with cooling curves for neutron stars and find that any putative neutron stars in these SNRs must be cooling faster than expected for traditional 1.35 M⊙ neutron stars.

We report on new pulsars discovered in Arecibo drift-scan datA. Processing of 2200 deg2 of data has resulted in the detection of 41 known and 12 new pulsars. New pulsars include two millisecond pulsars, one solitary and one binary recycled pulsar, and one pulsar with very unusual pulse profile morphology and complex drifting subpulse behavior.

We have completed a search for radio pulsars using the Parkes 64 m telescope, covering ∼4500 deg2 between 15° and 30° from the Galactic plane. Each pointing was observed for 265 s with the 13-beam multibeam system at a frequency of 1374 MHz. The signal from each beam was processed by a 96-channel filterbank and sampled every 125 μs, with a bandwidth of 288 MHz. This strategy affords rapid sky coverage and good sensitivity to pulsars with periods as short as 1 ms, whose existence would constrain the neutron star equation of state. Data were analyzed using the workstation cluster at the Swinburne Centre for Astrophysics and Supercomputing. This effort has yielded 26 new pulsars, including seven recycled pulsars. Taken together with the previous Swinburne Intermediate Latitude Pulsar Survey, a total of 95 new pulsars were found over nearly 7500 deg2 of sky between 5° and 30° from the plane of the Galaxy. This large sample of newly discovered objects contains no young pulsars.

We are conducting deep searches for radio pulsations at L-band (∼ 20 cm) towards more than 30 globular clusters (GCs) using the 305 m Arecibo telescope in Puerto Rico and the 100 m Green Bank Telescope in West VirginiA. With roughly three quarters of our search data analyzed, we have discovered 12 new millisecond pulsars (MSPs), 11 of which are in binary systems, and at least three of which eclipse. We have timing solutions for several of these systems.

We report on the progress of our search for highly dispersed pulsars near the Galactic Center at 5 GHz using the 100-m radio telescope in Effelsberg. We also present key aspects of our new survey for millisecond pulsars at 21 cm in parts of the northern sky. This survey will greatly benefit from the L-band multibeam receiver and a new FFT-based backend which are currently under construction at the MPIfR.

Pulsars are among the most highly polarized sources in the universe. The NVSS has cataloged 2 million radio sources with linear polarization measurements, from which we have selected 253 sources, with polarization percentage greater than 25%, as targets for pulsar searches. We believe that such a sample is not biased by selection effects against ultra-short spin or orbit periods. Using the Parkes 64-m telescope, we conducted searches with sample intervals of 50 μs and 80 μs, sensitive to submillisecond pulsars. Unfortunately we did not find any new pulsars.

We trace all pulsar/SNR associations proposed in the literature, and find that 20 pairs of associations are highly likely real because the pulsar wind nebulae around the pulsars have been detected.

The number of known pulsars has significantly increased over the past few years. We have searched the literature to find papers announcing the discovery of pulsars or giving improved parameters for them. Data from the papers have been entered into a new pulsar catalog that can be accessed via a web interface or from the command line (on Solaris or Linux machines). The user may request over 120 different parameters, select pulsars of interest, generate custom variables and choose between different ways of displaying or tabulating the datA. Full bibliographic references are available for all observed parameters.