[en] Two isolated pulsars, the Crab and PSR B0540-69, were observed during the Science Verification Phase with the NFIs on board BeppoSAX. Here we present results from these two observations. In particular, we determine the spectral variations of the phase component P2, P1 and Ip of the Crab light curve using the P1/P2 and Ip/P2 ratio. We also give a brief summary of the spectral and temporal analysis. Moreover, we present the light curve of PSR B0540-69 in different energy bands and, using the best period derived from the BeppoSAX observation together with the previous ones, determine the rotational parameters of the pulsar and the relative breaking index

[en] We present some results of an RXTE observation on PSR B1937+21, the fastest known millisecond pulsar (P≅1.56 ms). The pulse profile, detected up to ∼20 keV, shows a double peak, with the main component much stronger than the other. The peak phase separation is 0.526±0.002 and the pulsed spectrum over the energy range 2-25 keV is well described by a power law with a photon index equal to 1.14±0.07. We find that the X-ray pulses are closely aligned in phase with the giant pulses observed in the radio band. This result suggest that giant radio pulses and X-ray pulses originate in the same region of the magnetosphere due to a high and fluctuating electron density that occasionally emits coherently in the radio band. The X-ray events, however, do not show any clustering in time indicating that no X-ray flares are produced

[en] The unique pulsar/Be star system PSR B1259-63/SS2883 had their second 'usable' periastron fly-by on May 29 ∼ 19:00 UT (T). The original plan of observing the pulsar with the BeppoSAX NFIs some two months before and after periastron and to monitor it during the passage with five, one week interleaved observations, could not be accomplished. PSR B1259-63 was instead observed five times by BeppoSAX during 1997: on March 22 (T-68 days) and on September 2, 8, 17, 25 (T +96, 102, 111, 118 days) for a total exposure time of 178.7 ks for each MECS and 36.1 ks for the LECS. Here we present the preliminary results from the spectral and temporal analysis and compare them with previous ROSAT and ASCA observations

[en] We report on highlight results on celestial sources observed in the high energy band (> 20 keV) with BeppoSAX. In particular we review the spectral properties of sources that belong to different classes of objects, i.e., stellar coronae (Algol), supernova remnants (Cas A), low mass X-ray binaries (Cygnus X-2 and the X-ray burster GS1826-238), black hole candidates (Cygnus X-1) and Active Galactic Nuclei (Mkn 3). We detect, for the first time, the broad-band spectrum of a stellar corona up to 100 keV; for Cas A we report upper limits to the ⁴⁴Ti line intensities that are lower than those available to date; for Cyg X-2 we report the evidence of a high energy component; we report a clear detection of a broad Fe K line feature from Cyg X-1 in soft state and during its transition to hard state; Mkn 3 is one of several Seyfert 2 galaxies detected with BeppoSAX at high energies, for which Compton scattering process is important

[en] The γ-ray burst GRB970508 was observed simultaneously by the Gamma Ray Burst Monitor (GRBM) and one of the X-ray Wide Field Cameras (WFC) aboard BeppoSAX. The latter provided a position within 1.9' radius. A series of follow-up observations with the Narrow Field Instruments (NFI) was then performed in a period from ∼ 6 hours to 6 days after the main event. A previously unknown source, which we associate with the afterglow of the GRB, was discovered in the error box. We find that, after the initial burst, X-ray emission is still present and decays as ∼ t^-1.1 up to ∼ 6 x 10⁴ s. This is followed by a burst of activity with a duration ∼ 10⁵ s. The energy produced in this event is a substantial fraction of the total energy of the GRB, which means that the afterglow is not a remnant of the initial burst (the GRB) that fades away smoothly. Our results support the idea that the processes generating the GRB and its afterglow are the same

[en] The Phoswich Detection System (PDS) is the high-energy (15-300 keV) instrument on board the Italian-Dutch X-ray astronomy satellite SAX. Functional tests were carried out at BICRON (Newbury, Ohio USA) and at LABEN (Vimodrone Italy). Full ground calibrations have been performed between the end of 1994 and the beginning of 1995. The authors describe in the following the system that they used to acquire and analyse the data coming from the PDS experiment during the ground tests and calibration. It will be used to store and maintain data during both the pre-operational and the operational phases. In a previous report (Dal Fiume D., Frontera F., Orlandini M., and Trifoglio M., AIP Conf. Proc., 61 (1994) 395) they described the general architecture of the data analysis system. In this report they give a detailed description of the entire system, including the hardware and software developed by LABEN to acquire data during on-ground tests. A complete description of the different modules, user interface, inter-process communications, analysis and display tools are presented. Current status of the project is discussed

[en] The Italian-Dutch satellite for X-ray Astronomy BeppoSAX is successfully operating on a 600 km equatorial orbit since May 1996. We present here the in-flight performance of the Gamma Ray Burst Monitor (GRBM) experiment during its first year of operation. The GRBM is performing very well, providing an amount of data on GRBs, some of which confirmed by other experiments onboard satellites. It also joined the 3rd Interplanetary Network as a new near-earth node. Important results have been obtained for GRBs (e.g. GRB970228) simultaneously detected in the Wide Field Cameras onboard the same satellite

[en] We present a large collection of photometric data on the blazar PKS 0537-441 in the VRIJHK bands taken in 2004-2009. At least three flare-like episodes with months duration and >3 mag amplitude are apparent. The spectral energy distribution is consistent with a power law, and no indication of a thermal component is found. We searched for short timescale variability, and an interesting event was identified in the J band, with a duration of ∼25 minutes.

[en] In these pages we present REM (Rapid Eye Mount), a fully robotized fast slewing telescope equipped with a high throughput NIR (Z', J, H, K) camera and an Optical slitless spectrograph (ROSS) optimized for the monitoring of the prompt afterglow of Gamma Ray Bursts. Covering the NIR domain REM can discover objects at extremely high red-shift and trigger large telescopes to observe them when they are still bright. The synergy between REM-IR cam and ROSS makes REM a powerful observing tool for any kind of fast transient phenomena

[en] Highlights: • Heat treatments of Wire Arc Additive Manufactured (WAAM) Ti-6Al-4V studied. • Microstructure and tensile properties sensitive to post process heat treatment. • WAAM has slow cooling rate, and as-built condition offered best blend of properties. • Annealing unnecessary, and reduced strength without significant gain in ductility. • Hot Isostatic Pressing did not measurably improve ductility in WAAM. Wire + Arc Additive Manufacturing (WAAM) is a promising manufacturing process for producing large aerospace components. Based on welding technology, the process is highly affordable, has a very high deposition rate and is not limited by chamber size. Ti-6Al-4V is a promising candidate material for this technology given that it is extensively used in aerospace applications and some large, high buy-fly ratio components can be more efficiently produced by WAAM than via the conventional machining from billet approach. There is currently limited knowledge about whether additional post processes including heat treatments and hot isostatic pressing are necessary to unlock the optimal mechanical properties of Ti-6Al-4V components produced by WAAM. This work explores a range of different post process treatments and the effects on the microstructure and tensile properties of Ti-6Al-4V components produced by WAAM. The relatively slow cooling rate (10-20Ks⁻¹) during the β-α transformation produced Widmanstätten-α and offered an optimal balance between strength and ductility. Hot Isostatic Pressing (HIPing) removed gas porosity but was not effective in improving strength or ductility. Residual tensile stresses in as-built components severely impair ductility and should be removed through stress relief treatments.