OSSERVATORIO ASTRONOMICO DI PALERMO GIUSEPPE S. VAIANA

Computer Facility at OAPa

The computer facility at the Osservatorio Astronomico di Palermo use a Local Area Network (LAN) to interconnect general purpose servers (DNS, SMTP, HTTP), scientific data analysis servers and Linux based personal workstations as well as computers for administrative purpose. Among others we have an HP ES 40 with 4 CPU Alpha EV67, a load balancing system with 6 AMD Opteron and 2 Intel Xeon CPU for 30 Gflop/s of theoretical peak performance. Two High Performance Computing (HPC) systems based on AMD Opteron processors with 24 and 12 CPUs deliver 105 and 48 Gflop/s respectively. The former is equipped with a low latency InfiniBand network. They are devoted to computation of astronomical plasma modelling using MPI based Magnetic Hydro Dynamic codes as part of the SCAN activities. Approx 6 TB of disk storage, full mirrored, are available for researchers and institute people.

The astronomical software tools available to the users of the OAPA LAN include:

IRAF, STSDAS, TABLES, PROS, EUVE analysis tools

MIDAS, EXSAS,

XANADU, FTOOLS [IRAF and Host Versions], SPEX

IDL with the ROSATLIB and ASTROLIB

A group of scientists of the OAPA has developed an IDL environment, called ASAP (Maggio et al. 1994, Comp. Phys. Comm., 81, 105) , build around a set of IDL procedures specifically devoted to the analysis of astrophysical plasma emission.

A group of scientists of the OAPA in collaboration with scientists of CFA has developed a complete system for the automated scientific analysis of the ROSAT PSPC data, that is based both on IRAF/IDL/FTOOL/XSPEC standard tools and new detection algorithm based on ``wavelet transforms'' developed at OAPA . This new algorithm is also capable to give consistent source intensities and upper-limits for undetected objects as well as an estimate of source extension. For further detailed description of the general mathematical properties of this wavelet transforms detection code see Damiani et al. 1997a and for a specific ROSAT PSPC application Damiani et al. 1997b ( Figures 1-11 [516 kB], Figure 12-15 [1137 kB] )

Other software developed in house includes:
An optimized time screening algorithm for ROSAT PSPC/HRI observations (Bocchino, Barbera, Sciortino 1997), implemented under the IRAF package and used in the Galpipe Project.
a model of the stellar coronal component of the Galaxy build in collaboration with scientists of ESA-SSD (cf. Favata et al. 1992, A&A, 256. 86; Micela et al. 1993, ApJ, 618, 412; Sciortino et al. 1995, A&A, 296, 370) ,
a software package to simulate the emission of the soft X-ray sky seen with imaging observatory like Jet-X, XMM and AXAF (Peres et al. 1994).
The Parallel Network and Communication Library, originally developed for the parallelization of data domain decomposition codes on the Meiko Computing Surface CS-1 (Reale, Barbera, Sciortino, Comp. Phy. Comm. 72, 129 1992) and then ported under PVM for use in our local workstation array (Reale, Bocchino, Sciortino, 1994 Comp. Phy. Comm. 83, 130)