The FITS is the standard file format in astronomy, and it has been extended to agree with astronomical needs of the day. However, astronomical datasets have been inflating year by year. In case of ALMA telescope, a ~ TB scale 4-dimensional data cube
may be produced for one target. Considering that typical Internet bandwidth is a few 10 MB/s at most, the original data cubes in FITS format are hosted on a VO server, and the region which a user is interested in should be cut out and transferred to the user (Eguchi et al., 2012). The system will equip a very high-speed disk array to process a TB scale data cube in a few 10 seconds, and disk I/O speed, endian conversion and data processing one will be comparable. Hence to reduce the endian conversion time is one of issues to realize our system. In this paper, I introduce a technique named just-in-time endian conversion, which delays the endian conversion for each pixel just before it is really needed, to sweep out the endian conversion time; by applying this method, the FITS processing speed increases 20% for single threading, and 40% for multi-threading compared to CFITSIO. The speed-up by the method tightly relates to modern CPU architecture to improve the efficiency of instruction pipelines due to break of causality, a programmed instruction code sequence.
The broad band spectra of two Swift/BAT AGNs obtained from Suzaku follow-up observations are studied: NGC 612 and NGC 3081. Fitting with standard models, we find that both sources show similar spectra characterized by a heavy absorption with $N_{rm{H
}} simeq 10^{24} rm{cm}^{-2}$, the fraction of scattered light is $f_{rm{scat}} = 0.5-0.8%$, and the solid angle of the reflection component is $Omega/2pi = 0.4-1.1$. To investigate the geometry of the torus, we apply numerical spectral models utilizing Monte Carlo simulations by Ikeda et al. (2009) to the Suzaku spectra. We find our data are well explained by this torus model, which has four geometrical parameters. The fit results suggest that NGC 612 has the torus half opening-angle of $simeq 60^{circ}-70^{circ}$ and is observed from a nearly edge-on angle with a small amount of scattering gas, while NGC 3081 has a very small opening angle $simeq 15^circ$ and is observed on a face-on geometry, more like the deeply buried new type AGNs found by Ueda et al. (2007). We demonstrate the potential power of direct application of such numerical simulations to the high quality broad band spectra to unveil the inner structure of AGNs.
We present the Suzaku broad band observations of two AGNs detected by the Swift/BAT hard X-ray (>15 keV) survey that did not have previous X-ray data, Swift J0601.9-8636 and Swift J0138.6-4001. The Suzaku spectra reveals in both objects a heavily abs
orbed power law component with a column density of NH =~ 10^{23.5-24} cm^{-2} that dominates above 10 keV, and an intense reflection component with a solid angle >~ $2pi$ from a cold, optically thick medium. We find that these AGNs have an extremely small fraction of scattered light from the nucleus, <~ 0.5% with respect to the intrinsic power law component. This indicates that they are buried in a very geometrically-thick torus with a small opening angle and/or have unusually small amount of gas responsible for scattering. In the former case, the geometry of Swift J0601.9-8636 should be nearly face-on as inferred from the small absorption for the reflection component. The discovery of two such objects in this small sample implies that there must be a significant number of yet unrecognized, very Compton thick AGNs viewed at larger inclination angles in the local universe, which are difficult to detect even in the currently most sensitive optical or hard X-ray surveys.
