AKARI MLHES Data Set Processing with FAST AKARI: Astronomical Infrared Satellite AKARI (formerly ASTRO-­‐F), is the second Japanese satellite dedicated to infrared astronomy, from the Institute of Space and Astronautical Science (ISAS) of the Japanese Aerospace Exploration Agency (JAXA). Its main objective is to perform an all-­‐sky survey with better spatial resolution and wider wavelength coverage than IRAS (Qirst US, UK, Dutch infrared satellite launched in 1983) , mapping the entire sky in six infrared bands. Figure 1: Artist rendition of the AKARI satellite. FAST: FIS-­‐AKARI Slow-­‐scan Tools FAST is a program that allows for interactive assessment of the data quality and on-­‐the-­‐Qly corrections to the time-­‐
series data on a pixel-­‐by-­‐pixel bases in order to manually correct glitches that would have been missed in the pipeline process. These corrections include: (1) e l i m i n a t e b a d o n -­‐ s k y c a l i b r a t i o n sequences, (2) Qlag out cosmic-­‐rays and their after-­‐effect affected time-­‐series readings from the data stream and (3) remove real sources from local sky-­‐Qlat frames, among other options. Figure 2: Flight path of AKARI during the all sky survey (red) and pointing missions (green). AKARI information: 1 m = 1 000 000 µm Launched: 21 February 2006 First light: 13 April 2006 End of science operation 17 June 2011 Mirror diameter: 68.5 cm Temperature: 6 K Wavelength range: 2-­‐180 µm Sun-­‐synchronous polar orbit Nominal altitude: 700 km Orbital period: 100 min Scan and pointing modes Figure 3 shows the electromagnetic spectrum and where the infrared light is Figure 9: Example of the three GUI control panels and three images that allows for pixel-­‐by-­‐
pixel inspection. Dark, responsivity and Qlat can be altered to remove anomalies. Figure 8: This map window shows the observed region and the dots represent the positions of acquired data. Both of the wide and narrow band images will be created. Figure 10: The dark, responsivity and Qlat images for an individual pixel over the time of the exposure. These are used to select the regions of data to be used in creating the images. Figures 8 – 11 are all used in conjunction to clean up both the narrow and wide bands one after the other. It should be noted that these Qigures only represent the LW (long wavelength) band which consists of the data from Wide-­‐L and N160. located. MLHES Mission Program The AKARI MLHES (excavating Mass Loss History in Extended dust shells of Evolved Stars) data set is the largest collection of the most sensitive far-­‐infrared (far-­‐IR) images of the cold extended circumstellar dust shells of evolved stars and it is the key to understanding the dusty mass loss phase of stellar evolution (PI: Yamamura). There are 144 objects which have been observed using AKARI’s Far-­‐Infrared Surveyor (FIS) which is one of two instruments shown in Qigure 4. FIS has two detector arrays (Qigure 5) with 4 bands which capture information from the extended emission targets in different wavelengths. Figure 4: AKARI has two instruments the FIS for far-­‐
infrared observations and the IRC (InfraRed Camera) for n e a r a n d m i d -­‐ i n f r a r e d observations. Figure 5: FIS two detector arrays (wide and narrow) are tilted 26.5 deg resect to the scan direction and have some dead (blue) and badly performing (green) pixels. Figure 6: Hardware SpeciQications of the Far-­‐Infrared Surveyor (FIS). Figure 7: The scan pattern of AKARI around a point source for the MLHES mission program Results The time-­‐series data for 175 pixels (40 for N60, 60 for Wide-­‐S, 45 for Wide-­‐L, and 30 for N160) in each of 144 objects was loaded and calibrated. Along with this calibration, feed back was given to help make improvements to the interface, different structures in the LW band were noted, and also errors in the program were recorded. These improvements are scheduled to be included in subsequent updates to the program. Figure 11: The fazz (imaging software) produced images for the Wide-­‐L (left) and N160 (right) data. Acknowledgements Figure 12: Example of a cosmic-­‐ray affected AKARI 50μm-­‐110μm Alpha Orion map before (left) and after (right) the using FAST. This shows how FAST can be used to clean up data. Some suggestions for improvement included moving the upper left corner key seen in Qigure 10, adding a way to keep track of Qlagged out data, and making the GUI panels resizable. Recorded new structures: LW bad performing pixels to include 47 and 75. LW pixels 15, 16, 17, 19, 20, 43, 44, 45 have unique and systematic structures such as arcing and more dramatic ramping. The error in the discrepancy between the gray scale time-­‐series display vs. pixel number and the intensity vs. time-­‐series was noted. East Asian and PaciQic Summer Institute (EAPSI) fellowship program and NSF/JSPS for this opportunity to conduct research abroad. Dr. Yamamura and his team at ISAS/JAXA for allowing me to form an international collaboration. The 4 Corners APS meeting for allowing me the opportunity to present my research. References Ikeda, N., Takita, S, et al. 2012, FAST User's Manual (ISAS: Sagamihara) Verdugo, E., Yamamura, I., Pearson, C. et al. 2007, AKARI FIS Data User Manual Version 1.3 (ISAS: Sagamihara) Yamamura, I. 2010, The AKARI Far-­‐Infrared Bright Source Catalogue, COSPAR ScientiQic Assembly, 38, 2496