Terms and acronyms associated with the ASCA mission and ASCA data analysis are defined below. For information about any of the FTOOLS try using the fhelp FTOOL by typing fhelp program name.
ASCA --- Advanced Satellite for Cosmology and Astrophysics.
Astro D --- The pre-launch name for ASCA
bit-rate --- The speed with which information was sent from ASCA to the ground. Can be either ``high'', ``medium'', or ``low''.
Bright mode --- A mode for the SIS detectors which groups the nine pixels around an event together and rejects some events based on the pattern of excited pixels.
Bright2 mode --- A simulated mode created on the ground from Faint mode data. It is similar to Bright mode except that corrections have been made for dark frame error and echo effect.
detector coordinates --- The raw position information for an event.
Faint mode --- A mode for the SIS which sends information for each pixel separately.
FITS --- Flexible Image Transport System. The standard file format for information exchange in astronomy.
FTOOLS --- a set of programs which manipulate FITS files.
flickering pixels --- Pixels which give intermittent false signals.
FRF --- First Reduction Files the raw files from Japan before any processing is done on them.
gain --- The relationship between the energy of an incoming photon and the PHA response.
hot pixel --- An SIS pixel which gives a false signal all the time.
GIF --- Graphics Interchange Format. A standard format for bit-map images for which there are many viewers such as xv and World Wide Web browsers.
GIS --- Gas Imaging Spectrometer. A type of detector on ASCA. There are two GISs called GIS2 and GIS3.
GO --- Guest Observer. This means you.
GOF --- Guest Observer Facility. A group of people at GSFC in charge of helping you.
GSFC --- Goddard Space Flight Center. The NASA center where your tape was made.
IRAF --- An astronomical data analysis package.
ISAS --- Institute of Space and Astronautical Science. The Japanese organisation in charge of ASCA.
MPC --- A GIS mode which optimises timing information, but throws away spatial information.
PH --- The normal GIS mode.
PHA --- Pulse Height Analyzer. The device which measures the energy of a photon, often used to refer to the raw numbers measured by the device.
PI --- Pulse Invariant. PHA values corrected for spatial and temporal changes in gain. Also Principal Investigator.
PPM --- Another graphics file format.
sequence number --- An eight digit number which identifies an observation.
SIS --- Solid-state Imaging Spectrometer. A type of detector on ASCA. There are two SISs called SIS0 and SIS1.
Universal Time --- Similar to Greenwich Mean Time
XANADU --- The official data analysis package for ASCA, including xspec, ximage, and xronos