Glossary

The following terms and acronyms are used in this Handbook.

 

ADU: Analog-to-digital Unit

ADC: Analog to digital Converter

ABMAG: –2.5 log (Fν) – 48.60 where Fν is the flux from the source in erg cm–2 sec-1 Hz-1

ABν: Correction to ABMAG to account for the fact that the source spectrum is not constant in Fν (ABMAG=V+ABν)

ACS: Advanced Camera for Surveys

APT: Astronomer’s Proposal Tool

aXe: Spectroscopic Data Extraction Software

BOP: Bright Object Protection

calwf3: WFC3 calibration pipeline software

CCD: Charge Coupled Device. Solid-state, light detecting device

CDS: Correlated Double Sampling

COS: Cosmic Origins Spectrograph

CP: Call for Proposals

CR: Cosmic ray

CR-SPLIT: Division of a CCD exposure into shorter exposures to be used for cosmic ray rejection

CSM: Channel select mechanism

CTE: Charge transfer efficiency

CVZ: Continuous viewing zone

DCL: Detector Characterization Laboratory at NASA GSFC

DN: Data number

DQ: Data quality

EE: Encircled energy

ETC: Exposure Time Calculator. ETCs are Web-based tools which can be accessed through the WFC3 Web pages.

FET: Field-effect Transistor

FGS: Fine Guidance Sensors

FITS: Flexible Image Transport System

FOV: Field of view

FPA: Focal-Plane Array

FSM: Filter select mechanism

FWHM: Full width at half maximum

GO: General Observer

GSC: Guide Star Catalog

GSFC: NASA’s Goddard Space Flight Center

Help Desk: Facility for getting help on HST related topics via email. help@stsci.edu.

HRC: High Resolution Channel of ACS (non-operational)

HST: Hubble Space Telescope

IPT: Integrated Product Team

IR: Infrared; also IR channel of WFC3

IRAF: Image Reduction and Analysis System. The environment in which ­STSDAS operates.

ISR: Instrument Science Report. Available at the WFC3 Web site.

K: Degree Kelvin

MBE: Molecular-beam Epitaxial

MPP: Multi Pinned Phased, a CCD mode that reduces dark current rate

MTF: Modulation Transfer Function

MUX: Multiplexer

NICMOS: Near-Infrared Camera and Multi-Object Spectrograph

NUV: Near ultraviolet (~2000 to 4000 Å)

OTA: Optical Telescope Assembly

PASP: Publications of the Astronomical Society of the Pacific

Phase I proposal: A proposal for observing time on HST

Phase II program: An approved HST program; includes precise detail of how program is to be executed

PI: Principal investigator

POM: Pick- off Mirror

PRF: Pixel Response Function

PSF: Point-spread function.

PyRAF: version of IRAF implemented in the Python language

QE: Quantum Efficiency

ramp: A sequence of non-destructive readouts comprising a single IR exposure

rms: Root mean square

SAA: South Atlantic Anomaly

SBC: Solar-Blind Channel of ACS

SDSS: Sloan Digital Sky Survey

SED: Spectral-energy Distribution

SIAF: Science Instrument Aperture File

SM4: Servicing Mission 4

SMOV: Servicing Mission Observatory Verification

S/N: signal-to-noise ratio

SOFA: Selectable Optical Filter Assembly

SOC: Scientific Oversight Committee

ST-ECF: Space Telescope European Coordinating Facility

STIS: Space Telescope Imaging Spectrograph

STScI: Space Telescope Science Institute

STSDAS: Space Telescope Science Data Analysis System. The complete suite of IRAF data analysis and calibration routines used to process HST data.

synphot: STSDAS synthetic photometry (IRAF) software package

TAC: Telescope Allocation Committee

TEC: Thermal Electric Coolers

UV: Ultraviolet

UVIS: Ultraviolet and Visual (CCD channel of WFC3)

WFC: Wide-Field Channel of ACS

WFC3: Wide Field Camera 3

WF/PC-1: Wide Field Planetary Camera-1. Original on-axis HST camera.

WFPC2: Wide Field Planetary Camera 2. Replacement for WF/PC-1 installed during first servicing mission of December 1993.