Glossary

The following terms and acronyms are used in this Handbook.

ADU

Analog-to-digital Unit

ADCAnalog-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

ABνCorrection 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

aXeSpectroscopic data extraction software (deprecated and replaced by hstaxe)

BOP

Bright Object Protection

calwf3

WFC3 calibration pipeline software

CCD

Charge Coupled Device; a solid-state, photon counting device

CDS

Correlated Double Sampling

COS

Cosmic Origins Spectrograph

CfP

Call for Proposals

CR

Cosmic ray

CR-SPLIT

Division of a CCD exposure into shorter exposures to be used for cosmic ray rejection

CSMChannel select mechanism

CTE

Charge Transfer Efficiency

CVZ

Continuous Viewing Zone

DCLDetector Characterization Laboratory at NASA/GSFC

DN

Data Number

DQ

Data Quality

EEEncircled energy

ETC

Exposure Time Calculator; ETCs are Web-based tools which can be accessed through the WFC3 ETC webpage

FET

Field-effect Transistor

FGS

Fine Guidance Sensors

FITS

Flexible Image Transport System, the standardized astronomical data format (see NASA/GSFC documentation)

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: http://hsthelp.stsci.edu or help@stsci.edu

HRC

High Resolution Channel of ACS (non-operational)

HST

Hubble Space Telescope

hstaxeGrism exposure analysis software (replaced aXe)

IPT

Integrated Product Team

IR

Infrared

IRAF

Image Reduction and Analysis System, the environment in which ­STSDAS operated; deprecated in 2018 (see article in STScI Newsletter Volume 35, Issue 03)

ISR

Instrument Science Report

K

Degree Kelvin

MAST

Barbara A. Mikulski Archive for Space Telescopes, an online-accessible data archive hosting data from missions including HST

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 (~2000–4000 Å)

OTA

Optical Telescope Assembly

PASP

Publications of the Astronomical Society of the Pacific

Phase I

A proposal for observing time on HST.

Phase II

An approved HST proposal; includes precise detail of how program is to be executed

PI

Principal investigator

POM

Pick-off Mirror

PRFPixel Response Function
PSFPoint-spread function
PyRAFIRAF version implemented in the Python language; deprecated as of 2018 (see note in IRAF entry)

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 

SNR

Signal-to-noise ratio

SOFASelectable Optical Filter Assembly
SOCScientific Oversight Committee
ST-ECFSpace Telescope European Coordinating Facility

STIS

Space Telescope Imaging Spectrograph

STScI

Space Telescope Science Institute

STSDAS

Space Telescope Science Data Analysis System, IRAF software for data analysis and calibration formerly used to process HST data; unsupported as of 2018 (see note in IRAF entry)

stsynphot

HST-specific synthetic photometry software package (designed to complement synphot); see stsynphot User's Guide, Lim et al. (2016)

synphot

Synthetic photometry software package; see synphot User's Guide, Lim et al. (2016)

TAC

Telescope Allocation Committee

TEC

Thermal Electric Coolers

TVThermal Vacuum (ground tests done before WFC3 was installed on HST)

UV

Ultraviolet

UVISUltraviolet and Visual (CCD channel of WFC3)
WFCWide-Field Channel of ACS
WFC3Wide 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 installed during first servicing mission of December 1993