ESP: Extended Surface Photometry

ESP exists to allow user to perform many of the processes required when profiling galaxies. The package, which can generate slices, contour analysis galaxy profiles, intensity analysis galaxy profiles, flat-field images, mask objects, detect bad flat fielding, remove bright objects and calculate scale lengths is documented in SUN/180.

Contents

• Introduction
• News, version 0.10
• Current version
• Documentation
• Authors and support

Introduction

The applications contained within the package are

SKEW

Detect/identify flatfielding faults

TOPPED

Remove cosmic ray events

FASTMED

Median filter images on a defined scale

HISTPEAK

Determine whole image statistics including: median count, modal count, kurtosis and skewness

LOBACK

Determine the local background value on a number of different parts of an image

ELLPRO

Perform galaxy profiling using intensity analysis

ELLFOU

Perform galaxy profiling using contour analysis

SECTOR

Generate galaxy pie slice cross-sections

GAUFIT

Perform 2-D Gaussian fitting to multiple sources

GRAPHS

Display graphs showing the profiling/cross-section results

SELFC/SELFCW/CORR

Help detect faint diffuse objects in an image

News, version 0.10

ESP is integrated into GAIA. It is the brains behind the `Surface Photometry' toolbox, under the `Image-analysis' menu.

ESP is aware of World Coordinate Systems.

The COSYS parameter has been removed from all ESP applications, so that all user input and output is now in the Current co-ordinate system of the NDF. The Current co-ordinate system is a characteristic of the WCS component of the NDF. Thus, instead of setting COSYS to use either 'Data' or 'World' co-ordinate sytems, you should now set the Current frame of the NDF's WCS component (e.g. using KAPPA's WCSFRAME apllication) to the desired co-ordinate system before running the ESP application.

Output to data files is however in Base (WCS GRID frame) co-ordinates, which are pixel co-ordinates guaranteed to start at (1,1).

For NDFs which have a WCS component with a SKY frame in it, the PSIZE parameter (pixel size in arc seconds) is now determined automatically rather than being solicited from the user. This can be overridded by specifying it on the command line.

ESP applications which generate output NDFs from input NDFs now propagate the WCS component where appropriate.

Changes between 0.10-1 and 0.10-8

The only significant difference from the 0.10-1 release of ESP is to make ESP WCS-aware (these changes were made by Mark Taylor).

Also, there were several changes to make ESP more compatible with GAIA.

There are a few other changes associated with code tidyups and minor bugfixes.

The user-visible changes are:

• The COSYS parameter has disappeared, made redundant by the addition of WCS facilities throughout the program.
• ELLPRO and ELLFOU now take an OUTCAT parameter, which specifies a file to receive output in the form of a catalogue, readable by the CAT library (see SUN/181).
• Added missing documentation to HISTPEAK and LOBACK.
• Slight changes to output formats, to a few parameter defaults and to a few error messages to make them more useful.

Current version

The current ESP distribution is 0.10-8.

• source: esp-0.10-8.tar.gz
• pre-built: ix86_Linux, alpha_OSF1

Documentation

The ESP documentation is contained in Starlink document SUN/180

• Canonical version at RAL
• The local version may be more up to date, but you should not link to this version.

Authors and support

• Grant Privett
• Norman Gray
• Mark Taylor

Norman Gray is the ESP maintainer. The ESP support page is now http://www.starlink.ac.uk/esp. This URL will redirect you here automatically, but it is this canonical URL which you should use when making links to these pages -- that way, your links will not break when and if these pages are next moved.