The latest version of the Chandra calibration database (CALDB 2.20) is now available for download from LEDAS.
The database browser BLASTA now supports searches of the new version of the Guide Star Catalog, GSC2.2. This version provides more accurate astrometry than GSC1.1, reaches 3-4 mag deeper and contains approx. 20 times as many objects (430 million vs. 18 million for GSC1.1). For a more detailed discussion of the new version of GSC, see the documentation at STScI.
The latest version of the Chandra calibration database (CALDB 2.17) is now available for download from LEDAS.
As a security measure, the LEDAS BROWSE captive account can now only be accessed via Secure Shell (SSH). Users will require an SSH client installed on their local machine in order to access BROWSE. The functionality of the service is otherwise unaffected.
To access the captive account, log in as user "ledas" to ledas.star.le.ac.uk. On the Unix command-line:-
% ssh -l ledas ledas.star.le.ac.uk
The password is empty (simply hit return).
If this is your first SSH login to the LEDAS system, you will be asked if you wish to add the host's ID key to your local database. Answer "yes". You will then be logged into the BROWSE account, and you can proceed as normal.
You may already have an SSH client installed on your machine -- if in doubt please consult your system administrator. SSH clients for Linux and MS Windows are available for free download from http://www.ssh.org/. If you encounter problems related to the BROWSE account itself, please contact firstname.lastname@example.org.
The Chandra data holdings at LEDAS are now automatically synchronised with the US data archives at CXC on a daily basis (previously, updates took place every two weeks).
The latest version of the HEASARC X-ray data reduction/analysis package HEASoft is now available for download. The current version consists of FTOOLS 5.2, FV 3.1, XIMAGE 4.1, XSPEC 11.2 and XSTAR 2.1h.
The online catalogues provided by BLASTA (including USNO-A2 and 2MASS) can now be queried directly from the image display/analysis software package GAIA. BLASTA source positions can be overlaid directly on sky images -- individual sources can be selected using the mouse, and their parameters displayed interactively.
To download and install GAIA on your local system, visit the Starlink Software Store.
To configure GAIA for BLASTA access, use the following procedure:-
LEDAS currently offers command-line access to the BROWSE database tool via telnet to the "ledas" captive account on host ledas.star.le.ac.uk. BROWSE provides a full range of commands for database query and data manipulation, together with utilities for display, analysis and export of data products.
As part of an effort to upgrade and secure the LEDAS network, we propose to move the captive account to Secure Shell (SSH) access only, and disable the telnet facility. The "telnet://" link on the LEDAS website will no longer be available, and users will require an SSH client installed on their local machine in order to access BROWSE. The functionality of the service will be otherwise unaffected.
You may already have an SSH client installed on your machine -- if in doubt please consult your system administrator. SSH clients for Linux and MS Windows are available for free download from http://www.ssh.org/.
If you have any questions about this planned change, or feel that it would cause you particular difficulties, please contact us at <email@example.com>. We anticipate that this change will take place approximately a month from now (late March).details). CALDB 2.12) is now available for download from LEDAS.
Public data from Chandra observations of the isolated neutron star RXJ185635-375 (total ~1.6GB) are now available for download from LEDAS.
The LEDAS Mirror of the ASCA Public Data Archive is now effectively complete, and all data have been reprocessed using revision 2 (Rev2) data processing. This reprocessing incorporates the final calibrations of time-dependent gains in both the SIS and GIS.
The latest version of the HEASARC X-ray data reduction/analysis software package HEASoft is now available for download from LEDAS. Release 5.1A fixes a number of bugs in the Solaris and Linux versions of the software.PIMMS has been updated to the latest version 3.2d. This update fixes a number of bugs with v3.2c, and includes the latest Chandra effective area curves required for Cycle 4 proposals.