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Downtime expected shortly as all LEDAS services are moved to a new server.

What's new with LEDAS?

Note: Further updates are provided on a separate page of new LEDAS database tables.


2008

April 2008: LEDAS & AstroGrid Presentation at NAM 2008

New capabilities for cross matching 500+ high energy catalogues in one go using AstroGrid and LEDAS

We demonstrate new capability to quickly search, query, cross match and run python science scripts against over 500 high energy archives simultaneously in the Leicester high Energy Data Archive System (LEDAS) and any other Virtual Observatory (VO) enabled public archives using a robust new VO Desktop suite pioneered by AstroGrid for April 2008 public release. We illustrate this with a range of examples of new science samples derived in this way including searches for e.g. X-ray bright, highly reddened galaxies using XMM, 2MASS and UKIDSS and counterparts to transient events or X-ray extended sources. We illustrate the real benefits of a single entry point and remote execution over traditional methods. Finally we describe ambitious and ongoing efforts to investigate extracting upper flux limits for any position observed by a given mission where no catalogued source is recorded using the example of rare, optically selected
BAL QSOs found in XMM observations.

April 2008: PIMMS and WebPIMMS upgraded to version 3.9f: Constellation-X, XEUS effective area curves

The X-ray mission simulator PIMMS (and the online counterpart WebPIMMS) have been upgraded to the current version 3.9f. V3.9f includes effective area curves for future missions Constellation-X and XEUS, as well as updated curves for Swift UVOT (except grisms) and for INTEGRAL ISGRI and JEM-X.

March 2008: Chandra CALDB updated to version 3.4.3

The Chandra CALDB calibration database has been upgraded to version 3.4.3. CalDB 3.4.3 includes two T_GAIN upgrades. The first is for the usual current epoch update to Epoch 32 (Nov 07 through Jan 08), and the second part is the -110C upgrade to include a single T_gain file for 16 Sep 1999 effective through 28 Jan 2000. This latter includes TGAIN corrections ONLY for ACIS-S1 and -S3, and requires an upgrade to the S1 and S3 GAIN file as well. There is a particular advantage here for these two chips, because users may now reprocess their own -110C ACIS data, and use mkacisrmf for S3 and S1 RMFs. Also, for gratings observations, they get the new improved S1 GAIN function we introduced for the -120C data with CalDB 3.3.0.

See the CALDB 3.4.3 Release Notes

2007

Dec 2007: Chandra CALDB updated to version 3.4.2

The Chandra CALDB calibration database has been upgraded to version 3.4.2. CALDB 3.4.2 contains the following additions:

* ACIS T_GAIN files for Epoch 31 (Aug-Oct 2007)
* Chandra Proposal Cycle 10 "PIMMS" effective area files

See details in the link CalDB 3.4.2 Release Notes.

Dec 2007: PIMMS, WebPIMMS updated to version 3.9e: Chandra effective area curves

The X-ray mission simulator PIMMS (and the online counterpart WebPIMMS) have been upgraded to the current version 3.9e. Version 3.9e includes new effective area curves for the Chandra instruments. These versions are appropriate for Cycle 10 proposers.

Oct 2007: PIMMS, WebPIMMS updated to version 3.9d: Suzaku effective area curves

The X-ray mission simulator PIMMS (and the online counterpart WebPIMMS) have been upgraded to the current version 3.9d. Version 3.9d includes effective area curves for the Suzaku XIS and HXD instruments. The new versions are appropriate for Cycle 3 proposers.

Sep 2007: BLASTA updated to support SDSS Photometric Catalog (DR4)

The catalog search engine BLASTA has been updated to support the fourth data release of the Sloan Digital Sky Survey Photometric Catalogue. The Sloan Digital Sky Survey will map one-quarter of the entire sky and perform a redshift survey of galaxies, quasars and stars. Data Release 4 (DR4) covers 6670 square degrees and catalogs 180 million unique objects from CCD images taken through five filters (u-3655A, g-5155A, r-6480A, i-7105A, z-8630A) Photometry is better than 3%, and positions are accurate to about 0.1 arcsecond in each coordinate.

Sep 2007: Chandra CALDB updated to version 3.4.1

The Chandra CALDB calibration database has been upgraded to version 3.4.1. CALDB 3.4.1 is a cumulative upgrade to CalDB 3.3.0 or later versions; It includes the following:

* Updated and finalized ACIS BKGRND blank sky files, including the new BI CTI corrections for ACIS-5 and ACIS-7.
* Upgraded ACIS time-dependent gain (T_GAIN) data for Epoch 30 (May-July 2007).
* Upgraded HRC-I DEGAP (GAPLOOKUP) table

See details in the link CalDB 3.4.1 Release Notes.

Sep 2007: Spectral line analysis software PROFIT upgraded to version 2.0.0

Profit is a GUI (graphical user interface) tool for accessing high-resolution spectra. Profit displays spectra in various formats, allowing users to identify emission lines, to convert an identified line into velocity units using a user-selected wavelength, to store (and restore) individual spectra, to fit lines to gaussians, and other features. This is a mirror of the Profit homepage at HEASARC.

New Features: Version 2.0.0

  • Includes default energy boundaries for most X-ray missions, including the XMM RGS, Chandra LETG and HETG, and others. The user can still select observation-specific responses if available, but the default values are adequate for all data taken straight from the archives or processed in a standard fashion.
  • Menus are now "detachable," by selecting the "-----" item at the top of each menu.
  • Line fits are now more robust. Only the brightest 20-25 lines in a spectrum will be fit, and the rest ignored. This intentional limitation on the fitting dramatically reduces fit times and increases the chance that the fit will converge. The previous approach tried to fit each line, and it tended to fail easily.
  • Line fit values are reported in units of "Total Counts", rather than peak counts. This allows the reported values to be used directly when making line ratios, since there is no dependence on line width or position.
  • Clicking on the right mouse button allows horizontal "scrolling" of the plot.
  • Multiple data sets can be loaded and used simultaneously; all datasets that have been opened are available in the Spectrum menu.

Sep 2007: PIMMS and WebPIMMS upgraded to version 3.9c: XMM-Newton AO-7 support

The X-ray mission simulator PIMMS (and the online counterpart WebPIMMS) have been upgraded to the current version 3.9c. V3.9c includes a new set of effective area curves for XMM-Newton for AO-7 proposers. This reflects very minor calibration changes. However, at the same time, PIMMS now predicts count rates for EPIC/pn for PATTERN=0 events only, to provide a more conservative estimates for proposers. This change reduces the predicted count rates typically by a third. There is a corresponding minor change in pile-up correction routine so it will continue using the total (all PATTERN) count rates internally.

Aug 2007: Second XMM Serendipitous Source Survey 2XMM released

2XMM is the second comprehensive catalogue of serendipitous X-ray sources from the European Space Agency's (ESA) XMM-Newton observatory. The catalogue has been constructed by the XMM-Newton Survey Science Centre (SSC) on behalf of ESA. Access to the catalogue and a wide range of associated data products is available from LEDAS through the search engine ARNIE5. The basic catalogue may also be downloaded as a VOTable.

The 2XMM catalogue is the largest X-ray source catalogue ever produced, containing almost twice as many discrete sources as either the ROSAT survey or pointed catalogues. 2XMM complements deeper Chandra and XMM-Newton small area surveys, probing a much larger sky area. The schematic plot to the right, loosely based on Brandt & Hasinger 2005 (ARA&A 43, 827), shows the 2XMM catalogue in comparison with other X-ray surveys.

The 2XMM catalogue provides an effective dataset for generating large, well-defined samples of various types of astrophysical object, notably active galaxies (AGN), clusters of galaxies, interacting compact binaries and active stellar coronae, using the power of X-ray selection. The large sky area covered by the serendipitous survey also means that 2XMM is a rich resource for exploring the variety of the X-ray source populations and identifying rare source types.

The catalogue contains source detections drawn from 3491 XMM-Newton EPIC observations made between 2000 February 3 and 2007 March 31; all datasets were publicly available by 2007 May 01 but not all public observations are included in this catalogue. The catalogue contains 246897 X-ray source detections which relate to 191870 unique X-ray sources.

The median flux in the total photon energy band (0.2 - 12 keV) of the catalogue detections is ~ 2.5 × 10-14 erg cm-2 s-1; in the soft energy band (0.2 - 2 keV) the median flux is ~ 5.8 × 10-15, and in the hard band (2 - 12 keV) it is ~ 1.4 × 10-14. About 20% of the sources have total fluxes below 1 × 10-14 erg cm-2 s-1.

There are 20837 detections of extended emission in the catalogue. For 38320 detections spectra and time series were automatically extracted during processing, and a ?2-variability test was applied. 2307 detections in the catalogue are considered variable at a probability of 10-5 based on the null-hypothisis that the source is constant.

Aug 2007: CIAO updated to version 4.0beta2, ChiPS plotting software

The Chandra data reduction software CIAO has been updated to version 4.0beta2. The CIAO 4.0 Beta 2 release includes a new, more powerful version of ChIPS, the CIAO plotting package. It can be used during data analysis - e.g. to plot a lightcurve - and to create publication-quality figures. Details and documentation on the new system is available from the ChIPS website.

Several bug fixes to the CIAO tools are also included.

Sherpa is not included in CIAO 4.0 Beta 2. It will be released in Beta 3 (Fall 2007).

Aug 2007: Opacity Project files updated to version 3.3

The Opacity Project (OP) refers to an international collaboration that was formed in 1984 to calculate the extensive atomic data required to estimate stellar envelope opacities and to compute Rosseland mean opacities and other related quantities.

OP opacities have been recently revised to include inner-shell contributions. The new data and a suite of easy-to-use codes to compute Rosseland means and radiative accelerations can be downloaded as a tar file. This is an unofficial mirror of the Opacity Project page at ViZieR.

May 2007: Command-line/CGI access to BLASTA

Scripted access to the BLASTA catalogue search engine (which includes SDSS, 2MASS, GSC2.2, USNO-B1 and other large catalogues) is now possible using the special URL:

http://www.ledas.ac.uk/cgi-bin/scat

followed by the search parameters desired. As an example:

http://www.ledas.ac.uk/cgi-bin/scat?catalog=gsc&ra=10:00&dec=10:00&sys=J2000&rad=360&

where the available arguments defined here can be listed with

http://www.ledas.ac.uk/cgi-bin/scat?help

May 2007: CIAO and CALDB updated

The Chandra CIAO data reduction software and CALDB calibration database have been upgraded (CIAO 4.0beta1 and CALDB 3.4.0). The most notable change in CIAO 4.0 Beta 1 is that the ACIS dead area correction is turned on by default; refer to the How CIAO 4.0 Beta 1 and CALDB 3.4.0 Affect Your Analysis section for details. There is a new version of tgextract - named tgextract2 - which provides similar functionality, but allows large and asymmetric regions for better determination of background counts. Significant work has been done on the tool wavdetect, which has two new parameters. The sso_freeze tool has been enhanced so that it can create object-centered aspect solution which, among other uses, allows an object-centered exposure map to be generated. A number of bug fixes to the Data Model library and several CIAO tools are also included.

CIAO 4.0 Beta 1 is the first release of CIAO to be fully GPL compliant. OTS (off-the-shelf) software have been updated to current versions. A set of "smoke test" scripts are included to aid users in verifying installation of the release.

CALDB 3.4.0 is required for the proper operation of CIAO 4.0 Beta 1. CALDB 3.4.0 contains a number of updates, including ACIS time-dependent gain files, updated ACIS blank-sky background files, and HRC-I gain maps.

ChIPS and Sherpa are not included in CIAO 4.0 Beta 1. They will be released in CIAO 4.0 Beta 2 (Summer 2007) and Beta 3 (Fall 2007), respectively. Additional information on this release is available from the About CIAO 4.0 Beta 1 page.

Jan 2007: Two software patches for CIAO 3.4 users running MacOSX 10.4

The CIAO 3.4.1 patch fixes problems running prism and filtwin under Mac OS X 10.4 on PowerPC. This patch has no effect when installed under Mac OS X 10.2 or 10.3 on PowerPC. The patch file upgrades CIAO 3.4 to CIAO 3.4.1.

Jan 2007: CIAO software patches for Mac OSX users

There are two software patches for users running CIAO under Mac OS X 10.4.

(Solaris and Linux platforms are not affected.)

*Mac OS X 10.4 on PowerPC: CIAO 3.4 for Mac OS X 10.4 on PowerPC has been patched to 3.4.1. This patch fixes problems running prism and filtwin under 10.4 (Tiger). This patch has no effect when installed under Mac OS X 10.2 or 10.3 on PowerPC.

*Mac OS X 10.4 on Intel: the CIAO 3.4.1.1 patch makes it possible to run all tools and applications (e.g. Sherpa and ChIPS) in CIAO 3.4 under Mac OS X 10.4 on Intel.

Details are available in the CIAO 3.4.1 and 3.4.1.1 Release Notes. Refer to the OS-X Platform bug page for known issues.

Jan 2007: CIAO and CALDB updated

The Chandra CIAO calibration software and CALDB database have now been upgraded (CIAO 3.4 and CALDB 3.3.0). Note that CALDB 3.3.0 is required for the proper operation of CIAO 3.4.

The CIAO 3.4 and CALDB 3.3.0 releases primarily consist of changes related to the CTI corrections. The CTI-adjustment algorithm included in acis_process_events now accommodates the newly calibrated serial CTI on the back-illuminated CCDs. This is in addition to the continued support for parallel CTI. This CIAO release also contains two new tools for working with HRC data (hrc_build_badpix, hrc_dtfstats) and the ability to update WCS in non-Chandra images (reproject_aspect, wcs_match, wcs_update). Significant work has been done on the tool psf_project_ray, which has four new parameters. Plus bug fixes to the Data Model library and several CIAO tools. Finally, this release includes the PIMMS effective area file upgrade required for Cycle 9 proposal planning.

A section at the beginning of the CIAO 3.4 release notes highlights how CIAO 3.4 and CALDB 3.3.0 affect analyses that are in progress.

Installation instructions for CIAO and the CALDB are available on the Downloading CIAO page.

Jan 2007: PIMMS and WebPIMMS upgraded to version 3.9b

The X-ray mission simulator PIMMS (and the online counterpart WebPIMMS) have been upgraded to the current version 3.9b. V3.9b includes updated Chandra effective area curves appropriate for Cycle 9 proposers. It also fixes a bug that affected energy flux calculations of redshifted, table-based models (including Raymond-Smith) has been fixed. Note that analytical models (power-law, blackbody, bremsstrahlung) were never affected by this bug; neither were table-based models when not redshifted; nor the photon flux calculations of redshifted, table-based models.


2006

Nov 2006: Chandra calibration database CalDB updated to version 3.24

The latest version of the Chandra calibration database CalDB v3.2.4 is now available for download from LEDAS. CalDB 3.2.4 is a cumulative upgrade to CalDB 3.x.x. It includes six new ACIS time-dependent gain correction (T_GAIN) files which account for (1) a discontinuity in the gain versus time for ACIS chips I0 and I2 which occurred around 01 August 2005, and (2) includes two new T_GAIN epochs, namely 25 (Nov 2005-Jan 2006) and 26 (Feb-April 2006). See details in the CalDB 3.2.4 release notes.

Sept 2006: PIMMS and WebPIMMS upgraded to version 3.9

The X-ray mission simulator PIMMS (and the online counterpart WebPIMMS) have been upgraded to the current version 3.9. V3.9 includes a minor bug fix for command line users that affected Linux users (core dumps in certain situations). It also includes a new set of effective area curves for XMM-Newton EPIC instruments appropriate for AO-6 proposers, although the difference with previous versions is small. There is no update for the RGS effective area curves at this time. The XMM-Newton effective area curves can be downloaded separately to update existing installations of PIMMS.

Sept 2006: Chandra Data Archive Mirror modified

The Chandra Public Data Archive Mirror has now been modified, and is now the default data source for all requests originating from European users. By agreement with CXC requests for data from European users on the CXC site at Harvard will be automatically forwarded to LEDAS. Users should see a corresponding increase in download speeds.

Sept 2006: Chandra calibration database CalDB updated to version 3.23

The latest version of the Chandra calibration database CalDB v3.23 can now be downloaded from LEDAS. CalDB 3.2.3 is a patch upgrade to version 3.2.2, which includes two new files affecting only the HRC-I configuration, and both of which are used only by the pipeline/CIAO tool "hrc_process_events". One is an upgrade to the "degap" correction data table (GAPLOOKUP), and the other is a correction to the HRC-I gain map (GMAP) applicable to observations taken before UTC=1999-10-04T12:00:00, i.e. applicable only to the first two months of the Chandra mission.

CalDB 3.2.3 will be installed in Standard Data Processing, and released to the public as a cumulative upgrade to any and all preceding versions back to CalDB 3.0.0 (released in December 2004). For more information, see the CalDB v3.2.3 Release Notes.

August 2006: ARNIE5 catalogues available for direct download in VOTable format

A large fraction of the catalogues currently held in the ARNIE5 archive system can now be downloaded in VOTable format from the LEDAS anonymous FTP site. At present, the FTP repository includes gzipped VOTables for 412 catalogues of 200,000 rows or less. VOTables can be viewed in applications such as VOPlot and TOPCAT. For more information on the VOTable data format, see the IVOA Format Definition document.

August 2006: 2XMMp searchable via AstroGrid

2XMMp is the pre-release of the second comprehensive catalogue of serendipitous X-ray sources from the European Space Agency (ESA) XMM-Newton observatory. The catalogue is now accessible via a Virtual Observatory (VO) interface using software provided by the UK national VO project AstroGrid. Data held on the LEDAS VO server camelot.star.le.ac.uk can be searched using the AstroGrid 'Workbench' software. For more information on how to install and use AstroGrid software, see the Software User Guide.

August 2006: Serendipitous Source Catalogue (Pre-release) 2XMMp

2XMMp is the pre-release of the second comprehensive catalogue of serendipitous X-ray sources from the European Space Agency's (ESA) XMM-Newton observatory. The catalogue has been constructed by the XMM-Newton Survey Science Centre (SSC) on behalf of ESA.

The catalogue contains source detections drawn from 2400 XMM-Newton EPIC observations made between 2000 February 4 and 2006 April 20; all datasets were publicly available by 2006 May 31 but not all public observations in this catalogue. The catalogue contains 153105 X-ray source detections which relate to 123170 unique X-ray sources. The median flux (in the total energuy band 0.2- 12 keV) of the catalogue sources is ~2.4 × 10-14 erg cm-2 s-1; ~20% have fluxes below 1 × 10-14 erg cm-2 s-1.

This catalogue and associated data products (source and background images, time series plots, spectral plots) can now be accessed through the archive interface ARNIE5.

For more information see the XMM Catalogue public pages at the XMM-Newton Survey Science Centre.

July 2006: Important bug fix to WebPIMMS

There was a bug in the latest version of the online X-ray mission simulator WebPIMMS which caused multicomponent simulations of Swift observations to ignore all but the first component. This bug has now been fixed.

May 2006: PIMMS and WebPIMMS upgraded to v3.8a

The X-ray mission simulator PIMMS (and the online counterpart WebPIMMS) have been upgraded to the current version 3.8a. The latest version includes corrections for the dead-time fraction of XMM-Newton EPIC-pn burst mode, adds background and signal-to-noise information for Swift-BAT, and updates the effective area curves for Swift/XRT.

Apr 2006: RAS-NAM2006 Presentation

The presentation given at RAS-NAM2006: "The X-Ray Synoptic Viewer: X-Ray Data Access and Reduction in the Virtual Observatory" is now available for download as a Powerpoint file (715KB).

Mar 2006: CIAO patch 3.3.0.1 available for download

CIAO 3.3 has been patched to CIAO 3.3.0.1. This is a very small patch which contains a PIMMS effective area file upgrade required for Cycle 8 proposal planning. The patch is required *ONLY* if you plan to run PIMMS in interactive CLI mode (i.e. on the command line) via the tool "prop_pimms".
It is NOT required if you only run PIMMS through the web interface.

The patch is already installed on the HEAD-LAN or can be downloaded from
http://chandra.ledas.ac.uk/ciao/download/

Jan 2006: PIMMS and WebPIMMS updated to v3.7a2

The X-ray mission simulator software PIMMS (and the online counterpart WebPIMMS) have been upgraded to v3.7a2. This version contains corrected Chandra effective area curves for AO-8 proposals.



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