Guidance for use of buttons to access database contents
Access to the contents of the database is provided, initially, through a panel of (currently) 13 buttons. Each provides direct access to a particular type of data. The use of each of these is outlined below.
This button brings you to the root of the XID database, the list of all fields selected for observation by XMM. The resulting page summarises the planned observation details and gives additional information about the line-of-sight galactic column density and items such as the brightest optical object in the field, along with pointers to associated ROSAT and Chandra pointings. Importantly, from here, if the data exists in the DB, one can access the list of X sources in the field and optical catalogues and counterpart lists from the follow-up programme.
It should be noted that a `Field` here represents one or more XMM observations with essentially the same pointing direction, coming from the same proposal. The X-X source lists reflect possible multiple detections of the same object amongst these observations.
A sorting utility and selection on various parameters is possible. View Fields Table output
A summary of the basic properties of the performed XMM observation are listed. Coordinates, boresight galactic column density, nominal and GoodTimeInterval exposure times, mode and filter are provided (for the `best` exposure), along with the public release date for the observation. The `pipeline processed` (P), `PI authorisation for XID use` (A) and `selected for XID use` (X) flags are green if true or otherwise red (including uncertain). The magnitude of the brightest star in the field and a simple summary of the filters in which the field has been imaged for the XID programme, are shown. One can also view the XMM observation summary details and quick-look XID band images (if ingested) and whole-field DSS optical images (35'x35'). A link to data products exists on this page if available. A range of selection tools are available. Note that one can use & (and) and | (or) operators for the `Inst` and Opt-IR Filters selection tools, e.g. a) set Inst = PN | M1 and set Mode = FF will return PN or M1 observations where the mode was FullFrame (FF). b) setting Opt-IR Filters = i & r & U will return observations which have i, r and U band imaging data taken. View XMM Observations Table output
This gives details of follow-up optical imaging observations on a per exposure basis. This page contains details of quality information, e.g. seeing, ellipticity (trailing), zero-point error and limiting magnitude (for all 4 CCD's for the WFC) when available, along with links to observer reports and logs. Selection tools allow one, for example, to pull out exposures in the r or i bands (Filter = r | i) where the seeing measured from one or more CCDs lies between 1.0 and 2.0" (Seeing min=1.0, max=2.0) and where the trailing is in the range 0.1-0.5 (ellipticity min=0.1, max=0.5).
This is similar to the `byExposure' button but provides a numerical overview of the optical imaging observations per field, tabulating the number of exposures and total exposure time in each filter. The numerical link under `No. Exp` takes you to the details for the appropriate exposure(s), i.e. the `byExposure` page. The page also indicates if USNO or Supercosmos data exist and how many spectra are available for a given field.
On this page one gets an overview of the follow-up observing runs, with links to the observer reports and logs. Links are available to details of the observatory and to external web sites relating to the telescope/instruments. The type of observation, requested/allocated nights, observing semester, observation dates (when accepted), Observer name and run status information are shown. Links to the reports and observation logs are provided. For imaging obs., a link under the Summary column takes you to the details of the exposures in that run. Amongst other things, the selection tools allow users to extract runs from a given observatory site (e.g La Palma). One can bracket an observation date using the `Start date` or `End date` tools. Rejected proposals are indicated in red.
A basic tally of sources/fields in the various samples. Currently, for sources, the Faint, Medium and Bright samples refer to groupings defined by the XID-band flux in the database. This is based on an assumed power law slope of 1.7 and a column density of 3x1020 cm-2. The database also contains an `extragalactic` XID band flux which is based on an assumed power-law slope of 1.7 but the column density is taken to be the galactic H column along the line of sight to the field centre. It is anticipated that the summary information will be provided for the AXIS and other samples. For `source` samples, the table provides info on the total number of X objects falling into that sample, the number ID'd, the number probably ID'd and the number with no counterpart evident. For `Field` samples, the table reflects the total number of fields considered suitable for that sample, the number that are selected for the XID programme, the total observed and the number of XID selected ones observed.
This button gives direct access to the list of fields for which XMM products exist in the DB. From here one can browse the observation summary (including links to see the background light curves and total band PNG images) and view the XID band images. There are links to the images and source lists for download. This data is on a per observation basis. NOTE - there is a security issue here since downloadable files may belong to proprietary observations. Check the public release date on the `XMM Observations` page and, for safety, check with MGW before downloading data.
Provides direct access to a list of fields which have ingested optical product files. Links from here permit file downloads.
Gives a listing of details of Chandra pointings and XMM fields with which they overlap.
Gives a simple overview of XMM proposals (where available) - i.e. proposal number, PI, number of proposed observations under the proposal ID, the proposal title and the Panel to which the proposal was submitted.
This button yields a list of all unique XMM sources across all fields. It is the global version of the list obtained from the `XMM Fields` page. From this page, one can view available optical and X-ray finding charts, as well as accessing the key X-ray properties of the source (coordinates, per-instrument values for the detection ML, `PPS XID-band flux*`, `extragalactic XID flux**`, XID band count rate, total band count rate, hardness ratios, links to any ID info and details of counterparts - including spectral information and, in future, links to related OM/Chandra/RASSBSC data. For now, where a source is detected in more than 1 observation, many of the quantities are averages of those measured from the individual observations. This is imperfect, particularlty if different observing modes or filters are used - the original data pertaining to a given observation can, in principle, be accessed via the original data column
* - Assumes a power-law spectrum spectrum with slope (gamma) = 1.7, absorbed by a cold absorber with a column density of 3x1020 cm-2. The flux quoted is that measured at Earth for such a spectrum.
** - Assumes a power-law spectrum of slope=1.7, absorbed by a cold absorber with a column density equal to the galactic H column along the line of sight to the centre of the particular field. The flux quoted is corrected to zero absorption (i.e. that at the edge of the galaxy).
This page is the global version of the Optical sources (and optical counterpart) columns in the `XMM Fields` page. Key details include the list of magnitudes measured and, if applicable, the X source that the optical object is a counterpart of. Links to spectral details and spectral plots are available if ingested.
Yields summary information about RASSBSC objects. At present these are not related back to XMM sources.