CAISMI - CNR

Osservatorio Astrofisico di Arcetri

ARCHIVIO DATI TIRGO

Help and Tips.



Introduction

The Archive is formed with all files measured with ARcetri Near Infrared CAmera ( ARNICA). Each files contains (in FITS format) or a single exposure or the mean of single exposures taken at the same telescope position. The filer used can be either a Johnson broad band infrared filter (J, H, K), or a narrow band filter (see ARNICA) page for details). Most measures was acquired at the TIRGO telescope, while a smaller sample cames from the few telescopes Arnica was ported to (WHT, NOT, VATT and TNG). All frame are in FITS format and are 256x256 pixels in size. The archive contains more than 250.000 frames. Most files belongs to a compound measure (we call them "a mosaic"), see "background" for details.

Data are stored in CD-ROMs, in date order. Each CD-ROM contains a directory structure which reflects date: YY_MMM/MMM_DD/SS, where YY are the last two digit of year (00 for 2000), MMM are the first three letter of month name, DD are the day number, and SS are the save number (1-14, but can be split in 1A, 1B, ... 1H,2A, 2B, ...). (See here for details).

All data are made available "as are", they were acquired by many observers with different procedures, different aims and with a sky quality we cannot asses, so we cannot give ANY quality or usefulness guarantee. If an attempt to do an independent reduction has to be carried, we strongly suggest to look for the original logbooks (can be obtained from original observer, for a small subset we have a copy). In any case, if you try to use these data, we suggest to contact the observer(s). In the ARNICA) page some useful documentation and a reduction package can be found. The real data will be shortly available throught the archive interface, now can be asked to Ale. We collect also the logbooks, but our collection is incomplete. To get loogbook informations, please ask Ale.

The positions recorded with data are NOT accurate, and can comprise (and normally do) mechanical and astronomical corrections used for pointing.

Searching the Archive

String fields asks for a "sub-string search", which means the search matches if the string specified is located anywhere in the field. Numeric field asks for an exact match. The specified strings cannot contain wildcards or special characters. The search is "case independent". All string field do not contains any spaces or tabs, they have been automatically replaced by "_" (underscore). The search is performed as a logical AND between all non-blank fields.

The search keywords are:

Disk
The CD-ROM identifier. For TIRGO data it is NIR_1, ... NIR_53, ... . Older data can be split in two, (as NIR_9A, NIR_9B). Non TIRGO data are labelled WHT_1, NOT_2, ..., VATT_10, ... .
Acquisition date
The date of acquisition in YYYYMMGG format. All digit are numeric, but the field is treated as a string.
Observer
The name of observer(s), as declared by itself. Can contain many forms and nicknames.
Source
The name of source observed, as taken from TIRGO pointing catalogue, or as declared by observer for non TIRGO observations. The observer can use different form for the same identifier, and all spaces have been automatically replaced with "_". In a compound measure (we call them "a mosaic") a "#" character and a sequence number (two digits, starting with 00) is appended to the source name by the acquisition program. On other telscopes the name of source is usually typed in by observer.
Filter
The filter with which the measure was taken. It can be a Johnson broad band infrared filter (J, H, K), or a narrow band filter (see ARNICA page for details).
Measure Number
In this archive each compound measure ("a mosaic") is identified by a "measure number" which is unique in each CD- ROM. It start from 1 on each CD-ROM.
Right Ascension Declination
The co-ordinates of the point to which the telescope was pointed to. Format is [-]GG:PP:SS.D, and the fields are treated as strings. The positions recorded with data are NOT accurate, and can comprise (and normally do) mechanical and astronomical corrections used for pointing. Also on non TIRGO observations, these fields are often missing or incomplete.
Search from Measure
The search is restricted to frames with Measure Number greater than the specified value. The field is handled as a number.
Max record to return
This field limits the number of match to return. Often a search can match with a lot of frames, so can be useful to increase this field (the default is 30), but a trade-off with the difficulty of receiving and analysing a 3000 row response should be found!
Box search
These field defines a rectangular box, both in Right Ascension and in Declination. The co-ordinate boxes, all numeric, define the centre of the box, while the size is twice the number specified (in arc-minutes) in the fifth field (also numeric). No corrections for cos(delta) or precession corrections are applied. This search is performed with a logic AND with other field specification. Coordinates search do NOT handle 24->0 hours transition.
Get only 'Mosaic' first frames
This option make searches among a database subset containing only the first frames of a compound measure. Fast. Reccomanded.
Get all normal frames
The entire Archive is searched. Useful for retriving single frame measure or all frame of a compound measure. Slow (up to 45 seconds).
Include dummy/test frames
The Archive contains also some test or laboratory frames, so this field should normally left OFF. Slow (up to 45 seconds).

Search Result fields

Number
The internal number of the record.
Disk
The label of CD-ROM on which data are stored. For TIRGO data it is NIR_1, ... NIR_53, ... . Older data can be split in two, (as NIR_9A, NIR_9B). Non TIRGO data are labelled WHT_1, NOT_2, ..., VATT_10, ... .
Filename
The name of the fits file. The first four digits are the last integer digits of Julian date, while the last four contain a frame counter modulo 10000.
Meas_number
Each single or compound measure ("a mosaic") is identified by a "measure number" which is unique in each CD-ROM.
Date
The date of acquisition in YYYYMMGG format.
Observer
The name of observer(s), as declared by itself. Can contain many forms and nicknames.
Object_name
The name of source observed, as taken from TIRGO pointing catalogue, or as declared by observer for non TIRGO observations.
Integ_number
A frame counter modulo 10000.

Tips

In this Archive there are more than 250.000 files, hence, for a successful search, some specific strategies should be used.

String fields asks for a "sub-string search", which means the search matches if the string specified is located anywhere in the field. Numeric field asks for an exact match.

The specified strings cannot contain wildcards or special characters. The search is "case independent" and is performed as a logical AND between all non-blank fields.

All string field do not contains any spaces or tabs, they have been automatically substituted by "_" (underscore). Co-ordinate search (not box-search) also asks for a sub-string, and the format is "GG:MM:SS.D".

Box search defines a box in Right Ascention and in Declination, with a half-size defined in arc-minutes. The search is done numerically, but nor cos(delta) nor precession corrections are applied. This kind of search is slower. The positions recorded with data are NOT accurate, and can comprise (and normally do) mechanical and astronomical corrections used for pointing.

  1. For normal searches include a "#00" in source field. A complete infrared measure (see background) is normally composed of multiple frames. In this archive each compound measure (we call them "a mosaic") is identified by a "measure number" which is unique in each CD-ROM, also in each file to the source name is appended a "#" character and a sequence number (two digits, starting with 00). This choise is implied in the radiobutton "Get only 'Mosaic' first frames".
  2. Try different forms for source name. The observer can use different form for the same identifier, for instance "NGC_891", "NGC891", "N891", "N_891", U1831, UGC1831, CGCG538-052 all means the same galaxy. Remember that all spaces have been automatically replaced with "_". Note that each catalogue define a different name for the same object, the "NED search" button can be useful. Due to password protection we cannot provide a shorthand to Sindbad.
  3. Use a "big" box size. The positions recorded with data are NOT accurate, also nor cos(delta) nor precession corrections are applied. Also coordinates search do NOT handle 24->0 hours transition.
  4. Tune "Max record to return". Often a search can match a lot of frames, so is useful to increase this field (the default is 30), but a trade-off with the difficulty of receiving and analysing a 3000 row response should be found.
  5. To get a complete measure frame list, once identified, the most efficient way is to specify ONLY disk name and measure number and select the "get all frames" radiobutton.
  6. To get also the standard frames, specify the disk and acquisition date. Watch the data changes at midnight!
  7. Observer field can be very useful, but often observers use "nicknames", different from night to night.

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