There are two types of IMAPS-1 data:
raw images, and corrected, coadded images.
Only the coadded files have assigned wavelengths.
To download an IMAPS file, click on any of the listed image numbers
for the desired target. This will display a list of links to
individual files that can then be downloaded.
The name resolver you want to use, if you want to resolve an object
into its coordinates.
You can resolve an object name either before a search,
or you can redraw the form with the
resolved coordinates in place. You can also elect
not to resolve the object name when doing the search,
but to search the IMAPS database on the object name given.
To resolve an object name before a search, enter the object name
in the Object Name field,
select either NED or SIMBAD
for the resolver, and hit the Search button.
is the NASA Extragalactic Database at Caltech in Pasadena, California, and
is the Set of Identifications, Measurements, and Bibliography for
Astronomical Data at the Centre de Données astronomiques
in Strasbourg, France.
The object name will be sent to the chosen resolver,
which will send back the coordinates. (If the object name is not recognized by the resolver,
or there is some other problem with the SIMBAD or NED services, then the search form will
be redrawn with an error message at the top.) These coordinates will then be used to search
the IMAPS database, along with whatever other query qualifications you have given.
We recommend that you use object name resolution to find observations of specific objects in the database.
This is the most reliable way to look up observations, because the observer could have given any object na
at all (for example, NGC1976 instead of M42, or PARALLEL-FIELD).
However, if you do know the object name that the observer used, you can select Don't resolve,
in which case the object name will not be resolved into coordinates,
but will be used as a search qualification in the database.
(This will happen only when you press the Search button.)
The SIMBAD and NED object name resolvers can resolve only fixed objects;
they cannot compute the positions of moving objects (planets, comets, etc.).
To find moving objects, try selecting the appropriate object class, entering
an object name that could match what you're looking for, and selecting Don't resolve
for the name resolver. NED is an extragalactic database, and generally won't resolve object names
within the Milky Way galaxy.
The Right Ascension and Declination around which you want to search.
A number of formats are accepted for the RA and Dec. Here are some examples:
Hours, minutes and Seconds
12 22 31.98 29 53 45.55
12h 22m 31.98s 29d 53m 45.55s
12h 22' 31.98" 29d 53' 45.55"
12h 22' 31.98" -29d 53' 45.55"
12h 22' 31".98 -29d 53' 45".55
Hours/Degrees and Minutes (no seconds)
12 22 29 53
12h 22m 29d 53m
12h 22' 29d 53'
12h 22' -29d 53'
The RA may be given in decimal degrees by indicating
a D or d after the degrees:
12d 22m 29d 53m
Spacing is not important, as long as the value is unambiguous, and that
you can delimit the hours/degrees, minutes, and (optional) seconds with
letters, colons, spaces, or any character that's not a digit or a
Note also that seconds of the form 31".98 or 31s.98 are accepted. This
should make it easy to cut and paste values into these fields from
The radius of the search box around the RA and Dec, in floating-point arcminutes
This used to be the "radius" of a coordinate box, but we now compute the angular separation between each r
esult dataset and the search center, so this really is a radius. (The results will be sorted on the angul
ar separation by default.) So this really is a circular radius around the search position. One result is t
hat you can do fancy stuff like searching for all observations between 2 and 8 arcminutes from the center
of a galaxy (just give 2 .. 8 for the radius).
The IMAPS image number (or exposure sequence number)
listed in the table and contained in the file names,
desribes the order in which the IMAPS observations were obtained.
Exposure numbers ran from 0000 to 0721, however the first 79
were test exposures and not archived. The IMAPS-2
sequnce numbers will begin where IMAPS-1 left off.
With IMAPS-1, a series of observations were usually taken of
a particular star.
The series would usually include 2-4 exposures from each
of the 4 echelle positions, plus a background exposure
which involved leaving the aperture open and the telescope pointed toward
the object but turning off the high voltage.
Exposures within these series taken at the same echelle position
were possible candidates for coadding.
The average start date and time, in GMT, for the coadded
images, based on the observation start dates calculated for the
raw image files. Since the coadded exposures were usually taken
consecutively, the observing times generally differ by only a
This entry describes either the position of the echelle grating
(a number from 1 to 4) or whether a background exposure was obtained
(a value of "B").
Each grating position covers 1/4 of each echelle order, so a series
of four exposure is needed to cover the entire echelle spectrum.
The assigned file name. The raw data sets file names
use the naming convention imaps1_0nnn.fits where nnn is the 3-digit
exposure sequence number assigned by Princeton Observatory describing
the order in which targets were observed (i.e., the first archived
observation is imaps1_0079.fits and the last target is imaps1_0721.fits.
Clicking on the raw file name in the IMAPS-1 finding list table
will download the selected raw data FITS file.
The coadded scan file names are defined as imaps1_nnn-mmm.fits where
nnn is the first coadded observation number and mmm is the last.
You may now search on any column in the mission database. Select the field
you wish to search on and type in the qualification. You may find the valid
range of values by clicking on the field name. NOTE that if you choose a
field in BOTH the form and in the User Option field, then you may not get
results or the result you expect.
You may choose the columns to be displayed in the output.
A set of columns that are commonly requested has been chosen as a default.
The default set of columns is:
Obs Start Time
Category (Object Class)
Angular Separation (')
You remove output columns by highlighting the column to be removed and then clicking on
the remove button to the right of the list of chosen output columns.
You may determine the order of column placement by highlighting a column and then clicking
on the up or down buttons to the right of the list of chosen output columns.
You may add a column to the list of chosen columns. Select the desired column on the pull down
menu beneath the list of chosen output columns. Then click on the add button. The column will
be added to the bottom of the output column list.
Choose how you want the output rows sorted. You can select
up to three fields to sort on. The rows will be sorted in the order of
the first sort field; if two rows have the same sort field, they will be
sorted in order of the second sort field, and so on.
For each field, you can select that the rows be sorted in reverse
order on that field by selecting the reverse checkbox. For example,
you can sort the rows with the most recent observations first by selecting
Observation Date for the first sort field and selecting the reverse
checkbox next to it.
Some queries will be capable of returning thousands of rows or more.
such large search results tend to use up memory on both the client
and server sides, and aren't usually useful. By default, we limit
the number of rows displayed to 100 rows, but you can increase (or
decrease) this limit as needed.
Select this checkbox if you want to see the SQL query
that the IMAPS Search engine constructs from your query qualifications.
The query will be shown at the end of the search results.
SQL (Standard Query Language, pronounced either "ess cue ell" or "sequel") is a language used
used by most relational database systems for retrieving information from database tables.
The IMAPS Search Page takes your search specifications and converts them
to an SQL query to run on our database. Viewing the generated query is often useful for
debugging, and may also be useful for SQL-literate users who want to see what logic was used
in the query. (In fact, this may be useful for most people, since SQL is pretty easy to understand.)
Select this checkbox if you want to have a set of distinct rows displayed. This is
useful if you would like to see a distinct list of objects with certain criteria e.g. all
the objects within an object class. To make this function useful, you should not select column names
such as Data Id, Mark or Observation Date in as output columns as all output is considered when making row