This service allows registered users to create mosaics of 2MASS, SDSS, or DSS data for any covered region of the sky in a variety of resolutions and coordinate systems. Processing is done in the background on a server cluster, and progress for multiple jobs can be monitored by the user.

The underlying software is capable of handling any standard projection (see http://fits.gsfc.nasa.gov/fits_wcs.html), but a simple tangent plane (TAN) projection was chosen for this initial interface. Fuller control over the projection (and other World Coordinate System parameters) is planned for the near future.

Coordinate/Object:

The Coordinate/Object field combines in a single interface the name resolution look-up services of NED and SIMBAD as well as coordinate transformation.

The same input field is used for either name resolution or coordinate input and the service dynamically determines its content. Both decimal degree and sexagesimal inputs are accepted. If the input field contains a string which can be interpreted as a coordinate representation, it is used as such. If not, the string is sent first to NED, then to SIMBAD to attempt name resolution. The range of name formats acceptable is set by those projects.

Coordinates entered into the interface allow for all information to be contained in a single string. The parser is very forgiving, so all of the following are valid (and give the results you would expect). For coordinate inputs, Equatorial J2000 is assumed unless specified otherwise.

• 0042443-411608
• 00:42:44.3 -41:16:08
• 00h42m44.3s -41d16m08s
• 00 42 44.3 -41 16 08
• 34.5565 54.2321 gal
• 34. 54. ecl
• M83
• 344.489624 40.248115 Equ B1950
• Barnard's Star

Survey/Band

Choose which data set and band to use for your mosaic:

• J, H, or K_s from the Two-Micron All-Sky Survey (2MASS)
• u, g, r, i, or z from the Sloan Digital Sky Survey (SDSS)
• POSS1 Blue and Red; POSS2/UKSTU Blue, Red, and IR;
  GSC1 and GSC2; and Quick-V from the STScI Digitized Sky Survey (DSS)

Only some of these image sets cover the whole sky.
See here for more information on wavelengths and coverage.

Region Size

Enter the size (in degrees) to be used for the width/height of the final mosaic.

Pixel Resolution

There are two resolution options available for the user. The first is a dropdown menu containing the native resolutions of the three available surveys. If neither of these resolutions is desired, the user may choose "Custom" from the dropdown menu, and enter a custom resolution (in arcsec) in the text area provided.

Coordinate System

The following coordinate systems are available in the Montage Mosaic service:

• FK5 (Equatorial J2000)
• GAL (Galactic)
• ECL (Ecliptic J2000)
• FK4 (Equatorial B1950)
• ICRS (International Reference)
• SGAL (Supergalactic)

Label (optional)

This string will be shown on the results page and in messages. It has no effect on the processing and is intended to help the user keep track of specific jobs.

Read about:

• Monitoring Background Jobs
• Retrieving Data