Help: MACHO Query

Data file acquisition is the result of a 3 step process:
(1) user specifies the record selection criteria using the query input form;
(2) user reviews, and optionally edits, the logical query generated from the input form;
(3) on display of the selected record summaries, the user selects

display of a complete Observation record;

display of a partial Observation record - lacking the PSF and transformation parameters for Macho Project chunks;

retrieval of an Observation image.

Search Query Generation

The database search returns all records which satisfy the logical expression built from the user's input. The generated search query is composed of the form's fields separated by AND. Each field may be a composite of subfields. In that case, the generated field is composed of the subfields separated by OR. If no value is entered for a field and no default provided, it is not included. An example of the generated search query is: ObsId_input AND ObsDate_input AND Exposure_input AND Airmass_input .

The syntax of the field is defined by the record data. Refer to the descriptions below to determine if a field

allows a subfield list; or

is alphanumeric or numeric. On the input form, a list is represented by subfields separated by a comma (',').

Numeric subfields may be either

an unadorned value,

a value preceded by an arithmetic symbol ('=', '<', '<=', '>', '>=', '<>'),

a value followed by an arithmetic symbol ('=', '<', '<=', '>', '>=', '<>'), or

two values separated by the range indicator (':').

For example, an ObsId subfield defined thusly:
"20, >500, 100:200, 10>"
results in the logical sub-expression:
"((ObsId=20) OR (ObsId>500) OR (ObsId=100:200) OR (ObsId<10))" . Refer here for detailed information on the generated expressions.

Query Form

The form's search fields are:

RA

Right Ascension of the center point in bounding box defined by the RA/Dec/radius parameters.

Format is upto 8 characters: HH:MM:SS . Subfields may not be empty.

Example: 10:5:2

Example: 10:5:0.4

Dec

Declination of the center point in bounding box defined by the RA/Dec/radius parameters.

Format is 9 characters: [-]DD:MM:SS . Subfields may not be empty.

Example: -73:50:18

Example: 73:50:18.5

Search Radius(arcmin)

Radius of the bounding box defined by the RA/Dec/radius parameters.

Format is numeric. Units are arcminutes.

Example: 10

Equinox

Select the equinox in which the RA/Dec are expressed.

Options are: J2000, B1950

Field

Identifier for a Field centered on a MACHO Project predetermined RA/Dec. Refer here for the Macho Field definitions.

Format is numeric. Arithmetic constructs, lists and ranges may be used.

Example: 100:110 , 231, >300

Domain

Identifier for the set of Fields comprising a MACHO Project predetermined Domain. Refer here for the Macho Domain definitions.

Any subset of the following are allowed: LMC, SMC, Bulge-1, Bulge-2, Bulge-3. If none are selected, the search is not restricted by domain.

SideOfPier

Position of the telecope camera relative to its supporting pier.

Options are: both, east of pier, west of pier. Use both if pier position is irrelevant.

ObsId

Identifier assigned to an observation.

Format is numeric. Arithmetic constructs, lists and ranges may be used.

Example: 4000:5000,6000,>7000

ObsDate

Date of observation.

format is YYYYMMDD . Note the use of 4 digits for the year. Arithmetic constructs, lists and ranges may be used.

Example: <19990704

Example: =20001125

Exposure

Image exposure time.

Format is numeric. Units are seconds. Arithmetic constructs, lists and ranges may be used.

Example: 3600

PhotType

Photometry type of reduced data.

Options are: Any, SOD, NoPhot, Unknown

Select the default: Any if photometry processing unimportant.

Select SOD to retrieve all SOD reduced observations.

Select NoPhot to retrieve all unreduced observations.

Unknown is defined for the MACHO ObsState record but is not currently used.

Seeing

Average width of the point spread function calculated by SoDoPhot.

Format is numeric. Units are 0.63 arcsec pixels. Arithmetic constructs, lists and ranges may be used.

Example: 2560

Airmass

Mass column of atmosphere along the line of sight relative to the mass column at zenith.

Format is numeric. Arithmetic constructs, lists and ranges may be used.

Example: 2560

AveSkyValue

Brightness of the sky over the entire image. It's calculated as a simple average of all subimages' average-sky-value. The latter was calculated during SoDoPhot photometry reduction.

Format is numeric. Units are counts. Arithmetic constructs, lists and ranges may be used.

Example: 2500:2560, 2300

Query Form Reset

Select the Reset button to return the form to default values.

Query Form Submission

Select the Submit button to initiate input field validation and the subsequent creation of the database search expression.

Acknowledgement to use when referencing MACHO Project data

"This paper utilizes public domain data originally obtained by the MACHO Project, whose work was performed under the joint auspices of the U.S. Department of Energy, National Nuclear Security Administration by the University of California, Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48, the National Science Foundation through the Center for Particle Astrophysics of the University of California under cooperative agreement AST-8809616, and the Mount Stromlo and Siding Spring Observatory, part of the Australian National University."

email enquiries

and