Multiple Object Search (Table Formatting)

IPAC ASCII Column-Aligned Format (Download example.)

Pros: All table formats work equally well, however, this table is very easy to read because it is column-aligned. This document also allows additional column attributes, such as units or data types.

Cons: The data must be properly aligned within each column boundary.

The IPAC ASCII Column-Aligned Format, also known as IPAC Table Format, requires the following structure:

• Rows starting with a vertical line ( | ) are table header lines and define the table column layout and metadata. The first of these (the only one required) must contain the names of each column (e.g., ra, dec, flux).
• The columns in the header row are separated by a vertical line ( | ) to show the boundaries of each column. There is also a vertical line at the beginning and end of the header row.
• There must be at least one row of data in the row directly following the header row, and the data should align with the column names
• The number of cells containing data is equal to or less than the number of columns
• The data columns are lined up because they are column-aligned, which also makes the data more readable.
• Data must fit within the boundaries of each column and not extend beyond the vertical header lines.

Example of a basic IPAC ASCII Column-Aligned Format file:

|  object     |                ra            |         dec         |
     M56                  289.147941100             30.184500500
     ic4710               277.158208330             66.982277780
     hoix                  49.383333330             69.045833330
     tol89                210.339833330            -33.063777780
     ngc 4552             188.915863750             12.556341390
     M82                  148.969687500             69.679383330
     mrk33                158.132833330             54.401027780
     ngc1097               41.579375000            -30.274888890
     arp 22               179.874583330            -19.297222220
     M 65                 169.733166670             13.092222220

Note: Your table can contain:

• All three columns (object, ra, dec). In this case, ra/dec will be used to resolve the search position, and the contents of the "object" column will be used simply as a label for your output results.
• object only. Each object will be resolved by NED/SIMBAD into a searchable position.
• ra/dec only. No object-name label will be attached to the rows on the output page.

In the above example, notice the vertical lines ( | ) between object, ra, and dec indicate the column boundaries. Additionally, the data are aligned to clearly identify the columns and do not span across multiple columns.

The IPAC ASCII Column-Aligned Format also has the added flexibility of allowing additional header rows so tables can have additional information such as comments, data types, and keywords. To learn more about this capability and how to use multiple header rows, read the Keyword and Comment Lines and Column Headers section of the DDGEN table documentation.

Comma-Separated Values (CSV) or Comma-Delimited Format (Download example.)

This is a format commonly exported from Microsoft Excel as a .csv file. In this format, each data cell is separated by a comma.

Pros: This is a compact format that has little risk of inserting non-printable characters (even tabs).

Cons: Files can appear unwieldy if commas are used within the data cells, which then requires that the entire is cell quoted (e.g., 1.23, "he said, ""No""",3.45 ).

Requirements for CSV tables include:

• The first line must contain the names of each column.
• If data within a cell includes a comma, the data must be enclosed within quotation marks (e.g., "M56,148").
• The columns in the header row are separated by commas ( , ).
• The data provided in the table are separated by commas ( , ).
• The number of cells containing data is equal to or less than the number of columns.
• Blank lines will be treated as blank data records, so omit them if possible.

Example of Comma-Separated Values (CSV) Format (also known as Comma Delimited):

object,ra,dec
M56,289.147941100,30.184500500
ic4710,277.158208330,-66.982277780
hoix,149.383333330,69.045833330
tol89,210.339833330,-33.063777780
ngc 4552,188.915863750,12.556341390
M82,148.969687500,69.679383330
mrk33,158.132833330,54.401027780
ngc1097,41.579375000,-30.274888890
arp 22,179.874583330,-19.297222220
M 65,169.733166670,13.092222220 

Note: Your table can contain:

• All three columns (object, ra, dec). In this case, ra/dec will be used to resolve the search position, and the contents of the "object" column will be used simply as a label for your output results.
• object only. Each object will be resolved by NED/SIMBAD into a searchable position.
• ra/dec only. No object-name label will be attached to the rows on the output page.

Tab-Delimited Format (Download example.)

This is a format commonly exported from Microsoft Excel as a .txt file by selecting Tab-Delimited when saving the file. In this format, each data cell is separated by a tab character.

Pros: From a processing standpoint, this is the most program-friendly format. It is very compact and easy to parse. From a user's perspective, it is a format that can be easily created with Microsoft Excel by saving the file as Text (Tab Delimited).

Cons: Because tab characters are interpreted differently by different systems, users must understand that tabs are used in IPAC's table formatting context as a means of separating data -- NOT for data alignment. Users must take special care to not use tabs within a data cell, which will create too many columns and cause a failed table upload. Also, use one tab separator per column space, even if the data don't align exactly on the screen.

Requirements for tab-delimited tables are virtually identical to those for comma-separated and include:

• The first line must contain the names of each column.
• The columns in the header row are separated by tabs.
• The data provided in the table are separated by tabs.
• The number of cells containing data is equal to or less than the number of columns.
• Blank lines will be treated as blank data records, so omit them if possible.

Example of Tab-Delimited Format:

object	ra	dec
M56	289.147941100	30.184500500
ic4710	277.158208330	-66.982277780
hoix	149.383333330	69.045833330
tol89	210.339833330	-33.063777780
ngc 4552	188.915863750	12.556341390
M82	148.969687500	69.679383330
mrk33	158.132833330	54.401027780
ngc1097	41.579375000	-30.274888890
arp 22	179.874583330	-19.297222220
M 65	169.733166670	13.092222220 

Note: Your table can contain:

• All three columns (object, ra, dec). In this case, ra/dec will be used to resolve the search position, and the contents of the "object" column will be used simply as a label for your output results.
• object only. Each object will be resolved by NED/SIMBAD into a searchable position.
• ra/dec only. No object-name label will be attached to the rows on the output page.

In the above example, the columns are lined up using tab characters between each cell. Note the columns may not line up exactly, even if tabs are applied consistently (as in row #5). Resist the temptation to add additional tabs in order to make the data align correctly; this will only create ambiguity with your data, and your table upload will fail.

Simple List of Object Names (Download examples: IPAC table or CSV file)

Pros: IPAC table or CSV table with a single keyword header for a list of objects.

Cons: This format requires name resolution using external name databases if data provided are object names. Each lookup query takes a few seconds per object, so processing large lists may be slow. Coordinates are transformed to RA and Dec in decimal degrees

Requirements for this format are minimal:

• Each line has one item.
• The entire line is treated as an object name

Examples:

|   object|
 M56
 ic4710
 hoix
 ngc 4552
 M82
 ngc1097
 M 65

object,
M56,
ic4710,
hoix,
ngc 4552,
M82,
ngc1097,
M 65,