Accession Number : AD0250596

Title :   AN ABSOLUTE ISOPHOTOMETRY OF THE SOUTHERN MILKY WAY AND TWO FIELDS IN ORION

Corporate Author : AUSTRALIAN NATIONAL UNIV CANBERRA

Personal Author(s) : JOHNSON, HUGH M.

Report Date : MAY 1960

Pagination or Media Count : 1

Abstract : THE FORM AND ABSOLUTE BRIGHTNESS OF THE SOUTHERN MILKY WAY ARE REPRESENTED BY MEANS OF ISOPHOTAL CHARTS IN 3 PASSBANDS. ONE OF THE PASSBANDS IS CENTERED ON H(ALPHA) AND ANOTHER NEAR H(BETA) SO THAT STRONG EMISSIONS OF H II REGIONS ARE SELECTED; THE THIRD PASSES A YELLOW CONTINUUM SERVING AS A STANDARD NEARLY FREE OF NEBULAR EMISSIONS. THE ISOPHOTAL CHARTS SHOW 78 FIELDS, EACH 11.5 DEGREES IN DIAMETER ALONG 182 DEGREES OF THE MILKY WAY;THE CENTERS LIE ROUGHLY 7 DEGREES APART ONTHE GALACTIC EQUATOR. TWO MORE FIELDS ARE CENTERED ON ORIONIS (THETA AND LAMBDA). EACH CHART SHOWS A FIELD IN 3 PASSBANDS CENTERED NEAR 6560A IN THE UPPER LEFT, 4810A IN THE LOWER LEFT, AND 6070A ON THE MIDDLE RIGHT. THE PLATES FOR THE CHARTS WERE TAKEN WITH A 8-IN. F/1 FIELD FLATTENED SCHMIDT CAMERA;A TUBE SENSITOMETER EXPOSED SPOTS ON THE MARGINS OF THE PLATES. THE ISOPHOTES WERE TRACED FROM ENLARGEMENTS OF THE PLATES, ON A SAMPLE ANALYSIS IS MADE OF THE H II REGION AROUND ETA CACARINEA IN ORDER TO SHOW PROBLEMS ARISING WITH THE USE OF THE CHARTS

Descriptors :   *GALAXIES, *PHOTOMETERS, ASTRONOMICAL CAMERAS.

Distribution Statement : APPROVED FOR PUBLIC RELEASE