CDROM/AJ/V106/P0056 H II Regions in NGC 6814 (Knapen+ 1993) ================================================================================ Statistics and Properties of HII Regions in NGC 6814 Johan H. Knapen, Nina Arnth-Jensen, Jordi Cepa & John E. Beckman <1993, AJ, 106, 56> =1993AJ....106...56K ================================================================================ Abstract: We present a new Halpha image of high quality of the grand-design galaxy NGC 6814, and describe statistical properties of the HII region population. We have determined positions, angular sizes, and calibrated fluxes of 735 individual HII regions. We construct luminosity functions (LFs) for the complete sample, separately for arm and interarm regions, and for HII regions within and outside the limiting radius corresponding to the bright optical disk. The slope of the LF for the complete sample agrees well with values published for other Sbc and Sc galaxies. LFs for HII regions in the arms, in the interarm regions, in the inner part, and in the outer part of the galaxy all have the same slopes. We show and discuss the diameter distribution of the HII regions, both for the complete sample and for the separate arm, interarm, inner, and outer disk samples. There is no evidence for a different population of HII regions in the spiral arms, nor is there evidence for the existence of a significant population of density-bounded HII regions. We discuss implications for massive star forming processes in this galaxy, and discuss possible differences from other grand-design spirals. File Summary: -------------------------------------------------------------------------------- File Name Lrecl Records Explanations -------------------------------------------------------------------------------- table.dat 48 735 HII regions in NGC 6814 -------------------------------------------------------------------------------- Comments for file: table.dat -------------------------------------------------------------------------------- This table lists the 735 HII regions catalogued in the disk of the grand-design spiral galaxy NGC 6814, using a new H alpha image. The center is also included in the list. The table was not included in the printed paper. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 3 I3 --- Id *Identification number of the HII region 4 1X --- --- Always '.' 5-12 F8.2 arcsec RAnuc *Right ascension offset from the nucleus 13-20 F8.2 arcsec DEnuc *Declination offset from the nucleus 21-27 F7.1 arcsec Dist *Deprojected distance from the center 28-34 F7.2 arcsec Diam Diameter of the HII region 35-45 F11.4 erg/s Lum Log total integrated luminosity of HII region 46-47 2X --- --- Blank 48 A1 --- Type *Type assigment given to the HII region -------------------------------------------------------------------------------- Notes for file: table.dat -------------------------------------------------------------------------------- Id: Identification number of the HII region. HII regions closely grouped in the galaxy have generally closely grouped numbers. RAnuc, DEnuc: Not corrected for inclination of the galaxy. Dist: Deprojected distance from the center. An inclination angle of 20 degrees and a position angle of PA=167 degrees were used for the deprojection. Type: Type assigment given to the HII region. C is the center (not an HII region, but included for comparison); A means Arm HII region; I interarm; and O outer HII region. An outer HII region is defined as lying outside the area of the strong spiral arms, d>43 arcsec or 0.4 R25. -------------------------------------------------------------------------------- ================================================================================ (End) Lee Brotzman [ADS] 08-Mar-1995