J/MNRAS/297/255 HII region catalogue of M100 (Knapen, 1998) ================================================================================ Statistical properties of HII regions in the disc of M100 Knapen J.H. =1998MNRAS.297..255K ================================================================================ ADC_Keywords: H II regions ; Galaxies, optical Keywords: HII regions - galaxies: individual: M100 - galaxies: ISM - galaxies: spiral - galaxies: structure Description: From a new mosaic image in the H-{alpha} line of the complete disc of the spiral galaxy M100, a catalogue is composed listing 1948 individual HII regions. For each HII region, the catalogue gives its position relative to the centre of the galaxy, its deprojected distance to the centre, its radius, and its calibrated luminosity. An indication is included as to whether the HII region is located in the arms, between them, or in the circumnuclear star-forming region. The H-{alpha} image of M100 was obtained during two observing runs with the 4.2m WHT on La Palma, using the TAURUS camera in imaging mode. Since the field of view in this setup is limited by the filter size to around 5' diameter, four fields of the galaxy were imaged, two (eastern half of M100) during the night of 27 May 1991, and two (western half) during the night of 14 March 1992. Narrow band redshifted H-{alpha} filters with width of 15{AA} were used for the observations, centred at 6601{AA} for the H-{alpha} line observations (redshifted using the galaxy's systemic velocity of 1571km/s) and at 6577{AA} and 6565{AA} for the continuum. Exposure times were 1200 seconds for both the on-line and the continuum image on the first night, and 2x900 seconds on the second night. An EEV CCD chip was used during both observing runs, with a projected pixel size of 0.279arcsec, and a size of 1180x1280 pixels. Objects: ----------------------------------------- RA (2000) DE Designation(s) ----------------------------------------- 12 22 54.8 +15 49 20 M100 = NGC 4321 ----------------------------------------- File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file catalog.dat 54 1948 The catalogue of HII regions in M100 -------------------------------------------------------------------------------- Byte-by-byte Description of file: catalog.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 I4 --- ID [1,1948]+ identification number 7- 13 F7.2 arcsec Xpos X position (toward East) from centre (1) 16- 22 F7.2 arcsec Ypos Y position (toward North) from centre (1) 25- 30 F6.2 arcsec Dist Deprojected distance from centre (1) 32- 37 F6.2 deg PA Position angle wrt centre, N over E 40- 43 F4.2 arcsec Radius Radius of HII region, in arcsec 46- 52 F7.2 10+29W Flux Calibrated Flux in units of 10**36 erg/s 54 I1 --- Location [0,2] 0=interarm; 1=arm; 2=centre -------------------------------------------------------------------------------- Note (1): the centre is 12 20 22.9 +16 05 58 (B1950) -------------------------------------------------------------------------------- Acknowledgements: Johan Knapen ================================================================================ (End) Francois Ochsenbein [CDS] 21-Jul-1998