J/MNRAS/297/255 HII region catalogue of M100 (Knapen, 1998)
Statistical properties of HII regions in the disc of M100
Knapen J.H.
<Mon. Not. R. Astron. Soc. 297, 255 (1998)>
=1998MNRAS.297..255K 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-α 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-α 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-α filters with width of 15Å were
used for the observations, centred at 6601Å for the H-α line
observations (redshifted using the galaxy's systemic velocity of
1571km/s) and at 6577Å and 6565Å 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:
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RA (2000) DE Designation(s)
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12 22 54.8 +15 49 20 M100 = NGC 4321
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 54 1948 The catalogue of HII regions in M100
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Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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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
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Note (1): the centre is 12 20 22.9 +16 05 58 (B1950)
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Acknowledgements:
Johan Knapen
(End) Francois Ochsenbein [CDS] 21-Jul-1998