Astron. Astrophys. Suppl. Ser. 137, 495-504

An H$_\alpha$ catalogue of galaxies in Hickson compact groups

I. The sample

P. Severgnini^1,4 - B. Garilli¹ - P. Saracco² - G. Chincarini^2,3

Send offprint request: P. Severgnini

1 - IFCTR/CNR, Via Bassini, 15, 20133 Milano, Italy
e-mail: bianca@ifctr.mi.cnr.it
2 - Osservatorio Astronomico di Brera-Merate, Milano, Italy
e-mail: saracco@merate.mi.astro.it
3 - Dip. di Fisica, Univ. Milano, Via Celoria, 16, 20133 Milano, Italy
e-mail: guido@merate.mi.astro.it
4 - Univ. degli Studi di Firenze, Dip. Astronomia e Scienza dello Spazio, Via Fermi 5, 50125 Firenze (Arcetri), Italy
e-mail: paolas@arcetri.astro.it

Received January 8; accepted April 21, 1999

Abstract:

We present H$_\alpha$ photometry for a sample of 95 galaxies in Hickson Compact Groups obtained from observations of 31 groups. The Catalogue lists isophotal and adaptive aperture (Kron aperture) flux measurements for about 75$\%$ of the accordant galaxies inside the observed HCGs, 22 out of which are upper limits. Non standard data reduction procedures have been used to obtain the continuum subtracted H$_\alpha$ images for each HCG of the target sample. Flux calibration has also been performed in order to obtain H$_\alpha$ luminosities for the whole sample. Both the data reduction and calibration procedures are carefully described in this paper. The new data listed in this Catalogue are of great importance in understanding the star formation rate inside HCG galaxies and in giving new insights on its dependence on galaxy interactions.

Key words: galaxies: clusters: general -- galaxies: evolution -- galaxies: interaction