TY - JOUR
T1 - An X-ray and optical study of the cluster A33
AU - Colafrancesco, S.
AU - Mullis, C. R.
AU - Wolter, A.
AU - Gioia, I. M.
AU - Maccacaro, T.
AU - Antonelli, A.
AU - Fiore, F.
AU - Kaastra, J.
AU - Mewe, R.
AU - Rephaeli, Y.
AU - Fusco-Femiano, R.
AU - Antonuccio-Delogu, V.
AU - Matteucci, F.
AU - Mazzotta, P.
PY - 2000/6/1
Y1 - 2000/6/1
N2 - We report the first detailed X-ray and optical observations of the medium-distant cluster A33 obtained with the Beppo-SAX satellite and with the UH 2.2 m and Keck II telescopes at Mauna Kea. The information deduced from X-ray and optical imaging and spectroscopic data allowed us to identify the X-ray source 1SAXJ0027.2-1930 as the X-ray counterpart of the A33 cluster. The faint, F2-10 keV ≈ 2.4 10-13 erg s-1 cm-2, X-ray source 1SAXJ0027.2-1930, ∼ 2 arcmin away from the optical position of the cluster as given in the Abell catalogue, is identified with the central region of A33. Based on six cluster galaxy redshifts, we determine the redshift of A33, z = 0.2409; this is lower than the value derived by Leir & Van Den Bergh (1977). The source X-ray luminosity, L2-10 keV = 7.7 1043 erg s-1 cm-2, and intracluster gas temperature, T = 2.9 keV, make this cluster interesting for cosmological studies of the cluster LX - T relation at intermediate redshifts. Two other X-ray sources in the A33 field are identified. An AGN at z = 0.2274, and an M-type star, whose emissions are blended to form an extended X-ray emission ∼ 4 arcmin north of the A33 cluster. A third possibly point-like X-ray source detected ∼ 3 arcmin north-west of A33 lies close to a spiral galaxy at z = 0.2863 and to an elliptical galaxy at the same redshift as the cluster.
AB - We report the first detailed X-ray and optical observations of the medium-distant cluster A33 obtained with the Beppo-SAX satellite and with the UH 2.2 m and Keck II telescopes at Mauna Kea. The information deduced from X-ray and optical imaging and spectroscopic data allowed us to identify the X-ray source 1SAXJ0027.2-1930 as the X-ray counterpart of the A33 cluster. The faint, F2-10 keV ≈ 2.4 10-13 erg s-1 cm-2, X-ray source 1SAXJ0027.2-1930, ∼ 2 arcmin away from the optical position of the cluster as given in the Abell catalogue, is identified with the central region of A33. Based on six cluster galaxy redshifts, we determine the redshift of A33, z = 0.2409; this is lower than the value derived by Leir & Van Den Bergh (1977). The source X-ray luminosity, L2-10 keV = 7.7 1043 erg s-1 cm-2, and intracluster gas temperature, T = 2.9 keV, make this cluster interesting for cosmological studies of the cluster LX - T relation at intermediate redshifts. Two other X-ray sources in the A33 field are identified. An AGN at z = 0.2274, and an M-type star, whose emissions are blended to form an extended X-ray emission ∼ 4 arcmin north of the A33 cluster. A third possibly point-like X-ray source detected ∼ 3 arcmin north-west of A33 lies close to a spiral galaxy at z = 0.2863 and to an elliptical galaxy at the same redshift as the cluster.
KW - Cosmology: Observations
KW - Galaxies clusters: Individual: A33
KW - Galaxies: Active observations: X-rays
KW - Intergalactic medium
UR - http://www.scopus.com/inward/record.url?scp=26144440372&partnerID=8YFLogxK
U2 - 10.1051/aas:2000205
DO - 10.1051/aas:2000205
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AN - SCOPUS:26144440372
SN - 0365-0138
VL - 144
SP - 187
EP - 194
JO - Astronomy and Astrophysics Supplement Series
JF - Astronomy and Astrophysics Supplement Series
IS - 2
ER -