We report the detection of 1WGA J1226.9+3332 as an arcminute-scale extended X-ray source with the Chandra X-Ray Observatory. The Chandra observation and R- and K-band imaging strongly support the identification of 1WGA 1226.9+3332 as a high-redshift cluster of galaxies, most probably at z = 0.85 +/- 0.15, with an inferred temperature kT = 10(-3)(+4) keV, and an unabsorbed luminosity (in a r = 120" aperture) of 1.3(-0.14)(+0.16) x 10(45) ergs s(-1) (0.5-10 keV). This indication of redshift is also supported by the K- and R-band imaging and is in agreement with the spectroscopic redshift of 0.89 found by Ebeling and coworkers. The surface brightness profile is consistent with a beta model with beta = 0.770 +/- 0.025, r(c) = 18."1+/-0."9 (corresponding to 101 +/- 5 kpc at z = 0.89), and S(0) = 1.02 +/- 0.08 counts arcsec(-2). 1WGA J1226.9+3332 was selected as an extreme X-ray-loud source with F-X/F-V >60; this selection method, thanks to the large area sampled, seems to be a highly efficient method for finding luminous, high-z clusters of galaxies.
1WGA J1226.9 + 3332: A high-redshift cluster discovered by Chandra / Cagnoni, I.; Elvis, M.; Kim, D. -W.; Mazzotta, P.; Huang, J. -S.; Celotti, A.. - In: THE ASTROPHYSICAL JOURNAL. - ISSN 0004-637X. - 560:1(2001), pp. 86-91. [10.1086/322423]
1WGA J1226.9 + 3332: A high-redshift cluster discovered by Chandra
Celotti A.
2001-01-01
Abstract
We report the detection of 1WGA J1226.9+3332 as an arcminute-scale extended X-ray source with the Chandra X-Ray Observatory. The Chandra observation and R- and K-band imaging strongly support the identification of 1WGA 1226.9+3332 as a high-redshift cluster of galaxies, most probably at z = 0.85 +/- 0.15, with an inferred temperature kT = 10(-3)(+4) keV, and an unabsorbed luminosity (in a r = 120" aperture) of 1.3(-0.14)(+0.16) x 10(45) ergs s(-1) (0.5-10 keV). This indication of redshift is also supported by the K- and R-band imaging and is in agreement with the spectroscopic redshift of 0.89 found by Ebeling and coworkers. The surface brightness profile is consistent with a beta model with beta = 0.770 +/- 0.025, r(c) = 18."1+/-0."9 (corresponding to 101 +/- 5 kpc at z = 0.89), and S(0) = 1.02 +/- 0.08 counts arcsec(-2). 1WGA J1226.9+3332 was selected as an extreme X-ray-loud source with F-X/F-V >60; this selection method, thanks to the large area sampled, seems to be a highly efficient method for finding luminous, high-z clusters of galaxies.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.