Open AccessThe XMM Large‐Scale Structure survey: an initial sample of galaxy groups and clusters to a redshift z < 0.6 ★
Author(s) -
Willis J. P.,
Pacaud F.,
Valtchanov I.,
Pierre M.,
Ponman T.,
Read A.,
Andreon S.,
Altieri B.,
Quintana H.,
Dos Santos S.,
Birkinshaw M.,
Bremer M.,
Duc P.A.,
Galaz G.,
Gosset E.,
Jones L.,
Surdej J.
Publication year - 2005
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2005.09473.x
Subject(s) - physics , astrophysics , redshift , luminosity , surface brightness , galaxy , velocity dispersion , galaxy cluster , astronomy , redshift survey , cluster (spacecraft) , galaxy group , photometric redshift , computer science , programming language
We present X‐ray and optical spectroscopic observations of 12 galaxy groups and clusters identified within the X‐ray Multi‐Mirror ( XMM ) Large‐Scale Structure (LSS) survey. Groups and clusters are selected as extended X‐ray sources from a 3.5 deg 2 XMM image mosaic above a flux limit 8 × 10 −15 erg s −1 cm −2 in the [0.5–2] keV energy band. Deep BVRI images and multi‐object spectroscopy confirm each source as a galaxy concentration located within the redshift interval 0.29 < z < 0.56 . We combine line‐of‐sight velocity dispersions with the X‐ray properties of each structure computed from a two‐dimensional surface brightness model and a single temperature fit to the XMM spectral data. The resulting distribution of X‐ray luminosity, temperature and velocity dispersion indicate that the XMM –LSS survey is detecting low‐mass clusters and galaxy groups to redshifts z < 0.6 . Confirmed systems display little or no evidence for X‐ray luminosity evolution at a given X‐ray temperature compared to lower‐redshift X‐ray group and cluster samples. A more complete understanding of these trends will be possible with the compilation of a statistically complete sample of galaxy groups and clusters anticipated within the continuing XMM –LSS survey.