The galaxy stellar mass function of X-ray detected groups

Context. The fraction of galaxies bound in groups in the nearby Universe is high (50% at z ~ 0). Systematic studies of galaxy properties in groups are important in order to improve our understanding of the evolution of galaxies and of the physical phenomena occurring within this environment. Aims. We have built a complete spectrophotometric sample of galaxies within X-ray detected, optically spectroscopically confirmed groups and clusters (G&C), covering a wide range of halo masses at z ≤ 0.6. Methods. In the context of the XXL survey, we analyse a sample of 164 G&C in the XXL-North region (XXL-N), at z ≤ 0.6, with a wide range of virial masses (1.24 × 1013 ≤ M500,scal(M⊙) ≤ 6.63 × 1014) and X-ray luminosities ((2.27 × 1041 ≤ L500,scalXXL(erg s−1) ≤ 2.15 × 1044)). The G&C are X-ray selected and spectroscopically confirmed. We describe the membership assignment and the spectroscopic completeness analysis, and compute stellar masses. As a first scientific exploitation of the sample, we study the dependence of the galaxy stellar mass function (GSMF) on global environment. Results. We present a spectrophotometric characterisation of the G&C and their galaxies. The final sample contains 132 G&C, 22 111 field galaxies and 2225 G&C galaxies with r-band magnitude <20. Of the G&C, 95% have at least three spectroscopic members, and 70% at least ten. The shape of the GSMF seems not to depend on environment (field versus G&C) or X-ray luminosity (used as a proxy for the virial mass of the system). These results are confirmed by the study of the correlation between mean stellar mass of G&C members and L500,scalXXL. We release the spectrophotometric catalogue of galaxies with all the quantities computed in this work. Conclusions. As a first homogeneous census of galaxies within X-ray spectroscopically confirmed G&C at these redshifts, this sample will allow environmental studies of the evolution of galaxy properties.

Download Full-text

Erratum: Deconstructing the Galaxy stellar mass function with UKIDSS and CANDELS: the impact of colour, structure and environment

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stw390 ◽

2016 ◽

Vol 458 (4) ◽

pp. 3478-3478 ◽

Cited By ~ 1

Author(s):

Alice Mortlock ◽

Christopher. J. Conselice ◽

William G. Hartley ◽

Ken Duncan ◽

Caterina Lani ◽

...

Keyword(s):

Mass Function ◽

Stellar Mass ◽

The Galaxy ◽

The Impact

Download Full-text

Galaxy and mass assembly: luminosity and stellar mass functions in GAMA groups

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa2889 ◽

2020 ◽

Vol 499 (1) ◽

pp. 631-652

Author(s):

J A Vázquez-Mata ◽

J Loveday ◽

S D Riggs ◽

I K Baldry ◽

L J M Davies ◽

...

Keyword(s):

Star Formation ◽

Formation Rate ◽

Mass Function ◽

Stellar Mass ◽

Dark Matter Halo ◽

Central Mass ◽

The Galaxy ◽

Star Formation In Galaxies ◽

Low Mass ◽

Mass Assembly

ABSTRACT How do galaxy properties (such as stellar mass, luminosity, star formation rate, and morphology) and their evolution depend on the mass of their host dark matter halo? Using the Galaxy and Mass Assembly group catalogue, we address this question by exploring the dependence on host halo mass of the luminosity function (LF) and stellar mass function (SMF) for grouped galaxies subdivided by colour, morphology, and central/satellite. We find that spheroidal galaxies in particular dominate the bright and massive ends of the LF and SMF, respectively. More massive haloes host more massive and more luminous central galaxies. The satellites LF and SMF, respectively, show a systematic brightening of characteristic magnitude, and increase in characteristic mass, with increasing halo mass. In contrast to some previous results, the faint-end and low-mass slopes show little systematic dependence on halo mass. Semi-analytic models and simulations show similar or enhanced dependence of central mass and luminosity on halo mass. Faint and low-mass simulated satellite galaxies are remarkably independent of halo mass, but the most massive satellites are more common in more massive groups. In the first investigation of low-redshift LF and SMF evolution in group environments, we find that the red/blue ratio of galaxies in groups has increased since redshift z ≈ 0.3 relative to the field population. This observation strongly suggests that quenching of star formation in galaxies as they are accreted into galaxy groups is a significant and ongoing process.

Download Full-text

X-Raying the Dynamics of Globular Clusters

Symposium - International Astronomical Union ◽

10.1017/s0074180900147205 ◽

1985 ◽

Vol 113 ◽

pp. 43-61 ◽

Cited By ~ 1

Author(s):

Jonathan E. Grindlay

Keyword(s):

Globular Clusters ◽

Mass Function ◽

Initial Mass Function ◽

Giant Molecular Clouds ◽

Stellar Content ◽

X Ray ◽

Triple Systems ◽

Compact Binary ◽

The Galaxy ◽

Show Evidence

Recent studies of the x-ray sources in globular clusters have provided important new clues for both the dynamical processes in clusters and the stellar content and evolution of globular clusters. Very deep x-ray images of several globular clusters show evidence for diffuse x-ray emission from hot gas which may be related by a simple shock model to properties of both the cluster, such as its orbit in the Galaxy, and the interstellar medium in the halo of the Galaxy. The x-ray surveys conducted with the Einstein Observatory are reviewed and the results derived for the luminosity function, masses and nature of the compact x-ray sources are discussed. The evidence for the compact binary nature of the sources is now overwhelming, but long-term x-ray variability studies previously reported may suggest that some of the systems are in fact triple systems with distant companions. Possible relationships between the initial mass function, stellar density and cluster evolution are discussed, and our arguments that the ostensibly similar compact x-ray sources in the galactic bulge are remnants of a population of globular clusters disrupted by giant molecular clouds are updated.

Download Full-text

A systematic search for galaxy proto-cluster cores at z ∼ 2

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa1757 ◽

2020 ◽

Vol 496 (3) ◽

pp. 3169-3181

Author(s):

Makoto Ando ◽

Kazuhiro Shimasaku ◽

Rieko Momose

Keyword(s):

Galaxy Formation ◽

Mass Range ◽

Mass Function ◽

Stellar Mass ◽

Dark Matter Halo ◽

Massive Galaxies ◽

Quenching Efficiency ◽

The Galaxy ◽

Mass Assembly ◽

Cluster Cores

ABSTRACT A proto-cluster core is the most massive dark matter halo (DMH) in a given proto-cluster. To reveal the galaxy formation in core regions, we search for proto-cluster cores at z ∼ 2 in ${\sim}1.5\, \mathrm{deg}^{2}$ of the COSMOS field. Using pairs of massive galaxies [log (M*/M⊙) ≥ 11] as tracers of cores, we find 75 candidate cores, among which 54 per cent are estimated to be real. A clustering analysis finds that these cores have an average DMH mass of $2.6_{-0.8}^{+0.9}\times 10^{13}\, \mathrm{M}_{\odot }$, or $4.0_{-1.5}^{+1.8}\, \times 10^{13} \, \mathrm{M}_{\odot }$ after contamination correction. The extended Press–Schechter model shows that their descendant mass at z = 0 is consistent with Fornax-like or Virgo-like clusters. Moreover, using the IllustrisTNG simulation, we confirm that pairs of massive galaxies are good tracers of DMHs massive enough to be regarded as proto-cluster cores. We then derive the stellar mass function (SMF) and the quiescent fraction for member galaxies of the 75 candidate cores. We find that the core galaxies have a more top-heavy SMF than field galaxies at the same redshift, showing an excess at log (M*/M⊙) ≳ 10.5. The quiescent fraction, $0.17_{-0.04}^{+0.04}$ in the mass range 9.0 ≤ log (M*/M⊙) ≤ 11.0, is about three times higher than that of field counterparts, giving an environmental quenching efficiency of $0.13_{-0.04}^{+0.04}$. These results suggest that stellar mass assembly and quenching are accelerated as early as z ∼ 2 in proto-cluster cores.

Download Full-text