Browsing Research Output by Author "11290471 - Loubser, Susan Ilani"

Now showing items 1-20 of 26

    • Abundance ratios and IMF slopes in the dwarf elliptical galaxy NGC 1396 with MUSE 

      Mentz, J.J.; Loubser, S.I.; La Barbera, F.; Peletier, R.F.; Falcón-Barroso, J. (Oxford Univ Press, 2016)
      Deep observations of the dwarf elliptical (dE) galaxy NGC 1396 (MV = −16.60, Mass ∼4 × 108 M⊙), located in the Fornax cluster, have been performed with the Very Large Telescope/Multi Unit Spectroscopic Explorer spectrograph ...

    • Age-dating luminous red galaxies observed with the Southern African Large Telescope 

      Ratsimbazafy, A.L.; Loubser, S.I.; Crawford, S.M.; Cress, C.M.; Bassett, B.A.; Vaisanen, P. (Oxford Univ Press, 2017)
      We measure a value for the cosmic expansion of H(z) = 89 ± 23(stat) ± 44(syst) km s−1 Mpc−1 at a redshift of z ≃ 0.47 based on the differential age technique. This technique, also known as cosmic chronometers, uses the age ...

    • The close pair fraction of BCGs since z = 0.5: major mergers dominate recent BCG stellar mass growth 

      Groenewald, Danièl N.; Loubser, S. Ilani; Skelton, Rosalind E.; Gilbank, David G. (Oxford Univ Press, 2017)
      Using the redMaPPer (red-sequence Matched-filter Probabilistic Percolation) cluster catalogue based on the Sloan Digital Sky Survey (SDSS) photometry, we investigate the importance of major mergers in the stellar mass ...

    • Clustering algorithms: sensitivity of mass determination using A 3581 

      Wilson, S.; Oozeer, N.; Loubser, S.I. (Wiley-VCH, 2013)
      In this paper we discuss various methods for clustering in order to determine estimates of the cluster mass, focusing on the cluster A3581. Using virtual observatory (VO) tools, possible galaxy cluster candidates are ...

    • Constraining the dark matter density in galaxy clusters 

      Loubser, S.I.; Donahue, M.; Voit, M. (PoS, 2015)
      We illustrate the potential of using stellar velocity dispersion profiles of brightest cluster galaxies (BCGs), in combination with X-ray and weak-lensing derived cluster mass profiles, to constrain the matter distribution ...

    • The detailed nature of active central cluster galaxies 

      Loubser, S.I. (South African Institute of Physics, 2014)
      We present detailed IFU observations of the central few kiloparsecs of the ionised nebulae surrounding four active central cluster galaxies in cooling flow clusters. All four galaxies have Hα filaments, and existing data ...

    • The detailed nature of active central cluster galaxies 

      Loubser, S.I.; Soechting, I.K. (Oxford Univ Press, 2013)
      We present detailed integral field unit observations of the central few kiloparsecs of the ionized nebulae surrounding four active central cluster galaxies (CCGs) in cooling flow clusters (Abell 0496, 0780, 1644 and ...

    • Did brightest cluster galaxies experience more than one star formation epoch? 

      Viljoen, D.N.; Loubser, S.I. (Cambridge University Press, 2012)
      We use the full spectrum fitting ability of ULySS, with the Pegase.HR stellar population model to fit the observed spectra of 40 brightest cluster galaxies in order to determine whether a single or a composite stellar ...

    • Diversity in the stellar velocity dispersion profiles of a large sample of brightest cluster galaxies z ≤ 0.3 

      Loubser, S.I.; Hoekstra, H.; Babul, A.; O'Sullivan, E. (Oxford Univ Press, 2018)
      We analyse spatially resolved deep optical spectroscopy of brightestcluster galaxies (BCGs) located in 32 massive clusters with redshifts of 0.05 ≤ z ≤ 0.30 to investigate their velocity dispersion profiles. We compare ...

    • Dynamical masses of brightest cluster galaxies. I. Stellar velocity anisotropy and mass-to-light ratios 

      Loubser, S.I.; Babul, A.; Hoekstra, H.; Bahé, Y.M.; O'Sullivan, E. (Oxford Univ press, 2020)
      We investigate the stellar and dynamical mass profiles in the centres of 25 brightest cluster galaxies (BCGs) at redshifts of 0.05 ≤ z ≤ 0.30. Our spectroscopy enables us to robustly measure the Gauss–Hermite higher order ...

    • Dynamical modelling of brightest cluster galaxies: constraints on the IMF 

      Loubser, S.I. (Cambridge Univ Press, 2020)
      We study the stellar and dynamical masses, as well as the stellar populations, of brightest cluster galaxies (BCGs) located in 32 massive clusters, and for a sub-sample of these use the results to place constraints on the ...

    • Evidence of AGN feedback and sloshing in the X-ray luminous NGC 1550 galaxy group 

      Kolokythas, Konstantinos; Loubser, Ilani; O’Sullivan, Ewan; Giacintucci, Simona; Worrall, Diana M. (Oxford Univ Press, 2020)
      We present results from Giant Metrewave Radio Telescope and Chandra observations of the NGC 1550 galaxy group. Although previously thought of as relaxed, we show evidence that gas sloshing and active galactic nucleus (AGN) ...

    • Fuelling (and quenching) star formation in brightest cluster galaxies 

      Loubser, S.I.; Ratsimbazafy, A. (PoS, 2015)
      We have obtained detailed, spatially-resolved SALT spectroscopy over the entire optical wavelength range for eight nearby, active brightest cluster galaxies (BCGs) in X-ray luminous groups and clusters. This enables us ...

    • Investigating brightest cluster galaxies: kinematics with SALT 

      Loubser, S.I. (South African Institute of Physics, 2014)
      We present detailed, high spatial and spectral resolution, longslit observations of four active central cluster galaxies (CCGs) in cooling flow clusters (Abell 0085, 0133, 0644 and Ophiuchus). Our sample consists of CCGs ...

    • Investigating the hot gas in active brightest cluster galaxies 

      Ratsimbazafy, A.L.; Loubser, S.I.; Donahue, M.; Voit, G.M. (PoS, 2016)
      We investigate a crucial phase in the cooling–feedback cycle in the star forming Brightest Clus- ter Galaxies (BCGs) by looking at the optical emission line properties of the reheated gas that ultimately causes the cycle ...

    • Investigating the star formation histories of the brightest cluster galaxies 

      Groenewald, D.N.; Loubser, S.I. (Oxford Univ Press, 2014)
      This article is devoted to the study of the central stellar populations of the brightest cluster galaxies (BCGs). High signal-to-noise ratio, long-slit spectra for a sample of 39 galaxies were fitted against two stellar ...

    • The MeerKAT Fornax survey 

      Serra, P.; Loubser, S.I.; De Blok, W.J.G.; Bryan, G.L.; Colafrancesco, S. (Sissa Medialab, 2016)
      We present the science case and observations plan of the MeerKAT Fornax Survey, an H I and radio continuum survey of the Fornax galaxy cluster to be carried out with the SKA precursor MeerKAT. Fornax is the second most ...

    • Mg2 gradients as a signature of brightest cluster galaxy evolution 

      Loubser, S.I.; Sánchez-Blázquez, P. (Wiley, 2011)
      We have fitted the Mg2 absorption index gradients for 21 brightest cluster galaxies (BCGs), in the nearby Universe, for which we have obtained high signal-to-noise ratio, long-slit spectra on the Gemini telescopes. This ...

    • An overview of the MHONGOOSE survey: observing nearby galaxies with MeerKAT 

      De Blok, W.J.G.; Loubser, S.I.; Adams, E.A.K.; Amram, P.; Athanassoula, E. (Sissa Medialab, 2016)
      MHONGOOSE is a deep survey of the neutral hydrogen distribution in a representative sample of 30 nearby disk and dwarf galaxies with H I masses from ∼ 10 6 to ∼ 10 11 M , and luminosities from M R ∼ 12 ...

    • The regulation of star formation in cool-core clusters: imprints on the stellar populations of brightest cluster galaxies 

      Loubser, S.I.; Babul, A.; Hoekstra, H.; Mahdavi, A.; Donahue, M. (Oxford Univ Press, 2016)
      A fraction of brightest cluster galaxies (BCGs) show bright emission in the ultraviolet and the blue part of the optical spectrum, which has been interpreted as evidence of recent star formation. Most of these results ...