Compact Groups analysis using weak gravitational lensing
| Autor: | Diego G. Lambas, Elizabeth Johana Gonzalez, Martín Chalela, G. Foëx |
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| Rok vydání: | 2017 |
| Předmět: |
Physics
Cosmology and Nongalactic Astrophysics (astro-ph.CO) 010308 nuclear & particles physics Ciencias Físicas FOS: Physical sciences Astronomy and Astrophysics GROUPS: GENERAL [GALAXIES] purl.org/becyt/ford/1.3 [https] Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics - Astrophysics of Galaxies 01 natural sciences Astronomía purl.org/becyt/ford/1 [https] WEAK [GRAVITATIONAL LENSING] Compact group Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) 0103 physical sciences 010303 astronomy & astrophysics CIENCIAS NATURALES Y EXACTAS Weak gravitational lensing Astrophysics::Galaxy Astrophysics Astrophysics - Cosmology and Nongalactic Astrophysics |
| Zdroj: | CONICET Digital (CONICET) Consejo Nacional de Investigaciones Científicas y Técnicas instacron:CONICET |
| DOI: | 10.48550/arxiv.1702.00402 |
| Popis: | We present a weak lensing analysis of a sample of SDSS Compact Groups (CGs). Using the measured radial density contrast profile, we derive the average masses under the assumption of spherical symmetry, obtaining a velocity dispersion for the Singular Isothermal Spherical model, $\sigma_V = 270 \pm 40 \rm ~km~s^{-1}$, and for the NFW model, $R_{200}=0.53\pm0.10\,h_{70}^{-1}\,\rm Mpc$. We test three different definitions of CGs centres to identify which best traces the true dark matter halo centre, concluding that a luminosity weighted centre is the most suitable choice. We also study the lensing signal dependence on CGs physical radius, group surface brightness, and morphological mixing. We find that groups with more concentrated galaxy members show steeper mass profiles and larger velocity dispersions. We argue that both, a possible lower fraction of interloper and a true steeper profile, could be playing a role in this effect. Straightforward velocity dispersion estimates from member spectroscopy yields $\sigma_V \approx 230 \rm ~km~s^{-1}$ in agreement with our lensing results. Comment: 12 pages, 10 figures. Submitted to MNRAS |
| Databáze: | OpenAIRE |
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