The First Galaxy Cluster Discovered by the VISTA Variables in the Vía Láctea Survey
| Autor: | Dante Minniti, G. Damke, Sebastián Gurovich, F. Milla Castro, Laura D. Baravalle, M. de los Ríos, J. Díaz Tello, Carlos Valotto, B. Sanchez, M. V. Alonso, M. Domínguez, J. L. Nilo Castellón, M. Soto, Rodolfo H. Barbá, H. Cuevas Larenas |
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| Rok vydání: | 2019 |
| Předmět: |
Physics
010504 meteorology & atmospheric sciences Milky Way purl.org/becyt/ford/1.7 [https] GALAXIES [INFRARED] Astronomy and Astrophysics Astrophysics Astrophysics - Astrophysics of Galaxies 01 natural sciences Spectral line Galaxy Redshift Luminosity purl.org/becyt/ford/1 [https] Space and Planetary Science 0103 physical sciences CLUSTERS: GENERAL [GALAXIES] Cluster (physics) 010303 astronomy & astrophysics SURVEYS Galaxy cluster 0105 earth and related environmental sciences Photometric redshift |
| Zdroj: | CONICET Digital (CONICET) Consejo Nacional de Investigaciones Científicas y Técnicas instacron:CONICET |
| ISSN: | 1538-4357 |
| Popis: | We report the first confirmed detection of the galaxy cluster VVV-J144321-611754 at very low latitudes (l = 315.836$^{\circ}$, b = -1.650$^{\circ}$) located in the tile d015 of the VISTA Variables in the V\'ia L\'actea (VVV) survey. We defined the region of 30$\times$ 30 $arcmin^2$ centered in the brightest galaxy finding 25 galaxies. For these objects, extinction-corrected median colors of (H - K$_{s}$) = 0.34 $\pm$ 0.05 mag, (J - H) = 0.57 $\pm$ 0.08 mag and (J - K$_{s}$) = 0.87 $\pm$ 0.06 mag, and R$_{1/2}$ = 1.59 $\pm$ 0.16 $arcsec$; C = 3.01 $\pm$ 0.08; and Sersic index, n = 4.63 $\pm$ 0.39 were estimated. They were visually confirmed showing characteristics of early-type galaxies in the near-IR images. An automatic clustering analysis performed in the whole tile found that the concentration of galaxies VVV-J144321-611754 is a real, compact concentration of early-type galaxies. Assuming a typical galaxy cluster with low X-ray luminosity, the photometric redshift of the brightest galaxy is $z = $ 0.196 $\pm$ 0.025. Follow-up near-IR spectroscopy with FLAMINGOS-2 at the Gemini-South telescope revealed that the two brighter cluster galaxies have typical spectra of early-type galaxies and the estimated redshift for the brightest galaxy VVV-J144321.06-611753.9 is $z =$ 0.234$\pm$0.022 and for VVV-J144319.02-611746.1 is $z =$ 0.232$\pm$0.019. Finally, these galaxies clearly follow the cluster Red Sequence in the rest-frame near-IR color--magnitude diagram with the slope similar to galaxy cluster at redshift of 0.2. These results are consistent with the presence of a bona fide galaxy cluster beyond the Milky Way disk. Comment: Manuscript accepted for publication in The Astrophysical Journal |
| Databáze: | OpenAIRE |
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