A Gemini view of the galaxy cluster RXC J1504-0248: insights on the nature of the central gaseous filaments

Autor(es)

Soja, A. C. ^[1] ; Sodre, Jr., L. ^[1] ; Monteiro-Oliveira, R. ^{[1, 2]} ; Cypriano, E. S. ^[1] ; Lima Neto, G. B. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Dept Astron, R Matao 1226, BR-05508090 Sao Paulo - Brazil

^[2] Univ Fed Rio Grande do Sul, Inst Fis, Dept Astron, Campus Vale, BR-91501970 Porto Alegre, RS - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Monthly Notices of the Royal Astronomical Society; v. 477, n. 3, p. 3279-3292, JUL 2018.
• Citações Web of Science: 2

Resumo

We revisit the galaxy cluster RXC J1504-0248, a remarkable example of a structure with a strong cool core in a near redshift (z = 0.216). We performed a combined analysis using photometric and spectroscopic data obtained at Gemini South Telescope. We estimated the cluster mass through gravitational lensing, obtaining M-200 = 5.3 +/- 0.4 x 10(14) h(70)(-1) M-circle dot R-200 = 1.56 +/- 0.04 h(70)(-1) Mpc, in agreement with a virial mass estimate. This cluster presents a prominent filamentary structure associated with its brightest cluster galaxy, located mainly along its major axis and aligned with the X-ray emission. A combined study of three emission line diagnostic diagrams has shown that the filament emission falls in the so-called transition region of these diagrams. Consequently, several ionizing sources should be playing a meaningful role. We have argued that old stars, often invoked to explain low-ionization nuclear emission-line region emission, should not be the major source of ionization. We have noticed that most of the filamentary emission has line ratios consistent with the shock excitation limits obtained from shock models. We also found that line fluxes are related to gas velocities (here estimated from line widths) by power laws with slopes in the range expected from shock models. These models also show, however, that only similar to 10 per cent of Ha luminosity can be explained by shocks. We conclude that shocks probably associated with the cooling of the intracluster gas in a filamentary structure may indeed be contributing to the filament nebular emission, but cannot be the major source of ionizing photons. (AU)

• Processo FAPESP: 14/13723-3 - Aglomerados de galáxias como portais para o universo escuro
• Beneficiário: Eduardo Serra Cypriano
• Modalidade de apoio: Auxílio à Pesquisa - Regular