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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Imagery and long-slit spectroscopy of the polar ring galaxy AM 2020-504

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Freitas-Lemes, P. [1] ; Rodrigues, I. [1] ; Faundez-Abans, M. [2] ; Dors, Jr., O. L. [1] ; Fernandes, I. F. [3]
Total Authors: 5
[1] Univ Vale Paraiba, BR-12244000 Sao Jose Dos Campos, SP - Brazil
[2] MCTI Lab Nacl Astrofis, BR-37504364 Itajuba, MG - Brazil
[3] Univ Estadual Feira de Santana, Dept Fis, BR-44036900 Feira de Santana, BA - Brazil
Total Affiliations: 3
Document type: Journal article
Source: Monthly Notices of the Royal Astronomical Society; v. 427, n. 4, p. 2772-2779, DEC 2012.
Web of Science Citations: 9

Interactions between galaxies are very common. There are special types of interactions that produce systems called polar ring galaxies (PRGs), composed of a lenticular, elliptical or spiral host galaxy, surrounded by a ring of stars and gas, orbiting in an approximately polar plane. In this paper, we study AM 2020-504, a PRG with an elliptical host galaxy, and a narrow and well-defined ring, probably formed by accretion of material from a donor galaxy, collected by the host galaxy. Our observational study is based on BVRI broad-band imagery as well as long-slit spectroscopy in the wavelength range 4100-8600 angstrom, performed at the 1.6-m telescope at the Observatorio do Pico dos Dias, Brazil. We have estimated a redshift of z = 0.01683, corresponding to a heliocentric radial velocity of 5045 +/- 23 km s(-1). The (B - R) colour map shows that the ring is bluer than the host galaxy, which indicates that the ring is a younger structure. Standard diagnostic diagrams have been used to classify the main ionizing source of selected emission-line regions (nucleus, host galaxy and ring). We find that the ring regions are mainly ionized by massive stars, while the nucleus presents the characteristics of an active galactic nucleus. Using two empirical methods, we have found oxygen abundances for the H II regions located in the ring in the range 12+log(O/H) = 8.3-8.8 dex. We have also found the presence of an oxygen gradient across the ring, and it appears that AM 2020-504 follows the metallicity-luminosity relation of spiral galaxies. These results support the accretion scenario for this object and they rule out cold accretion as the source for the H I gas in the polar ring. (AU)

FAPESP's process: 10/17136-4 - Dynamics of Polar Ring Galaxies
Grantee:Priscila Freitas Lemes
Support type: Scholarships in Brazil - Doctorate
FAPESP's process: 09/14787-7 - Physical properties of star formation regions in circumnuclear rings and in (U)LIRGs
Grantee:Oli Luiz Dors Junior
Support type: Research Grants - Young Investigators Grants