A stellar overdensity associated with the Small Magellanic Cloud

• Autor(a) principal: Pieres, Adriano
• Data de Publicação: 2017
• Outros Autores: Santiago, Basilio Xavier, Drlica-Wagner, Alex, Bechtol, Keith, Marel, Roeland Paul van der, Besla, Gurtina, Martin, Nicolas F., Belokurov, Vasily, Gallart, Carme, Martínez-Delgado, David, Marshall, Jennifer L., Nöel, N. E. D., Majewski, Steven Raymond, Cioni, Maria-Rosa L., Li, T. S., Hartley, William, Luque Canaza, Elmer Fidel, Conn, Blair Campbell, Walker, Alistair, Balbinot, Eduardo, Stringfellow, Guy S., Olsen, Knut A. G., Nidever, D.L., Costa, Luiz N. da, Ogando, Ricardo L.C., Maia, Marcio Antonio Geimba, Fausti Neto, Angelo, Abbott, Timothy M. C., Abdalla, Filipe B., Allam, Sahar S., Annis, James T., Benoit-Lévy, Aurélien, Carnero Rosell, Aurelio, Carrasco Kind, Matías, Carretero Palacios, Jorge, Cunha, Carlos Eduardo, D'Andrea, Christopher B., Desai, S., Diehl, H. Thomas, Doel, Peter, Flaugher, Brenna, Fosalba Vela, Pablo, García-Bellido, Juan, Gruen, Daniel, Gruendl, Robert A., Gschwend, Julia de Figueiredo, Gutierrez, Gaston R., Honscheid, K., James, David J., Kuehn, Kyler, Kuropatkin, Nikolay P., Menanteau, Felipe, Miquel, Ramon, Plazas Malagón, Andrés Alejandro, Romer, Anita K., Sako, Mari, Sanchez-Alvaro, Eusebio, Scarpine, Victor Emanuel, Schubnell, Michael, Sevilla Noarbe, Ignacio, Smith, Robert Christopher, Soares-Santos, Marcelle, Sobreira, Flávia, Suchyta, Eric, Swanson, Molly E. C., Tarle, Gregory, Tucker, Douglas L., Wester, William Carl
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/169027
• topic: Pequena Nuvem de Magalhães; Mapeamentos astronômicos; Formacao de estrelas; Galaxies: interactions; Magellanic Clouds

We report the discovery of a stellar overdensity 8◦ north of the centre of the Small Magellanic Cloud (SMC; Small Magellanic Cloud Northern Over-Density; SMCNOD), using data from the first 2 yr of the Dark Energy Survey (DES) and the first year of theMAGellanic SatelLITEs Survey (MagLiteS). The SMCNOD is indistinguishable in age, metallicity and distance from the nearby SMC stars, being primarily composed of intermediate-age stars (6 Gyr, Z=0.001), with a small fraction of young stars (1 Gyr, Z=0.01). The SMCNOD has an elongated shape with an ellipticity of 0.6 and a size of 6◦ × 2◦. It has an absolute magnitude of MV = −7.7, rh = 2.1 kpc, and μV(r < rh) = 31.2 mag arcsec−2. We estimate a stellar mass of 105 M , following a Kroupa mass function. The SMCNOD was probably removed from the SMC disc by tidal stripping, since it is located near the head of the Magellanic Stream, and the literature indicates likely recent Large Magellanic Cloud-SMC encounters. This scenario is supported by the lack of significant HI gas. Other potential scenarios for the SMCNOD origin are a transient overdensity within the SMC tidal radius or a primordial SMC satellite in advanced stage of disruption.