Small-scale star formation as revealed by VVVX galactic cluster candidates

Borissova, J.; Kurtev, R.; Amarinho, N.; Alonso-Garcia, J.; Ramirez Alegria, S.; Bernal, S.; Medina, N.; Chene, A-N; Ivanov, V. D.; Lucas, P. W.; Minniti, D.

Abstract

We report a search and analysis of obscured cluster candidates in the 'VISTA Variables in the Via Lactea eXtended (VVVX)' ESO Public Survey area encompassing the region between 229 degrees.4 < l < 295 degrees.2 and -4 degrees.3 b < 4 degrees.4 of the southern Galactic disc. We discover and propose 88 new clusters. We improve the completeness of the embedded cluster population in this region, adding small size (linear diameters of 0.2-1.4 pc) and relatively far objects (heliocentric distance between 2 and 4 kpc) to existing catalogues. Nine candidates are proposed to be older open cluster candidates. Three of them (VVVX CL 204, CL 207, CL 208) have sufficient numbers of well-resolved stellar members to allow us to determine some basic cluster parameters. We confirm their nature as older, low-mass open clusters. Photometric analysis of 15 known clusters shows that they have ages above 20 Myr, and masses below 2000 M-circle dot: in general, their proper motions follow the motion of the disc. We outline some groups of clusters, most probably formed within the same dust complex. Broadly, our candidates follow the network of filamentary structure in the remaining dust. Thus, in this part of the southern disc of the Galaxy, we have found recent star formation, producing small size and young clusters, in addition to the well-known, massive young clusters, including NGC 3603, Westerlund 2, and the Carina Nebula Complex.

Más información

Título según WOS: Small-scale star formation as revealed by VVVX galactic cluster candidates
Título de la Revista: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Volumen: 499
Número: 3
Editorial: OXFORD UNIV PRESS
Fecha de publicación: 2020
Página de inicio: 3522
Página final: 3533
DOI:

10.1093/MNRAS/STAA3045

Notas: ISI