@Article{NikzatLCCZRBMBB:2022:LoVaSt,
               author = "Nikzat, F. and Lopes, Carlos Eduardo Ferreira and Catelan, M. and 
                         Contreras Ramos, R. and Zoccali, M. and Rojas Arriagada, A. and 
                         Braga, V. F. and Minniti, D. and Borissova, J. and Becker, I.",
          affiliation = "{Pontificia Universidad Cat{\'o}lica de Chile} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Pontificia 
                         Universidad Cat{\'o}lica de Chile} and {Pontificia Universidad 
                         Cat{\'o}lica de Chile} and {Pontificia Universidad Cat{\'o}lica 
                         de Chile} and {Pontificia Universidad Cat{\'o}lica de Chile} and 
                         {INAF-Osservatorio Astronomico di Roma} and {Universidad 
                         Andr{\'e}s Bello} and {Millennium Institute of Astrophysics} and 
                         {Pontificia Universidad Cat{\'o}lica de Chile}",
                title = "The VVV survey: Long-period variable stars: I. Photometric catalog 
                         of ten VVV/OGLE tiles",
              journal = "Astronomy and Astrophysics",
                 year = "2022",
               volume = "660",
                pages = "eA35",
                month = "Apr.",
             keywords = "Catalogs, Galaxy: bulge, Galaxy: halo, Galaxy: structure, Stars: 
                         AGB and post-AGB, Stars: variables: general.",
             abstract = "Context. Long-period variable stars (LPVs) are pulsating red 
                         giants, primarily in the asymptotic giant branch phase, and they 
                         include both Miras and semi-regular variables (SRVs). Their 
                         period-age and period-luminosity relations enable us to trace 
                         different stellar populations, as they are intrinsically very 
                         bright and cover a wide range in distances and ages. Aims. The 
                         purpose of this study is to establish a census of LPV stars in a 
                         region close to the Galactic center, using the six-year database 
                         of the Vista Variables in the V{\'{\i}}a L{\'a}ctea (VVV) ESO 
                         Public Survey, as well as to describe the methodology that was 
                         employed to search for and characterize LPVs using VVV data. 
                         Near-IR surveys such as VVV provide a unique opportunity to probe 
                         the high-extinction innermost regions of the Milky Way. The 
                         detection and analysis of the intrinsically bright Miras in this 
                         region could provide us with an excellent probe of the properties 
                         of the Milky Way far behind its bulge. Methods. We used 
                         point-spread function photometry for all available Ks-band images 
                         in ten VVV tiles, covering 16.42 in total, overlapping fields 
                         observed in the course of the Optical Gravitational Lensing 
                         Experiment (OGLE)-III survey. We designed a method to select LPV 
                         candidates, and we used the known variables from OGLE-III and 
                         other known variables from the literature to test our approach. 
                         The reduced I2 statistic, along with the flux-independent index 
                         K(fi), were used in our analysis. The Lomb-Scargle period search 
                         method, Fourier analysis, template fitting, and visual inspection 
                         were then performed to refine our sample and characterize the 
                         properties of the stars included in our catalog. Results. A final 
                         sample of 130 Mira candidates, of which 129 are new discoveries, 
                         was thus obtained, with periods in the range between about 80 and 
                         1400 days. Moreover, a sample of 1013 LPV candidates is also 
                         presented, whose periods are however not sufficiently constrained 
                         by the available data. A fraction of the latter may eventually 
                         turn out to be SRVs. Ages are measured for these stars based on a 
                         reassessment of the period-age relations available in the 
                         literature. The Miras in our catalog include 18 stars satisfying 
                         the requirements to serve as reliable distance indicators and 
                         which are not saturated in the VVV Ks-band images. Their distances 
                         are accordingly derived and discussed. A number of objects that 
                         are seemingly placed far behind the Milky Waya' s bulge was 
                         detected.",
                  doi = "10.1051/0004-6361/202141805",
                  url = "http://dx.doi.org/10.1051/0004-6361/202141805",
                 issn = "0004-6361 and 1432-0746",
             language = "en",
           targetfile = "nikzat_2022_vvv.pdf",
        urlaccessdate = "15 maio 2024"
}