Browsing by Author "Smith, Leigh C."

Now showing items 1-15 of 15

    • AGN candidates in the VVV near-IR galaxy catalogue 

      Baravalle, Laura D.; Schmidt, Eduardo O.; Alonso, M. Victoria; Pichel, Ana; Minniti, Dante; Rodríguez-Kamenetzky, Adriana R.; Masetti, Nicola; Villalon, Carolina; Smith, Leigh C.; Lucas, Philip W. (2023-04-30)
      The goal of this work is to search for Active Galactic Nuclei (AGN) in the Galactic disc at very low latitudes with |b|< 2°. For this, we studied the five sources from the VVV near-infrared (IR) galaxy catalogue that have ...

    • An Automated tool to detect variable sources in the Vista Variables in the Vía Láctea Survey. The VVV Variables (V^4) catalog of tiles d001 and d002 

      Medina, Nicolás; Borissova, Jura; Bayo, Amelia; Kurtev, Radostin; Navarro-Molina, Claudio; Kuhn, Michael; Kumar, Nanda; Lucas, Philip W.; Catelan, Márcio; Minniti, Dante; Smith, Leigh C. (2018-08-24)
      Time-varying phenomena are one of the most substantial sources of astrophysical information, and their study has led to many fundamental discoveries in modern astronomy. We have developed an automated tool to search for ...

    • A Benchmark White Dwarf-Ultracool Dwarf Wide Field Binary 

      Ferreira, Thiago; Saito, Roberto K.; Minniti, Dante; Mejías, Andrea; Caceres, Claudio; Alonso-García, Javier; Beamín, Juan Carlos; Smith, Leigh C.; Gomez, Matías; Lucas, Philip W.; Ivanov, Valentin D. (2023-12-19)
      We present the discovery and multi-wavelength characterisation of VVV J1438-6158 AB, a new field wide-binary system consisting of a 4.6(+5.5-2.4) Gyr and Teff = 9500+/-125 K DA white dwarf (WD) and a Teff = 2400+/-50 K M8 ...

    • Discovery of a new nearby globular cluster with extreme kinematics located in the extension of a halo stream 

      Minniti, Dante; Fernández-Trincado, José G.; Gómez, Matías; Smith, Leigh C.; Lucas, Philip W.; Ramos, R. Contreras (2021-06-01)
      Context. We report the discovery of VVV-CL160, a new nearby globular cluster (GC) with extreme kinematics, located in the Galactic plane at l = 10.1477 deg, b = 0.2999 deg. Aims. We aim to characterize the physical properties ...

    • The extinction law in the inner 3 × 3 deg 2of the Milky Way and the red clump absolute magnitude in the inner bar-bulge 

      Sanders, Jason L.; Smith, Leigh C.; González-Fernández, Carlos; Lucas, Philip; Minniti, Dante (2022-08-01)
      The extinction law from 0.9 to 8 microns in the inner 3x3 deg^2 of the Milky Way is measured using data from VISTA Variables in the Via Lactea, GLIMPSE and WISE. Absolute extinction ratios are found by requiring that the ...

    • The globular cluster VVV CL002 falling down to the hazardous Galactic centre 

      Minniti, Dante; Matsunaga, Noriyuki; Fernández-Trincado, José G.; Otsubo, Shogo; Sarugaku, Yuki; Takeuchi, Tomomi; Katoh, Haruki; Hamano, Satoshi; Ikeda, Yuji; Kawakita, Hideyo; Lucas, Philip W.; Smith, Leigh C.; Petralia, Ilaria; Rita Garro, Elisa; Saito, Roberto K.; Alonso-García, Javier; Gómez, Matías; Gabriela Navarro, María (2024-03-15)
      Context. The Galactic centre is hazardous for stellar clusters because of the strong tidal force in action there. It is believed that many clusters were destroyed there and contributed stars to the crowded stellar field ...

    • The Milky Way bar/bulge in proper motions: a 3D view from VIRAC & Gaia 

      Clarke, Jonathan P.; Wegg, Christopher; Gerhard, Ortwin; Smith, Leigh C.; Lucas, Philip; Wylie, Shola M. (2019-11)
      We have derived absolute proper motions of the entire Galactic bulge region from VIRAC and Gaia. We present these as both integrated on-sky maps and, after isolating standard candle red clump (RC) stars, as a function of ...

    • Mira variables in the Milky Way’s nuclear stellar disc: discovery and classification 

      Sanders, Jason L.; Matsunaga, Noriyuki; Kawata, Daisuke; Smith, Leigh C.; Minniti, Dante; Lucas, Philip W. (2022-11-30)
      The properties of the Milky Way's nuclear stellar disc give crucial information on the epoch of bar formation. Mira variables are promising bright candidates to study the nuclear stellar disc, and through their period-age ...

    • Ongoing astrometric microlensing events from VVV and Gaia 

      McGill, Peter; Smith, Leigh C.; Evans, N. Wyn; Belokurov, Vasily; Lucas, Philip W. (2019-07)
      We extend predictive microlensing event searches using the Vista Variables in the Via Lactea survey and the second Gaia data release. We identify two events with maxima in 2019 that require urgent follow-up. First, we ...

    • Self-consistent modelling of the Milky Way's Nuclear Stellar Disc 

      Sormani, Mattia C.; Sanders, Jason L.; Fritz, Tobias K.; Smith, Leigh C.; Gerhard, Ortwin; Schoedel, Rainer; Magorrian, John; Neumayer, Nadine; Nogueras-Lara, Francisco; Feldmeier-Krause, Anja; Mastrobuono-Battisti, Alessandra; Schultheis, Mathias; Shahzamanian, Banafsheh; Vasiliev, Eugene; Klessen, Ralf S.; Lucas, Philip; Minniti, Dante (2022-03-22)
      The Nuclear Stellar Disc (NSD) is a flattened high-density stellar structure that dominates the gravitational field of the Milky Way at Galactocentric radius $30\lesssim R\lesssim 300$ pc. We construct axisymmetric ...

    • Variable star classification across the Galactic bulge and disc with the VISTA Variables in the Vía Láctea survey 

      Molnar, Thomas A.; Sanders, Jason L.; Smith, Leigh C.; Belokurov, Vasily; Lucas, Philip; Minniti, Dante (2021-10-30)
      We present VIVACE, the VIrac VAriable Classification Ensemble, a catalogue of variable stars extracted from an automated classification pipeline for the Vista Variables in the V\'ia L\'actea (VVV) infrared survey of the ...

    • Variable stars in the VVV globular clusters. II. NGC6441, NGC6569, NGC6626 (M28), NGC6656 (M22), 2MASS-GC02, and Terzan10 

      Alonso-García, Javier; Smith, Leigh C.; Catelan, Márcio; Minniti, Dante; Navarrete, Camila; Borissova, Jura; Carballo-Bello, Julio A.; Ramos, Rodrigo Contreras; Fernández-Trincado, José G.; Lopes, Carlos E. Ferreira; Gran, Felipe; Garro, Elisa R.; Geisler, Doug; Guo, Zhen; Hempel, Maren; Kerins, Eamonn; Lucas, Philip W.; Palma, Tali; Ramírez, Karla Peña; Alegría, Sebastián Ramírez; Saito, Roberto K. (2021-07-12)
      Context. The Galactic globular clusters (GGCs) located in the inner regions of the Milky Way suffer from high extinction that makes their observation challenging. High densities of field stars in their surroundings complicate ...

    • VVV-WIT-04: an extragalactic variable source caught by the VVV Survey 

      Saito, Roberto K.; Minniti, Dante; Ivanov, Valentin D.; Masetti, Nicola; Navarro, Maria Gabriela; Fernandes, Roberto Cid; Ruschel-Dutra, Daniel; Smith, Leigh C.; Lucas, Philip W.; Gonzalez-Fernandez, Carlos; Ramos, Rodrigo Contreras (2019-09-20)
      We report the discovery of VVV-WIT-04, a near-infrared (near-IR) variable source towards the Galactic disc located ∼0.2 arcsec apart from the position of the radio source PMN J1515−5559. The object was found serendipitously ...

    • VVV-WIT-08: the giant star that blinked 

      Smith, Leigh C.; Koposov, Sergey E.; Lucas, Philip W.; Sanders, Jason L.; Minniti, Dante; Udalski, Andrzej; Evans, N. Wyn; Aguado, David; Ivanov, Valentin D.; Saito, Roberto K.; Fraga, Luciano; Pietrukowicz, Pawel; Penoyre, Zephyr; González-Fernández, Carlos (2021-06-11)
      We report the serendipitous discovery of a late-type giant star that exhibited a smooth, eclipse-like drop in flux to a depth of 97 per cent. Minimum flux occurred in April 2012 and the total event duration was a few hundred ...

    • VVV-WIT-12 and Its Fashionable Nebula: A 4 yr Long-period Young Stellar Object with a Light Echo? 

      Saito, Roberto K.; Stecklum, Bringfried; Minniti, Dante; Lucas, Philip W.; Guo, Zhen; Smith, Leigh C.; Fraga, Luciano; Navarete, Felipe; Beamin, Juan Carlos; Morris, Calum (2023-11-14)
      We report the serendipitous discovery of VVV-WIT-12, an unusual variable source that seems to induce variability in its surrounding nebula. The source belongs to the rare objects that we call WITs (short for What Is This?) ...