Browsing by Author "Alonso-García, Javier"

Now showing items 1-12 of 12

    • 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 ...

    • Characterization of the VVV Survey RR Lyrae Population across the Southern Galactic Plane 

      Minniti, Dante; Dékány, Istvan; Majaess, Daniel; Palma, Tali; Pullen, Joyce; Rejkuba, Marina; Alonso-García, Javier; Catelan, Marcio; Ramos, Rodrigo Contreras; Gonzalez, Oscar A.; Hempel, Maren; Irwin, Mike; Lucas, Philip W.; Saito, Roberto K.; Tissera, Patricia; Valenti, Elena; Zoccali, Manuela (2017-03-27)
      Deep near-IR images from the VISTA Variables in the Vía Láctea (VVV) Survey were used to search for RR Lyrae stars in the Southern Galactic plane. A sizable sample of 404 RR Lyrae of type ab stars was identified across a ...

    • Extinction ratios in the inner Galaxy as revealed by the VVV survey 

      Alonso-García, Javier; Minniti, Dante; Catelan, Márcio; Ramos, Rodrigo Contreras; Gonzalez, Oscar A.; Hempel, Maren; Lucas, Philip W.; Saito, Roberto K.; Valenti, Elena; Zoccali, Manuela (2017-11-01)
      Interstellar extinction towards the Galactic Center is large and significantly differential. Its reddening and dimming effects in red clump stars in the Galactic Bulge can be exploited to better constrain the extinction ...

    • FSR 1716: A new Milky Way Globular Cluster confirmed using VVV RR Lyrae stars 

      Minniti, Dante; Palma, Tali; Dékány, Istvan; Hempel, Maren; Rejkuba, Marina; Pullen, Joyce; Alonso-García, Javier; Barbá, Rodolfo; Barbuy, Beatriz; Bica, Eduardo; Bonatto, Charles; Borissova, Jura; Catelan, Marcio; Carballo-Bello, Julio A.; Chene, Andre Nicolas; Clariá, Juan J.; Cohen, Roger E.; Contreras-Ramos, Rodrigo; Dias, Bruno; Emerson, Jim; Froebrich, Dirk; Buckner, Anne S. M.; Geisler, Douglas; Gonzalez, Oscar A.; Gran, Felipe; Hagdu, Gergely; Irwin, Mike; Ivanov, Valentin D.; Kurtev, Radostin; Lucas, Philip W.; Majaess, Daniel; Mauro, Francesco; Moni-Bidin, Christian; Navarrete, Camila; Alegría, Sebastian Ramírez; Saito, Roberto K.; Valenti, Elena; Zoccali, Manuela (2017-03-24)
      We use deep multi-epoch near-IR images of the VISTA Variables in the V\'ia L\'actea (VVV) Survey to search for RR Lyrae stars towards the Southern Galactic plane. Here we report the discovery of a group of RR Lyrae stars ...

    • 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 ...

    • High-density Reflection Spectroscopy of Black Hole X-Ray Binaries in the Hard State 

      Liu, Honghui; Jiang, Jiachen; Zhang, Zuobin; Bambi, Cosimo; Fabian, Andrew C.; Alonso-García, Javier; Ingram, Adam; Kara, Erin; Steiner, James F.; Tomsick, John A.; Walton, Dominic J.; Young, Andrew J. (2023-07-12)
      We present a high-density relativistic reflection analysis of 21 spectra of six black hole X-ray binaries in the hard state with data from NuSTAR and Swift. We find that 76% of the observations in our sample require a disk ...

    • Milky Way demographics with the VVV survey. IV. PSF photometry from almost one billion stars in the Galactic bulge and adjacent southern disk 

      Alonso-García, Javier; Saito, Roberto K.; Hempel, Maren; Minniti, Dante; Pullen, Joyce; Catelan, Márcio; Ramos, Rodrigo Contreras; Cross, Nicholas J. G.; Gonzalez, Oscar A.; Lucas, Philip W.; Palma, Tali; Valenti, Elena; Zoccali, Manuela (2018-11-01)
      Context. The inner regions of the Galaxy are severely affected by extinction, which limits our capability to study the stellar populations present there. The Vista Variables in the Vía Láctea (VVV) ESO Public Survey has ...

    • The most variable VVV sources: eruptive protostars, dipping giants in the Nuclear Disc and others 

      Lucas, P. W.; Smith, L. C.; Guo, Z.; Peña, C. Contreras; Minniti, D.; Miller, N.; Alonso-García, Javier; Catelan, M.; Borissova, J.; Saito, R. K.; Kurtev, R.; Navarro, M. G.; Morris, C.; Muthu, H.; Froebrich, D.; Ivanov, V. D.; Bayo, A.; Garatti, A. Caratti o; Sanders, J. L. (2024-02-01)
      We have performed a comprehensive search of a VISTA Variables in the Via Lactea (VVV) data base of 9.5 yr light curves for variable sources with ΔKs ≥ 4 mag, aiming to provide a large sample of high amplitude eruptive young ...

    • A new near-IR window of low extinction in the Galactic plane 

      Minniti, Dante; Saito, Roberto K.; Gonzalez, Oscar A.; Alonso-García, Javier; Rejkuba, Marina; Barbá, Rodolfo; Irwin, Mike; Kammers, Roberto; Lucas, Philip; Majaess, Daniel; Valenti, Elena (2018-08-01)
      Aims. The windows of low extinction in the Milky Way (MW) plane are rare but important because they enable us to place structural constraints on the opposite side of the Galaxy, which has hither to been done rarely. Methods. ...

    • New VVV Survey Globular Cluster Candidates in the Milky Way Bulge 

      Minniti, Dante; Geisler, Douglas; Alonso-García, Javier; Palma, Tali; Beamin, Juan Carlos; Borissova, Jura; Catelan, Marcio; Clariá, Juan J.; Cohen, Roger E.; Ramos, Rodrigo Contreras; Dias, Bruno; Fernandez-Trincado, Jose; Gomez, Matias; Hempel, Maren; Ivanov, Valentin D.; Kurtev, Radostin; Lucas, Philip; Moni-Bidin, Christian; Pullen, Joyce; Alegría, Sebastian Ramírez; Saito, Roberto K.; Valenti, Elena (2017-11-10)
      It is likely that a number of Galactic globular clusters remain to be discovered, especially toward the Galactic bulge. High stellar density combined with high and differential interstellar reddening are the two major ...

    • Spectroscopic confirmation of high-amplitude eruptive YSOs and dipping giants from the VVV survey 

      Guo, Zhen; Lucas, P. W.; Kurtev, R.; Borissova, J.; Peña, C. Contreras; Yurchenko, S. N.; Smith, L. C.; Minniti, D.; Saito, R. K.; Bayo, A.; Catelan, M.; Alonso-García, Javier; Garatti, A. Caratti o; Morris, C.; Froebrich, D.; Tennyson, J.; Maucó, K.; Aguayo, A.; Miller, N.; Muthu, H. D. S. (2024-02-01)
      During the pre-main-sequence (pre-MS) evolution stage of a star, significant amounts of stellar mass are accreted during episodic accretion events, such as multidecade FUor-type outbursts. Here, we present a near-infrared ...

    • 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 ...