Browsing University of Hertfordshire by Author "Saito, R. K."

Now showing items 1-11 of 11

    • A colour-excess extinction map of the southern Galactic disc from the VVV and GLIMPSE surveys 

      Soto, M.; Barbá, R.; Minniti, D.; Kunder, A.; Majaess, D.; Nilo-Castellón, J. L.; Alonso-García, J.; Leone, G.; Morelli, L.; Haikala, L.; Firpo, V.; Lucas, P.; Emerson, J. P.; Bidin, C. Moni; Geisler, D.; Saito, R. K.; Gurovich, S.; Ramos, R. Contreras; Rejkuba, M.; Barbieri, M.; Roman-Lopes, A.; Hempel, M.; Alonso, M. V.; Baravalle, L. D.; Borissova, J.; Kurtev, R.; Milla, F. (2019-09-01)
      An improved high-resolution and deep A Ks foreground dust extinction map is presented for the Galactic disc area within 295◦ ≾ l ≾ 350◦, −1.0◦ ≾ b ≾ +1.0◦. At some longitudes the map reaches up to |b| ~ 2.25◦, for a total ...

    • Discovery of a mid-infrared protostellar outburst of exceptional amplitude 

      Lucas, P. W.; Elias, Jay; Points, Sean; Guo, Z.; Stecklum, B.; Vorobyov, E.; Morris, C.; Borissova, J.; Kurtev, R.; Pena, C. Contreras; Medina, N.; Minniti, D.; Ivanov, V. D.; Saito, R. K. (2020-09-23)
      We report the discovery of a mid-infrared outburst in a Young Stellar Object (YSO) with an amplitude close to 8 mag at lambda ~ 4.6 microns. WISEA J142238.82-611553.7 is one of 23 highly variable WISE sources discovered ...

    • Discovery of new globular clusters in the Sagittarius dwarf galaxy 

      Minniti, D.; Ripepi, V.; Fernández-Trincado, J. G.; Alonso-García, J.; Smith, L. C.; Lucas, P. W.; Gómez, M.; Pullen, J. B.; Garro, E. R.; Cádiz, F. Vivanco; Hempel, M.; Rejkuba, M.; Saito, R. K.; Palma, T.; Clariá, J. J.; Gregg, M.; Majaess, D. (2021-03-12)
      Context. Globular clusters (GCs) are witnesses of the past accretion events onto the Milky Way. In particular, the GCs of the Sagittarius (Sgr) dwarf galaxy are important probes of an on-going merger. Aims. Our main goal ...

    • Evidence of distant spiral arms in the Galactic disk quadrant IV from VVV red clump giants 

      Kammers, R.; Saito, R. K.; Botan, E.; Minniti, D.; Alonso-García, J.; Smith, L. C.; Lucas, P. W. (2022-09-09)
      The discovery of new clear windows in the Galactic plane using the VVV near-IR extinction maps allows the study of the structure of the Milky Way (MW) disk. The ultimate goal of this work is to map the spiral arms in the ...

    • 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 ...

    • New Galactic star clusters discovered in the VVV survey 

      Borissova, J.; Bonatto, C.; Kurtev, R.; Clarke, J. R. A.; Penaloza, F.; Sale, S. E.; Minniti, D.; Alonso-Garcia, J.; Artigau, E.; Barba, R.; Bica, E.; Baume, G. L.; Catelan, M.; Chene, A. N.; Dias, B.; Folkes, S. L.; Froebrich, D.; Geisler, D.; de Grijs, R.; Hanson, M. M.; Hempel, M.; Ivanov, V. D.; Kumar, M. S. N.; Lucas, P.W.; Mauro, F.; Moni Bidin, C.; Rejkuba, M.; Saito, R. K.; Tamura, M.; Toledo, I. (2011-08)
      Context. VISTA Variables in the Via Lactea (VVV) is one of the six ESO Public Surveys operating on the new 4-m Visible and Infrared Survey Telescope for Astronomy (VISTA). VVV is scanning the Milky Way bulge and an adjacent ...

    • 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 ...

    • Stellar variability in the VVV survey : Overview and first results 

      Catelan, M.; Minniti, D.; Lucas, P.W.; Dékány, I.; Saito, R. K.; Angeloni, R.; Alonso-García, J.; Hempel, M.; Hełminiak, K.; Jordán, A.; Ramos, R. Contreras; Navarrete, C.; Beamín, J. C.; Rojas, A. F.; Gran, F.; Lopes, C. E Ferreira; Peña, C. Contreras; Kerins, E.; Huckvale, L.; Rejkuba, M.; Cohen, R.; Mauro, F.; Borissova, J.; Amigo, P.; Eyheramendy, S.; Pichara, K.; Espinoza, N.; Navarro, C.; Hajdu, G.; Espinoza, D. N Calderón; Muro, G. A.; Andrews, H.; Motta, V.; Kurtev, R.; Emerson, J.P.; Bidin, C. Moni; Chené, A.-N. (Cambridge University Press, 2014-03-03)
      The Vista Variables in the Vía Láctea (VVV) ESO Public Survey is an ongoing time-series, near-infrared (IR) survey of the Galactic bulge and an adjacent portion of the inner disk, covering 562 square degrees of the sky, ...

    • The VVV Infrared Variability Catalog (VIVA-I) 

      Lopes, C. E. Ferreira; Cross, N. J. G.; Catelan, M.; Minniti, D.; Hempel, M.; Lucas, P. W.; Angeloni, R.; Jablonsky, F.; Braga, V. F.; Leao, I. C.; Herpich, F. R.; Alonso-Garcia, J.; Papageorgiou, A.; Pichara, K.; Saito, R. K.; Bradley, A.; Beamin, J. C.; Cortes, C.; Medeiros, J. R. De; Russell, Christopher M. P. (2020-08)
      Thanks to the VISTA Variables in the Via Lactea (VVV) ESO Public Survey it is now possible to explore a large number of objects in those regions. This paper addresses the variability analysis of all VVV point sources having ...

    • VVV-WIT-01: highly obscured classical nova or protostellar collision? 

      Lucas, P. W.; Minniti, D.; Kamble, A.; Kaplan, D. L.; Cross, N.; Dekany, I.; Ivanov, V. D.; Kurtev, R.; Saito, R. K.; Smith, L. C.; Catelan, M.; Masetti, N.; Toledo, I.; Hempel, M.; Thompson, M. A.; Peña, C. Contreras; Forbrich, J.; Krause, M.; Dale, J.; Borissova, J.; Emerson, J.P. (2020-03)
      A search of the first Data Release of the VISTA Variables in the Via Lactea (VVV) Survey discovered the exceptionally red transient VVV-WIT-01 (H-Ks=5.2). It peaked before March 2010, then faded by ~9.5 mag over the following ...

    • VVVX-Gaia Discovery of a Low Luminosity Globular Cluster in the Milky Way Disk 

      Garro, E. R.; Minniti, D.; Gómez, M.; Alonso-García, J.; Barbá, R. H.; Barbuy, B.; Clariá, J. J.; Chené, A. N.; Dias, B.; Hempel, M.; Ivanov, V. D.; Lucas, P. W.; Majaess, D.; Mauro, F.; Bidin, C. Moni; Palma, T.; Pullen, J. B.; Saito, R. K.; Smith, L.; Surot, F.; Alegría, S. Ramírez; Rejkuba, M.; Ripepi, V. (2020-10-22)
      Milky Way globular clusters (MW GCs) are difficult to identify at low Galactic latitudes because of high differential extinction and heavy star crowding. The new deep near-IR images and photometry from the VISTA Variables ...