Browsing by Author "Villanueva, V."
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- ItemDiscovery of a brown dwarf companion to the A3V star beta Circini(2015) Smith, L.; Lucas, P.; Pena, C.; Kurtev, R.; Marocco, F.; Jones, H.; Beamin Muhlenbrock, Juan Carlos; Napiwotzki, R.; Borissova, J.; Burningham, B.; Faherty, J.; Pinfield, D.; Gromadzki, M.; Ivanov, V.; Minniti, D.; Stimson, W.; Villanueva, V.
- ItemThe ALMA-CRISTAL survey Discovery of a 15 kpc-long gas plume in a z=4.54 Lyman-α blob(2024) Solimano, M.; Gonzalez-Lopez, J.; Aravena, M.; Herrera-Camus, R.; De Looze, I.; Schreiber, N. M. Foerster; Spilker, J.; Tadaki, K.; Assef, R. J.; Barcos-Munoz, L.; Davies, R. L.; Diaz-Santos, T.; Ferrara, A.; Fisher, D. B.; Guaita, L.; Ikeda, R.; Johnston, E. J.; Lutz, D.; Mitsuhashi, I.; Moya-Sierralta, C.; Relano, M.; Naab, T.; Posses, A. C.; Telikova, K.; Uebler, H.; van der Giessen, S.; Veilleux, S.; Villanueva, V.Massive star-forming galaxies in the high-redshift universe host large reservoirs of cold gas in their circumgalactic medium (CGM). Traditionally, these reservoirs have been linked to diffuse H I Lyman-alpha (Ly alpha) emission extending beyond approximate to 10 kpc scales. In recent years, millimeter and submillimeter observations have started to identify even colder gas in the CGM through molecular and/or atomic tracers such as the [C II] 158 mu m transition. In this context, we studied the well-known J1000+0234 system at z = 4.54 that hosts a massive dusty star-forming galaxy (DSFG), a UV-bright companion, and a Ly alpha blob. We combined new ALMA [C II] line observations taken by the CRISTAL survey with data from previous programs targeting the J1000+0234 system, and achieved a deep view into a DSFG and its rich environment at a 0 ''. 2 = 1.3 kpc resolution. We identified an elongated [C II]-emitting structure with a projected size of 15 kpc stemming from the bright DSFG at the center of the field, with no clear counterpart at any other wavelength. The plume is oriented approximate to 40 degrees away from the minor axis of the DSFG, and shows significant spatial variation of its spectral parameters. In particular, the [C II] emission shifts from 180 km s(-1 )to 400 km s(-1) between the bottom and top of the plume, relative to the DSFG's systemic velocity. At the same time, the line width starts at 400 - 600 km s(-1) but narrows down to 190 km s(-1) at the top end of the plume. We discuss four possible scenarios to interpret the [C II] plume: a conical outflow, a cold accretion stream, ram pressure stripping, and gravitational interactions. While we cannot strongly rule out any of these with the available data, we disfavor the ram pressure stripping scenario due to the requirement of special hydrodynamic conditions.
- ItemThe ALMA-CRISTAL survey: Dust temperature and physical conditions of the interstellar medium in a typical galaxy at z=5.66(2024) Villanueva, V.; Herrera-Camus, R.; Gonzalez-Lopez, J.; Aravena, M.; Assef, R. J.; Baeza-Garay, M.; Barcos-Munoz, L.; Bovino, S.; Bowler, R. A. A.; da Cunha, E.; De Looze, I.; Diaz-Santos, T.; Ferrara, A.; Foerster Schreiber, N. M.; Algera, H.; Ikeda, R.; Killi, M.; Mitsuhashi, I.; Naab, T.; Relano, M.; Spilker, J.; Solimano, M.; Palla, M.; Price, S. H.; Posses, A.; Tadaki, K.; Telikova, K.; Ubler, H.We present new lambda(rest) = 77 mu m dust continuum observations from the Atacama Large Millimeter/submillimeter Array of HZ10 (CRISTAL-22). This dusty main sequence galaxy at z = 5.66 was observed as part of the [CII] Resolved Ism in STar-forming Alma Large program (CRISTAL). The high angular resolution of the ALMA Band 7 and new Band 9 data (similar to 0 ''.4) reveals the complex structure of HZ10, which comprises two main components (HZ10-C and HZ10-W), along with a bridge-like dusty emission between them (i.e., "the bridge"). Using a modified blackbody function to model the dust spectral energy distribution (SED), we constrained the physical conditions of the interstellar medium (ISM) and its variations among the different components identified in HZ10. We find that HZ10-W (the more UV-obscured component) has an SED dust temperature of T-SED similar to 51.2 +/- 13.1 K; this was found to be similar to 5 K higher (which is statistically insignificant; i.e., less than 1 sigma) than that of the central component and previous global estimations for HZ10. Our new ALMA data allow us to reduce the uncertainties of global T-SED measurements by a factor of similar to 2.3, compared to previous studies. The HZ10 components have [CII]-to-far-infrared (FIR) luminosity ratios and FIR surface densities values that are consistent with local starburst galaxies. However, HZ10-W shows a lower [CII]/FIR ratio compared to the other two components (albeit still within the uncertainties), which may suggest a harder radiation field destroying polycyclic aromatic hydrocarbon associated with [CII] emission (e.g., active galactic nuclei or young stellar populations). While HZ10-C appears to follow the tight IRX-beta(UV) relation seen in local UV-selected starburst galaxies and high-z star-forming galaxies, we find that both HZ10-W and the bridge depart from this relation and are well described by dust-screen models with holes in front of a hard UV radiation field. This suggests that the UV emission, which is likely coming from young stellar populations, is strongly attenuated in the "dustier" components of the HZ10 system.
- ItemVALES V : a kinematic analysis of the molecular gas content in H-ATLAS galaxies at z similar to 0.03-0.35 using ALMA(2019) Molina, J.; Ibar, Edo; Villanueva, V.; Escala, A.; Cheng, C.; Baes, M.; Messias, H.; Yang, C.; Bauer, Franz Erik; Werf, van der
- ItemVVV high proper motion stars - I. The catalogue of bright K-S <= 13.5 stars(OXFORD UNIV PRESS, 2017) Kurtev, R.; Gromadzki, M.; Beamin, J. C.; Folkes, S. L.; Ramirez, K. Pena; Ivanov, V. D.; Borissova, J.; Villanueva, V.; Minniti, D.; Mendez, R.; Lucas, P. W.; Smith, L. C.; Pinfield, D. J.; Kuhn, M. A.; Jones, H. R. A.; Antonova, A.; Yip, A. K. P.Knowledge of the stellar content near the Sun is important for a broad range of topics ranging from the search for planets to the study of Milky Way (MW) structure. The most powerful method for identifying potentially nearby stars is proper motion (PM) surveys. All old optical surveys avoid, or are at least substantially incomplete, near the Galactic plane. The depth and breadth of the 'VISTA Variables in Via Lactea' (VVV) near-IR survey significantly improves this situation. Taking advantage of the VVV survey data base, we have measured PMs in the densest regions of the MW bulge and southern plane in order to complete the census of nearby objects. We have developed a custom PM pipeline based on VVV catalogues from the Cambridge Astronomy Survey Unit, by comparing the first epoch of JHKS with the multiepoch K-S bands acquired later. Taking advantage of the large time baseline between the Two Micron All Sky Survey (2MASS) and the VVV observations, we also obtained 2MASS-VVV PMs. We present a near-IR PMcatalogue for the whole area of the VVV survey, which includes 3003 moving stellar sources. All of these have been visually inspected and are real PM objects. Our catalogue is in very good agreement with the PM data supplied in IR catalogues outside the densest zone of the MW. The majority of the PM objects in our catalogue are nearby M-dwarfs, as expected. This new data base allows us to identify 57 common PM binary candidates, among which are two new systems within 30 pc of the Sun.
- ItemVVV IR high proper motion stars(UNIVERSIDAD NACIONAL AUTONOMA MEXICO INSTITUTO ASTRONOMIA, 2015) Kurtev, R.; Gromadzki, M.; Beamin Muhlenbrock, Juan Carlos; Pena, K.; Folkes, S.; Ivanov, V. D.; Borissova, J.; Kuhn, M.; Villanueva, V.; Minniti, D.; Mendez, R.; Lucas, P.; Smith, L.; Pinfield, D.; Antonova, A.; Vieira, K; VanAltena, W; Mendez, RAWe used the VISTA Variables en Via Lactea (VVV) survey to search for large proper motion (PM) objects in the zone of avoidance in the Milky Way bulge and southern Galactic disk. This survey is multi-epoch and already spans a period of more than four years, giving us an excellent opportunity for proper motion and parallax studies. We found around 1700 PM objects with PM>30 mas yr(-1). The majority of them are early and mid M-dwarfs. There are also few later spectral type objects, as well as numerous new K- and G-dwarfs. 75 of the stars have PM>300 mas(-1) and 189 stars have PM>200 mas(-1). There are only 42 previously known stars in the VVV area with proper motion PM>200 mas(-1). We also found three dM+WD binaries and new members of the immediate solar vicinity of 25 pc. We generated a catalog which will be a complementary to the existing catalogs outside this zone.