Subvenciones relacionadas:
General
Nuestro grupo pequeño esta bien conocido y respetado internacionalmente por nuestro trabajo inovativo e importante en varios aspectos de la estructura y la evolución de las galaxias espirales cercanas. Usamos principalmente observaciones en varias longitudes de onda, explotando las sinergías que nos permiten responder a las cuestiones más pertinentes sobre las propiedades principales de las galaxias, y cómo las galaxias han evolucionado hasta su actual estatus. Usamos imagenes y espectroscopía, en el ultravioleta, óptico, infrarrojo, milimétrico y radio, usando al máximo las facilidades de observación a nuestra disposición en España, en la ESO y en otros sitios, combinando los datos con herramientas de análisis modernas. El éxito de esta forma de trabajar se puede medir de las oportunidades de trabajo que se presentan a los que fueron miembros del grupo, del número y de la calidad de las colaboraciones con científicos importantes, de las citas a nuestro trabajo, y de las invitaciones para organizar o hablar en los congresos más importantes en el campo.
En los últimos años nuestro grupo ha puesto mucho énfasis en abrir nuevas lineas de investigación conjuntas con informáticos, considerando el cambio de paradigma que está por venir debido a las enormes cantidades de datos que pronto producirán telescopios como LSST, Euclid, y SKA. Colaboramos con informáticos en la preparación de herramientas de análisis, incluyendo para la detección de estructura a partir del ruido, la corrección para la luz dispersa y el cirro de nuestra Vía Láctea, y el uso de técnicas basadas en machine learning. Así, una vez los telescopios LSST (2020) y Euclid (2023) empiezan a producir sus juegos de datos enormes, nuestro grupo estará preparado para analizarlos y extraer la ciencia.
Miembros
Resultados
- A partir de mapas térmicos y non-térmicos en radio del centro de NGC 1097 hemos descubierto que la formación de estrellas masivas se apaga por efectos non-térmicos, incluido la presión del campo magnético, rayos cósmicos y turbulencia.
- En el centro de NGC 7742 hemos detectado un disco interno y dos componentes estelares: una población vieja que contra-rota con el gas, y una joven, concentrado en un anillo, que rota con el gas.
- Hemos re-analizadas nuestras imágenes profundas IR de discos gruesos para corregir por el point spread function (PSF) extendido, confirmando todos nuestros previos resultados y en particular confirmando la presencia de una masa significativa en el componente del disco grueso.
- Analizando un mapa nuevo a alta resolución en el radio continuo a 1.5 GHz de e-Merlin, junto con imágenes de HST y SDSS de NGC 5322, una galaxia elíptica que contiene chorros en radio, hemos encontrado que un chorro de baja luminosidad puede haber acabado con la formación estelar en el nucleo.
- A partir de observaciones con MUSE de la emisión Lyman-α a bajo brillo superficial alrededor de galaxias débiles a redshifts entre 3 y 6 hemos encontrado que la cobertura proyectoada en el cielo se aproxima al 100%.
Actividad científica
Publicaciones relacionadas
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ARRAKIS: atlas of resonance rings as known in the S4GContext. Resonance rings and pseudorings (here collectively called rings) are thought to be related to the gathering of material near dynamical resonances caused by non-axisymmetries in galaxy discs. This means that they are the result of secular evolution processes that redistribute material and angular momentum in discs. Studying them may giveComerón, S. et al.
Fecha de publicación:
22014 -
Unveiling the Structure of Barred Galaxies at 3.6 μm with the Spitzer Survey of Stellar Structure in Galaxies (S4G). I. Disk BreaksWe have performed two-dimensional multicomponent decomposition of 144 local barred spiral galaxies using 3.6 μm images from the Spitzer Survey of Stellar Structure in Galaxies. Our model fit includes up to four components (bulge, disk, bar, and a point source) and, most importantly, takes into account disk breaks. We find that ignoring the diskSeibert, Mark et al.
Fecha de publicación:
22014 -
The circumnuclear environment of NGC 613: a nuclear starburst caught in the act?We present near-infrared (H- and K-band) integral-field observations of the inner ˜700 pc of the active spiral galaxy NGC 613, obtained with SINFONI on the Very Large Telescope. We use emission-line ratios to determine the dominant excitation mechanisms in different regions within our field of view, in particular, the active nucleus and the starLançon, A. et al.
Fecha de publicación:
22014 -
Morphological Parameters of a Spitzer Survey of Stellar Structure in GalaxiesThe morphology of galaxies can be quantified to some degree using a set of scale-invariant parameters. Concentration (C), asymmetry (A), smoothness (S), the Gini index (G), the relative contribution of the brightest pixels to the second-order moment of the flux (M 20), ellipticity (E), and the Gini index of the second-order moment (GM ) have allHolwerda, B. W. et al.
Fecha de publicación:
12014 -
Embedded Star Formation in S4G Galaxy Dust LanesStar-forming regions that are visible at 3.6 μm and Hα but not in the u, g, r, i, z bands of the Sloan Digital Sky Survey are measured in five nearby spiral galaxies to find extinctions averaging ~3.8 mag and stellar masses averaging ~5 × 104 M ☉. These regions are apparently young star complexes embedded in dark filamentary shock fronts connectedMizusawa, Trisha et al.
Fecha de publicación:
12014 -
Interlocking Resonance Patterns in Galaxy DisksWe have developed a method for finding dynamical resonances in disk galaxies using the change in sense of the radial component of the in-plane velocity at a resonance radius. Using simulations we show that we would expect to find these changes at corotation radii with a weaker effect at the Lindblad resonances. The method works well withQuerejeta, M. et al.
Fecha de publicación:
12014 -
Shock Excited Molecules in NGC 1266: ULIRG Conditions at the Center of a Bulge-dominated GalaxyWe investigate the far infrared (IR) spectrum of NGC 1266, a S0 galaxy that contains a massive reservoir of highly excited molecular gas. Using the Herschel Fourier Transform Spectrometer, we detect the 12CO ladder up to J = (13-12), [C I] and [N II] lines, and also strong water lines more characteristic of UltraLuminous IR Galaxies (ULIRGs). TheDale, D. A. et al.
Fecha de publicación:
122013 -
Massive star formation in galaxies with excess ultraviolet emissionFrom an analysis of almost 2000 Galaxy Evolution Explorer images of galaxies with morphological types ranging from E to Sab, we have found a significant subset (28 per cent) that show ultraviolet (UV) emission outside R25. We have obtained Hα imaging of 10 such galaxies, and found that their star formation rates are similar in the UV and in HαHagen, Lea M. Z. et al.
Fecha de publicación:
122013 -
The bifurcated age-metallicity relation of Milky Way globular clusters and its implications for the accretion history of the galaxyWe use recently derived ages for 61 Milky Way (MW) globular clusters (GCs) to show that their age-metallicity relation (AMR) can be divided into two distinct, parallel sequences at [Fe/H] ≳ -1.8. Approximately one-third of the clusters form an offset sequence that spans the full range in age (˜10.5-13 Gyr), but is more metal rich at a given age byLeaman, R. et al.
Fecha de publicación:
112013 -
The James Clerk Maxwell Telescope Nearby Galaxies Legacy Survey - IX. 12CO J = 3→2 observations of NGC 2976 and NGC 3351We present 12CO J = 3→2 maps of NGC 2976 and NGC 3351 obtained with the James Clerk Maxwell Telescope (JCMT), both early targets of the JCMT Nearby Galaxy Legacy Survey (NGLS). We combine the present observations with 12CO J = 1→0 data and find that the computed 12CO J = 3→2 to 12CO J = 1→0 line ratio (R31) agrees with values measured in other NGLSTan, Boon-Kok et al.
Fecha de publicación:
112013 -
X-Ray Nuclear Activity in S4G Barred Galaxies: No Link between Bar Strength and Co-occurrent Supermassive Black Hole FuelingStellar bars can lead to gas inflow toward the center of a galaxy and stimulate nuclear star formation. However, there is no compelling evidence on whether they also feed a central supermassive black hole: by measuring the fractions of barred active and inactive galaxies, previous studies have yielded conflicting results. In this paper, we aim toCisternas, M. et al.
Fecha de publicación:
102013 -
The Ages of 55 Globular Clusters as Determined Using an Improved \Delta V^HB_TO Method along with Color-Magnitude Diagram Constraints, and Their Implications for Broader IssuesAges have been derived for 55 globular clusters (GCs) for which Hubble Space Telescope Advanced Camera for Surveys photometry is publicly available. For most of them, the assumed distances are based on fits of theoretical zero-age horizontal-branch (ZAHB) loci to the lower bound of the observed distributions of HB stars, assuming reddenings fromVandenBerg, D. A. et al.
Fecha de publicación:
102013 -
On the Origin of Lopsidedness in Galaxies as Determined from the Spitzer Survey of Stellar Structure in Galaxies (S4G)We study the m = 1 distortions (lopsidedness) in the stellar components of 167 nearby galaxies that span a wide range of morphologies and luminosities. We confirm the previous findings of (1) a high incidence of lopsidedness in the stellar distributions, (2) increasing lopsidedness as a function of radius out to at least 3.5 exponential scaleZaritsky, Dennis et al.
Fecha de publicación:
82013 -
The Impact of Bars on Disk Breaks as Probed by S4G ImagingWe have analyzed the radial distribution of old stars in a sample of 218 nearby face-on disks, using deep 3.6 μm images from the Spitzer Survey of Stellar Structure in Galaxies. In particular, we have studied the structural properties of those disks with a broken or down-bending profile. We find that, on average, disks with a genuine singleMuñoz-Mateos, Juan Carlos et al.
Fecha de publicación:
72013 -
The Comparative Chemical Evolution of an Isolated Dwarf Galaxy: A VLT and Keck Spectroscopic Survey of WLMBuilding on our previous spectroscopic and photometric analysis of the isolated Local Group dwarf irregular (dIrr) galaxy WLM, we present a comparison of the metallicities of its red giant branch stars with respect to the well-studied Local Group dwarf spheroidal galaxies (dSphs) and Magellanic Clouds. We calculate a mean metallicity of [Fe/H] =–1Tolstoy, Eline et al.
Fecha de publicación:
42013 -
The 2011 Periastron Passage of the Be Binary δ ScorpiiWe describe the results of the world-wide observing campaign of the highly eccentric Be binary system δ Scorpii 2011 periastron passage which involved professional and amateur astronomers. Our spectroscopic observations provided a precise measurement of the system orbital period at 10.8092 ± 0.0005 yr. Fitting of the He II 4686 Å line radialReinecke, N. et al.
Fecha de publicación:
42013 -
Hydrogen volume densities in nearby galaxies - I. An automated approachUsing a simple model of photodissociated atomic hydrogen on a galactic scale, it is possible to derive total hydrogen volume densities. These densities, obtained through a combination of atomic hydrogen, far-ultraviolet and metallicity data, provide an independent probe of the combined atomic and molecular hydrogen gas in galactic discs. We presentKnapen, J. H. et al.
Fecha de publicación:
22013 -
Hα kinematics of S4G spiral galaxies - I. NGC 864We present a study of the kinematics of the isolated spiral galaxy NGC 864, using Hα Fabry-Perot data obtained with the Galaxy Hα Fabry-Perot System (GHαFaS) instrument at the William Herschel Telescope in La Palma, complemented with images at 3.6 μm, in the R band and in Hα filter, and integral-field spectroscopic data. The resulting data cubesSeibert, Mark et al.
Fecha de publicación:
122012 -
A unified picture of breaks and truncations in spiral galaxies from SDSS and S4G imagingThe mechanism causing breaks in the radial surface-brightness distribution of spiral galaxies is not yet well known. Despite theoretical efforts, there is not a unique explanation for these features and the observational results are not conclusive. In an attempt to address this problem, we have selected a sample of 34 highly inclined spiralSeibert, Mark et al.
Fecha de publicación:
122012 -
Spectral Energy Distributions of Type 1 Active Galactic Nuclei in the COSMOS Survey. I. The XMM-COSMOS SampleThe "Cosmic Evolution Survey" (COSMOS) enables the study of the spectral energy distributions (SEDs) of active galactic nuclei (AGNs) because of the deep coverage and rich sampling of frequencies from X-ray to radio. Here we present an SED catalog of 413 X-ray (XMM-Newton)-selected type 1 (emission line FWHM > 2000 km s–1) AGNs with Magellan, SDSSElvis, M. et al.
Fecha de publicación:
112012