137 research outputs found
U B V R I Photometry of Stellar Structures throughout the Disk of the Barred Galaxy NGC 3367
We report new detailed surface U, B, V, R, and I photometry of 81 stellar
structures in the disk of the barred galaxy NGC 3367. The images show many
different structures indicating that star formation is going on in the most
part of the disk. NGC 3367 is known to have a very high concentration of
molecular gas distribution in the central regions of the galaxy and bipolar
synchrotron emission from the nucleus with two lobes (at 6 kpc) forming a
triple structure similar to a radio galaxy. We have determined the U, B, V, R,
and I magnitudes and U - B, B - V, U - V, and V - I colors for the central
region (nucleus), a region which includes supernovae 2003 AA, and 79 star
associations throughout NGC 3367. Estimation of ages of star associations is
very difficult due to several factors, among them: filling factor, metallicity,
spatial distribution of each structure and the fact that we estimated the
magnitudes with a circular aperture of 16 pixels in diameter, equivalent to
kpc. However, if the colors derived for NGC 3367 were similar to
the colors expected of star clusters with theoretical evolutionary star tracks
developed for the LMC and had a similar metallicity, NGC 3367 show 51 percent
of the observed structures with age type SWB I (few tens of Myrs), with seven
sources outside the bright surface brightness visible disk of NGC 3367.Comment: Accepted for publication (abr 2007) in The Astronomical Journal (July
2007 issue
Fabry Perot Halpha Observations of the Barred Spiral NGC 3367
We report the gross properties of the velocity field of the barred spiral
galaxy NGC 3367. The following values were found: inclination with respect to
the plane of the sky, i=30 deg; position angle (PA) of receding semi major axis
PA=51 and systemic velocity V(sys)=3032 km/s. Large velocity dispersion are
observed of upt o 120 km/s in the nuclear region, of up to 70 km/s near the
eastern bright sources just beyond the edge of the stellar bar where three
spiral arms seem to start and in the western bright sources at about 10 kpc.
Deviations from normal circular velocities are observed from all the disk but
mainly from the semi circle formed by the string of south western Halpha
sources. An estimate of the dynamical mass is M(dyn)=2x10^11 Msolar.Comment: Accepted to be published in May 2001 issue in the A.J. 19 pages, 7
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Volcanic eruption of Cumbre Vieja, La Palma, Spain: A first insight to the particulate matter injected in the troposphere
The volcanic eruption of Cumbre Vieja (La Palma Island, Spain), started on 19 September 2021 and was declared terminated on 25 December 2021. A complete set of aerosol measurements were deployed around the volcano within the first month of the eruptive activity. This paper describes the results of the observations made at Tazacorte on the west bank of the island where a polarized micro-pulse lidar was deployed. The analyzed two-and-a-half months (16 October–31 December) reveal that the peak height of the lowermost and strongest volcanic plume did not exceed 3 km (the mean of the hourly values is 1.43 ± 0.45 km over the whole period) and was highly variable. The peak height of the lowermost volcanic plume steadily increased until week 11 after the eruption started (and 3 weeks before its end) and started decreasing afterward. The ash mass concentration was assessed with a method based on the polarization capability of the instrument. Two days with a high ash load were selected: The ash backscatter coefficient, aerosol optical depth, and the volume and particle depolarization ratios were, respectively, 3.6 (2.4) Mm−1sr−1, 0.52 (0.19), 0.13 (0.07) and 0.23 (0.13) on 18 October (15 November). Considering the limitation of current remote sensing techniques to detect large-to-giant particles, the ash mass concentration on the day with the highest ash load (18 October) was estimated to have peaked in the range of 800–3200 μg m−3 in the lowermost layer below 2.5 km.This research was funded by the Spanish Ministry of Science and Innovation (PID2020- 118793GA-I00, PID2019-104205GB-C21, EQC2018-004686-P and PID2019-103886RB-I00), the H2020 program from the European Union (GA no. 19ENV04, 654109, 778349, 871115 and 101008004), and the Unit of Excellence “María de Maeztu” (MDM-2017-0737) financed by the Spanish State Research Agency (AEI). The authors wish to thank ACTRIS, AEROSPAIN and Junta de Castilla y León (ref: VA227P20) for supporting the calibration of the AERONET sun photometers used in this publication, and also to Ayuntamiento de Tazacorte, Ayuntamiento de Fuencaliente and Cabildo Insular de La Palma for their help in terms of infrastructure and logistics. M.-Á.L.-C. and C.V.C.-P. are supported by the INTA predoctoral contract program. E.J.W. is funded by the NASA Radiation Sciences Program and Earth Observing System.Peer ReviewedArticle signat per 16 autors/es: Michaël Sicard (1,2), Carmen Córdoba-Jabonero (3), Africa Barreto (4), Ellsworth J. Welton (5), Cristina Gil-Díaz (1),Clara V. Carvajal-Pérez (3), Adolfo Comerón (1), Omaira García (4), Rosa García (6), María-Ángeles López-Cayuela (3),Constantino Muñoz-Porcar (1), Natalia Prats (4), Ramón Ramos (4), Alejandro Rodríguez-Gómez (1), Carlos Toledano (7), Carlos Torres (4) // (1) CommSensLab, Department of Signal Theory and Communications, Universitat Politècnica de Catalunya, 08034 Barcelona, Spain; (2) Ciències i Tecnologies de l’Espai-Centre de Recerca de l’Aeronàutica i de l’Espai/Institut d’Estudis Espacials de Catalunya (CTE-CRAE/IEEC), Universitat Politècnica de Catalunya, 08034 Barcelona, Spain; (3) Atmospheric Research and Instrumentation Branch, Instituto Nacional de Técnica Aeroespacial (INTA), 28850 Torrejon de Ardoz, Spain; (4) Izaña Atmospheric Research Center, State Meteorological Agency of Spain (AEMET), 38001 Santa Cruz de Tenerife, Spain: (5) Code 612, Goddard Space Flight Center, National Aeronautics and Space Administration, Greenbelt, MD 20771, USA; (6) TRAGSATEC, 28006 Madrid, Spain; (7) Group of Atmospheric Optics, Universidad de Valladolid, 47011 Valladolid, SpainPostprint (published version
Aerosol characterisation in the subtropical eastern North Atlantic region using long-term AERONET measurements
A comprehensive characterisation of atmospheric aerosols in the subtropical eastern North Atlantic
has been carried out using long-term ground-based Aerosol Robotic NETwork (AERONET) photometric observations over the period 2005–2020 from a unique network made up of four stations strategically located from
sea level to 3555 m on the island of Tenerife. This site can be considered a sentinel for the passage of airmasses
going to Europe from Africa, and therefore the aerosol characterisation performed here adds important information for analysing their evolution during their path toward Northern Europe. Two of these stations (Santa Cruz
de Tenerife – SCO – at sea level and La Laguna – LLO – at 580 m a.s.l.) are located within the marine atmospheric boundary layer (MABL), and the other two (Izaña – IZO – at 2373 m a.s.l. and Teide Peak – TPO – at
3555 m a.s.l.) are high mountain stations within the free troposphere (FT). Monthly climatology of the aerosol
optical depth (AOD), Ångström exponent (AE), aerosol concentration, size distribution and aerosol optical properties has been obtained for the MABL and FT. Measurements that are quite consistent across the four sites have
been used to categorise the main atmospheric scenarios, and these measurements confirm an alternation between
predominant background conditions and predominant dust-loaded Saharan air mass conditions caused by seasonal dust transport over the subtropical North Atlantic. Background conditions prevail in the MABL and FT for
most of the year, while dust-laden conditions dominate in July and August.The authors also acknowledge the support from ACTRIS, Ministerio
de Ciencia e Innovación, Spain, through the projects SYNERA
(PID2020-118793GA-I00) and ePOLAAR (RTI2018-097864-BI00) and from Junta de Castilla y León (grant no. VA227P20)
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BioTIME: A database of biodiversity time series for the Anthropocene.
MotivationThe BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene.Main types of variables includedThe database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record.Spatial location and grainBioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km2 (158 cm2) to 100 km2 (1,000,000,000,000 cm2).Time period and grainBioTIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year.Major taxa and level of measurementBioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates.Software format.csv and .SQL
Izaña Atmospheric Research Center. Activity Report 2019-2020
Editors: Emilio Cuevas, Celia Milford and Oksana Tarasova.[EN]The Izaña Atmospheric Research Center (IARC), which is part of the State Meteorological Agency of Spain (AEMET), is a site of excellence in atmospheric science. It manages four observatories in Tenerife including the high altitude Izaña Atmospheric Observatory. The Izaña Atmospheric Observatory was inaugurated in 1916 and since that date has carried out uninterrupted meteorological and climatological observations, contributing towards a unique 100-year record in 2016.
This reports are a summary of the many activities at the Izaña Atmospheric Research Center to the broader community. The combination of operational activities, research and development in state-of-the-art measurement techniques, calibration and validation and international cooperation encompass the vision of WMO to provide world leadership in expertise and international cooperation in weather, climate, hydrology and related environmental issues.[ES]El Centro de Investigación Atmosférica de Izaña (CIAI), que forma parte de la Agencia Estatal de Meteorología de España (AEMET), representa un centro de excelencia en ciencias atmosféricas. Gestiona cuatro observatorios en Tenerife, incluido el Observatorio de Izaña de gran altitud, inaugurado en 1916 y que desde entonces ha realizado observaciones meteorológicas y climatológicas ininterrumpidas y se ha convertido en una estación centenaria de la OMM.
Estos informes resumen las múltiples actividades llevadas a cabo por el Centro de Investigación Atmosférica de Izaña. El liderazgo del Centro en materia de investigación y desarrollo con respecto a las técnicas de medición, calibración y validación de última generación, así como la cooperación internacional, le han otorgado una reputación sobresaliente en lo que se refiere al tiempo, el clima, la hidrología y otros temas ambientales afines
Izaña Atmospheric Research Center. Activity Report 2015-2016
This report is a summary of the many activities at the Izaña Atmospheric Research Center to the broader community. The combination of operational activities, research and development in state-of-the-art measurement techniques, calibration and validation and international cooperation encompass the vision of WMO to provide world leadership in expertise and international cooperation in weather, climate, hydrology and related environmental issues
Effects of chronic alcoholism in the sensitivity to luminance contrast in vertical sinusoidal gratings
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