2,562 research outputs found
Optical photometry of the UCM Lists I and II
We present Johnson B CCD photometry for the whole sample of galaxies of the
Universidad Complutense de Madrid (UCM) Survey Lists I and II. They constitute
a well-defined and complete sample of galaxies in the Local Universe with
active star formation. The data refer to 191 S0 to Irr galaxies at an averaged
redshift of 0.027, and complement the already published Gunn r, J and K
photometries. In this paper the observational and reduction features are
discussed in detail, and the new colour information is combined to search for
clues on the properties of the galaxies, mainly by comparing our sample with
other surveys.Comment: 14 pages, 7 PostScript figures, accepted for publication in A&AS,
also available vi ftp at ftp://cutrex.fis.ucm.es/pub/OUT/pag/PAPERS
Stellar populations in local star-forming galaxies. I.-Data and modelling procedure
We present an analysis of the integrated properties of the stellar
populations in the Universidad Complutense de Madrid Survey of Halpha-selected
galaxies. In this paper, the first of a series, we describe in detail the
techniques developed to model star-forming galaxies using a mixture of stellar
populations, and taking into account the observational uncertainties. We assume
a recent burst of star formation superimposed on a more evolved population. The
effects of the nebular continuum, line emission and dust attenuation are taken
into account. We also test different model assumptions including the choice of
specific evolutionary synthesis model, initial mass function, star formation
scenario and the treatment of dust extinction. Quantitative tests are applied
to determine how well these models fit our multi-wavelength observations for
the UCM sample. Our observations span the optical and near infrared, including
both photometric and spectroscopic data. Our results indicate that extinction
plays a key role in this kind of studies, revealing that low- and
high-extinction objects may require very different extinction laws and must be
treated differently. We also demonstrate that the UCM Survey galaxies are best
described by a short burst of star formation occurring within a quiescent
galaxy, rather than by continuous star formation. A detailed discussion on the
inferred parameters, such as the age, burst strength, metallicity, star
formation rate, extinction and total stellar mass for individual objects, is
presented in paper II of this series.Comment: 18 pages, 8 PostScript figures, minor changes to match the published
versio
Determination of diquat by flow injection-chemiluminescence
A simple, economic, sensitive and rapid method for the determination of the pesticide diquat was described. This new method was based on the coupling of flow injection analysis methodology and direct chemiluminescent detection; to the authors' knowledge, this approach had not been used up to now with this pesticide. It was based on its oxidation with ferricyanide in alkaline medium; significant improvements in the analytical signal were achieved by using high temperatures and quinine as sensitiser. Its high throughput (144 h(-1)), together with its low limit of detection (2 ng mL(-1)), achieved without need of preconcentration steps, permitted the reliable quantification of diquat over the linear range of (0.01-0.6) mu g mL(-1) in samples from different origins (river, tap, mineral and ground waters), even in the presence of a 40-fold concentration of paraquat, a pesticide commonly present in the commercial formulations of diquat.López-Paz, JL.; Catalá-Icardo, M.; Antón Garrido, B. (2009). Determination of diquat by flow injection-chemiluminescence. Analytical and Bioanalytical Chemistry. 394(4):1073-1079. doi:10.1007/s00216-009-2609-zS107310793944Hayes WJ Jr, Laws ER Jr (1991) Handbook of pesticide toxicology, Academic Press, San DiegoUS Environmental Protection Agency. http://www.epa.gov/06WDW/contaminants/dw_contamfs/diquat.html (accessed in August 2008)Horwitz W (2000) Official methods of analysis of AOAC International 17th edition. AOAC International, Gaithersburg, MD, USAHara S, Sasaki N, Takase D, Shiotsuka S, Ogata K, Futagami K, Tamura K (2007) Anal Sci 23(5):523–531Rial Otero R, Cancho Grande B, Pérez Lamela C, Simal Gandara J, Aria Estevez M (2006) J Chromatogr Sci 44(9):539–542Aramendia MA, Borau V, Lafont F, Marinas JM, Moreno JM, Porras JM, Urbano FJ (2006) Food Chem 97(1):181–188Nuñez O, Moyano E, Galceran MT (2004) Anal Chim Acta 525(2):183–190Martinez Vidal JL, Belmonte Vega A, Sanchez Lopez FJ, Garrido Frenich AJ (2004) Chromatogr A 1050(2):179–184Lee XP, Kumazawa T, Fujishiro M, Hasegawa C, Arinobu T, Seno H, Sato K (2004) J Mass Spectrom 39(10):1147–1152De Almeida RM, Yonamine M (2007) J Chromatogr B 853(1–2):260–264De Souza D, Machado SAS (2006) Electroanalysis 18(9):862–872De Souza D, Da Silva MRC, Machado SAS (2006) Electroanalysis 18(23):2305–2313Picó Y, Rodriguez R, Manes J (2003) Trends Anal Chem 22(3):133–151Ishiwata T (2004) Bunseki Kagaku 53(8):863–864Carneiro MC, Puignou L, Galcerán MT (2000) Anal Chim Acta 408:263Luque M, Rios A, Valcarcel M (1998) Analyst 123(11):2383–2387Perez Ruiz T, Martínez Lozano C, Tomas V (1991) Int J Environ Anal Chem 44(4):243–252Perez Ruiz T, Martínez Lozano C, Tomas V (1991) Anal Chim Acta 244(1):99–104Townshend A (1990) Analyst 115:495–500López Paz JL, Catalá Icardo M (2008) Anal Chim Acta 625:173–179Pawlicová Z, Sahuquillo I, Catalá Icardo M, García Mateo JV, Martínez Calatayud J (2006) Anal Sci 22:29–34Albert García JR, Catalá Icardo M, Martínez Calatayud J (2006) Talanta 69:608–614Tomlin CDS (1997) The pesticide manual, 11th edn.The British Crop Protection CouncilUKCatalá-Icardo M, Martínez-Calatayud J (2008) Crit Rev Anal Chem 38:118–130Ministerio de Medio Ambiente y Medio Rural y Marino. http://www.marm.es/ (accessed in September 2008)US Environmental Protection Agency. http://www.epa.gov/OGWWDW/contaminants (accessed in October 2008
Spatial analysis of the Halpha emission in the local star-forming UCM galaxies
We present a photometric study of the Halpha emission in the Universidad
Complutense de Madrid (UCM) Survey galaxies. This work complements our
previously-published spectroscopic data. We study the location of the
star-forming knots, their intensity, concentration, and the relationship of
these properties with those of the host galaxy. We also estimate that the
amount of Halpha emission that arises from the diffuse ionized gas is about
15-30% of the total Halpha flux for a typical UCM galaxy. This percentage seems
to be independent of the Hubble type. Conversely, we found that an `average'
UCM galaxy harbours a star formation event with 30% of its Halpha luminosity
arising from a nuclear component. The implications of these results for
higher-redshift studies are discussed, including the effects of galaxy size and
the depth of the observations. A correlation between the SFR and the Balmer
decrement is observed, but such correlation breaks down for large values of the
extinction. Finally, we recalculate the Halpha luminosity function and star
formation rate density of the local Universe using the new imaging data. Our
results point out that, on average, spectroscopic observations detected about
one third of the total emission-line flux of a typical UCM galaxy. The new
values obtained for the Halpha luminosity density and the star formation rate
density of the local Universe are 10^(39.3+/-0.2) erg s-1 Mpc-3, and
rho_SFR=0.016^(+0.007)_(-0.004) Mass_sun yr-1 Mpc-3 (H_0=50 km s-1 Mpc-1,
Omega_M=1.0, Lambda=0). The corresponding values for the `concordance
cosmology' (H_0=70 km s-1 Mpc-1, Omega_M=0.3, Lambda=0.7) are 10^(39.5+/-0.2)
erg s-1 Mpc-3 rho_SFR=0.029^(+0.008)_(-0.005) Mass_sun yr-1 Mpc-3.Comment: 48 pages, 11 PostScript figures, 2 tables, accepted for publication
in ApJ. Halpha images available at
http://www.ucm.es/info/Astrof/UCM_Survey/UCM/ha_images.htm
CALIFA, the Calar Alto Legacy Integral Field Area survey: I. Survey presentation
We present here the Calar Alto Legacy Integral Field Area (CALIFA) survey,
which has been designed to provide a first step in this direction.We summarize
the survey goals and design, including sample selection and observational
strategy.We also showcase the data taken during the first observing runs
(June/July 2010) and outline the reduction pipeline, quality control schemes
and general characteristics of the reduced data. This survey is obtaining
spatially resolved spectroscopic information of a diameter selected sample of
galaxies in the Local Universe (0.005< z <0.03). CALIFA has been
designed to allow the building of two-dimensional maps of the following
quantities: (a) stellar populations: ages and metallicities; (b) ionized gas:
distribution, excitation mechanism and chemical abundances; and (c) kinematic
properties: both from stellar and ionized gas components. CALIFA uses the PPAK
Integral Field Unit (IFU), with a hexagonal field-of-view of
\sim1.3\sq\arcmin', with a 100% covering factor by adopting a three-pointing
dithering scheme. The optical wavelength range is covered from 3700 to 7000
{\AA}, using two overlapping setups (V500 and V1200), with different
resolutions: R\sim850 and R\sim1650, respectively. CALIFA is a legacy survey,
intended for the community. The reduced data will be released, once the quality
has been guaranteed. The analyzed data fulfill the expectations of the original
observing proposal, on the basis of a set of quality checks and exploratory
analysis.
We conclude from this first look at the data that CALIFA will be an important
resource for archaeological studies of galaxies in the Local Universe.Comment: 32 pages, 29 figures, Accepted for publishing in Astronomy and
Astrophysic
CALIFA : a diameter-selected sample for an integral field spectroscopy galaxy survey
JMA acknowledges support from the European Research Council Starting Grant (SEDmorph; P.I. V. Wild).We describe and discuss the selection procedure and statistical properties of the galaxy sample used by the Calar Alto Legacy Integral Field Area (CALIFA) survey, a public legacy survey of 600 galaxies using integral field spectroscopy. The CALIFA "mother sample" was selected from the Sloan Digital Sky Survey (SDSS) DR7 photometric catalogue to include all galaxies with an r-band isophotal major axis between 45 '' and 79 : 2 '' and with a redshift 0 : 005 M-r > -23 : 1 and over a stellar mass range between 10(9.7) and 10(11.4) M-circle dot. In particular, within these ranges, the diameter selection does not lead to any significant bias against - or in favour of - intrinsically large or small galaxies. Only below luminosities of M-r = -19 (or stellar masses <10(9.7) M-circle dot) is there a prevalence of galaxies with larger isophotal sizes, especially of nearly edge-on late-type galaxies, but such galaxies form <10% of the full sample. We estimate volume-corrected distribution functions in luminosities and sizes and show that these are statistically fully compatible with estimates from the full SDSS when accounting for large-scale structure. For full characterization of the sample, we also present a number of value-added quantities determined for the galaxies in the CALIFA sample. These include consistent multi-band photometry based on growth curve analyses; stellar masses; distances and quantities derived from these; morphological classifications; and an overview of available multi-wavelength photometric measurements. We also explore different ways of characterizing the environments of CALIFA galaxies, finding that the sample covers environmental conditions from the field to genuine clusters. We finally consider the expected incidence of active galactic nuclei among CALIFA galaxies given the existing pre-CALIFA data, finding that the final observed CALIFA sample will contain approximately 30 Sey2 galaxies.Peer reviewe
The Calibration of Monochromatic Far-Infrared Star Formation Rate Indicators
(Abridged) Spitzer data at 24, 70, and 160 micron and ground-based H-alpha
images are analyzed for a sample of 189 nearby star-forming and starburst
galaxies to investigate whether reliable star formation rate (SFR) indicators
can be defined using the monochromatic infrared dust emission centered at 70
and 160 micron. We compare recently published recipes for SFR measures using
combinations of the 24 micron and observed H-alpha luminosities with those
using 24 micron luminosity alone. From these comparisons, we derive a reference
SFR indicator for use in our analysis. Linear correlations between SFR and the
70 and 160 micron luminosity are found for L(70)>=1.4x10^{42} erg/s and
L(160)>=2x10^{42} erg/s, corresponding to SFR>=0.1-0.3 M_sun/yr. Below those
two luminosity limits, the relation between SFR and 70 micron (160 micron)
luminosity is non-linear and SFR calibrations become problematic. The
dispersion of the data around the mean trend increases for increasing
wavelength, becoming about 25% (factor ~2) larger at 70 (160) micron than at 24
micron. The increasing dispersion is likely an effect of the increasing
contribution to the infrared emission of dust heated by stellar populations not
associated with the current star formation. The non-linear relation between SFR
and the 70 and 160 micron emission at faint galaxy luminosities suggests that
the increasing transparency of the interstellar medium, decreasing effective
dust temperature, and decreasing filling factor of star forming regions across
the galaxy become important factors for decreasing luminosity. The SFR
calibrations are provided for galaxies with oxygen abundance 12+Log(O/H)>8.1.
At lower metallicity the infrared luminosity no longer reliably traces the SFR
because galaxies are less dusty and more transparent.Comment: 69 pages, 19 figures, 2 tables; accepted for publication on Ap
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