GHASP: an Hα\alpha kinematic survey of spiral galaxies - X. Surface photometry, decompositions and the Tully-Fisher relation in the Rc-band

We present Rc-band surface photometry for 170 of the 203 galaxies in GHASP, Gassendi H-Alpha survey of SPirals, a sample of late-type galaxies for which high-resolution Fabry-Perot H{\alpha} maps have previously been obtained. Our data set is constructed by new Rc-band observations taken at the Observatoire de Haute-Provence (OHP), supplemented with Sloan Digital Sky Survey (SDSS) archival data, obtained with the purpose of deriving homogeneous photometric profiles and parameters. Our results include Rc-band surface brightness profiles for 170 galaxies and $ugriz$ profiles for 108 of these objects. We catalogue several parameters of general interest for further reference, such as total magnitude, effective radius and isophotal parameters -- magnitude, position angle, ellipticity and inclination. We also perform a structural decomposition of the surface brightness profiles using a multi-component method in order to separate disks from bulges and bars, and to observe the main scaling relations involving luminosities, sizes and maximum velocities. We determine the Rc-band Tully Fisher relation using maximum velocities derived solely from H$\alpha$ rotation curves for a sample of 80 galaxies, resulting in a slope of $-8.1 \pm 0.5$, zero point of $-3.0 \pm 1.0$ and an estimated intrinsic scatter of $0.28 \pm 0.07$. We note that, different from the TF-relation in the near-infrared derived for the same sample, no change in the slope of the relation is seen at the low-mass end (for galaxies with $V_{max} < 125$ km/s). We suggest that this different behaviour of the Tully Fisher relation (with the optical relation being described by a single power-law while the near-infrared by two) may be caused by differences in the stellar mass to light ratio for galaxies with $V_{max} < 125$ km/s.Comment: 17 pages, 11 figure

The Compact Group of Galaxies HCG 31 is in an early phase of merging

We have obtained high spectral resolution (R = 45900) Fabry-Perot velocity maps of the Hickson Compact Group HCG 31 in order to revisit the important problem of the merger nature of the central object A+C and to derive the internal kinematics of the candidate tidal dwarf galaxies in this group. Our main findings are: (1) double kinematic components are present throughout the main body of A+C, which strongly suggests that this complex is an ongoing merger (2) regions $A2$ and E, to the east and south of complex A+C, present rotation patterns with velocity amplitudes of $\sim 25 km s^{-1}$ and they counterrotate with respect to A+C, (3) region F, which was previously thought to be the best example of a tidal dwarf galaxy in HCG 31, presents no rotation and negligible internal velocity dispersion, as is also the case for region $A1$. HCG 31 presents an undergoing merger in its center (A+C) and it is likely that it has suffered additional perturbations due to interactions with the nearby galaxies B, G and Q.Comment: 5 pages + figures - Accepted to ApJ Lette

Ages, metallicities and α\alpha-element enhancement for galaxies in Hickson compact groups

Central velocity dispersions and eight line-strength Lick indices have been determined from 1.3${\rm \AA}$ resolution long-slit spectra of 16 elliptical galaxies in Hickson compact groups. These data were used to determine galaxy properties (ages, metallicities and $\alpha$-element enhancements) and allowed a comparison with the parameters determined for a sample of galaxies in lower density environments, studied by Gonz\'alez (1993). The stellar population parameters were derived by comparison to single stellar population models of Thomas et al. (2003) and to a new set of SSP models for the indices Mg$_2$, Fe5270 and Fe5335 based on synthetic spetra. These models, based on an update version of the fitting functions presented in Barbuy et al. (2003), are fully described here. Our main results are: (1) the two samples have similar mean values for the metallicities and [$\alpha$/Fe] ratios, (2) the majority of the galaxies in compact groups seem to be old (median age of 14 Gyr for eight galaxies for which ages could be derived), in agreement with recent work by Proctor et al. (2004). These findings support two possible scenarios: compact groups are either young systems whose members have recently assembled and had not enough time to experience any merging yet or, instead, they are old systems that have avoided merging since their time of formation.Comment: Accepted for publication in A

Is there hope for BNF in common beans?

Although since 1984 there are Rhizobium strains available for common bean inoculation in Brazil, a survey in 2014 showed that only 15% of the Brazilian farmers adopt inoculation as a routine practice. Part of this disbelief in relation to common beans inoculation can be attributed to the fact that supposedly, bean inoculation would not be able to support increased yield levels in high-tech farms, being appropriate only for small farms. A series of demonstration units carried out since 2012, under farm conditions in the Cerrado region, have showed that a 10.8% mean increase in yield were obtained only with inoculation in relation to the treatment without inoculation and without nitrogen fertilization (whose average yield was 3163 kg ha-1). It was also found that inoculation with supplementation of 60 kg ha-1 of N promoted yield levels (4010 kg ha-1) higher than those with 120 kg ha-1 N as urea (3411 kg ha-1)

Diversidade genética da soja entre períodos e entre programas de melhoramento no Brasil.

O objetivo deste trabalho foi detectar os efeitos do melhoramento sobre a diversidade do germoplasma da soja cultivada nas três ultimas décadas, por meio da comparação de seis programas de melhoramento e períodos de lançamento de cultivares, utilizando locos microssatélites. Em relação aos programas de melhoramento, todos os locos apresentaram diferenças significativas em suas distribuições alélicas. Alguns locos eram compostos de alelos exclusivos em alguns programas de melhoramento, enquanto outros foram compostos sempre dos mesmos alelos em maior freqüência para todos os programas. A AMOVA indicou maior porção da variância devido a cultivares dentro de programas e somente 5,3% (p0,05). Os resultados sugerem que o germoplasma de soja utilizado em programas de melhoramento no Brasil manteve nível constante de diversidade genética nos últimos 30 anos, além de relativa heterogeneidade de determinados programas.Nome correto do quarto autor ARANTES, N. E