The compact group--fossil group connection: observations of a massive compact group at z=0.22

It has been suggested that fossil groups could be the cannibalized remains of compact groups, that lost energy through tidal friction. However, in the nearby universe, compact groups which are close to the merging phase and display a wealth of interacting features (such as HCG 31 and HCG 79) have very low velocity dispersions and poor neighborhoods, unlike the massive, cluster-like fossil groups studied to date. In fact, known z=0 compact groups are very seldom embedded in massive enough structures which may have resembled the intergalactic medium of fossil groups. In this paper we study the dynamical properties of CG6, a massive compact group at z=0.220 that has several properties in common with known fossil groups. We report on new g' and i' imaging and multi-slit spectroscopic performed with GMOS on Gemini South. The system has 20 members, within a radius of 1 h_70^-1 Mpc, a velocity dispersion of 700 km/s and has a mass of 1.8 x 10^14 h_70^-1 Msun, similar to that of the most massive fossil groups known. The merging of the four central galaxies in this group would form a galaxy with magnitude M_r' ~ -23.4, typical for first-ranked galaxies of fossil groups. Although nearby compact groups with similar properties to CG 6 are rare, we speculate that such systems occurred more frequently in the past and they may have been the precursors of fossil groups.Comment: 7 pages, 3 figures (one color, low resolution), uses emulateapj.sty. Accepted for publication in ApJ Lette

Mass Distribution in Hickson Compact Groups of Galaxies

This study presents the mass distribution for a sample of 18 late-type galaxies in nine Hickson Compact Groups. We used rotation curves from high resolution 2D velocity fields of Fabry-Perot observations and J-band photometry from the 2MASS survey, in order to determine the dark halo and the visible matter distributions. The study compares two halo density profile, an isothermal core-like distribution and a cuspy one. We also compare their visible and dark matter distributions with those of galaxies belonging to cluster and field galaxies coming from two samples: 40 cluster galaxies of Barnes et al (2004) and 35 field galaxies of Spano et al. (2008). The central halo surface density is found to be constant with respect to the total absolute magnitude similar to what is found for the isolated galaxies. This suggests that the halo density is independent to galaxy type and environment. We have found that core-like density profiles fit better the rotation curves than cuspy-like ones. No major differences have been found between field, cluster and compact group galaxies with respect to their dark halo density profiles.Comment: 35 pages, 21 figures. Accept for publication in Astronomical Journa

Intra-group Light in Hickson Compact Groups

We have analyzed the intra-group light component of 3 Hickson Compact Groups (HCG 79, HCG 88 and HCG 95) with detections in two of them: HCG 79, with $46\pm11$ of the total $B$ band luminosity and HCG 95 with $11\pm26$. HCG 88 had no component detected. This component is presumably due to tidally stripped stellar material trapped in the group potential and represents an efficient tool to determine the stage of dynamical evolution and to map its gravitational potential. To detect this low surface brightness structure we have applied the wavelet technique OV\_WAV, which separates the different components of the image according to their spatial characteristic sizes.Comment: Small update on the associated institutions lis

The effect of social media and celebrities on Millennials’ Consumers : the Pantene example

The present dissertation provides an overview of significant marketing related topics such as digital branding, digital marketing, targeting, positioning, social media as a marketing tool and the effectiveness of celebrity endorsers’ campaigns. These topics are discussed and analysed in a case study focused on the haircare industry, where Pantene takes the centre stage. The case study introduces this extremely competitive industry, whose dynamics have been shifting due to the price sensitivity of the average consumer. Additionally, consumers spend, nowadays, most of their free time connected to the online world; therefore, brands have now to establish a presence in the digital world, in order to connect with its target audience. The entire dissertation revolves around the huge potential of social media as a marketing instrument that must be capitalized in today’s fast moving world. The main dilemma this dissertation attempts to resolve and provide an answer to, focus on how can Pantene target a younger age segment of consumers. To this end, celebrity endorsers are also worthy of being highlighted, as they perform a crucial role in influencing millennials’ behaviours and perceptions. A market research is performed, afterwards, in order to clarify the issues raised above and from which, a set of recommendations was produced. To conclude, a Teaching Note summarizes the case study and provides indications on how to explore it in a classroom environment.A presente dissertação oferece uma visão geral de importantes temas na área do marketing, como marketing e branding digitais, targeting, posicionamento, redes sociais como instrumentos de marketing e a eficácia de campanhas protagonizadas por celebridades. Estes tópicos são discutidos e analisados num caso de estudo focado na indústria do cuidado capilar, onde a Pantene ganha um lugar de destaque. O caso de estudo introduz esta indústria extremamente competitiva, cujas dinâmicas têm sido alvo de alterações devido à sensibilidade do consumidor médio relativamente ao preço. Adicionalmente, os consumidores passam, nos dias de hoje, a maioria do seu tempo livre conectados ao mundo online; por isso mesmo, as marcas têm de estabelecer a sua presença no mundo digital, de modo a estarem ligadas às suas audiências. Esta dissertação concerne o grande potencial das redes sociais enquanto instrumento de marketing que tem de ser concretizado nos altamente mutáveis dias de hoje. O grande dilema a que esta dissertação pretende dar resposta é o seguinte: como pode a Pantene atrair um segmento jovem de consumidores? Com este objectivo em mente, focamo-nos nas celebridades visto que elas desempenham um papel crucial em influenciar os comportamentos e percepções da Geração Y. Subsequentemente, de modo a clarificar as questões levantadas anteriormente, é apresentando um estudo de mercado, a partir do qual foi produzido um conjunto de recomendações. Para concluir, uma Nota de Ensino resume o caso de estudo e fornece indicações de como explorá-lo num ambiente de aula

Marangoni instabilities under microgravity and in liquid-liquid systems with an interfacial chemical reaction

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