Hunting for open clusters in \textit{Gaia} DR2: the Galactic anticentre

The Gaia Data Release 2 (DR2) provided an unprecedented volume of precise astrometric and excellent photometric data. In terms of data mining the Gaia catalogue, machine learning methods have shown to be a powerful tool, for instance in the search for unknown stellar structures. Particularly, supervised and unsupervised learning methods combined together significantly improves the detection rate of open clusters. We systematically scan Gaia DR2 in a region covering the Galactic anticentre and the Perseus arm $(120 \leq l \leq 205$ and $-10 \leq b \leq 10)$, with the goal of finding any open clusters that may exist in this region, and fine tuning a previously proposed methodology successfully applied to TGAS data, adapting it to different density regions. Our methodology uses an unsupervised, density-based, clustering algorithm, DBSCAN, that identifies overdensities in the five-dimensional astrometric parameter space $(l,b,\varpi,\mu_{\alpha^*},\mu_{\delta})$ that may correspond to physical clusters. The overdensities are separated into physical clusters (open clusters) or random statistical clusters using an artificial neural network to recognise the isochrone pattern that open clusters show in a colour magnitude diagram. The method is able to recover more than 75% of the open clusters confirmed in the search area. Moreover, we detected 53 open clusters unknown previous to Gaia DR2, which represents an increase of more than 22% with respect to the already catalogued clusters in this region. We find that the census of nearby open clusters is not complete. Different machine learning methodologies for a blind search of open clusters are complementary to each other; no single method is able to detect 100% of the existing groups. Our methodology has shown to be a reliable tool for the automatic detection of open clusters, designed to be applied to the full Gaia DR2 catalogue.Comment: 8 pages, accepted by Astronomy and Astrophysics (A&A) the 14th May, 2019. Tables 1 and 2 available at the CD

Gaia keeps on delivering: expanding the open cluster population with EDR3

Stars and planetary system

Gaia keeps on delivering: expanding the open cluster population with EDR3

Stars and planetary system

Intense myocyte formation from cardiac stem cells in human cardiac hypertrophy

It is generally believed that increase in adult contractile cardiac mass can be accomplished only by hypertrophy of existing myocytes. Documentation of myocardial regeneration in acute stress has challenged this dogma and led to the proposition that myocyte renewal is fundamental to cardiac homeostasis. Here we report that in human aortic stenosis, increased cardiac mass results from a combination of myocyte hypertrophy and hyperplasia. Intense new myocyte formation results from the differentiation of stem-like cells committed to the myocyte lineage. These cells express stem cell markers and telomerase. Their number increased >13-fold in aortic stenosis. The finding of cell clusters with stem cells making the transition to cardiogenic and myocyte precursors, as well as very primitive myocytes that turn into terminally differentiated myocytes, provides a link between cardiac stem cells and myocyte differentiation. Growth and differentiation of these primitive cells was markedly enhanced in hypertrophy, consistent with activation of a restricted number of stem cells that, through symmetrical cell division, generate asynchronously differentiating progeny. These clusters strongly support the existence of cardiac stem cells that amplify and commit to the myocyte lineage in response to increased workload. Their presence is consistent with the notion that myocyte hyperplasia significantly contributes to cardiac hypertrophy and accounts for the subpopulation of cycling myocytes

Maquinària amb nom de dona. Estudi i documentació en perspectiva de gènere del fons industrial del Museu del Calçat i de la Pell

[cat]El Museu del Calçat i de la Pell compta amb un fons singular, entenent-se com l’única institució museística dedicada, en la seva totalitat, al patrimoni i la memòria industrial de les Illes Balears. No obstant això, en la discursiva general, manca una anàlisi detallada del paper que va tenir la dona obrera dins la indústria. A Mallorca, la història industrial des d’una perspectiva de gènere compta amb alguns estudis molt valuosos que permeten aproximar-se a la globalitat del fenomen. És gràcies a aquests que s’evidencia una manca d’investigació en la temàtica industrial des d’una perspectiva de gènere, i encara més quan es plasma al camp de l’estudi dels béns patrimonials conservats. En aquest sentit, l’article proposa visibilitzar i posar en valor el rol de la dona dins la indústria del calçat a Mallorca a través de l’estudi i la documentació dels béns mobles conservats al Museu del Calçat i de la Pell.[eng]The Footwear and Leather Museum has a unique collection. It is understood as the only institution which is entirely dedicated to the industrial heritage of the Balearic Islands. However, there isn’t a detailed analysis of the women workers role’s in the industry. Mallorca has some very valuable studies about industrial history from a gender perspective that allows to approach the whole phenomenon. However, there is a lack of research in the industrial subject from a gender perspective, and even more, when it is reflected in the heritage studies. In this way, the article proposes to make visible and emphasize the women role in the footwear mallorcan industry, through the study and documentation of the moveable cultural heritage preserved at the Footwear and Leather Museum

Gaia kinematics reveal a complex lopsided and twisted Galactic disc warp

There are few warp kinematic models of the Galaxy able to characterise structure and kinematics. These models are necessary to study the lopsidedness of the warp and the twisting of the line-of-nodes of the stellar warp, already seen in gas and dust. We use the \Gaia~Data Release 2 astrometric data up to $G=20$mag to characterise the structure of the Galactic warp, the vertical motions and the dependency on the age. We use two populations up to galactocentric distances of $16$kpc, a young (OB-type) and an old (Red Giant Branch, RGB). We use the nGC3 PCM and LonKin methods based on the Gaia observables, together with 2D projections of the positions and proper motions in the Galactic plane. We confirm the age dependency of the Galactic warp, both in positions and kinematics, being the height of the Galactic warp of about $0.2$kpc for the OB sample and of $1.$kpc for the RGB at a galactocentric distance of $14$kpc. Both methods find that the onset radius is $12\sim 13$kpc for the OB sample and $10\sim 11$kpc for the RGB. From the RGB sample, we find from galactocentric distances larger than $10$kpc the line-of-nodes twists away from the Sun-anticentre line towards galactic azimuths $\sim 180-200^{\circ}$ increasing with radius, though possibly influenced by extinction. The RGB sample reveals a slightly lopsided stellar warp with $\sim 250$pc between the up and down sides. The line of maximum of proper motions in latitude is systematically offset from the line-of-nodes estimated from the spatial data, which our models predict as a kinematic signature of lopsidedness. We also show a prominent wave-like pattern of a bending mode different in the OB and RGB, and substructures that might not be related to the Galactic warp nor to a bending mode. GDR2 triggers the need for complex kinematic models, flexible enough to combine both wave-like patterns and an S-shaped lopsided warp.[abridged]Comment: 14 pages (+7 pages of appendix), matches the accepted version in A&A after referee comments (June 5th 2019

Large Eddy simulations of isolated and installed jet noise using the high-order discontinuous Galerkin method

A recently developed computational framework for jet noise is used to compute the noise generated by an isolated and installed jet. The framework consists of two parts. In the first part, the spectral/hp element framework Nektar++ is used to compute the near-field flow. Nektar++ solves the unfiltered Navier-Stokes equations on unstructured grids using the high-order discontinuous Galerkin method. The discrete equations are integrated in time using an implicit scheme based on the matrix-free Newton-GMRES method. In the second part, the Antares library is used to compute the far-field noise. Antares solves the Ffowcs Williams - Hawkings equation for a permeable integration surface in the time domain using a source-time dominant algorithm. The simulations are validated against experimental data obtained in the Doak Laboratory Flight Jet Rig, located at the University of Southampton. For the isolated jet, good agreement is achieved, both in terms of the flow statistics and the far-field noise. The discrepancies observed for the isolated jet are believed to be caused by an under-resolved boundary layer in the simulations. For the installed jet, the flow statistics are also well predicted. In the far-field, very good agreement is achieved for downstream observers. For upstream observers, some discrepancies are observed for very high and very low frequencies

A machine learning-based tool for open cluster membership determination in Gaia DR3

Membership studies characterising open clusters with Gaia data, most using DR2, are so far limited at magnitude G = 18 due to astrometric uncertainties at the faint end. Our goal is to extend current open cluster membership lists with faint members and to characterise the low-mass end, which members are important for many applications, in particular for ground-based spectroscopic surveys. We use a deep neural network architecture to learn the distribution of highly reliable open cluster member stars around known clusters. After that, we use the trained network to estimate new open cluster members based on their similarities in a high-dimensional space, five-dimensional astrometry plus the three photometric bands. Due to the improved astrometric precisions of Gaia DR3 with respect to DR2, we are able to homogeneously detect new faint member stars (G > 18) for the known open cluster population. Our methodology can provide extended membership lists for open clusters down to the limiting magnitude of Gaia, which will enable further studies to characterise the open cluster population, e.g. estimation of their masses, or their dynamics. These extended membership lists are also ideal target lists for forthcoming ground-based spectroscopic surveys.Comment: 10 pages, 6 figures. Submitted to Astronomy & Astrophysic

L’endocarst i les mines de la serra de na Burguesa (Mallorca, Illes Balears). 2. Estat actual del coneixement paleontològic, de la vegetació pteridofítica i briofítica de les entrades de les cavitats i biospeleològic

Es presenta l’estat de la qüestió sobre el coneixement paleontològic, biospeleològic i de la vegetació pteridofítica i briofítica de les cavitats de la serra de na Burguesa (serra de Tramuntana, Illa de Mallorca). En aquesta serra s’han trobat jaciments d’origen càrstic que han lliurat fòssils de vertebrats quaternaris molt importants com n’és el cas de Myotragus batei. La flora briofítica i pteridofítica de les entrades de les cavitats no presenta peculiaritats importants, a excepció del Clot des Cero on s’hi pot trobar: Homalia lusitanica i Asplenium scolopendrium. Referent a la fauna invertebrada, hi ha endemismes singulars com Entomobrya vadelli i pel que fa als vertebrats, remarcar la importància de les coves del Pilar com a estació de la ratapinyada Miniopterus schreibersii.The state of the art knowledge palaeontological biospeleològic and vegetation pteridofítica briofítica and the cavities of the Sierra Na Burguesa (Tramuntana, Majorca) are know. In this mountain karstic deposits we are found and studied Quaternary vertebrate fossil important how the case Myotragus batei. The briophytic and pteridophytic flora of entries cavities are not important, except Clot des Cero whit Homalia lusitanica and Asplenium scolopendrium. Regarding invertebrate fauna, there are endemic Entomobrya vadelli, only know from this cave, and vertebrate stressed the importance of caves as Pilar with the bat Miniopterus schreibersii station