Fourteen candidate RR Lyrae star streams in the inner Galaxy

We apply the GC3 stream-finding method to RR Lyrae stars (RRLS) in the Catalina survey. We find two RRLS stream candidates at $>4\sigma$ confidence and another 12 at $>3.5\sigma$ confidence over the Galactocentric distance range $4 < D/{\rm kpc} < 26$. Of these, only two are associated with known globular clusters (NGC 1261 and Arp2). The remainder are candidate `orphan' streams, consistent with the idea that globular cluster streams are most visible close to dissolution. Our detections are likely a lower bound on the total number of dissolving globulars in the inner galaxy, since many globulars have few RRLS while only the brightest streams are visible over the Galactic RRLS background, particularly given the current lack of kinematical information. We make all of our candidate streams publicly available and provide a new GALSTREAMS Python library for the footprints of all known streams and overdensities in the Milky Way.Comment: 18 pages, 4 figures. Accepted for publication at MNRAS. GALSTREAMS Milky Way Streams Footprint Library are available at https://github.com/cmateu/galstreams . All RRL data and code used in the paper are available at https://cmateu.github.io/Cecilia_Mateu_WebPage/CatalinaGC3_Streams.htm

The QUEST RR Lyrae Survey: III. The Low Galactic Latitude Catalogue

We present results for the QUEST RR Lyrae Survey at low galactic latitude, conducted entirely with observations obtained with the QUEST mosaic camera and the 1.0/1.5m J\"urgen Stock Schmidt telescope at the National Observatory of Venezuela. The survey spans an area of 476 sq. deg on the sky, with multi-epoch observations in the V, R and I photometric bands for 6.5x10^6 stars in the galactic latitude range 30<= b(deg) <=+25, in a direction close to the Galactic Anticenter 190<= l(deg)<= 230. The variability survey has a typical number of 30 observations per object in V and I and ~25 in R, with up to ~120-150 epochs in V and I and up to ~100 in R in the best sampled regions. The completeness magnitudes of the survey are V=R=18.5 mag, and I=18.0 mag. We identified 211 RR Lyrae stars, 160 bona fide stars of type ab and 51 candidates of type c, ours being the first deep RR Lyrae survey conducted at low galactic latitude.The completeness of the RR Lyrae survey was estimated in >95 per cent and ~85 per cent for RRab and RRc stars respectively. Photometric metallicities were computed based on the light curves and individual extinctions calculated from minimum light colours for each RRab star. Distances were obtained with typical errors ~7 per cent. The RR Lyrae survey simultaneously spans a large range of heliocentric distances 0.5<= R_hel(kpc)<=40 and heights above the plane -15<=z(kpc)<=+20, with well known completeness across the survey area, making it an ideal set for studying the struc ture of the Galactic thick disk.Comment: 24 pages, 17 figures, 8 tables. Accepted for publication in MNRA

Empirical completeness assessment of the Gaia DR2, Pan-STARRS 1 and ASAS-SN-II RR Lyrae catalogues

RR Lyrae stars are an important and widely used tracer of the most ancient populations of our Galaxy, mainly due to their standard candle nature. The availability of large scale surveys of variable stars is allowing us to trace the structure of our entire Galaxy, even in previously inaccessible areas like the Galactic disc. In this work we aim to provide an empirical assessment of the completeness of the three largest RR Lyrae catalogues available: Gaia DR2, PanSTARRS-1 and ASAS-SN-II. Using a joint probabilistic analysis of the three surveys we compute 2D and 3D completeness maps in each survey's full magnitude range. At the bright end (G<13) we find ASAS-SN-II and Gaia are near 100% complete in RRab at high latitude (|b|>20deg); ASAS-SN-II has the best completeness at low latitude for RRab and at all latitudes for RRc. At the faint end (G>13), Gaia DR2 is the most complete catalogue for both RR Lyrae types, at any latitude, with median completeness rates of 95% (RRab) and >85% (RRc) outside the ecliptic plane (|\beta|>25deg). We confirm a high and uniform completeness of PanSTARRS-1 RR Lyrae at 91% (RRab) and 82% (RRc) down to G~18, and provide the first estimate of its completeness at low galactic latitude (|b|<20deg) at an estimated median 65% (RRab) and 50-60% (RRc). Our results are publicly available as 2D and 3D completeness maps, and as functions to evaluate each survey's completeness versus distance or per line-of sight.Comment: 15 pages, 14 figures, 4+10 tables. Accepted for publication at MNRAS. Completeness maps and Python utils to plot and/or recompute them, available at https://github.com/cmateu/rrl_completenes

Detection of satellite remnants in the Galactic Halo with Gaia III. Detection limits for Ultra Faint Dwarf Galaxies

We present a method to identify Ultra Faint Dwarf Galaxy (UFDG) candidates in the halo of the Milky Way using the future Gaia catalogue and we explore its detection limits and completeness. The method is based on the Wavelet Transform and searches for over-densities in the combined space of sky coordinates and proper motions, using kinematics in the search for the first time. We test the method with a Gaia mock catalogue that has the Gaia Universe Model Snapshot (GUMS) as a background, and use a library of around 30 000 UFDGs simulated as Plummer spheres with a single stellar population. For the UFDGs we use a wide range of structural and orbital parameters that go beyond the range spanned by real systems, where some UFDGs may remain undetected. We characterize the detection limits as function of the number of observable stars by Gaia in the UFDGs with respect to that of the background and their apparent sizes in the sky and proper motion planes. We find that the addition of proper motions in the search improves considerably the detections compared to a photometric survey at the same magnitude limit. Our experiments suggest that Gaia will be able to detect UFDGs that are similar to some of the known UFDGs even if the limit of Gaia is around 2 magnitudes brighter than that of SDSS, with the advantage of having a full-sky catalogue. We also see that Gaia could even find some UFDGs that have lower surface brightness than the SDSS limit.Comment: Accepted for publication in MNRA

Discovery of Extended Tidal Tails around the Globular Cluster Palomar 13

We use photometry from the DECam Legacy Survey to detect candidate tidal tails extending ~5 deg on either side of the Palomar 13 globular cluster. The tails are aligned with the proper motion of Palomar 13 and are consistent with its old, metal-poor stellar population. We identify three RR Lyrae stars that are plausibly associated with the tails, in addition to four previously known in the cluster. From these RR Lyrae stars, we find that the mean distance to the cluster and tails is $23.6 \pm 0.2$ kpc and estimate the total (initial) luminosity of the cluster to be $L_V=5.1^{+9.7}_{-3.4}\times 10^3 L_\odot$, consistent with previous claims that its initial luminosity was higher than its current luminosity. Combined with previously-determined proper motion and radial velocity measurements of the cluster, we find that Palomar 13 is on a highly eccentric orbit ($e\sim 0.8$) with a pericenter of ~9 kpc and an apocenter of ~69 kpc, and a recent pericentric passage of the cluster ~75 Myr ago. We note a prominent linear structure in the interstellar dust map that runs parallel to the candidate tidal features, but conclude that reddening due to dust is unlikely to account for the structure that we observe. If confirmed, the Palomar 13 stellar stream would be one of very few streams with a known progenitor system, making it uniquely powerful for studying the disruption of globular clusters, the formation of the stellar halo, and the distribution of matter within our Galaxy.Comment: 8 pages, 4 figures, 1 table. Submitted to AAS journal

Consumption habits: the case of the Producers' Fair of the National University of La Matanza

El Instituto de Medio Ambiente de la Universidad Nacional de la Matanza organiza, con el apoyo del Instituto Nacional de Tecnología Agropecuaria, desde el año 2015 ferias de agricultura familiar en su campus. Los objetivos de la Feria cuyo lema es “Del Productor al Consumidor”, que en cada evento cuenta con unos 40 feriantes, son sensibilizar a la comunidad educativa y a la población local en relación con la agricultura familiar y a la Economía Social y Solidaria y dar a conocer formas de producción más amigables con el ambiente dentro de un modelo de producción socialmente inclusivo. El artículo enmarca la feria en la realidad nacional en relación con la seguridad alimentaria y resume los resultados de dos tomas de opinión que se han realizado a los consumidores para relevar sus hábitos de consumo y expectativas de alimentos adquiridos en una feria de agricultura familiar.the environment institute of the national university of la Matanza organizes, with the support from the national institute of agrarian technology and since 2015, family agriculture fairs on its campus. the aims of the fair, whose slogan is "From the producer to the consumer" and which counts with some forty participants in each event, are raising awareness in the educational community and the local population about family agriculture and social, solidary economy and publi cizing the most environment-friendly ways of production within a socially inclusive production model. the article frames the fair within the national reality in regards to food safety and it summarizes the results of two opinion surveys from consumers carried out to gather information about their consumption habits and their expectations about food acquired at a family agriculture fair.food acquired at a family agriculture fair.Fil: Jäger, Mariano. Universidad Nacional de la Matanza. Instituto de Medio Ambiente; ArgentinaFil: Feito, Maria Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Matanza. Instituto de Medio Ambiente; ArgentinaFil: Pelizzari, Cecilia. Universidad Nacional de la Matanza. Instituto de Medio Ambiente; ArgentinaFil: Mateu, Silvana. Universidad Nacional de la Matanza. Instituto de Medio Ambiente; ArgentinaFil: Battista, Susana. Universidad Nacional de la Matanza. Instituto de Medio Ambiente; ArgentinaFil: Solari, Camila. Universidad Nacional de la Matanza. Instituto de Medio Ambiente; Argentin