@article{ZhangLideGrijsetal.2015, author = {Zhang, Chaoli and Li, Chengyuan and de Grijs, Richard and Bekki, Kenji and Deng, Licai and Zaggia, Simone and Rubele, Stefano and Piatti, Andres E. and Cioni, Maria-Rosa L. and Emerson, Jim and For, Bi-Qing and Ripepi, Vincenzo and Marconi, Marcella and Ivanov, Valentin D. and Chen, Li}, title = {The vmc survey. XVIII. radial dependence of the Low-Mass, 0.55-0.82M(circle dot) stellar mass function in the galactic globular cluster 47 tucanae}, series = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, volume = {815}, journal = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, number = {2}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {0004-637X}, doi = {10.1088/0004-637X/815/2/95}, pages = {9}, year = {2015}, language = {en} } @article{SundeGrijsSubramanianetal.2017, author = {Sun, Ning-Chen and de Grijs, Richard and Subramanian, Smitha and Cioni, Maria-Rosa L. and Rubele, Stefano and Bekki, Kenji and Ivanov, Valentin D. and Piatti, Andr{\´e}s E. and Ripepi, Vincenzo}, title = {The VMC Survey. XXII. Hierarchical star formation in the 30 Doradus-N158-N159-N160 star-forming complex}, series = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, volume = {835}, journal = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, number = {2}, publisher = {Institute of Physics Publ.}, address = {Bristol}, issn = {0004-637X}, doi = {10.3847/1538-4357/835/2/171}, pages = {10}, year = {2017}, abstract = {We study the hierarchical stellar structures in a similar to 1.5 deg(2) area covering the 30. Doradus-N158-N159-N160 starforming complex with the VISTA Survey of. Magellanic Clouds. Based on the young upper main-sequence stars, we find that the surface densities cover a wide range of values, from log(Sigma.pc(2))less than or similar to -2.0 to log(Sigma. pc(2)) greater than or similar to 0.0. Their distributions are highly non-uniform, showing groups that frequently have subgroups inside. The sizes of the stellar groups do not exhibit characteristic values, and range continuously from several parsecs to more than 100. pc; the cumulative size distribution can be well described by a single power law, with the power-law index indicating a projected fractal dimension D-2 = 1.6 +/- 0.3. We suggest that the phenomena revealed here support a scenario of hierarchical star formation. Comparisons with other star-forming regions and galaxies are also discussed.}, language = {en} } @article{SundeGrijsSubramanianetal.2017, author = {Sun, Ning-Chen and de Grijs, Richard and Subramanian, Smitha and Bekki, Kenji and Bell, Cameron P. M. and Cioni, Maria-Rosa L. and Ivanov, Valentin D. and Marconi, Marcella and Oliveira, Joana M. and Piatti, Andres E. and Ripepi, Vincenzo and Rubele, Stefano and Tatton, Ben L. and van Loon, Jacco Th.}, title = {The VMC Survey. XXII. Hierarchical Star Formation in the 30 Doradus-N158-N159-N160 Star-forming Complex}, series = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, volume = {849}, journal = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {0004-637X}, doi = {10.3847/1538-4357/aa911e}, pages = {16}, year = {2017}, abstract = {Star formation is a hierarchical process, forming young stellar structures of star clusters, associations, and complexes over a wide range of scales. The star-forming complex in the bar region of the Large Magellanic Cloud is investigated with upper main-sequence stars observed by the VISTA Survey of the Magellanic Clouds. The upper main-sequence stars exhibit highly nonuniform distributions. Young stellar structures inside the complex are identified from the stellar density map as density enhancements of different significance levels. We find that these structures are hierarchically organized such that larger, lower-density structures contain one or several smaller, higher-density ones. They follow power-law size and mass distributions, as well as a lognormal surface density distribution. All these results support a scenario of hierarchical star formation regulated by turbulence. The temporal evolution of young stellar structures is explored by using subsamples of upper main-sequence stars with different magnitude and age ranges. While the youngest subsample, with a median age of log(tau/yr) = 7.2, contains the most substructure, progressively older ones are less and less substructured. The oldest subsample, with a median age of log(tau/yr) = 8.0, is almost indistinguishable from a uniform distribution on spatial scales of 30-300. pc, suggesting that the young stellar structures are completely dispersed on a timescale of similar to 100. Myr. These results are consistent with the characteristics of the 30. Doradus complex and the entire Large Magellanic Cloud, suggesting no significant environmental effects. We further point out that the fractal dimension may be method dependent for stellar samples with significant age spreads.}, language = {en} } @article{SubramanianRubeleSunetal.2017, author = {Subramanian, Smitha and Rubele, Stefano and Sun, Ning-Chen and Girardi, Leo and de Grijs, Richard and van Loon, Jacco Th. and Cioni, Maria-Rosa L. and Piatti, Andres E. and Bekki, Kenji and Emerson, Jim and Ivanov, Valentin D. and Kerber, Leandro and Marconi, Marcella and Ripepi, Vincenzo and Tatton, Benjamin L.}, title = {The VMC Survey - XXIV. Signatures of tidally stripped stellar populations from the inner Small Magellanic Cloud}, series = {Monthly notices of the Royal Astronomical Society}, volume = {467}, journal = {Monthly notices of the Royal Astronomical Society}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0035-8711}, doi = {10.1093/mnras/stx205}, pages = {2980 -- 2995}, year = {2017}, language = {en} } @article{RomitaLadaCioni2016, author = {Romita, Krista and Lada, Elizabeth and Cioni, Maria-Rosa L.}, title = {EMBEDDED CLUSTERS IN THE LARGE MAGELLANIC CLOUD USING THE VISTA MAGELLANIC CLOUDS SURVEY}, series = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, volume = {821}, journal = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {0004-637X}, doi = {10.3847/0004-637X/821/1/51}, pages = {10}, year = {2016}, abstract = {We present initial results of the first large-scale survey of embedded star clusters in molecular clouds in the Large Magellanic Cloud (LMC) using near-infrared imaging from the Visible and Infrared Survey Telescope for Astronomy Magellanic Clouds Survey. We explored a ~1.65 deg2 area of the LMC, which contains the well-known star-forming region 30 Doradus as well as ~14\% of the galaxy's CO clouds, and identified 67 embedded cluster candidates, 45 of which are newly discovered as clusters. We have determined the sizes, luminosities, and masses for these embedded clusters, examined the star formation rates (SFRs) of their corresponding molecular clouds, and made a comparison between the LMC and the Milky Way. Our preliminary results indicate that embedded clusters in the LMC are generally larger, more luminous, and more massive than those in the local Milky Way. We also find that the surface densities of both embedded clusters and molecular clouds is ~3 times higher than in our local environment, the embedded cluster mass surface density is ~40 times higher, the SFR is ~20 times higher, and the star formation efficiency is ~10 times higher. Despite these differences, the SFRs of the LMC molecular clouds are consistent with the SFR scaling law presented in Lada et al. This consistency indicates that while the conditions of embedded cluster formation may vary between environments, the overall process within molecular clouds may be universal.}, language = {en} } @article{RipepiMarconiMorettietal.2016, author = {Ripepi, V. and Marconi, M. and Moretti, M. I. and Clementini, Gisella and Cioni, Maria-Rosa L. and de Grijs, R. and Emerson, J. P. and Groenewegen, M. A. T. and Ivanov, V. D. and Piatti, A. E.}, title = {THE VMC SURVEY. XIX. CLASSICAL CEPHEIDS IN THE SMALL MAGELLANIC CLOUD}, series = {The astrophysical journal : an international review of spectroscopy and astronomical physics ; Supplement series}, volume = {224}, journal = {The astrophysical journal : an international review of spectroscopy and astronomical physics ; Supplement series}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {0067-0049}, doi = {10.3847/0067-0049/224/2/21}, pages = {199 -- 229}, year = {2016}, abstract = {The "VISTA near-infrared YJK(s) survey of the Magellanic Clouds System" (VMC) is collecting deep K-s-band time-series photometry of pulsating variable stars hosted by the two Magellanic Clouds and their connecting Bridge. In this paper, we present Y, J, K-s light curves for a sample of 4172 Small Magellanic Cloud (SMC) Classical Cepheids (CCs). These data, complemented with literature V values, allowed us to construct a variety of period-luminosity (PL), period-luminosity-color (PLC), and period-Wesenheit (PW) relationships, which are valid for Fundamental (F), First Overtone (FO), and Second Overtone (SO) pulsators. The relations involving the V, J, K-s bands are in agreement with their counterparts in the literature. As for the Y band, to our knowledge, we present the first CC PL, PW, and PLC relations ever derived using this filter. We also present the first near-infrared PL, PW, and PLC relations for SO pulsators to date. We used PW(V, K-s) to estimate the relative SMC-LMC distance and, in turn, the absolute distance to the SMC. For the former quantity, we find a value of Delta mu = 0.55. +/- 0.04 mag, which is in rather good agreement with other evaluations based on CCs, but significantly larger than the results obtained from older population II distance indicators. This discrepancy might be due to the different geometric distributions of young and old tracers in both Clouds. As for the absolute distance to the SMC, our best estimates are mu(SMC) = 19.01 +/- 0.05 mag and mu(SMC) = 19.04 +/- 0.06 mag, based on two distance measurements to the LMC which rely on accurate CC and eclipsing Cepheid binary data, respectively.}, language = {en} } @article{PiattiIvanovRubeleetal.2016, author = {Piatti, Andres E. and Ivanov, Valentin D. and Rubele, Stefano and Marconi, Marcella and Ripepi, Vincenzo and Cioni, Maria-Rosa L. and Oliveira, Joana M. and Bekki, Kenji}, title = {The VMC Survey - XXI. New star cluster candidates discovered from infrared photometry in the Small Magellanic Cloud}, series = {Monthly notices of the Royal Astronomical Society}, volume = {460}, journal = {Monthly notices of the Royal Astronomical Society}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0035-8711}, doi = {10.1093/mnras/stw1000}, pages = {383 -- 395}, year = {2016}, language = {en} } @article{PiattideGrijsRubeleetal.2015, author = {Piatti, Andres E. and de Grijs, Richard and Rubele, Stefano and Cioni, Maria-Rosa L. and Ripepi, Vincenzo and Kerber, Leandro}, title = {The VMC survey - XV. The Small Magellanic Cloud-Bridge connection history as traced by their star cluster populations}, series = {Monthly notices of the Royal Astronomical Society}, volume = {450}, journal = {Monthly notices of the Royal Astronomical Society}, number = {1}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0035-8711}, doi = {10.1093/mnras/stv635}, pages = {552 -- 563}, year = {2015}, abstract = {We present results based on YJK(s) photometry of star clusters located in the outermost, eastern region of the Small Magellanic Cloud (SMC). We analysed a total of 51 catalogued clusters whose colour-magnitude diagrams (CMDs), having been cleaned from field-star contamination, were used to assess the clusters' reality and estimate ages of the genuine systems. Based on CMD analysis, 15 catalogued clusters were found to be possible non-genuine aggregates. We investigated the properties of 80 per cent of the catalogued clusters in this part of the SMC by enlarging our sample with previously obtained cluster ages, adopting a homogeneous scale for all. Their spatial distribution suggests that the oldest clusters, log(t yr(-1)) >= 9.6, are in general located at greater distances to the galaxy's centre than their younger counterparts - 9.0 <= log(t yr(-1)) <= 9.4 - while two excesses of clusters are seen at log(t yr(-1)) similar to 9.2 and log(t yr(-1)) similar to 9.7. We found a trail of younger clusters which follow the wing/bridge components. This long spatial sequence does not only harbour very young clusters, log(t yr(-1)) similar to 7.3, but it also hosts some of intermediate ages, log(t yr(-1)) similar to 9.1. The derived cluster and field-star formation frequencies as a function of age are different. The most surprising feature is an observed excess of clusters with ages of log(t yr(-1)) <9.0, which could have been induced by interactions with the LMC.}, language = {en} } @article{PiattideGrijsRipepietal.2015, author = {Piatti, Andres E. and de Grijs, Richard and Ripepi, Vincenzo and Ivanov, Valentin D. and Cioni, Maria-Rosa L. and Marconi, Marcella and Rubele, Stefano and Bekki, Kenji and For, Bi-Qing}, title = {The VMC survey - XVI. Spatial variation of the cluster formation activity in the innermost regions of the Large Magellanic Cloud}, series = {Monthly notices of the Royal Astronomical Society}, volume = {454}, journal = {Monthly notices of the Royal Astronomical Society}, number = {1}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0035-8711}, doi = {10.1093/mnras/stv2054}, pages = {839 -- 848}, year = {2015}, language = {en} } @article{NideverOlsenWalkeretal.2017, author = {Nidever, David L. and Olsen, Knut and Walker, Alistair R. and Katherina Vivas, A. and Blum, Robert D. and Kaleida, Catherine and Choi, Yumi and Conn, Blair C. and Gruendl, Robert A. and Bell, Eric F. and Besla, Gurtina and Munoz, Ricardo R. and Gallart, Carme and Martin, Nicolas F. and Olszewski, Edward W. and Saha, Abhijit and Monachesi, Antonela and Monelli, Matteo and de Boer, Thomas J. L. and Johnson, L. Clifton and Zaritsky, Dennis and Stringfellow, Guy S. and van der Marel, Roeland P. and Cioni, Maria-Rosa L. and Jin, Shoko and Majewski, Steven R. and Martinez-Delgado, David and Monteagudo, Lara and Noel, Noelia E. D. and Bernard, Edouard J. and Kunder, Andrea and Chu, You-Hua and Bell, Cameron P. M. and Santana, Felipe and Frechem, Joshua and Medina, Gustavo E. and Parkash, Vaishali and Seron Navarrete, J. C. and Hayes, Christian}, title = {SMASH: Survey of the MAgellanic Stellar History}, series = {The astronomical journal}, volume = {154}, journal = {The astronomical journal}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {0004-6256}, doi = {10.3847/1538-3881/aa8d1c}, pages = {310 -- 326}, year = {2017}, abstract = {The Large and Small Magellanic Clouds are unique local laboratories for studying the formation and evolution of small galaxies in exquisite detail. The Survey of the MAgellanic Stellar History (SMASH) is an NOAO community Dark Energy Camera (DECam) survey of the Clouds mapping 480 deg2 (distributed over similar to 2400 square degrees at similar to 20\% filling factor) to similar to 24th. mag in ugriz. The primary goals of SMASH are to identify low surface brightness stellar populations associated with the stellar halos and tidal debris of the Clouds, and to derive spatially resolved star formation histories. Here, we present a summary of the survey, its data reduction, and a description of the first public Data Release (DR1). The SMASH DECam data have been reduced with a combination of the NOAO Community Pipeline, the PHOTRED automated point-spread-function photometry pipeline, and custom calibration software. The astrometric precision is similar to 15 mas and the accuracy is similar to 2 mas with respect to the Gaia reference frame. The photometric precision is similar to 0.5\%-0.7\% in griz and similar to 1\% in u with a calibration accuracy of similar to 1.3\% in all bands. The median 5s point source depths in ugriz are 23.9, 24.8, 24.5, 24.2, and 23.5 mag. The SMASH data have already been used to discover the Hydra II Milky Way satellite, the SMASH 1 old globular cluster likely associated with the LMC, and extended stellar populations around the LMC out to R. similar to. 18.4 kpc. SMASH DR1 contains measurements of similar to 100 million objects distributed in 61 fields. A prototype version of the NOAO Data Lab provides data access and exploration tools.}, language = {en} }