TY  - JOUR
A1  - Zhang, Chaoli
A1  - Li, Chengyuan
A1  - de Grijs, Richard
A1  - Bekki, Kenji
A1  - Deng, Licai
A1  - Zaggia, Simone
A1  - Rubele, Stefano
A1  - Piatti, Andres E.
A1  - Cioni, Maria-Rosa L.
A1  - Emerson, Jim
A1  - For, Bi-Qing
A1  - Ripepi, Vincenzo
A1  - Marconi, Marcella
A1  - Ivanov, Valentin D.
A1  - Chen, Li
T1  - 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
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
KW  - galaxies: clusters: individual (47 Tucanae)
KW  - globular clusters: general
KW  - Hertzsprung-Russell and C-M diagrams
KW  - stars: low-mass
KW  - stars: luminosity function, mass function
Y1  - 2015
U6  - https://doi.org/10.1088/0004-637X/815/2/95
SN  - 0004-637X
SN  - 1538-4357
VL  - 815
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Sun, Ning-Chen
A1  - de Grijs, Richard
A1  - Subramanian, Smitha
A1  - Cioni, Maria-Rosa L.
A1  - Rubele, Stefano
A1  - Bekki, Kenji
A1  - Ivanov, Valentin D.
A1  - Piatti, Andrés E.
A1  - Ripepi, Vincenzo
T1  - The VMC Survey. XXII. Hierarchical star formation in the 30 Doradus-N158-N159-N160 star-forming complex
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - 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.
KW  - galaxies: clusters: general
KW  - infrared: stars
KW  - Magellanic Clouds
KW  - stars: formation
Y1  - 2017
U6  - https://doi.org/10.3847/1538-4357/835/2/171
SN  - 0004-637X
SN  - 1538-4357
VL  - 835
IS  - 2
PB  - Institute of Physics Publ.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Sun, Ning-Chen
A1  - de Grijs, Richard
A1  - Subramanian, Smitha
A1  - Bekki, Kenji
A1  - Bell, Cameron P. M.
A1  - Cioni, Maria-Rosa L.
A1  - Ivanov, Valentin D.
A1  - Marconi, Marcella
A1  - Oliveira, Joana M.
A1  - Piatti, Andres E.
A1  - Ripepi, Vincenzo
A1  - Rubele, Stefano
A1  - Tatton, Ben L.
A1  - van Loon, Jacco Th.
T1  - The VMC Survey. XXII. Hierarchical Star Formation in the 30 Doradus-N158–N159–N160 Star-forming Complex
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - 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.
KW  - infrared: stars
KW  - Magellanic Clouds
KW  - stars: formation
Y1  - 2017
U6  - https://doi.org/10.3847/1538-4357/aa911e
SN  - 0004-637X
SN  - 1538-4357
VL  - 849
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Subramanian, Smitha
A1  - Rubele, Stefano
A1  - Sun, Ning-Chen
A1  - Girardi, Leo
A1  - de Grijs, Richard
A1  - van Loon, Jacco Th.
A1  - Cioni, Maria-Rosa L.
A1  - Piatti, Andres E.
A1  - Bekki, Kenji
A1  - Emerson, Jim
A1  - Ivanov, Valentin D.
A1  - Kerber, Leandro
A1  - Marconi, Marcella
A1  - Ripepi, Vincenzo
A1  - Tatton, Benjamin L.
T1  - The VMC Survey - XXIV. Signatures of tidally stripped stellar populations from the inner Small Magellanic Cloud
JF  - Monthly notices of the Royal Astronomical Society
KW  - stars: individual: red clump stars
KW  - galaxies: interactions
KW  - Magellanic Clouds
Y1  - 2017
U6  - https://doi.org/10.1093/mnras/stx205
SN  - 0035-8711
SN  - 1365-2966
VL  - 467
SP  - 2980
EP  - 2995
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Schmidt, Thomas
A1  - Cioni, Maria-Rosa L.
A1  - Niederhofer, Florian
A1  - Bekki, Kenji
A1  - Bell, Cameron P. M.
A1  - de Grijs, Richard
A1  - El Youssoufi, Dalal
A1  - Ivanov, Valentin D.
A1  - Oliveira, Joana M.
A1  - Ripepi, Vincenzo
A1  - van Loon, Jacco Th.
T1  - The VMC survey: XLV. Proper motion of the outer LMC and the impact of the SMC
JF  - Astronomy and astrophysics
N2  - Context. The Large Magellanic Cloud (LMC) is the most luminous satellite galaxy of the Milky Way and, owing to its companion, the Small Magellanic Cloud (SMC), represents an excellent laboratory to study the interaction of dwarf galaxies. Aims. The aim of this study is to investigate the kinematics of the outer regions of the LMC by using stellar proper motions to understand the impact of interactions, for example with the SMC about 250 Myr ago. Methods. We calculate proper motions using multi-epoch K s -band images from the VISTA survey of the Magellanic Cloud system (VMC). Observations span a time baseline of 2-5 yr. We combine the VMC data with data from the Gaia Early Data Release 3 and introduce a new method to distinguish between Magellanic and Milky Way stars based on a machine learning algorithm. This new technique enables a larger and cleaner sample selection of fainter sources as it reaches below the red clump of the LMC. Results. We investigate the impact of the SMC on the rotational field of the LMC and find hints of stripped SMC debris. The southeastern region of the LMC shows a slow rotational speed compared to the overall rotation. N-body simulations suggest that this could be caused by a fraction of stripped SMC stars located in that particular region that move opposite to the expected rotation.
KW  - Galaxy: kinematics and dynamics
KW  - Magellanic Clouds
KW  - galaxies:
KW  - interactions
KW  - proper motions
KW  - surveys
Y1  - 2022
U6  - https://doi.org/10.1051/0004-6361/202142148
SN  - 0004-6361
SN  - 1432-0746
VL  - 663
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Romita, Krista
A1  - Lada, Elizabeth
A1  - Cioni, Maria-Rosa L.
T1  - EMBEDDED CLUSTERS IN THE LARGE MAGELLANIC CLOUD USING THE VISTA MAGELLANIC CLOUDS SURVEY
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - 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.
KW  - galaxies: star clusters: general
KW  - Magellanic Clouds
KW  - stars: formation
Y1  - 2016
U6  - https://doi.org/10.3847/0004-637X/821/1/51
SN  - 0004-637X
SN  - 1538-4357
VL  - 821
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Ripepi, Vincenzo
A1  - Marconi, M.
A1  - Moretti, M. I.
A1  - Clementini, Gisella
A1  - Cioni, Maria-Rosa L.
A1  - de Grijs, Richard
A1  - Emerson, J. P.
A1  - Groenewegen, M. A. T.
A1  - Ivanov, V. D.
A1  - Piatti, A. E.
T1  - THE VMC SURVEY. XIX. CLASSICAL CEPHEIDS IN THE SMALL MAGELLANIC CLOUD
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics ; Supplement series
N2  - 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.
KW  - distance scale
KW  - Magellanic Clouds
KW  - stars: oscillations
KW  - stars: variables: Cepheids
Y1  - 2016
U6  - https://doi.org/10.3847/0067-0049/224/2/21
SN  - 0067-0049
SN  - 1538-4365
VL  - 224
SP  - 199
EP  - 229
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Piatti, Andres E.
A1  - Ivanov, Valentin D.
A1  - Rubele, Stefano
A1  - Marconi, Marcella
A1  - Ripepi, Vincenzo
A1  - Cioni, Maria-Rosa L.
A1  - Oliveira, Joana M.
A1  - Bekki, Kenji
T1  - The VMC Survey - XXI. New star cluster candidates discovered from infrared photometry in the Small Magellanic Cloud
JF  - Monthly notices of the Royal Astronomical Society
KW  - techniques: photometric
KW  - galaxies: individual: SMC
KW  - Magellanic Clouds
Y1  - 2016
U6  - https://doi.org/10.1093/mnras/stw1000
SN  - 0035-8711
SN  - 1365-2966
VL  - 460
SP  - 383
EP  - 395
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Piatti, Andres E.
A1  - de Grijs, Richard
A1  - Rubele, Stefano
A1  - Cioni, Maria-Rosa L.
A1  - Ripepi, Vincenzo
A1  - Kerber, Leandro
T1  - The VMC survey - XV. The Small Magellanic Cloud-Bridge connection history as traced by their star cluster populations
JF  - Monthly notices of the Royal Astronomical Society
N2  - 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.
KW  - techniques: photometric
KW  - galaxies: individual: SMC
KW  - Magellanic Clouds
Y1  - 2015
U6  - https://doi.org/10.1093/mnras/stv635
SN  - 0035-8711
SN  - 1365-2966
VL  - 450
IS  - 1
SP  - 552
EP  - 563
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Piatti, Andres E.
A1  - de Grijs, Richard
A1  - Ripepi, Vincenzo
A1  - Ivanov, Valentin D.
A1  - Cioni, Maria-Rosa L.
A1  - Marconi, Marcella
A1  - Rubele, Stefano
A1  - Bekki, Kenji
A1  - For, Bi-Qing
T1  - The VMC survey - XVI. Spatial variation of the cluster formation activity in the innermost regions of the Large Magellanic Cloud
JF  - Monthly notices of the Royal Astronomical Society
KW  - techniques: photometric
KW  - galaxies: individual: LMC
KW  - Magellanic Clouds
Y1  - 2015
U6  - https://doi.org/10.1093/mnras/stv2054
SN  - 0035-8711
SN  - 1365-2966
VL  - 454
IS  - 1
SP  - 839
EP  - 848
PB  - Oxford Univ. Press
CY  - Oxford
ER  -