TY - JOUR
T1 - The VMC survey - XLVIII. Classical cepheids unveil the 3D geometry of the LMC
AU - Ripepi, Vincenzo
AU - Chemin, Laurent
AU - Molinaro, Roberto
AU - Cioni, Maria-Rosa L.
AU - Bekki, Kenji
AU - Clementini, Gisella
AU - de Grijs, Richard
AU - De Somma, Giulia
AU - El Youssoufi, Dalal
AU - Girardi, Léo
AU - Groenewegen, Martin A. T.
AU - Ivanov, Valentin
AU - Marconi, Marcella
AU - McMillan, Paul J.
AU - van Loon, Jacco Th
PY - 2022/5/1
Y1 - 2022/5/1
N2 - We employed the VISTA near-infrared YJKssurvey of the Magellanic System (VMC) to analyse the Y, J, and Ks light curves of δ Cepheid stars (DCEPs) in the Large Magellanic Cloud (LMC). Our sample consists of 4408 objects accounting for 97 per cent of the combined list of OGLE IV and Gaia DR2 DCEPs. We determined a variety of period-luminosity (PL) and period-Wesenheit PW relationships for Fundamental (F) and First Overtone (1O) pulsators. We discovered for the first time a break in these relationships for 1O DCEPs at P= 0.58 d. We derived relative individual distances for DCEPs in the LMC with a precision of ∼1 kpc, calculating the position angle of the line of nodes and inclination of the galaxy: θ = 145.6 ± 1.0 deg and i = 25.7 ± 0.4 deg. The bar and the disc are seen under different viewing angles. We calculated the ages of the pulsators, finding two main episodes of DCEP formation lasting ∼40 Myr which happened 93 and 159 Myr ago. Likely as a result of its past interactions with the SMC, the LMC shows a non-planar distribution, with considerable structuring: the bar is divided into two distinct portions, the eastern and the western displaced by more than 1 kpc from each other. Similar behaviour is shown by the spiral arms. The LMC disc appears 'flared' and thick, with a disc scale height of h ∼0.97 kpc. This feature can be explained by strong tidal interactions with the Milky Way and/or the Small Magellanic Cloud or past merging events with now disrupted LMC satellites.
AB - We employed the VISTA near-infrared YJKssurvey of the Magellanic System (VMC) to analyse the Y, J, and Ks light curves of δ Cepheid stars (DCEPs) in the Large Magellanic Cloud (LMC). Our sample consists of 4408 objects accounting for 97 per cent of the combined list of OGLE IV and Gaia DR2 DCEPs. We determined a variety of period-luminosity (PL) and period-Wesenheit PW relationships for Fundamental (F) and First Overtone (1O) pulsators. We discovered for the first time a break in these relationships for 1O DCEPs at P= 0.58 d. We derived relative individual distances for DCEPs in the LMC with a precision of ∼1 kpc, calculating the position angle of the line of nodes and inclination of the galaxy: θ = 145.6 ± 1.0 deg and i = 25.7 ± 0.4 deg. The bar and the disc are seen under different viewing angles. We calculated the ages of the pulsators, finding two main episodes of DCEP formation lasting ∼40 Myr which happened 93 and 159 Myr ago. Likely as a result of its past interactions with the SMC, the LMC shows a non-planar distribution, with considerable structuring: the bar is divided into two distinct portions, the eastern and the western displaced by more than 1 kpc from each other. Similar behaviour is shown by the spiral arms. The LMC disc appears 'flared' and thick, with a disc scale height of h ∼0.97 kpc. This feature can be explained by strong tidal interactions with the Milky Way and/or the Small Magellanic Cloud or past merging events with now disrupted LMC satellites.
KW - galaxies: photometry
KW - galaxies: stellar content
KW - galaxies: structure
KW - Magellanic Clouds
KW - stars: distances
KW - stars: variables: Cepheids
UR - http://www.scopus.com/inward/record.url?scp=85127950238&partnerID=8YFLogxK
UR - http://purl.org/au-research/grants/arc/CE170100013
U2 - 10.1093/mnras/stac595
DO - 10.1093/mnras/stac595
M3 - Article
AN - SCOPUS:85127950238
SN - 0035-8711
VL - 512
SP - 563
EP - 582
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 1
ER -