The VMC survey - XLVIII. Classical cepheids unveil the 3D geometry of the LMC

Vincenzo Ripepi*, Laurent Chemin, Roberto Molinaro, Maria-Rosa L. Cioni, Kenji Bekki, Gisella Clementini, Richard de Grijs, Giulia De Somma, Dalal El Youssoufi, Léo Girardi, Martin A. T. Groenewegen, Valentin Ivanov, Marcella Marconi, Paul J. McMillan, Jacco Th van Loon

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

26 Citations (Scopus)

Abstract

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.

Original languageEnglish
Pages (from-to)563-582
Number of pages20
JournalMonthly Notices of the Royal Astronomical Society
Volume512
Issue number1
DOIs
Publication statusPublished - 1 May 2022

Keywords

  • galaxies: photometry
  • galaxies: stellar content
  • galaxies: structure
  • Magellanic Clouds
  • stars: distances
  • stars: variables: Cepheids

Fingerprint

Dive into the research topics of 'The VMC survey - XLVIII. Classical cepheids unveil the 3D geometry of the LMC'. Together they form a unique fingerprint.

Cite this