Report
The VMC Survey -- XLVIII. Classical Cepheids unveil the 3D geometry of the LMC
| العنوان: | The VMC Survey -- XLVIII. Classical Cepheids unveil the 3D geometry of the LMC |
|---|---|
| المؤلفون: | Ripepi, V., Chemin, L., Molinaro, R., Cioni, M. R. L., Bekki, K., Clementini, G., de Grijs, R., De Somma, G., Youssoufi, D. El, Girardi, L., Groenewegen, M. A. T., Ivanov, V., Marconi, M., McMillan, P. J., van Loon, J. Th. |
| سنة النشر: | 2022 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics |
| الوصف: | We employed the {\it VISTA near-infrared $YJK_\mathrm{s}$ survey of the Magellanic System} (VMC), to analyse the $Y,\,J,\,K_\mathrm{s}$ light curves of $\delta$ 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 {\it 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 $\sim$1 kpc, calculating the position angle of the line of nodes and inclination of the galaxy: $\theta$=145.6$\pm$1.0 deg and $i$=25.7$\pm$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 $\sim$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 $h\sim 0.97$ 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. Comment: 22 pages, 21 figures, accepted for publication on MNRAS. Tables 1 and 2 are available in advance of publication upon request from the first author |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1093/mnras/stac595 |
| URL الوصول: | http://arxiv.org/abs/2203.01780 |
| رقم الانضمام: | edsarx.2203.01780 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1093/mnras/stac595 |
|---|