Disk of the Small Magellanic Cloud as traced by Cepheids

Abstract

The structure and evolution of the disk of the Small Magellanic Cloud (SMC) are traced by studying the Cepheids. We aim to estimate the orientation measurements of the disk, such as the inclination and the position angle of the line of nodes, and the depth of the disk. We used the V and I band photometric data of the fundamental and first-overtone Cepheids from the Optical Gravitational Lensing Experiment survey. The period-luminosity relations were used to estimate the relative distance and reddening of each Cepheid. A weighted least-square plane fitting method was then applied to estimate the structural parameters. The line-of-sight depth and then the orientation corrected depth or thickness of the disk were estimated from the relative distance measurements. The period-age-colour relation of Cepheids were used to derive the age of the Cepheids. A break in the PL relations of the fundamental-mode and first-overtone Cepheids at P ~ 2.95 days and P ~ 1 day are observed. An inclination of 64${}^o$.4$\pm$0${}^o$.7 and a PA${}_{lon}$=155${}^o$.3$\pm$6${}^o$.3 are obtained from the full sample. A reddening map of the SMC disk is also presented. The orientation-corrected depth or thickness of the SMC disk is found to be 1.76 $\pm$ 0.6 kpc. The scale height is estimated to be 0.82 $\pm$ 0.3 kpc. The age distribution of Cepheids matches the SMC cluster age distribution. The radial variation of the disk parameters mildly indicate structures/disturbances in the inner SMC (0.5 $<$ r $<$ 2.5 degree). Some of the Cepheids found in front of the fitted plane in the eastern regions are possibly the youngest tidally stripped counterpart of the H {\sc i} gas of the Magellanic Bridge. The Cepheids behind the fitted plane are most likely the population in the Counter Bridge predicted in recent numerical simulations. Different scenarios for the origin of the extra-planar Cepheids are also discussed.

arXiv commentAccepted for publication in the journal Astronomy & Astrophysics, 18 pages, 18 figures

References in corpus (39)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• Are the Magellanic Clouds on their First Passage about the Milky Way?
• Third-Epoch Magellanic Cloud Proper Motions I: HST/WFC3 data and Orbit Implications
• Magellanic Cloud Structure from Near-IR Surveys I: The Viewing Angles of the LMC
• The Role of Dwarf Galaxy Interactions in Shaping the Magellanic System and Implications for Magellanic Irregulars
• N-body Simulations of the Small Magellanic Cloud and the Magellanic Stream
• The Proper Motion of the Large Magellanic Cloud using HST
• A New Look at the Kinematics of Neutral Hydrogen in the Small Magellanic Cloud
• Is the SMC Bound to the LMC? The HST Proper Motion of the SMC
• Simulations of the Magellanic Stream in a First Infall Scenario
• Hierarchical Star Formation from the Time-Space Distribution of Star Clusters in the Large Magellanic Cloud
• The Tidal Origin of the Magellanic Stream and the Possibility of a Stellar Counterpart
• Cepheid Period-Radius and Period-Luminosity Relations and the Distance to the LMC
• Ages and Luminosities of Young SMC/LMC Star Clusters and the recent Star Formation History of the Clouds
• Classical Cepheid Pulsation Models. X. The Period-Age Relation
• Spectroscopic Survey of Red Giants in the SMC. I: Kinematics
• Formation and evolution of the Magellanic Clouds. I.Origin of structural, kinematical, and chemical properties of the Large Magellanic Cloud
• The Line-of-Sight Depth of Populous Clusters in the Small Magellanic Cloud
• The 3D structure of the Small Magellanic Cloud
• A Study of Edge-On Galaxies with the Hubble Space Telescope's Advanced Camera for Surveys. II. Vertical distribution of the resolved stellar population
• Structure of the Large Magellanic Cloud from 2MASS
• The Morphologies of the Small Magellanic Cloud
• Three dimensional maps of the Magellanic Clouds using RR Lyrae Stars and Cepheids II. The Small Magellanic Cloud
• A Tidally-Stripped Stellar Component of the Magellanic Bridge
• New period-luminosity and period-color relations of classical Cepheids: III. Cepheids in SMC
• Kinematics of massive stars in the Small Magellanic Cloud
• Three dimensional maps of the Magellanic Clouds using RR~Lyrae stars and Cepheids - I. The Large Magellanic Cloud
• Red Giants in the Small Magellanic Cloud. I. Disk and Tidal Stream Kinematics
• Uncertainties on the theoretical predictions for classical Cepheid pulsational quantities
• The Magellanic Squall: Gas Replenishment from the Small to Large Magellanic Cloud
• New period-luminosity and period-color relations of classical Cepheids. IV. The low-metallicity galaxies IC 1613, WLM, Pegasus, Sextans A and B, and Leo A in comparison to SMC
• Recent star formation history of the Large and Small Magellanic Clouds
• Period-color and amplitude-color relations in classical Cepheid variables III: The Large Magellanic Cloud Cepheid models
• Formation of the Small Magellanic Cloud: ancient major merger as a solution to the kinematical differences between old stars and HI gas
• Kinematical Structure of the Magellanic System
• Period-colour and amplitude-colour relations in classical Cepheid variables IV: The multi-phase relations
• B,V Photometry of Variable Stars in the Northeast Arm of the Small Magellanic Cloud
• The Faint Cepheids of the Small Magellanic Cloud: an evolutionary selection effect?
• Population I Cepheids and star formation history of the Large Magellanic Cloud

Cited by in corpus (31)

• Gaia Data Release 2: Kinematics of globular clusters and dwarf galaxies around the Milky Way
• Clustering of Local Group distances: publication bias or correlated measurements? III. The Small Magellanic Cloud
• A re-classification of Cepheids in the Gaia Data Release 2
• The VMC Survey. XXV. The 3D structure of the Small Magellanic Cloud from Classical Cepheids
• The effect of metallicity on Cepheid Period-Luminosity relations from a Baade-Wesselink analysis of Cepheids in the Milky Way and Magellanic Clouds
• An Improved Calibration of the Wavelength Dependence of Metallicity on the Cepheid Leavitt law
• On the dynamics of the Small Magellanic Cloud through high-resolution ASKAP HI observations
• Photometric metallicity map of the Small Magellanic Cloud
• The VMC Survey -- XXXIV. Morphology of Stellar Populations in the Magellanic Clouds
• The VMC Survey. XIX. Classical Cepheids in the Small Magellanic Cloud
• High-precision distance measurements with classical pulsating stars
• The VMC Survey -- XLVIII. Classical Cepheids unveil the 3D geometry of the LMC
• A SkyMapper view of the Large Magellanic Cloud: The dynamics of stellar populations
• Toward an internally consistent astronomical distance scale
• Reddening map and recent star formation in the Magellanic Clouds based on OGLE IV Cepheids
• The VMC Survey -- XL. Three-dimensional structure of the Small Magellanic Cloud as derived from red clump stars
• Gaia view of a stellar sub-structure in front of the Small Magellanic Cloud
• The VMC survey - XVII. The proper motion of the Small Magellanic Cloud and of the Milky Way globular cluster 47 Tucanae
• Multiwavelength Period-Luminosity and Period-Luminosity-Color relations at maximum-light for Mira variables in the Magellanic Clouds
• On the nature of a shell of young stars in the outskirts of the Small Magellanic Cloud
• Bridge over troubled gas: clusters and associations under the SMC and LMC tidal stresses
• Role of Thermal and Non-thermal Processes in the ISM of Magellanic Clouds
• Period-Luminosity Relations Derived From the OGLE-III Fundamental Mode Cepheids II: The Small Magellanic Cloud Cepheids
• Period-Luminosity relations derived from the OGLE-III First-overtone mode Cepheids in the Magellanic Clouds
• A multiphase study of theoretical and observed light curves of classical Cepheids in the Magellanic Clouds
• A New Optical Polarization Catalog for the Small Magellanic Cloud: The Magnetic Field Structure
• Discrete star formation events in the central Bar of the Small Magellanic Cloud
• The VMC Survey -- LIV. Anomalous Cepheids in the Magellanic Clouds Period-Luminosity relations in the near-infrared bands
• The influential effect of blending, bump, changing period and eclipsing Cepheids on the Leavitt law
• Population I Cepheids and understanding star formation history of the Small Magellanic Cloud
• Cepheid Metallicity in the Leavitt Law (C--MetaLL) survey: VIII. High-Resolution IGRINS Spectroscopy of 23 Classical Cepheids: Validating NIR Abundances