Study of Galactic Structure Using UVIT/AstroSat Star Counts

Abstract

The structure of our Galaxy has been studied from ultraviolet (UV) star counts obtained with the Ultra-Violet Imaging Telescope (UVIT) on board the {\em AstroSat} satellite, in Far-UV (FUV) and Near-UV (NUV) bands. The F154W (BaF2) and N263M (NUVB4) filters were used in the FUV and NUV bands, respectively. The point sources are separated from the extra-galactic sources of UVIT observations using infrared (IR) color cut method. The observed UVIT star counts match well with the simulations obtained from the Besançon model of stellar population synthesis towards several Galactic directions. We also estimated the scale length and scale height of the thick disc and the scale height of the thin disc using the space density function and the exponential density law for the stars of intermediate Galactic latitudes. The scale length of the thick disc ranges from 3.11 to 5.40 kpc whereas the scale height ranges from 530$\pm$32 pc to 630$\pm$29 pc. The scale height of the thin disc comes out to be in the range of 230$\pm$20 pc to 330$\pm$11 pc.

arXiv commentAccepted for publication in Journal of Astrophysics and Astronomy

References in corpus (24)

• The Sloan Digital Sky Survey: Technical Summary
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• The Galaxy Evolution Explorer: A Space Ultraviolet Survey Mission
• Monitoring stellar orbits around the Massive Black Hole in the Galactic Center
• The Galaxy in Context: Structural, Kinematic and Integrated Properties
• The Milky Way Tomography with SDSS: I. Stellar Number Density Distribution
• Star counts in the Galaxy. Simulating from very deep to very shallow photometric surveys with the TRILEGAL code
• Revised Catalog of GALEX Ultraviolet Sources. I. The All-sky Survey: GUVcat_AIS
• Stellar populations in the Milky Way bulge region : Towards solving the Galactic bulge and bar shapes using 2MASS data
• Starcounts Redivivus. IV. Density Laws Through Photometric Parallaxes
• Elemental Abundance Ratios in Stars of the Outer Galactic Disk. I. Open Clusters
• A First Constraint on the Thick Disk Scale Length: Differential Radial Abundances in K Giants at Galactocentric Radii 4, 8, and 12 kpc
• In-orbit Calibrations of the Ultra-Violet Imaging Telescope
• Additional Calibration of the Ultra-Violet Imaging Telescope on board AstroSat
• A Short Scale Length for the α-Enhanced Thick Disk of the Milky Way: Evidence from Low-Latitude SEGUE Data
• Galactic Stellar Populations in the Era of SDSS and Other Large Surveys
• Flare in the Galactic stellar outer disc detected in SDSS-SEGUE data
• Estimation of galactic model parameters in high latitudes with SDSS
• The Information Of The Milky Way From 2MASS Whole Sky Star Count: The Structure Parameters
• A Galaxy Model from 2MASS Star Counts in the Whole Sky Including the Plane
• Constraining the Galactic structure parameters with the XSTPS-GAC and SDSS photometric surveys
• Estimation of Galactic Model Parameters and Metalicity Distribution in Intermediate Latitudes with SDSS
• Estimation of Galactic model parameters with the SDSS and metallicity distribution in two fields in the anti-centre direction of the Galaxy
• A Stellar Population Synthesis Model for the Study of Ultraviolet Star Counts of the Galaxy