Exploring faint white dwarfs and the luminosity function with Subaru HSC and SDSS in Stripe 82

Abstract

We present 5,080 white dwarf (WD) candidates selected from stars matching between the multi-band imaging datasets of the Subaru Hyper Suprime-Cam (HSC) Survey and the Sloan Digital Sky Survey (SDSS) in the Stripe82 region covering about 165~deg${}^2$. We select WD candidates from the ``reduced proper motion'' diagram by combining the apparent magnitude in the range $i=19$ -- 24 and the proper motion measured from the datasets among a baseline of $\sim$ 14~years. We refine the WD candidates by fitting blackbody and template WD atmosphere models to HSC photometries for each candidate, enabling the estimation of distance and tangential velocity ($v_{\mathrm{t}}$). The deep HSC data allow us to identify low-temperature ($<4000$~K) and faint WD candidates down to absolute magnitude, $M_{\mathrm{bol}}\simeq 17$. We evaluate the selection function of our WD candidates using a mock catalogue of spatial and kinematic distributions of WDs in the (thin and thick) disc and halo regions based on a Galactic model. We construct samples of disc and halo WD candidates by selecting WDs with tangential velocity, $40<v_{\mathrm{t}}/[\mathrm{km}{\mathrm{s}}^{-1}]<80$ and $200<v_{\mathrm{t}}/[\mathrm{km}{\mathrm{s}}^{-1}]<500$, respectively. The total number densities of the disc and halo WDs are $(9.33\pm 0.89)\times 10^{-3}$~pc${}^{-3}$ and $(6.34\pm 2.90)\times 10^{-4}$~pc${}^{-3}$. Our luminosity functions (LF) extend down to fainter absolute magnitudes compared with previous work. The faint WDs could represent the oldest generation of building blocks over the past $\sim$10 billion years of the assembly history of our Milky Way.

20 pages, 23 figures, published by MNRAS

References in corpus (64)

• Astropy: A Community Python Package for Astronomy
• emcee: The MCMC Hammer
• Gaia Data Release 2. Summary of the contents and survey properties
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• Gaia Data Release 3: Summary of the content and survey properties
• The 2.5 m Telescope of the Sloan Digital Sky Survey
• The USNO-B Catalog
• The Milky Way Tomography with SDSS: I. Stellar Number Density Distribution
• The merger that led to the formation of the Milky Way's inner stellar halo and thick disk
• The Hyper Suprime-Cam SSP Survey: Overview and Survey Design
• The Pan-STARRS1 Photometric System
• The SuperCOSMOS Sky Survey. Paper I: Introduction and Description
• First Data Release of the Hyper Suprime-Cam Subaru Strategic Program
• The Sloan Digital Sky Survey Quasar Catalog: Sixteenth Data Release
• The Hyper Suprime-Cam Software Pipeline
• A Three-Dimensional Map of Milky-Way Dust
• The Formation Rate, Mass and Luminosity Functions of DA White Dwarfs from the Palomar Green Survey
• An Improved Spectroscopic Analysis of DA White Dwarfs from the Sloan Digital Sky Survey Data Release 4
• SDSS DR7 White Dwarf Catalog
• Photometric Calibration of the First 1.5 Years of the Pan-STARRS1 Survey
• Third Data Release of the Hyper Suprime-Cam Subaru Strategic Program
• A Comprehensive Spectroscopic Analysis of DB White Dwarfs
• Gaia Early Data Release 3: The Gaia Catalogue of Nearby Stars
• The Pan-STARRS 1 Photometric Reference Ladder, Release 12.0
• White Dwarf Mass Distribution in the SDSS
• 3D maps of the local ISM from inversion of individual color excess measurements
• On the Spectral Evolution of Hot White Dwarf Stars. I. A Detailed Model-Atmosphere Analysis of Hot White Dwarfs from SDSS DR12
• Pan-STARRS Photometric and Astrometric Calibration
• The Remarkable Deaths of 9 - 11 Solar Mass Stars
• New white dwarf and subdwarf stars in the Sloan Digital Sky Survey Data Release 12
• The birth of the Milky Way as uncovered by accurate stellar ages with Gaia
• Three-dimensional mapping of the local interstellar medium with composite data
• New white dwarf stars in the Sloan Digital Sky Survey Data Release 10
• New cooling sequences for old white dwarfs
• The initial-final mass relationship of white dwarfs revisited: effect on the luminosity function and mass distribution
• A Catalog of Spectroscopically Identified White Dwarf Stars in the First Data Release of the Sloan Digital Sky Survey
• The SuperCOSMOS Sky Survey. Paper II: Image detection, parameterisation, classification and photometry
• 3D maps of interstellar dust in the Local Arm: using $Gaia$, 2MASS and APOGEE-DR14
• The SDSS Coadd: 275 deg^2 of Deep SDSS Imaging on Stripe 82
• The White Dwarf Luminosity Function from SDSS Imaging Data
• The SuperCOSMOS Sky Survey. Paper III: Astrometry
• LAMOST Spectroscopic Survey of the Galactic Anti-centre (LSS-GAC): target selection and the first release of value-added catalogues
• The local high velocity tail and the Galactic escape speed
• The Sloan Digital Sky Survey Stripe 82 Imaging Data: Depth-Optimized Co-adds Over 300 Deg^2 in Five Filters
• Characterization and Photometric Performance of the Hyper Suprime-Cam Software Pipeline
• White Dwarf Luminosity and Mass Functions from Sloan Digital Sky Survey Spectra
• New full evolutionary sequences of H and He atmosphere massive white dwarf stars using MESA
• The Metallicity Dependence of the Minimum Mass for Core-Collapse Supernovae
• The Star Formation History of the Solar Neighbourhood from the White Dwarf Luminosity Function
• A Photometric and Spectroscopic Investigation of the DB White Dwarf Population using SDSS and Gaia Data
• The kinematics of late type stars in the solar cylinder studied with SDSS data
• The white dwarf luminosity function
• A Deep Proper Motion Catalog Within the Sloan Digital Sky Survey Footprint. II. The White Dwarf Luminosity Function
• White dwarf and subdwarf stars in the Sloan Digital Sky Survey Data Release 16
• The Gaia DR2 halo white dwarf population: the luminosity function, mass distribution and its star formation history
• The mass function of hydrogen-rich white dwarfs: robust observational evidence for a distinctive high-mass excess near 1Msun
• Ultracool white dwarfs and the age of the Galactic disc
• Comparison of Atmospheric Parameters Determined from Spectroscopy and Photometry for DA White Dwarfs in the Sloan Digital Sky Survey
• DA white dwarfs from the LSS-GAC survey DR1: the preliminary luminosity and mass functions and formation rate
• Black-Body Stars
• The White Dwarf Luminosity Functions from the Pan-STARRS 1 3π Steradian Survey
• Proper motion measurements for stars up to $100$ kpc with Subaru HSC and SDSS Stripe 82
• A maximum volume density estimator generalized over a proper motion-limited sample
• Hunting isolated neutron stars with proper motions from wide-area optical surveys

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