scholarly journals WHITE DWARF LUMINOSITY AND MASS FUNCTIONS FROM SLOAN DIGITAL SKY SURVEY SPECTRA

2007 ◽  
Vol 135 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Steven DeGennaro ◽  
Ted von Hippel ◽  
D. E. Winget ◽  
S. O. Kepler ◽  
Atsuko Nitta ◽  
...  
Keyword(s):  
White Dwarf ◽  
Sloan Digital Sky Survey ◽  
Sky Survey ◽  
Mass Functions

scholarly journals White Dwarf Stars

2017 ◽  
Vol 45 ◽  
pp. 1760023
Author(s):  
S. O. Kepler ◽  
Alejandra Daniela Romero ◽  
Ingrid Pelisoli ◽  
Gustavo Ourique
Keyword(s):  
White Dwarf ◽  
Final Stage ◽  
White Dwarfs ◽  
Sloan Digital Sky Survey ◽  
Dwarf Stars ◽  
Multiple Systems ◽  
White Dwarf Stars ◽  
Sky Survey ◽  
Data Release ◽  
Low Mass

White dwarf stars are the final stage of most stars, born single or in multiple systems. We discuss the identification, magnetic fields, and mass distribution for white dwarfs detected from spectra obtained by the Sloan Digital Sky Survey up to Data Release 13 in 2016, which lead to the increase in the number of spectroscopically identified white dwarf stars from 5[Formula: see text]000 to 39[Formula: see text]000. This number includes only white dwarf stars with [Formula: see text], i.e., excluding the Extremely Low Mass white dwarfs, which are necessarily the byproduct of stellar interaction.

scholarly journals The frequency of gaseous debris discs around white dwarfs

2020 ◽  
Vol 493 (2) ◽  
pp. 2127-2139 ◽  
Author(s):  
Christopher J Manser ◽  
Boris T Gänsicke ◽  
Nicola Pietro Gentile Fusillo ◽  
Richard Ashley ◽  
Elmé Breedt ◽  
...  
Keyword(s):  
White Dwarf ◽  
White Dwarfs ◽  
Signal To Noise Ratio ◽  
Infrared Emission ◽  
Sloan Digital Sky Survey ◽  
Emission Lines ◽  
Occurrence Rate ◽  
Limited Sample ◽  
Sky Survey ◽  
Gaseous Disc

ABSTRACT A total of 1–3 per cent of white dwarfs are orbited by planetary dusty debris detectable as infrared emission in excess above the white dwarf flux. In a rare subset of these systems, a gaseous disc component is also detected via emission lines of the Ca ii 8600 Å triplet, broadened by the Keplerian velocity of the disc. We present the first statistical study of the fraction of debris discs containing detectable amounts of gas in emission at white dwarfs within a magnitude and signal-to-noise ratio limited sample. We select 7705 single white dwarfs spectroscopically observed by the Sloan Digital Sky Survey (SDSS) and Gaia with magnitudes g ≤ 19. We identify five gaseous disc hosts, all of which have been previously discovered. We calculate the occurrence rate of a white dwarf hosting a debris disc detectable via Ca ii emission lines as $0.067\, \pm \, ^{0.042}_{0.025}$ per cent. This corresponds to an occurrence rate for a dusty debris disc to have an observable gaseous component in emission as 4 ± $_{2}^{4}$ per cent. Given that variability is a common feature of the emission profiles of gaseous debris discs, and the recent detection of a planetesimal orbiting within the disc of SDSS J122859.93+104032.9, we propose that gaseous components are tracers for the presence of planetesimals embedded in the discs and outline a qualitative model. We also present spectroscopy of the Ca ii triplet 8600 Å region for 20 white dwarfs hosting dusty debris discs in an attempt to identify gaseous emission. We do not detect any gaseous components in these 20 systems, consistent with the occurrence rate that we calculated.

scholarly journals Component masses of young, wide, non-magnetic white dwarf binaries in the Sloan Digital Sky Survey Data Release 7

2014 ◽  
Vol 440 (4) ◽  
pp. 3184-3201 ◽  
Author(s):  
R. B. Baxter ◽  
P. D. Dobbie ◽  
Q. A. Parker ◽  
S. L. Casewell ◽  
N. Lodieu ◽  
...  
Keyword(s):  
Survey Data ◽  
White Dwarf ◽  
Sloan Digital Sky Survey ◽  
Sky Survey ◽  
Data Release

scholarly journals Pulsating white dwarfs in cataclysmic variables: The marriage of ZZ Cet and dwarf nova

2004 ◽  
Vol 193 ◽  
pp. 382-386 ◽  
Author(s):  
Brian Warner ◽  
Patrick A. Woudt
Keyword(s):  
White Dwarf ◽  
Large Amplitude ◽  
White Dwarfs ◽  
Cataclysmic Variables ◽  
Sloan Digital Sky Survey ◽  
Dwarf Novae ◽  
Dwarf Nova ◽  
Sky Survey

AbstractThere are now four dwarf novae known with white dwarf primaries that show large amplitude non-radial oscillations of the kind seen in ZZ Cet stars. We compare the properties of these stars and point out that by the end of the Sloan Digital Sky Survey more than 30 should be known.

scholarly journals A hot white dwarf luminosity function from the Sloan Digital Sky Survey

2009 ◽  
Vol 508 (1) ◽  
pp. 339-344 ◽  
Author(s):  
J. Krzesinski ◽  
S. J. Kleinman ◽  
A. Nitta ◽  
S. Hügelmeyer ◽  
S. Dreizler ◽  
...  
Keyword(s):  
White Dwarf ◽  
Luminosity Function ◽  
Sloan Digital Sky Survey ◽  
Sky Survey

scholarly journals White-dwarf + main-sequence binaries identified from the ninth data release of the Sloan Digital Sky Survey

2014 ◽  
Vol 445 (2) ◽  
pp. 1331-1338 ◽  
Author(s):  
Lifang Li ◽  
Fenghui Zhang ◽  
Quanwang Han ◽  
Xiaoyang Kong ◽  
Xiaobo Gong
Keyword(s):  
White Dwarf ◽  
Main Sequence ◽  
Sloan Digital Sky Survey ◽  
Sky Survey ◽  
Data Release

scholarly journals A photometric selection of white dwarf candidates in Sloan Digital Sky Survey Data Release 10

2015 ◽  
Vol 448 (3) ◽  
pp. 2260-2274 ◽  
Author(s):  
Nicola Pietro Gentile Fusillo ◽  
Boris T. Gänsicke ◽  
Sandra Greiss
Keyword(s):  
Survey Data ◽  
White Dwarf ◽  
Sloan Digital Sky Survey ◽  
Sky Survey ◽  
Data Release ◽  
Selection Of

scholarly journals A New Very Cool White Dwarf Discovered by the Sloan Digital Sky Survey

2001 ◽  
Vol 549 (1) ◽  
pp. L109-L113 ◽  
Author(s):  
Hugh C. Harris ◽  
Brad M. S. Hansen ◽  
James Liebert ◽  
Daniel E. Vanden Berk ◽  
Scott F. Anderson ◽  
...  
Keyword(s):  
White Dwarf ◽  
Sloan Digital Sky Survey ◽  
Sky Survey

scholarly journals White dwarf and subdwarf stars in the Sloan Digital Sky Survey Data Release 14

2019 ◽  
Vol 486 (2) ◽  
pp. 2169-2183 ◽  
Author(s):  
S O Kepler ◽  
Ingrid Pelisoli ◽  
Detlev Koester ◽  
Nicole Reindl ◽  
Stephan Geier ◽  
...  
Keyword(s):  
Survey Data ◽  
White Dwarf ◽  
White Dwarfs ◽  
Main Sequence ◽  
Sloan Digital Sky Survey ◽  
Dwarf Stars ◽  
White Dwarf Stars ◽  
Sky Survey ◽  
Data Release ◽  
Hot Subdwarfs

ABSTRACT White dwarfs carry information on the structure and evolution of the Galaxy, especially through their luminosity function and initial-to-final mass relation. Very cool white dwarfs provide insight into the early ages of each population. Examining the spectra of all stars with 3σ proper motion in the Sloan Digital Sky Survey Data Release 14, we report the classification for 20 088 spectroscopically confirmed white dwarfs, plus 415 hot subdwarfs, and 311 cataclysmic variables. We obtain Teff, log  g, and mass for hydrogen atmosphere white dwarf stars (DAs), warm helium atmosphere white dwarfs (DBs), hot subdwarfs (sdBs and sdOs), and estimate photometric Teff for white dwarf stars with continuum spectra (DCs). We find 15 793 sdAs and 447 dCs between the white dwarf cooling sequence and the main sequence, especially below $T_\mathrm{eff}\simeq 10\, 000$ K; most are likely low-mass metal-poor main-sequence stars, but some could be the result of interacting binary evolution.

scholarly journals The Hubble Sequence at z ∼ 0 in the IllustrisTNG simulation with deep learning

2019 ◽  
Vol 489 (2) ◽  
pp. 1859-1879 ◽  
Author(s):  
Marc Huertas-Company ◽  
Vicente Rodriguez-Gomez ◽  
Dylan Nelson ◽  
Annalisa Pillepich ◽  
Connor Bottrell ◽  
...  
Keyword(s):  
Neural Network ◽  
Morphological Type ◽  
Sloan Digital Sky Survey ◽  
High Mass ◽  
Complete Sample ◽  
Hubble Sequence ◽  
Sky Survey ◽  
Mass Size ◽  
S0 Galaxies ◽  
Mass Functions

ABSTRACT We analyse the optical morphologies of galaxies in the IllustrisTNG simulation at z ∼ 0 with a convolutional neural network trained on visual morphologies in the Sloan Digital Sky Survey. We generate mock SDSS images of a mass complete sample of $\sim 12\, 000$ galaxies in the simulation using the radiative transfer code SKIRT and include PSF and noise to match the SDSS r-band properties. The images are then processed through the exact same neural network used to estimate SDSS morphologies to classify simulated galaxies in four morphological classes (E, S0/a, Sab, Scd). The CNN model classifies simulated galaxies in one of the four main classes with the same uncertainty as for observed galaxies. The mass–size relations of the simulated galaxies divided by morphological type also reproduce well the slope and the normalization of observed relations which confirms a reasonable diversity of optical morphologies in the TNG suite. However we find a weak correlation between optical morphology and Sersic index in the TNG suite as opposed to SDSS which might require further investigation. The stellar mass functions (SMFs) decomposed into different morphologies still show some discrepancies with observations especially at the high-mass end. We find an overabundance of late-type galaxies ($\sim 50{{\ \rm per\ cent}}$ versus $\sim 20{{\ \rm per\ cent}}$) at the high-mass end [log(M*/M⊙) > 11] of the SMF as compared to observations according to the CNN classifications and a lack of S0 galaxies ($\sim 20{{\ \rm per\ cent}}$ versus $\sim 40{{\ \rm per\ cent}}$) at intermediate masses. This work highlights the importance of detailed comparisons between observations and simulations in comparable conditions.

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