Testing white dwarf cosmochronology using wide double white dwarfs

2019 ◽  
Vol 15 (S357) ◽  
pp. 197-201
Author(s):  
Tyler Heintz ◽  
JJ Hermes
Keyword(s):  
White Dwarf ◽  
White Dwarfs ◽  
Mass Relation ◽  
Final Mass ◽  
Gaia Dr2

AbstractWe present a sample of nearly 650 widely separated double white dwarf binaries found using Gaia DR2 astrometry. We derive preliminary total ages for each white dwarf in our sample using Gaia photometry and compare the total ages of both components of each binary in our sample. We find agreement within 3 sigma between the two ages ∼85% of the time with median age uncertainties of ∼3.5 Gyr depending on which initial-final mass relation is used. When a subsample with the most precise ages is used, the agreement within 3 sigma drops to ∼70% with median age uncertainties of 300-600 Myr.

scholarly journals Constraining axion-like particles using the white dwarf initial-final mass relation

2021 ◽  
Vol 2021 (09) ◽  
pp. 010 ◽  
Author(s):  
Matthew J. Dolan ◽  
Frederick J. Hiskens ◽  
Raymond R. Volkas
Keyword(s):  
White Dwarf ◽  
Mass Relation ◽  
Final Mass

scholarly journals Ensemble evolutionary studies of white dwarfs in open star clusters

2019 ◽  
Vol 15 (S357) ◽  
pp. 179-183
Author(s):  
Kurtis A Williams
Keyword(s):  
White Dwarfs ◽  
Binary Star ◽  
Open Cluster ◽  
Star Clusters ◽  
Mass Relation ◽  
Correlated Errors ◽  
Open Star Clusters ◽  
Open Star ◽  
Final Mass ◽  
Evolutionary Studies

AbstractWhite dwarfs (WDs) in open star clusters are a highly useful ensemble of stars. While numerous researchers use open cluster WDs to study the initial-final mass relation, numerous other evolutionary studies are also enabled by this sample of stars, including searches for stochastic mass loss, studies of binary star evolution, and measurements of metallicity impacts on WD formation and evolution. However, it is crucial to use astrometric data such as proper motions to remove contaminating field WDs from open cluster samples; multi-epoch ground based imaging is needed for most open cluster WDs. Also, the strongly correlated errors in the initial mass - final mass plane must be considered; we illustrate the importance of this consideration using a large open cluster WD sample and Monte Carlo techniques.

scholarly journals Central Stars of Planetary Nebulae in Galactic Open Clusters: Providing additional data for the White Dwarf Initial-to-Final-Mass Relation

2018 ◽  
Vol 14 (S343) ◽  
pp. 400-401
Author(s):  
Vasiliki Fragkou ◽  
Quentin A. Parker ◽  
Albert Zijlstra ◽  
Richard Shaw ◽  
Foteini Lykou
Keyword(s):  
White Dwarf ◽  
Additional Data ◽  
Open Cluster ◽  
Central Star ◽  
Open Clusters ◽  
Physical Parameters ◽  
Mass Relation ◽  
Carbon And Nitrogen ◽  
Final Mass ◽  
Central Stars

AbstractAccurate (< 10%) distances of Galactic star clusters allow a precise estimation of the physical parameters of any physically associated Planetary Nebula (PN) and also that of its central star (CSPN) and its progenitor. The progenitor’s mass can be related to the PN’s chemical characteristics and, furthermore, provides additional data for the widely used white dwarf (WD) initial-to-final mass relation (IFMR) that is crucial for tracing the development of both carbon and nitrogen in entire galaxies. To date, there is only one PN (PHR1315- 6555) confirmed to be physically associated with a Galactic open cluster (ESO 96 -SC04) that has a turn-off mass ∼2Mʘ. Our deep HST photometry was used for the search of the CSPN of this currently unique PN. In this work, we present our results.

The completeness of Gaia-selected samples of white dwarfs

2019 ◽  
Vol 15 (S357) ◽  
pp. 170-174
Author(s):  
Terry D. Oswalt ◽  
Jay B. Holberg ◽  
Edward M. Sion
Keyword(s):  
White Dwarf ◽  
Proper Motion ◽  
White Dwarfs ◽  
Color Index ◽  
Apparent Magnitude ◽  
Order Of Magnitude ◽  
Gaia Dr2 ◽  
Photometric Color

AbstractThe Gaia DR2 has dramatically increased the ability to detect faint nearby white dwarfs. The census of the local white dwarf population has recently been extended from 25 pc to 50 pc, effectively increasing the sample by roughly an order of magnitude. Here we examine the completeness of this new sample as a function of variables such as apparent magnitude, distance, proper motion, photometric color index, unresolved components, etc.

scholarly journals THE WHITE DWARF POPULATION IN NGC 1039 (M34) AND THE WHITE DWARF INITIAL-FINAL MASS RELATION

2008 ◽  
Vol 135 (6) ◽  
pp. 2163-2176 ◽  
Author(s):  
Kate H. R. Rubin ◽  
Kurtis A. Williams ◽  
M. Bolte ◽  
Detlev Koester
Keyword(s):  
White Dwarf ◽  
Mass Relation ◽  
Final Mass

scholarly journals Gaia white dwarfs within 40 pc II: the volume-limited Northern hemisphere sample

2020 ◽  
Vol 499 (2) ◽  
pp. 1890-1908 ◽  
Author(s):  
Jack McCleery ◽  
Pier-Emmanuel Tremblay ◽  
Nicola Pietro Gentile Fusillo ◽  
Mark A Hollands ◽  
Boris T Gänsicke ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
White Dwarf ◽  
White Dwarfs ◽  
Binary Systems ◽  
Mass Range ◽  
Wide Binary ◽  
William Herschel ◽  
Initial Selection ◽  
Gaia Dr2 ◽  
Kinematic Properties

ABSTRACT We present an overview of the sample of Northern hemisphere white dwarfs within 40 pc of the Sun detected from Gaia Data Release 2 (DR2). We find that 521 sources are spectroscopically confirmed degenerate stars, 111 of which were first identified as white dwarf candidates from Gaia DR2 and followed up recently with the William Herschel Telescope and Gran Telescopio Canarias. Three additional white dwarf candidates remain spectroscopically unobserved and six unresolved binaries are known to include a white dwarf but were not in our initial selection in the Gaia DR2 Hertzsprung–Russell diagram. Atmospheric parameters are calculated from Gaia and Pan-STARRS photometry for all objects in the sample, confirming most of the trends previously observed in the much smaller 20 pc sample. Local white dwarfs are overwhelmingly consistent with Galactic disc kinematics, with only four halo candidates. We find that DAZ white dwarfs are significantly less massive than the overall DA population ($\overline{M}_\mathrm{DAZ}$ = 0.59 M⊙, $\overline{M}_\mathrm{DA}$ = 0.66 M⊙). It may suggest that planet formation is less efficient at higher mass stars, producing more massive white dwarfs. We detect a sequence of crystallized white dwarfs in the mass range from 0.6 $\lesssim M/\mbox{$\mathrm{M}_\odot $}\ \lesssim$ 1.0 and find that the vast majority of objects on the sequence have standard kinematic properties that correspond to the average of the sample, suggesting that their nature can be explained by crystallization alone. We also detect 26 double degenerates and white dwarf components in 56 wide binary systems.

scholarly journals The Initial–Final Mass Relationship of White Dwarfs in Common Proper Motion Pairs and Open Clusters

2006 ◽  
Vol 2 (S240) ◽  
pp. 380-382
Author(s):  
S. Catalán ◽  
I. Ribas ◽  
J. Isern ◽  
E. García–Berro ◽  
C. Allende Prieto
Keyword(s):  
White Dwarf ◽  
Proper Motion ◽  
White Dwarfs ◽  
Open Clusters ◽  
Type Star ◽  
Spectroscopic Observations ◽  
Final Mass ◽  
Semi Empirical ◽  
Relationship Of

AbstractWe have studied white dwarfs in common proper motion pairs (CPMPs) to improve the semi-empirical initial–final mass relationship of white dwarfs. In this contribution, we report new results obtained from spectroscopic observations of both members of several CPMPs composed of an F, G or K type star and a DA white dwarf.

scholarly journals CONSTRAINTS ON THE INITIAL-FINAL MASS RELATION FROM WIDE DOUBLE WHITE DWARFS

2015 ◽  
Vol 815 (1) ◽  
pp. 63 ◽  
Author(s):  
Jeff J. Andrews ◽  
Marcel A. Agüeros ◽  
A. Gianninas ◽  
Mukremin Kilic ◽  
Saurav Dhital ◽  
...  
Keyword(s):  
White Dwarfs ◽  
Mass Relation ◽  
Final Mass

scholarly journals The Initial–Final Mass Relation for Hydrogen-deficient White Dwarfs*

2021 ◽  
Vol 162 (4) ◽  
pp. 162
Author(s):  
Joseph W. Barnett ◽  
Kurtis A. Williams ◽  
A. Bédard ◽  
Michael Bolte
Keyword(s):  
White Dwarfs ◽  
Mass Relation ◽  
Final Mass

scholarly journals Gaia DR2 white dwarfs in the Hercules stream

2019 ◽  
Vol 629 ◽  
pp. L6 ◽  
Author(s):  
Santiago Torres ◽  
Carles Cantero ◽  
María E. Camisassa ◽  
Teresa Antoja ◽  
Alberto Rebassa-Mansergas ◽  
...  
Keyword(s):  
White Dwarf ◽  
White Dwarfs ◽  
Age Distribution ◽  
Thick Disk ◽  
Velocity Space ◽  
Dwarf Stars ◽  
The Past ◽  
White Dwarf Stars ◽  
Dynamic Variables ◽  
Gaia Dr2

Aims. We analyzed the velocity space of the thin- and thick-disk Gaia white dwarf population within 100 pc by searching for signatures of the Hercules stellar stream. We aimed to identify objects belonging to the Hercules stream, and by taking advantage of white dwarf stars as reliable cosmochronometers, to derive a first age distribution. Methods. We applied a kernel density estimation to the UV velocity space of white dwarfs. For the region where a clear overdensity of stars was found, we created a 5D space of dynamic variables. We applied a hierarchichal clustering method, HDBSCAN, to this 5D space, and identified those white dwarfs that share similar kinematic characteristics. Finally, under general assumptions and from their photometric properties, we derived an age estimate for each object. Results. The Hercules stream was first revealed as an overdensity in the UV velocity space of the thick-disk white dwarf population. Three substreams were then found: Hercules a and Hercules b, formed by thick-disk stars with an age distribution that peaked 4 Gyr in the past and extends to very old ages; and Hercules c, with a ratio of 65:35 of thin to thick stars and a more uniform age distribution that is younger than 10 Gyr.

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