Improved Constraints on the Initial-to-final Mass Relation of White Dwarfs Using Wide Binaries

Abstract We present observational constraints for the initial-to-final mass relation (IFMR) derived from 11 white dwarfs (WDs) in wide binaries (WBs) that contain a turnoff/subgiant primary. Because the components of WBs are coeval to a good approximation, the age of the WD progenitor can be determined from the study of its wide companion. However, previous works that used WBs to constrain the IFMR suffered from large uncertainties in the initial masses because their main-sequence primaries are difficult to age-date with good precision. Our selection of WBs with slightly evolved primaries avoids this problem by restricting to a region of parameter space where isochrone ages are significantly easier to determine with precision. The WDs of two of our originally selected binaries were found to be close double degenerates and are not used in the IFMR analysis. We obtained more precise constraints than existing ones in the mass range 1–2 M ⊙, corresponding to a previously poorly constrained region of the IFMR. Having introduced the use of turnoff/subgiant–WD binaries, the study of the IFMR is not limited anymore by the precision in initial mass, but now the pressure is on final mass, i.e., the mass of the WD today. Looking at the full data set, our results would suggest a relatively large dispersion in the IFMR at low initial masses. More precise determinations of the mass of the WD components of our targets are necessary for settling this question.

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Ensemble evolutionary studies of white dwarfs in open star clusters

Proceedings of the International Astronomical Union ◽

10.1017/s1743921320000848 ◽

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.

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Content analysis of Twitter chatter about indoor tanning

Translational Behavioral Medicine ◽

10.1093/tbm/iby011 ◽

2018 ◽

Vol 9 (1) ◽

pp. 41-47 ◽

Cited By ~ 4

Author(s):

Molly E Waring ◽

Katie Baker ◽

Anthony Peluso ◽

Christine N May ◽

Sherry L Pagoto

Keyword(s):

Content Analysis ◽

Indoor Tanning ◽

Health Warnings ◽

Full Data ◽

Data Set ◽

Search Terms ◽

Falling Asleep ◽

Tanning Bed ◽

Positive Sentiment ◽

Selection Of

Abstract Twitter may be useful for learning about indoor tanning behavior and attitudes. The objective of this study was to analyze the content of tweets about indoor tanning to determine the extent to which tweets are posted by people who tan, and to characterize the topics of tweets. We extracted 4,691 unique tweets from Twitter using the terms “tanning bed” or “tanning salon” over 7 days in March 2016. We content analyzed a random selection of 1,000 tweets, double-coding 20% of tweets (κ = 0.74, 81% agreement). Most tweets (71%) were by tanners (n = 699 individuals) and included tweets expressing positive sentiment about tanning (57%), and reports of a negative tanning experience (17%), burning (15%), or sleeping in a tanning bed (9%). Four percent of tweets were by tanning salon employees. Tweets posted by people unlikely to be tanners (15%) included tweets mocking tanners (71%) and health warnings (29%). The term “tanning bed” had higher precision for identifying individuals who engage in indoor tanning than “tanning salon”; 77% versus 45% of tweets captured by these search terms were by individuals who engaged in indoor tanning, respectively. Extrapolating to the full data set of 4,691 tweets, findings suggest that an average of 468 individuals who engage in indoor tanning can be identified by their tweets per day. The majority of tweets were from tanners and included reports of especially risky habits (e.g., burning, falling asleep). Twitter provides opportunity to identify indoor tanners and examine conversations about indoor tanning.

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

The Astrophysical Journal ◽

10.1088/0004-637x/815/1/63 ◽

2015 ◽

Vol 815 (1) ◽

pp. 63 ◽

Cited By ~ 25

Author(s):

Jeff J. Andrews ◽

Marcel A. Agüeros ◽

A. Gianninas ◽

Mukremin Kilic ◽

Saurav Dhital ◽

...

Keyword(s):

White Dwarfs ◽

Mass Relation ◽

Final Mass

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Fragile Binaries: Observational Leverage on Difficult Astrophysical Problems

Proceedings of the International Astronomical Union ◽

10.1017/s1743921307004206 ◽

2006 ◽

Vol 2 (S240) ◽

pp. 300-305

Author(s):

T.D. Oswalt ◽

K.B. Johnston ◽

M. Rudkin ◽

T. Vaccaro ◽

D. Valls-Gabaud

Keyword(s):

Binary Stars ◽

White Dwarfs ◽

Main Sequence ◽

Age Determination ◽

Open Clusters ◽

Mass Relation ◽

Space Motion ◽

Sequence Components ◽

Determination Methods ◽

Cool White Dwarfs

AbstractLoosely bound,fragilebinary stars, whose separations may reach ∼ 0.1 pc, are like open clusters with two coeval components. They provide a largely overlooked avenue for the investigation of many astrophysical questions. For example, the orbital distribution of fragile binaries with two long-lived main-sequence components provides a sensitive test of the cumulative effects of the Galactic environment. In pairs where one component is evolved, the orbits have been amplified by post-main-sequence mass loss, potentially providing useful constraints on the initial-to-final mass relation for white dwarfs. The nearly featureless spectra of cool white dwarfs usually provide little information about intrinsic radial velocity, full space motion, population membership, metallicity, etc. However, distant main sequence companions provide benchmarks against which those properties can be determined. In addition, the cooling ages of white dwarf components provide useful limits on the ages of their main sequence companions, independent of other stellar age determination methods. This paper summarizes some of the ways fragile binaries provide useful leverage on these and other problems of interest.

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

The Astronomical Journal ◽

10.3847/1538-3881/ac1423 ◽

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

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Constraints on stellar evolution by observation of white dwarfs

Symposium - International Astronomical Union ◽

10.1017/s0074180900030953 ◽

1984 ◽

Vol 105 ◽

pp. 229-230 ◽

Cited By ~ 1

Author(s):

V. Weidemann

Keyword(s):

White Dwarfs ◽

Recent Observation ◽

Open Cluster ◽

High Mass ◽

Mass Relation ◽

List Type ◽

Intermediate Mass Stars ◽

Final Mass ◽

Star Production ◽

The Rich

The recent observation of white dwarfs in the open cluster NGC 2516 and the determination of their surface gravity and effective temperatures (Reimers and Koester, 1982) has enabled the establishment of the initial-final mass relation for low and intermediate mass stars which was published a few months ago and is presented here (Fig. 1 of Weidemann and Koester, 1983a). The most important conclusions drawn are: 1.The limiting mass for white dwarf progenitors is 8–9 M⊙ rather than 5–6 M⊙, with supernova production beyond;2.The rather flat run of the initial-final mass relation in the main range of star production, 1–5 M⊙, explains the observed narrow mass distribution of white dwarfs and central stars of planetary nebulae around 0.6 M⊙;3.High mass white dwarfs exist, as shown in the rich, young cluster NGC 2516, but are extremely rare in general.

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Testing white dwarf cosmochronology using wide double white dwarfs

Proceedings of the International Astronomical Union ◽

10.1017/s1743921320000782 ◽

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.

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