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Related papers: DAmodel: Hierarchical Bayesian Modelling of DA Whi…

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Hot DA white dwarfs have fully radiative pure hydrogen atmospheres that are the least complicated to model. Pulsationally stable, they are fully characterized by their effective temperature Teff, and surface gravity log g, which can be…

We have established a network of 19 faint (16.5 mag $< V < $19 mag) northern and equatorial DA white dwarfs as spectrophotometric standards for present and future wide-field observatories. Our analysis infers SED models for the stars that…

We present precise photometry and spectroscopy for 23 candidate spectrophotometric standard white dwarfs. The selected stars are distributed in the Northern hemisphere and around the celestial equators and are all fainter than r ~ 16.5 mag.…

The accurate flux calibration of observational data is vital for astrophysics and cosmology because absolute flux uncertainties of stellar standards propagate into scientific results. With the ever higher precision achieved by telescopic…

We present a synopsis of the project to establish thirty-two new faint ($ 16.5 \leq V \leq 19.8 $) DA white dwarfs as spectrophotometric standards distributed over the whole sky. Our results validate the use of fully radiative pure hydrogen…

In the era of modern digital sky surveys, uncertainties in the flux of stellar standards are commonly the dominant systematic error in photometric calibration and can often affect the results of higher-level experiments. The Hubble Space…

Solar and Stellar Astrophysics · Physics 2020-01-08 Nicola Pietro Gentile Fusillo , Pier-Emmanuel Tremblay , Ralph C. Bohlin , Susana E. Deustua , Jason S. Kalirai

Fainter standard stars are essential for the calibration of larger telescopes. This work adds to the CALSPEC (calibration spectra) database 19 faint white dwarfs (WDs) with all-sky coverage and V magnitudes between 16.5 and 18.7. Included…

Instrumentation and Methods for Astrophysics · Physics 2024-11-15 Ralph C. Bohlin , Susana Deustua , Gautham Narayan , Abhijit Saha , Annalisa Calamida , Karl D. Gordon , Jay B. Holberg , Ivan Hubeny , Thomas Matheson , Armin Rest

The spectral energy distributions for pure-hydrogen (DA) hot white dwarfs can be accurately predicted by model atmospheres. This makes it possible to define spectrophotometric calibrators by scaling the theoretical spectral shapes with…

Solar and Stellar Astrophysics · Physics 2015-05-13 C. Allende Prieto , I. Hubeny , J. A. Smith

We verified for photometric stability a set of DA white dwarfs with Hubble Space Telescope magnitudes from the near-ultraviolet to the near-infrared and ground-based spectroscopy by using time-spaced observations from the Las Cumbres…

We present initial results from a program aimed at establishing a network of hot DA white dwarfs to serve as spectrophotometric standards for present and future wide-field surveys. These stars span the equatorial zone and are faint enough…

We present a method which uses colour-colour cuts on SDSS photometry to select white dwarfs with hydrogen rich (DA) atmospheres without the recourse to spectroscopy. This method results in a sample of DA white dwarfs that is 95% complete at…

Solar and Stellar Astrophysics · Physics 2012-08-01 J. Girven , B. T. Gaensicke , D. Steeghs , D. Koester

Context. The advent of the Extremely Large Telescope (ELT) will increase the collecting area by more than an order of magnitude compared to the individual Unit Telescopes of the Very Large Telescope (VLT). Fainter spectrophotometric…

Instrumentation and Methods for Astrophysics · Physics 2025-08-11 N. P. Gentile Fusillo , S. Moehler , N. Przybilla , A. K. Elms , P. -E. Tremblay , W. Kausch , F. Kerber

The third data release of Gaia has provided low resolution spectra for ~100,000 white dwarfs (WDs) that, together with the excellent photometry and astrometry, represent an unrivalled benchmark for the study of this population. In this…

Solar and Stellar Astrophysics · Physics 2022-12-07 F. M. Jiménez-Esteban , S. Torres , A. Rebassa-Mansergas , P. Cruz , R. Murillo-Ojeda , E. Solano , C. Rodrigo , M. E. Camisassa

The determination of atmospheric parameters of white dwarf stars (WDs) is crucial for researches on them. Traditional methodology is to fit the model spectra to observed absorption lines and report the parameters with the lowest $\chi ^2$…

Instrumentation and Methods for Astrophysics · Physics 2021-11-29 Yong Yang , Jingkun Zhao , Jiajun Zhang , Xianhao Ye , Gang Zhao

We present a detailed calculation of model atmospheres for DA white dwarfs. Our atmosphere code solves the atmosphere structure in local thermodynamic equilibrium with a standard partial linearization technique, which takes into account the…

Astrophysics · Physics 2015-06-24 R. D. Rohrmann

We present a detailed model atmosphere analysis of hot white dwarfs in the Dark Energy Spectroscopic Instrument (DESI) Data Release 1. Our sample includes 19,321 unique targets with $G_{\rm BP}-G_{\rm RP}\leq0$. We use the DESI spectra…

White dwarf studies carry significant implications across multiple fields of astrophysics, including exoplanets, supernova explosions, and cosmological investigations. Thus, accurate determinations of their fundamental parameters (Teff and…

In astrophysics, we often aim to estimate one or more parameters for each member object in a population and study the distribution of the fitted parameters across the population. In this paper, we develop novel methods that allow us to take…

Solar and Stellar Astrophysics · Physics 2018-06-19 Shijing Si , David A. van Dyk , Ted von Hippel , Elliot Robinson , Aaron Webster , David Stenning

We describe automatic procedures for the selection of DA white dwarfs in the Hamburg/ESO objective-prism survey (HES). For this purpose, and the selection of other stellar objects (e.g., metal-poor stars and carbon stars), a flexible,…

Astrophysics · Physics 2009-10-31 N. Christlieb , L. Wisotzki , D. Reimers , D. Homeier , D. Koester , U. Heber

It is possible to reliably identify white dwarfs (WDs) without recourse to spectra, instead using photometric and astrometric measurements to distinguish them from Main Sequence stars and quasars. WDs' colours can also be used to infer…

Astrophysics · Physics 2010-02-22 Daniel J. Mortlock , Hiranya V. Peiris , Zeljko Ivezic
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