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Related papers: Faint white dwarf flux standards: data and models

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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.…

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…

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…

Free of any atmospheric contamination, HST provides the best available spectrophotometry from the far-UV to the near-IR for stars as faint as V~16. The HST CALSPEC standard star network is based on 3 standard candles: the hot, pure hydrogen…

Astrophysics · Physics 2007-05-23 Ralph C. Bohlin

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

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…

At present, the precision of deep ultraviolet photometry is somewhat limited by the dearth of faint ultraviolet standard stars. In an effort to improve this situation, we present a uniform catalog of eleven new faint (u sim17) ultraviolet…

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

Newly acquired data and improved data reduction algorithms mandate a fresh look at the absolute flux calibration of the CCD cameras on the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS). The goals are to achieve a 1\%…

Instrumentation and Methods for Astrophysics · Physics 2016-08-31 Ralph C. Bohlin

The spectrophotometric flux calibration of recent spectroscopic surveys has reached a limiting systematic precision of approximately 1-3 percent, and is often biased near the wavelengths associated with H I Balmer absorption. As we prepare…

Solar and Stellar Astrophysics · Physics 2026-01-12 Ryan Cooke , Nao Suzuki , J. Xavier Prochaska

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

We use hierarchical Bayesian modelling to calibrate a network of 32 all-sky faint DA white dwarf (DA WD) spectrophotometric standards ($16.5 < V < 19.5$) alongside three CALSPEC standards, from 912 \r{A} to 32 $\mu$m. The framework is the…

The measurement of precise absolute fluxes for stellar sources has been pursued with increased vigor since the discovery of the dark energy and the realization that its detailed understanding requires accurate spectral energy distributions…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 Ralph C. Bohlin , Karl D. Gordon , P. -E. Tremblay

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…

The collections of spectral energy distributions (SEDs) in the \emph{Hubble Space Telescope} (HST) CALSPEC database are augmented by 19 IR SEDs from Wide Field Camera 3 (WFC3) IR grism spectra. Together, the two IR grisms, G102 and G141,…

Instrumentation and Methods for Astrophysics · Physics 2019-03-29 Ralph C. Bohlin , Susana E. Deustua

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 use data from the Transiting Exoplanet Survey Satellite (TESS) to search for, and set limits on, optical to near-infrared photometric variability of the well-vetted, candidate James Webb Space Telescope (JWST) spectrophotometric…

A collection of spectral energy distributions (SEDs) is available in the Hubble Space Telescope (HST) CALSPEC database that is based on calculated model atmospheres for pure hydrogen white dwarfs (WDs). A much larger set (~100,000) of UV…

Instrumentation and Methods for Astrophysics · Physics 2018-04-04 Ralph C. Bohlin , Luciana Bianchi

Our aims are to determine flux densities and their photometric accuracy for a set of seventeen stars that range in flux from intermediately bright (<2.5 Jy) to faint (>5 mJy) in the far-infrared (FIR). We also aim to derive signal-to-noise…

Solar and Stellar Astrophysics · Physics 2018-05-30 Ulrich Klaas , Zoltan Balog , Markus Nielbock , Thomas Muller , Hendrik Linz , Csaba Kiss
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