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While the near-infrared wavelength regime is becoming more and more important for astrophysics there is a marked lack of spectrophotometric standard star data that would allow the flux calibration of such data. Furthermore, flux calibrating…

Instrumentation and Methods for Astrophysics · Physics 2014-08-11 S. Moehler , A. Modigliani , W. Freudling , N. Giammichele , A. Gianninas , A. Gonneau , W. Kausch , A. Lancon , S. Noll , T. Rauch , J. Vinther

The typical approach for removing telluric absorption lines from a science spectrum is to divide it by the spectrum of a standard star of spectral type A or B observed close in time and airmass. We present a new method, where we use a model…

Solar and Stellar Astrophysics · Physics 2013-12-10 Tim-Oliver Husser , Kathrin Ulbrich

Stellar spectra are often modeled and fit by interpolating within a rectilinear grid of synthetic spectra to derive the stars' labels: stellar parameters and elemental abundances. However, the number of synthetic spectra needed for a…

Solar and Stellar Astrophysics · Physics 2016-07-26 Yuan-Sen Ting , Charlie Conroy , Hans-Walter Rix

In this paper convexity constraints are derived for a background model of electron energy loss spectra (EELS) that is linear in the fitting parameters. The model outperforms a power-law both on experimental and simulated backgrounds,…

Data Analysis, Statistics and Probability · Physics 2023-08-31 Wouter Van den Broek , Daen Jannis , Jo Verbeeck

Understanding the evolution of the Milky Way calls for the precise abundance determination of many elements in many stars. A common perception is that deriving more than a few elemental abundances ([Fe/H], [$\alpha$/Fe], perhaps [C/H],…

Solar and Stellar Astrophysics · Physics 2017-07-05 Yuan-Sen Ting , Charlie Conroy , Hans-Walter Rix , Phillip Cargile

Generative diffusion models can provide powerful prior probability models for inverse problems in imaging, but existing implementations suffer from two key limitations: $(i)$ the prior density is represented implicitly, and $(ii)$ they rely…

Machine Learning · Computer Science 2026-05-19 Nicolas Zilberstein , Santiago Segarra , Eero Simoncelli , Florentin Guth

We report a method of correcting a near-infrared (0.90-1.35 $\mu$m) high-resolution ($\lambda/\Delta\lambda\sim28,000$) spectrum for telluric absorption using the corresponding spectrum of a telluric standard star. The proposed method uses…

Understanding the physical process responsible for the transport of energy in the core of $\alpha$ Centauri A is of the utmost importance if this star is to be used in the calibration of stellar model physics. Adoption of different parallax…

Solar and Stellar Astrophysics · Physics 2018-06-06 B. Nsamba , M. J. P. F. G. Monteiro , T. L. Campante , M. S. Cunha , S. G. Sousa

Well-calibrated spectropolarimetry studies at resolutions of $R>$10,000 with signal-to-noise ratios (SNRs) better than 0.01\% across individual line profiles, are becoming common with larger aperture telescopes. Spectropolarimetric studies…

Instrumentation and Methods for Astrophysics · Physics 2015-06-24 David Harrington , J. R. Kuhn , Rebecca Nevin

Earth's atmosphere imprints a large number of telluric absorption and emission lines on astronomical spectra, especially in the near infrared, that need to be removed before analysing the affected wavelength regions. These lines are…

Instrumentation and Methods for Astrophysics · Physics 2016-01-06 N. Rudolf , H. M. Günther , P. C. Schneider , J. H. M. M. Schmitt

Line spectral estimation is the problem of recovering the frequencies and amplitudes of a mixture of a few sinusoids from equispaced samples. However, in a variety of signal processing problems arising in imaging, radar, and localization we…

Information Theory · Computer Science 2016-09-28 Reinhard Heckel , Mahdi Soltanolkotabi

Precise continuum normalisation of merged \'{e}chelle spectra is a demanding task necessary for various detailed spectroscopic analyses. Automatic methods have limited effectiveness due to the variety of features present in the spectra of…

Instrumentation and Methods for Astrophysics · Physics 2022-03-30 Tomasz Różański , Ewa Niemczura , Jakub Lemiesz , Natalia Posiłek , Paweł Różański

Over the next decade, improvements in cosmological parameter constraints will be driven by surveys of large-scale structure. Its inherent non-linearity suggests that significant information will be embedded in higher correlations beyond the…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-19 Joyce Byun , Alexander Eggemeier , Donough Regan , David Seery , Robert E. Smith

We present a technique to synthesise telluric absorption and emission features both for in-situ wavelength calibration and for their removal from astronomical spectra. While the presented technique is applicable for a wide variety of…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 A. Seifahrt , H. U. Käufl , G. Zängl , J. L. Bean , M. J. Richter , R. Siebenmorgen

We applied machine learning to the entire data history of ESO's High Accuracy Radial Velocity Planet Searcher (HARPS) instrument. Our primary goal was to recover the physical properties of the observed objects, with a secondary emphasis on…

Solar and Stellar Astrophysics · Physics 2024-12-13 Vojtěch Cvrček , Martino Romaniello , Radim Šára , Wolfram Freudling , Pascal Ballester

Compressed Sensing suggests that the required number of samples for reconstructing a signal can be greatly reduced if it is sparse in a known discrete basis, yet many real-world signals are sparse in a continuous dictionary. One example is…

Information Theory · Computer Science 2015-07-24 Yuanxin Li , Yuejie Chi

We consider the problem of parameter estimation in a high-dimensional generalized linear model. Spectral methods obtained via the principal eigenvector of a suitable data-dependent matrix provide a simple yet surprisingly effective…

Statistics Theory · Mathematics 2025-07-11 Yihan Zhang , Hong Chang Ji , Ramji Venkataramanan , Marco Mondelli

Diffusion models are typically trained using pointwise reconstruction objectives that are agnostic to the spectral and multi-scale structure of natural signals. We propose a loss-level spectral regularization framework that augments…

Machine Learning · Computer Science 2026-03-04 Satish Chandran , Nicolas Roque dos Santos , Yunshu Wu , Greg Ver Steeg , Evangelos Papalexakis

Ground-based high-resolution spectrographs are key instruments for several astrophysical domains. Unfortunately, the observed spectra are contaminated by the Earth's atmosphere. While different techniques exist to correct for telluric lines…

Linear (spectro) polarimetry is usually performed using separate photon flux measurements after spatial or temporal polarization modulation. Such classical polarimeters are limited in sensitivity and accuracy by systematic effects and…

Optics · Physics 2010-05-28 Frans Snik , Theodora Karalidi , Christoph U. Keller
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