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This paper evaluates the performance of algorithms suitable to process the measurements from two laser beam metrology systems, in particular with reference to the Gaia Basic Angle Monitoring device. The system and signal characteristics are…

Instrumentation and Methods for Astrophysics · Physics 2014-08-05 Mario Gai , Alberto Riva , Deborah Busonero , Raffaella Buzzi , Federico Russo

The interpretation of cosmological observables requires the use of increasingly sophisticated theoretical models. Since these models are becoming computationally very expensive and display non-trivial uncertainties, the use of standard…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-14 Marcos Pellejero-Ibañez , Raul E. Angulo , Giovanni Aricó , Matteo Zennaro , Sergio Contreras , Jens Stücker

The second Gaia data release (Gaia-DR2) contains, beyond the astrometry, three-band photometry for 1.38 billion sources. We have used these three broad bands to infer stellar effective temperatures, Teff, for all sources brighter than G=17…

We present a method estimating the atmospheric parameters Teff, log g, [Fe/H] for stars observed, even at low signal to noise ratio, with the echelle spectrograph ELODIE on the 193cm telescope at Observatoire de Haute-Provence. The method…

Astrophysics · Physics 2007-05-23 D. Katz , C. Soubiran , R. Cayrel , M. Adda , R. Cautain

We present AspGap, a new approach to infer stellar labels from low-resolution Gaia XP spectra, including precise [$\alpha$/M] estimates for the first time. AspGap is a neural-network based regression model trained on APOGEE spectra. In the…

Solar and Stellar Astrophysics · Physics 2023-09-26 Jiadong Li , Kaze W. K. Wong , David W. Hogg , Hans-Walter Rix , Vedant Chandra

A key aspect in the determination of stellar properties is the comparison of observational constraints with predictions from stellar models. Asteroseismic Inference on a Massive Scale (AIMS) is an open source code that uses Bayesian…

To accurately reproduce measurements from the real world, simulators need to have an adequate model of the physical system and require the parameters of the model be identified. We address the latter problem of estimating parameters through…

Robotics · Computer Science 2022-03-01 Eric Heiden , Christopher E. Denniston , David Millard , Fabio Ramos , Gaurav S. Sukhatme

We consider the problem of parameter estimation from a generalized linear model with a random design matrix that is orthogonally invariant in law. Such a model allows the design have an arbitrary distribution of singular values and only…

Statistics Theory · Mathematics 2026-02-11 Yihan Zhang , Hong Chang Ji , Ramji Venkataramanan , Marco Mondelli

Through a series of simulated observations, we investigate the capability of the instruments aboard the forthcoming THESEUS mission for the detection of a characteristic signal from decaying dark matter (DM) in the keV-MeV energy range. We…

High Energy Astrophysical Phenomena · Physics 2020-12-09 Charles Thorpe-Morgan , Denys Malyshev , Andrea Santangelo , Josef Jochum , Barbara Jäger , Manami Sasaki , Sara Saeedi

Observed data is often contaminated by undiscovered interlopers, leading to biased parameter estimation. Here we present BEAMS (Bayesian Estimation Applied to Multiple Species) which significantly improves on the standard maximum likelihood…

Astrophysics · Physics 2008-11-26 Martin Kunz , Bruce A. Bassett , Renee Hlozek

Context. The study of the oldest and most metal-poor stars in our Galaxy promotes our understanding of the Galactic chemical evolution and the beginning of Galaxy and star formation. However, they are notoriously difficult to find, with…

Astrophysics of Galaxies · Physics 2022-08-04 Theodora Xylakis-Dornbusch , Norbert Christlieb , Karin Lind , Thomas Nordlander

In this paper, we explore the feasibility of using machine learning regression as a method of extracting basic stellar parameters and line-of-sight extinctions from spectro-photometric data. We built a stable gradient-boosted random-forest…

Modern large-scale photometric surveys have provided us with multi-band photometries of billions of stars. Determining the stellar atmospheric parameters, such as the effective temperature (\teff) and metallicities (\feh), absolute…

Solar and Stellar Astrophysics · Physics 2023-07-11 Mingxu Sun , Bingqiu Chen , Helong Guo , He Zhao , Ming Yang , Wenyuan Cui

We present a method to simultaneously infer the interstellar extinction parameters $A_0$ and $R_0$, stellar effective temperature $T_{\rm eff}$, and distance modulus $\mu$ in a Bayesian framework. Using multi-band photometry from SDSS and…

Astrophysics of Galaxies · Physics 2015-06-18 R. J. Hanson , C. A. L. Bailer-Jones

We present a method to estimate distances to stars with spectroscopically derived stellar parameters. The technique is a Bayesian approach with likelihood estimated via comparison of measured parameters to a grid of stellar isochrones, and…

For future surveys, spectroscopic follow-up for all supernovae will be extremely difficult. However, one can use light curve fitters, to obtain the probability that an object is a Type Ia. One may consider applying a probability cut to the…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-24 Michelle Lochner , Bruce A. Bassett , Melvin Varughese , Renée Hlozek , Martin Kunz , Mat Smith , James Newling

Gaia Data Release 3 contains a wealth of new data products for the community. Astrophysical parameters are a major component of this release. They were produced by the Astrophysical parameters inference system (Apsis) within the Gaia Data…

Access to knowledge of the point spread function (PSF) of adaptive optics(AO)-assisted observations is still a major limitation when processing AO data. This limitation is particularly important when image analysis requires the use of…

Instrumentation and Methods for Astrophysics · Physics 2023-05-10 A. Lau , R. JL. Fétick , B. Neichel , O. Beltramo-Martin , T. Fusco

The protoplanetary discs of T Tauri and Herbig Ae/Be stars have been studied by using geometric disc models to fit their spectral energy distribution (SED). The simulations provide means to reproduce the signatures of different…

Astrophysics · Physics 2009-11-13 A. Hetem , J. Gregorio-Hetem

We present a new method of DEEM, the direct energy encircling method, for characterising the performance of fibres in most astronomical spectroscopic applications. It's a versatile platform to measure focal ratio degradation (FRD),…

Instrumentation and Methods for Astrophysics · Physics 2019-12-25 Yunxiang Yan , Qi Yan , Gang Wang , Weimin Sun , A-Li Luo , Zhenyu Ma , Qiong Zhang , Jian Li , Shuqing Wang