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Related papers: Morphological components analysis for circumstella…

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The study of the atmospheres of transiting exoplanets requires a photometric precision, and repeatability, of one part in $\sim 10^4$. This is beyond the original calibration plans of current observatories, hence the necessity to…

Earth and Planetary Astrophysics · Physics 2015-08-06 Giuseppe Morello

Submillimeter observations with ALMA will be the essential next step in our understanding of how stars and planets form. Key projects range from detailed imaging of the collapse of pre-stellar cores and measuring the accretion rate of…

Astrophysics · Physics 2009-11-13 Ewine F. van Dishoeck , Jes K. Jorgensen

Principal Component Analysis (PCA) is a workhorse of modern data science. While PCA assumes the data conforms to Euclidean geometry, for specific data types, such as hierarchical and cyclic data structures, other spaces are more…

Machine Learning · Statistics 2024-07-11 Puoya Tabaghi , Michael Khanzadeh , Yusu Wang , Sivash Mirarab

This paper presents first results on the line profile shapes from a circumstellar envelope in bulk motion as modified by a microlensing event. Only geometrically and optically thin spherical shells in uniform expansion or rotation are…

Astrophysics · Physics 2007-05-23 R. Ignace , M. A. Hendry

Recent advances in our understanding of massive star formation have made clear the important role of protostellar disks in mediating accretion. Here we describe a simple, semi-analytic model for young, deeply embedded, massive accretion…

Astrophysics · Physics 2007-12-07 Kaitlin M. Kratter , Christopher D. Matzner , Mark. R. Krumholz

Circumstellar disks are an integral part of the star formation process and the sites where planets are formed. Understanding the physical processes that drive their evolution, as disks evolve from optically thick to optically thin, is…

Astrophysics · Physics 2016-09-08 Lucas A. Cieza

Abridged: Recent simulations have explored different ways to form accretion disks around low-mass stars. We aim to present observables to differentiate a rotationally supported disk from an infalling rotating envelope toward deeply embedded…

Solar and Stellar Astrophysics · Physics 2015-04-29 Daniel Harsono , Ewine van Dishoeck , Simon Bruderer , Zhi-Yun Li , Jes Jorgensen

We propose a new, efficient multi-scale method to decompose a map (or signal in general) into components maps that contain structures of different sizes. In the widely-used wave transform, artifacts containing negative values arise around…

Instrumentation and Methods for Astrophysics · Physics 2022-04-11 Guang-Xing Li

We suggest a two-dimensional wavelet devised to deduce the large-scale structure of a physical field (e.g., the Galactic magnetic field) from its integrals along straight paths from irregularly spaced data points to a fixed interior point…

Astrophysics · Physics 2009-11-07 R. Stepanov , P. Frick , A. Shukurov , D. Sokoloff

Advances in vectorial polarisation-resolved imaging are bringing new capabilities to applications ranging from fundamental physics through to clinical diagnosis. Imaging polarimetry requires determination of the Mueller matrix (MM) at every…

Detecting exoplanets and other faint sources of emitted and reflected light near a bright star requires deeply suppressing the starlight while efficiently transmitting the dim light from its surroundings. This suppression can be carried out…

Instrumentation and Methods for Astrophysics · Physics 2024-11-07 Eugene Serabyn , Michael Bottom

We propose a novel method for the description of spatial patterns formed by a coverage of point sets representing galaxy samples. This method is based on a complete family of morphological measures known as Minkowski functionals, which…

Astrophysics · Physics 2007-05-23 K. R. Mecke , T. Buchert , H. Wagner

High-resolution spectroscopy of strong chromospheric absorption lines delivers nowadays several millions of spectra per observing day, when using fast scanning devices to cover large regions on the solar surface. Therefore, fast and robust…

Solar and Stellar Astrophysics · Physics 2020-03-04 Ekaterina Dineva , Meetu Verma , Sergio Javier González Manrique , Pavol Schwartz , Carsten Denker

Exoplanets in protoplanetary disks cause localized deviations from Keplerian velocity in channel maps of molecular line emission. Current methods of characterizing these deviations are time consuming, and there is no unified standard…

Earth and Planetary Astrophysics · Physics 2023-01-04 Jason Terry , Cassandra Hall , Sean Abreau , Sergei Gleyzer

Astrometry covers a parameter space that cannot be reached by RV or transit methods to detect terrestrial planets on wide orbits. In addition, high accuracy astrometric measurements are necessary to measure the inclination of the planet's…

Earth and Planetary Astrophysics · Physics 2016-07-20 Quentin Kral , Jean Schneider , Grant Kennedy , Damya Souami

One of the main goals of modern observational cosmology is to map the large scale structure of the Universe. A potentially powerful approach for doing this would be to exploit three-dimensional spectral maps, i.e. the specific intensity of…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-18 Roland de Putter , Gilbert P. Holder , Tzu-Ching Chang , Olivier Dore

A galaxy's stellar mass is one of its most fundamental properties, but it remains challenging to measure reliably. With the advent of very large optical spectroscopic surveys, efficient methods that can make use of low signal-to-noise…

Aims: Stellar activity may complicate the analysis of high-precision radial-velocity spectroscopic data when looking for exoplanets signatures. We aim at quantifying the impact of stellar spots on stars with various spectral types and…

Astrophysics · Physics 2009-11-13 Morgan Desort , Anne-Marie Lagrange , Franck Galland , Stephane Udry , Michel Mayor

We present a modified version of the cosmic crystallography method, especially useful for testing closed models of negative spatial curvature. The images of clusters of galaxies in simulated catalogs are ``pulled back'' to the fundamental…

Astrophysics · Physics 2009-10-31 Helio V. Fagundes , Evelise Gausmann

We aim to present a tutorial on the detection, parameter estimation and statistical analysis of compact sources (far galaxies, galaxy clusters and Galactic dense emission regions) in cosmic microwave background observations. The topic is of…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-05 D. Herranz , P. Vielva