Results 41 to 50 of about 1,035 (121)

Statistical Issues Often Overlooked when Analyzing Astronomical Data

The Astrophysical Journal Supplement Series
The main topics covered in this paper are (1) controlling significance levels when applying the same hypothesis test to many (possibly millions) of datasets; (2) dealing with the fact that for very large datasets hypotheses are rejected for trivially ...
C. Koen
doaj   +1 more source

Classification of Chandra X-Ray Sources in Cygnus OB2

The Astrophysical Journal Supplement Series, 2023
We have devised a predominantly Naive Bayes−based method to classify X-ray sources detected by Chandra in the Cygnus OB2 association into members, foreground objects, and background objects.
Vinay L. Kashyap, Mario G. Guarcello, Nicholas J. Wright, Jeremy J. Drake, Ettore Flaccomio, Tom L. Aldcroft, Juan F. Albacete Colombo, Kevin Briggs, Francesco Damiani, Janet E. Drew, Eduardo L. Martin, Giusi Micela, Tim Naylor, Salvatore Sciortino   +13 more
doaj   +1 more source

Robust Estimates of Orientation between Astrometric Catalogs

The Astronomical Journal, 2023
Accurately comparing two celestial reference frames based on the observed position of a number of common objects requires to detect and appropriately process outliers, lest they spuriously influence the results.
Julien Frouard
doaj   +1 more source

Rigorous Analytic Solution to the Gravitational-wave Overlapping Event Rates

The Astrophysical Journal
In the era of the next-generation gravitational-wave detectors, signal overlaps will become prevalent due to the high detection rate and long signal duration, posing significant challenges to data analysis. While effective algorithms are being developed,
Ziming Wang, Zexin Hu, Lijing Shao
doaj   +1 more source

Multistage analysis in astrostatistics

, 2020
A sequence of statistical analyses often needs to be conducted by different groups of researchers where the output of each analysis feeds into subsequent analyses. The statistical and systematic uncertainties of estimated quantities, especially high dimensional quantities, are hard to quantify and difficult to carry forward into subsequent analyses. In
openaire   +3 more sources

Maximum-likelihood Regression with Systematic Errors for Astronomy and the Physical Sciences. II. Hypothesis Testing of Nested Model Components for Poisson Data

The Astrophysical Journal
A novel model of systematic errors for the regression of Poisson data is applied to hypothesis testing of nested model components with the introduction of a generalization of the Δ C statistic that applies in the presence of systematic errors. This paper
Massimiliano Bonamente, Dale Zimmerman, Yang Chen   +2 more
doaj   +1 more source

Multifidelity Emulator for Large-scale 21 cm Lightcone Images: A Few-shot Transfer Learning Approach with Generative Adversarial Network

The Astrophysical Journal
Emulators using machine learning techniques have emerged to efficiently generate mock data matching the large survey volume for upcoming experiments, as an alternative approach to large-scale numerical simulations.
Kangning Diao, Yi Mao
doaj   +1 more source

Adaptive Optics Near-Infrared Spectroscopy of the Sgr A* Cluster

, 2002
We present K-band $\lambda/\Delta\lambda$ ~ 2600 spectroscopy of five stars (K ~ 14 - 16 mag) within 0.''5 of Sgr A*, the radio source associated with the compact massive object suspected to be a 2.6 x 10$^{6}$ \msun black hole at the center of our ...
A. M. Ghez, E. E. Becklin, Eckart A., Genzel R., I. S. McLean, J. Larkin, M. Morris, S. Gezari   +7 more
core   +2 more sources

A Geometric Approach to Estimate Background in Astronomical Images

The Astrophysical Journal Supplement Series
Estimating the true background in an astronomical image is fundamental to detecting faint sources. In a typical low-photon-count astronomical image, such as in the far- and near-ultraviolet wavelength ranges, conventional methods relying on 3 σ clipping ...
Pushpak Pandey, Kanak Saha
doaj   +1 more source

SZ and CMB reconstruction using Generalized Morphological Component Analysis

, 2007
In the last decade, the study of cosmic microwave background (CMB) data has become one of the most powerful tools to study and understand the Universe.
Bennett, Bobin, Bouchet, Delabrouille, Donoho, Forni, J. Bobin, J. Fadili, J.-L. Starck, Jungman, Moudden, N. Aghanim, Pires, Starck, Sunyaev, Tseng, Y. Moudden, Zibulevsky   +17 more
core   +3 more sources