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The ambitious scientific goals of the SKA require a matching capability for calibration of atmospheric propagation errors, which contaminate the observed signals. We demonstrate a scheme for correcting the direction-dependent ionospheric…

Instrumentation and Methods for Astrophysics · Physics 2018-07-18 Maria Rioja , Richard Dodson , Thomas Franzen

Type Ia supernovae (SNe Ia) are standardizable candles that must be modeled empirically to yield cosmological constraints. To understand the robustness of this modeling to variations in the model training procedure, we build an end-to-end…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-22 M. Dai , D. O. Jones , W. D. Kenworthy , R. Kessler , J. D. R. Pierel , R. J. Foley , S. W. Jha , D. M. Scolnic

We analyze a set of 89 Type Ia supernovae (SN Ia) that have both optical and near-infrared (NIR) photometry to derive distances and construct low redshift ($z < 0.04$) Hubble diagrams. We construct mean light curve (LC) templates using a…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-08 Arturo Avelino , Andrew S. Friedman , Kaisey S. Mandel , David O. Jones , Peter J. Challis , Robert P. Kirshner

Type Ia supernovae (SNIa) have been used as approximate standard candles to measure cosmological parameters such as the Hubble constant and the deceleration parameter. These measurements rely on empirical correlations between peak…

Astrophysics · Physics 2007-05-23 Nicolas Regnault

We present an algorithm to photometrically calibrate wide field optical imaging surveys, that simultaneously solves for the calibration parameters and relative stellar fluxes using overlapping observations. The algorithm decouples the…

Transforming the instrumental photometry of ground-based telescopes into a calibrated physical flux in a well-defined passband is a major challenge in astronomy. Along with the intrinsic instrumental difference between telescopes sharing…

Instrumentation and Methods for Astrophysics · Physics 2025-07-08 S. Garrappa , E. O. Ofek , S. Ben-Ami , D. Polishook , A. Gal-Yam , Y. Shvartzvald , A. Krassilchtchikov , R. Konno , E. Segre , Y. M. Shani , Y. Sofer-Rimalt , M. Engel , A. Blumenzweig

We explore the systematic uncertainties of using Type Ia supernovae (SNe Ia) as cosmological probes, using the Supernova Legacy Survey Three Year data (SNLS3). We focus on studying the possible evolution of the stretch-luminosity parameter…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-07 Shuang Wang , Yun Wang

Optical flow estimation is a fundamental and long-standing visual task. In this work, we present a novel method, dubbed HMAFlow, to improve optical flow estimation in challenging scenes, particularly those involving small objects. The…

Computer Vision and Pattern Recognition · Computer Science 2024-11-18 Dianbo Ma , Kousuke Imamura , Ziyan Gao , Xiangjie Wang , Satoshi Yamane

We present an empirical method that uses multicolor light curve shapes (MLCS) to estimate the luminosity, distance, and total line-of-sight extinction of Type Ia supernovae (SN Ia). The empirical correlation between the MLCS and the…

Astrophysics · Physics 2009-07-09 Adam Riess , William Press , Robert Kirshner

SCUBA-2 is a 10000-bolometer submillimetre camera on the James Clerk Maxwell Telescope (JCMT). The instrument commissioning was completed in September 2011, and full science operations began in October 2011. To harness the full potential of…

This manual is intended to help ALMA and other interferometer users improve images by recognising limitations and how to overcome them and deciding when and how to use self-calibration. The images provided by the ALMA Science Archive are…

Instrumentation and Methods for Astrophysics · Physics 2022-07-13 A. M. S. Richards , E. Moravec , S. Etoka , E. B. Fomalont , A. F. Pérez-Sánchez , M. C. Toribio , R. A. Laing

The Chinese Space Station Survey Telescope (CSST) is a next-generation Stage-IV facility renowned for its wide field of view, high image quality, and multi-band observational capabilities. Among the five instruments onboard the CSST, the…

A spectral-energy distribution (SED) model for Type Ia supernovae (SNe Ia) is a critical tool for measuring precise and accurate distances across a large redshift range and constraining cosmological parameters. We present an improved model…

We present a method of extrapolating the spectroscopic behavior of Type Ia supernovae (SNe Ia) in the near-infrared (NIR) wavelength regime up to 2.30 $\mu$m using optical spectroscopy. Such a process is useful for accurately estimating…

We examine three SNe Type Ia datasets: Union2.1, JLA and Panstarrs to check their consistency using cosmology blind statistical analyses as well as cosmological parameter fitting. We find that Panstarrs dataset is the most stable of the…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-28 Ujjaini Alam , Jeremie Lasue

3D single-pixel imaging (SPI) is a promising imaging technique that can be ffexibly applied to various wavebands. The main challenge in 3D SPI is that the calibration usually requires a large number of standard points as references, which…

Image and Video Processing · Electrical Eng. & Systems 2024-10-11 Xinyue Ma , Chenxing Wang

SCALES is a high-contrast, infrared coronagraphic imager and integral field spectrograph (IFS) to be deployed behind the W.M. Keck Observatory adaptive optics system. A reflective optical design allows diffraction-limited imaging over a…

Obtaining reliable, matched photometry for galaxies imaged by different observatories represents a key challenge in the era of wide-field surveys spanning more than several hundred square degrees. Methods such as flux fitting, profile…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Kevin Bundy , David W. Hogg , Tim D. Higgs , Robert C. Nichol , Naoki Yasuda , Karen L. Masters , Dustin Lang , David A. Wake

The local distance ladder estimate of the Hubble constant ($H_0$) is important in cosmology, given the recent tension with the early universe inference. We estimate $H_0$ from the Type Ia supernova (SN~Ia) distance ladder, inferring SN~Ia…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-03 Suhail Dhawan , Stephen Thorp , Kaisey S. Mandel , Sam M. Ward , Gautham Narayan , Saurabh W. Jha , Thaisen Chant

We develop an improved phase calibration method of a reflective spatial light modulator (SLM) using interferometry by employing novel phase masks. We generate the optimised phase masks by using Iterative Fourier Transform Algorithm (IFTA)…

Optics · Physics 2022-04-26 Amar Deo Chandra , Ayan Banerjee
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