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Related papers: Astrometric imaging of crowded stellar fields with…

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We investigate blending, binarity and photometric biases in crowded-field CCD imaging. For this, we consider random blend losses, which correspond to the total number of stars left undetected in unresolved blends. We present a simple…

Astrophysics · Physics 2009-11-10 L. L. Kiss , T. R. Bedding

Line intensity mapping (LIM) proposes to efficiently observe distant faint galaxies and map the matter density field at high redshift. Building upon the formalism in the companion paper, we first highlight the degeneracies between cosmology…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-29 Emmanuel Schaan , Martin White

Astrometric detection and mass determination of Earth-mass exoplanets requires sub-microarcsec accuracy, which is theoretically possible with an imaging space telescope using field stars as an astrometric reference. The measurement must…

This paper presents and discusses the application of blind source separation to astrophysical data obtained with the WMAP satellite. Blind separation permits to identify and isolate a component compatible with CMB emission, and to measure…

Astrophysics · Physics 2007-05-23 G. Patanchon , J. Delabrouille , J. -F. Cardoso

Spatial-mode demultiplexing (SPADE) has recently been adopted to measure the separation in the transverse plane between two incoherent point-like sources. It has been argued that this approach may yield extraordinary performances in the…

I show that by observing microlensing events both astrometrically and photometrically, the Space Interferometry Mission (SIM) can measure the mass function of stellar remnants in the Galactic bulge including white dwarfs, neutron stars, and…

Astrophysics · Physics 2009-10-31 Andrew Gould

A novel interferometric method - SLIVER (Super Localization by Image inVERsion interferometry) - is proposed for estimating the separation of two incoherent point sources with a mean squared error that does not deteriorate as the sources…

Optics · Physics 2016-02-16 Ranjith Nair , Mankei Tsang

We present a novel technique to determine the absolute inclination of single stars using multi-wavelength sub-milliarcsecond astrometry. The technique exploits the effect of gravity darkening, which causes a wavelength-dependent astrometric…

Solar and Stellar Astrophysics · Physics 2015-05-19 Jeffrey L. Coughlin , Thomas E. Harrison , Dawn M. Gelino

Astrometric detection of a stellar wobble on the plane of the sky will provide us a next breakthrough in searching extrasolar planets. The Space Interferometry Mission (SIM) is expected to achieve a high-precision astrometry as accurate as…

Astrophysics · Physics 2009-11-10 Taku Takeuchi , T. Velusamy , D. N. C. Lin

In this work we derive analytic expressions and numerical recipes for finding the effective observed position of sources close enough on sky that their Point Spread Functions (PSF), modelled as Gaussian profiles, overlap. In particularly we…

Solar and Stellar Astrophysics · Physics 2026-03-24 Zephyr Penoyre

The conventional approach to high-precision narrow-angle astrometry using a long baseline interferometer is to directly measure the fringe packet separation of a target and a nearby reference star. This is done by means of a technique known…

Instrumentation and Methods for Astrophysics · Physics 2014-08-25 Y. Kok , M. J. Ireland , A. C. Rizzuto , P. G. Tuthill , J. G. Robertson , B. A. Warrington , W. J. Tango

We investigate the potential of photonic lantern (PL) fiber fed spectrometers for two-dimensional spectroastrometry. Spectroastrometry, a technique for studying small angular scales by measuring centroid shifts as a function of wavelength,…

Instrumentation and Methods for Astrophysics · Physics 2024-09-17 Yoo Jung Kim , Michael P. Fitzgerald , Jonathan Lin , Yinzi Xin , Daniel Levinstein , Steph Sallum , Nemanja Jovanovic , Sergio Leon-Saval

Classical optical interferometery requires maintaining live, phase-stable links between telescope stations. This requirement greatly adds to the cost of extending to long baseline separations, and limits on baselines will in turn limit the…

The CLEAN algorithm, widely used in radio interferometry for the deconvolution of radio images, performs well only if the raw radio image (dirty image) is, to good approximation, a simple convolution between the instrumental point-spread…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 I. M. Stewart , D. M. Fenech , T. W. B. Muxlow

Because of their limited angular resolution, far-infrared telescopes are usually affected by confusion phenomenon. Since several galaxies can be located in the same instrumental beam, only the brightest objects emerge from the fluctuations…

[Abridged] An increasing number of astronomical instruments (on Earth and space-based) provide hyperspectral images, that is three-dimensional data cubes with two spatial dimensions and one spectral dimension. The intrinsic limitation in…

Instrumentation and Methods for Astrophysics · Physics 2021-03-17 Axel Boulais , Olivier Berné , Guillaume Faury , Yannick Deville

We present numerical simulations for a possible synthesis imaging mode of the Space Interferometer Mission (SIM). We summarize the general techniques that SIM offers to perform imaging of high surface brightness sources, and discuss their…

Astrophysics · Physics 2009-10-31 T. Boeker , R. J. Allen

We develop a new photometry algorithm that is optimized for $Spitzer$ time series in crowded fields and that is particularly adapted to faint and/or heavily blended targets. We apply this to the 170 targets from the 2015 $Spitzer$…

Extragalactic surveys provide significant statistical data for the study of crucial galaxy parameters used to constrain galaxy evolution, e.g. stellar mass (M$_*$) and star formation rate (SFR), under different environmental conditions.…

Astrophysics of Galaxies · Physics 2024-06-12 Paula Calderón-Castillo , Neil M. Nagar , Sukyoung Yi , Yu-Yen Chang , Roger Leiton , Thomas M. Hughes

I propose a spatial-mode demultiplexing (SPADE) measurement scheme for the far-field imaging of spatially incoherent optical sources. For any object too small to be resolved by direct imaging under the diffraction limit, I show that SPADE…

Optics · Physics 2017-03-01 Mankei Tsang