Related papers: An X-ray photometry system I: Chandra ACIS
Extracting colorimetric image information from the spectral characteristics of image sensors is a key issue in accurate image acquisition. Technically feasible filter/sensor combinations usually do not replicate colorimetric responses with…
The Chandra Multiwavength Plane (ChaMPlane) Survey of the galactic plane incorporates serendipitous sources from selected Chandra pointings in or near the galactic plane (b < 12deg; >20 ksec; lack of bright diffuse or point sources) to…
Synthetic photometry is a great tool for studying globular clusters, especially for understanding the nature of their multiple populations. Our goal is to quantify the errors on synthetic photometry that are caused by uncertainties on…
With the recent shift towards mobile computing, new challenges for biometric authentication appear on the horizon. This paper provides a comprehensive study of cross-spectral iris recognition in a scenario, in which high quality color…
As part of the Chandra GTO program we are monitoring and surveying M31 using the HRC and ACIS cameras. These observations have resolved the nuclear X-ray source into five separate sources, one of which is very soft and may (or may not!) be…
The Planet Hunting and Asteroseismology Explorer Spectrophotometer, PHASES, is a concept for a space-borne instrument to obtain flux calibrated spectra and measure micro-magnitude photometric variations of nearby stars. The science drivers…
In an ultrasonic array system, increasing the aperture size to achieve a high resolution requires more transmit and receive channels, thus making it essential to have an analysis technique that can reconstruct the shape and physical…
To take advantage of high-resolution optics sensitive to a broad energy range, future X-ray imaging instruments will require thick detectors with small pixels. This pixel aspect ratio affects spectral response in the soft X-ray band, vital…
X-ray observations of galaxies have grown from a curiosity into a full-fledged field of astronomy. These observations provide unique information on black holes, binary stars, and the hot phase of the ISM, which can be used to constrain the…
We present our first results from 130 ks of X-ray observations obtained with the Advanced CCD Imaging Spectrometer on the Chandra X-ray Observatory. We reach a flux of 2 X 10^(-16) erg s^(-1) cm^(-2) in the 0.5-2 keV soft band and 2 X…
In this paper we deal with the problem of chromaticity, i.e. apparent position variation of stellar images with their spectral distribution, using neural networks to analyse and process astronomical images. The goal is to remove this…
The familiar tools of Fourier analysis and Fisher matrices are applied to derive the uncertainties on photometric, astrometric, and weak-lensing measurements of stars and galaxies in real astronomical images. Many effects or functions that…
Photometric instruments operating at far infrared to millimetre wavelengths often have broad spectral passbands (central wavelength/bandwidth ~ 3 or less), especially those operating in space. A broad passband can result in significant…
Refraction by the atmosphere causes the positions of sources to depend on the airmass through which an observation was taken. This shift is dependent on the underlying spectral energy of the source and the filter or bandpass through which…
Much of the baryonic matter in the Universe, including the most active and luminous sources, are best studied in the X-ray band. Key advances in X-ray optics and detectors have paved the way for the Advanced X-ray Imaging Satellite (AXIS),…
X-ray polarimetry promises to give new information about high-energy astrophysical sources, such as binary black hole systems, micro-quasars, active galactic nuclei, and gamma-ray bursts. We designed, built and tested a hard X-ray…
Hard X-ray observations are the most efficient way to discriminate accretion-powered sources from star-light. Furthermore, hard X-rays are less affected than other bands by obscuration. For these reasons the advent of imaging instruments…
Digital imaging has been steadily improving over the past decades and we are moving towards a wide use of multi- and hyperspectral cameras. A key component of such imaging systems are color filter arrays, which define the spectrum of light…
Traditional color and airmass corrections can typically achieve ~0.02 mag precision in photometric observing conditions. A major limiting factor is the variability in atmospheric throughput, which changes on timescales of less than a night.…
We propose a novel type filter for multicolor imaging to improve on the photometric redshift estimation of galaxies. An extra filter - specific to a certain photometric system - may be utilized with high efficiency. We present a case study…