相关论文: A Calibration of NICMOS Camera 2 for Low Count-Rat…

Due to the large dynamic ranges involved with separating the cosmological 21-cm signal from the Cosmic Dawn from galactic foregrounds, a well-calibrated instrument is essential to avoid biases from instrumental systematics. In this paper we…

We present near-infrared J and K band imaging of a sample of powerful radio source host galaxies with the Hubble Space Telescope NICMOS2 camera. These sources have been selected on their double lobed radio structure, and include a wide…

The Chandra COSMOS Survey (C-COSMOS) is a large, 1.8 Ms, Chandra program, that covers the central contiguous ~0.92 deg^2 of the COSMOS field. C-COSMOS is the result of a complex tiling, with every position being observed in up to six…

Expanding from previous work we present weak lensing measurements for a total sample of 30 distant ($z_\mathrm{median}=0.93$) massive galaxy clusters from the South Pole Telescope Sunyaev-Zel'dovich (SPT-SZ) Survey, measuring galaxy shapes…

With this paper we continue the preparation for a forthcoming summary report of our experiment with the Hubble Space Telescope (HST) to determine the Hubble constant using type Ia supernovae as standard candles. Two problems are addressed.…

The Hubble diagram of type-Ia supernovae (SNe-Ia) provides cosmological constraints on the nature of dark energy with an accuracy limited by the flux calibration of currently available spectrophotometric standards. The StarDICE experiment…

The Complete Calibration of the Colour-Redshift Relation survey (C3R2) is a spectroscopic effort involving ESO and Keck facilities designed to empirically calibrate the galaxy colour-redshift relation - P(z|C) to the Euclid depth…

Astronomers working with faint targets will benefit greatly from improved image quality on current and planned ground-based telescopes. At present, most adaptive optic systems are targeted at the highest resolution with bright guide stars.…

We present near-IR images of five luminous quasars at z~2 and one at z~4 obtained with an experimental adaptive optics instrument at the ESO Very Large Telescope. The observations are part of a program aimed at demonstrating the…

Using the ground-based V and I photometry of a sample of stars from the Groth Strip, we obtain the first empirical calibration of the F606W and F814W Hubble Space Telescope WFPC2 filters for 0.5<V-I<4.5. We present results in the form of…

A method is described intended for distributed calibration of a probe microscope scanner consisting in a search for a net of local calibration coefficients (LCCs) in the process of automatic measurement of a standard surface, whereby each…

We aim to examine the relative cross-calibration accuracy of the on-axis effective areas of the XMM-Newton EPIC pn and MOS instruments. Spectra from a sample of 46 bright, high-count, non-piled-up isolated on-axis point sources are stacked…

The next generation of Cherenkov telescope cameras feature Silicon Photo Multipliers (SiPM), which can guarantee excellent performance and allow for observation also under moonlight, increasing duty-cycle and therefore the physics reach. A…

We present a new calibration method based on cross-correlations with WMAP and apply it to data from the Atacama Cosmology Telescope (ACT). ACT's observing strategy and map making procedure allows an unbiased reconstruction of the modes in…

To achieve the sensitivity required to detect signals from neutral hydrogen from the Cosmic Dawn and Epoch of Reionisation it is critical to have a well-calibrated instrument which has a stable calibration over the course of the…

High-resolution JWST observations can test confusion-limited HST observations for a photometric bias that could affect extragalactic Cepheids and the determination of the Hubble constant. We present JWST NIRCAM observations in two epochs…

Accurate measurements of the Cosmic Microwave Background (CMB) anisotropy call for high precision and reliability of the in-flight calibration. For extended surveys the CMB dipole provides an excellent calibration source at frequencies…

In order for Wide-Field Infrared Survey Telescope (WFIRST) and other Stage IV dark energy experiments (e.g., Large Synoptic Survey Telescope; LSST, and Euclid) to infer cosmological parameters not limited by systematic errors, accurate…

NICMOS observations of the resolved object fluxes in the Hubble Deep Field North and the Hubble Ultra Deep Field are significantly below the fluxes attributed to a 1.4 - 1.8 microns Near InfraRed Background Excess (NIRBE) from previous low…

CONTEXT. 2MASS is the reference survey in the NIR part of the spectrum given its whole-sky coverage, large dynamic range, and proven calibration uniformity. However, previous studies disagree in the value of the zero points (ZPs) for its…