Engineering topics

Mauskopf, P.

Publications and source records attributed to Mauskopf, P..

7 records

DOE OSTI2023

Multi-probe analysis of the galaxy cluster CL J1226.9+3332: Hydrostatic mass and hydrostatic-to-lensing bias

The precise estimation of the mass of galaxy clusters is a major issue for cosmology. Large galaxy cluster surveys rely on scaling laws that relate cluster observables to their masses. From the high-resolution observations of ~45 galaxy clusters with the NIKA2 and XMM-Newton instruments, the NIKA2 Sunyaev-Zel’dovich Large Program should provide an accurate scaling relation between the thermal Sunyaev-Zel’dovich effect and the hydrostatic mass. In this paper we present an exhaustive analysis of the hydrostatic mass of the well-known galaxy cluster CL J1226.9+3332, the highest-redshift cluster in the NIKA2 Sunyaev-Zel’dovich Large Program at z = 0.89. We combined the NIKA2 observations with thermal Sunyaev-Zel’dovich data from the NIKA, Bolocam, and MUSTANG instruments and XMM-Newton X-ray observations, and tested the impact of the systematic effects on the mass reconstruction. We conclude that slight differences in the shape of the mass profile can be crucial when defining the integrated mass at R 500 , which demonstrates the importance of the modelling in the mass determination. We prove the robustness of our hydrostatic mass estimates by showing the agreement with all the results found in the literature. Another key factor for cosmology is the bias of the masses estimated assuming the hydrostatic equilibrium hypothesis. Based on the lensing convergence maps from the Cluster Lensing And Supernova survey with Hubble (CLASH) data, we obtain the lensing mass estimate for CL J1226.9+3332. From this we are able to measure the hydrostatic-to-lensing mass bias for this cluster, which spans from 1–b HSE/lens ~0.7 to 1, presenting the impact of data sets and mass reconstruction models on the bias.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2022

Candidate cosmic filament in the GJ526 field, mapped with the NIKA2 camera

Distinctive large-scale structures have been identified in the spatial distribution of optical galaxies up to redshift z ~ 1. In the more distant universe, the relationship between the dust-obscured population of star-forming galaxies observed at millimetre wavelengths and the network of cosmic filaments of dark matter apparent in all cosmological hydrodynamical simulations is still under study. Using the NIKA2 dual-band millimetre camera, we mapped a field of ~90 arcmin 2 in the direction of the star GJ526 simultaneously in its 1.15-mm and 2.0-mm continuum wavebands to investigate the nature of the quasi-alignment of five sources found ten years earlier with the MAMBO camera at 1.2 mm. We find that these sources are not clumps of a circumstellar debris disc around this star as initially hypothesized. Rather, they must be dust-obscured star-forming galaxies, or sub-millimetre galaxies (SMGs), in the distant background. The new NIKA2 map at 1.15 mm reveals a total of seven SMGs distributed in projection on the sky along a filament-like structure crossing the whole observed field. Furthermore, we show that the NIKA2 and supplemental Herschel photometric data are compatible with a model of the spectral energy distributions (SEDs) of these sources when a common redshift of 2.5 and typical values of the dust parameters for SMGs are adopted. Hence, we speculate that these SMGs might be located in a filament of the distant ‘cosmic web’. The length of this candidate cosmic filament crossing the whole map is at least 4 cMpc (comoving), and the separations between sources are between 0.25 cMpc and 1.25 cMpc at this redshift, in line with expectations from cosmological simulations. Nonetheless, further observations to determine the precise spectroscopic redshifts of these sources are required to definitively support this hypothesis of SMGs embedded in a cosmic filament of dark matter.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2020

An On-Chip Superconducting Kinetic Inductance Fourier Transform Spectrometer for Millimeter-Wave Astronomy

An on-chip FTS consists of two waveguides coupled to long superconducting transmission lines (STLs) (similar to 620 mm) using two coupling probes. The signal propagating on one of the STLs is phase-shifted with respect to the other line with a bias current that affects the nonlinear dependence of kinetic inductance, Lk(I)of the STL material. Here we describe the design and simulation of a superconducting on-chip FTS coupled to a dual polarization W-band (90-110 GHz) waveguide. These devices have applications in ground-based and space-based millimeter-wave spectral surveys.

Fourier transform spectrometer↗

DOE OSTI2020

Planar Self-similar Antennas for Broadband Millimeter-Wave Measurements

Self-similar antennas offer extremely broadband functionality and easily scalable designs. Self-similar designs with a four-arm layout are also suited for dual polarization through excitations of opposing arms, although there has only been limited use of them for millimeter-wave detectors. These antennas have been used for measurements of the cosmic microwave background (CMB), which encompass a wide frequency range and are now actively focusing more on polarization anisotropies. Here, we analyze multiple planar self-similar antenna designs with simulations in high-frequency structure simulator and ongoing physical testing. They all exhibit broadband operation between 130 and 230 GHz and can couple to both linear polarizations through the previously mentioned four-arm symmetry. Furthermore, simulations include each antenna design coupled to an extended hemispherical, AR-coated lenslet. From these, a basic bowtie-like arm design produced minimal polarization wobble with moderate beam efficiency, while a hybrid trapezoidal design provided high beam efficiency with small polarization wobble. Current fabrication versions of each are being tested, coupled to multichroic microwave kinetic inductance detectors. These planar self-similar antennas, when implemented in CMB and other detectors, could improve observations while simultaneously simplifying fabrication and detector layout.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

DOE OSTI2020

Full-Array Noise Performance of Deployment-Grade SuperSpec mm-Wave On-Chip Spectrometers

SuperSpec is an on-chip filter bank spectrometer designed for wideband moderate-resolution spectroscopy at millimeter wavelengths, employing TiN kinetic inductance detectors. SuperSpec technology will enable large-format spectroscopic integral field units suitable for high-redshift line intensity mapping and multi-object spectrographs. In previous results, we have demonstrated noise performance in individual detectors suitable for photon noise-limited ground-based observations at excellent mm-wave sites. Here, we present the noise performance of a full R similar to 275 spectrometer measured using deployment-ready RF hardware and software. We report typical noise equivalent powers through the full device of similar to 3x10 -16 W Hz -1/2 at expected sky loadings, which are photon noise dominated. Based on these results, we plan to deploy a six-spectrometer demonstration instrument to the Large Millimeter Telescope in early 2020.

47 OTHER INSTRUMENTATION↗

NASA NTRS2010

The Atacama Cosmology Telescope: The Receiver and Instrumentation

The Atacama Cosmology Telescope was designed to measure small-scale anisotropies in the Cosmic Microwave Background and detect galaxy clusters through the Sunyaev-Zel'dovich effect. The instrument is located on Cerro Taco in the Atacama Desert, at an altitude of 5190 meters. A six-met.er off-axis Gregorian telescope feeds a new type of cryogenic receiver, the Millimeter Bolometer Array Camera. The receiver features three WOO-element arrays of transition-edge sensor bolometers for observations at 148 GHz, 218 GHz, and 277 GHz. Each detector array is fed by free space mm-wave optics. Each frequency band has a field of view of approximately 22' x 26'. The telescope was commissioned in 2007 and has completed its third year of operations. We discuss the major components of the telescope, camera, and related systems, and summarize the instrument performance.

Swetz, D. S.↗

NASA NTRS2001

A measurement by BOOMERANG of multiple peaks in the angular power spectrum of the cosmic microwave background

This paper presents a measurement of the angular power spectrum of the Cosmic Microwave Background from l = 75 to l = 1025 (~10' to 5 degrees) from a combined analysis of four 150 GHz channels in the BOOMERANG experiment. The spectrum contains multiple peaks and minima, as predicted by standard adiabatic-inflationary models in which the primordial plasma undergoes acoustic oscillations.

BOOMERANG spectrum cosmos microwave↗