arXiv subjects

M. Ottiger

Publications and source records attributed to M. Ottiger.

4 recordsLinked to original sources

arXiv2025

Project 8 Apparatus for Cyclotron Radiation Emission Spectroscopy with $^\mathrm{83m}$Kr and Tritium

Cyclotron Radiation Emission Spectroscopy (CRES) is a novel technique for the precise measurement of relativistic electron energy. This technique is being employed by the Project~8 collaboration for measuring a high-precision tritium beta decay spectrum to perform a frequency-based measurement of the neutrino mass. In this work, we describe the Project 8 Phase II apparatus, used for the detection of the CRES signal from the conversion electrons of $\mathrm{^{83m}Kr}$ and the first CRES measurement of the beta-decay spectrum of molecular tritium.

physics.ins-det↗

arXiv2022

Large Interferometer For Exoplanets (LIFE): VIII. Where is the phosphine? Observing exoplanetary PH3 with a space based MIR nulling interferometer

Phosphine could be a key molecule in the understanding of exotic chemistry happening in (exo)planetary atmospheres. While it has been detected in the Solar System's giant planets, it has not been observed in exoplanets yet. In the exoplanetary context however it has been theorized as a potential biosignature molecule. The goal of our study is to identify which illustrative science cases for PH3 chemistry are observable with a space-based mid-infrared nulling interferometric observatory like the LIFE (Large Interferometer For Exoplanets) concept. We identified a representative set of scenarios for PH3 detections in exoplanetary atmospheres varying over the whole dynamic range of the LIFE mission. We used chemical kinetics and radiative transfer calculations to produce forward models of these informative, prototypical observational cases for LIFEsim, our observation simulator software for LIFE. In a detailed, yet first order approximation it takes a mission like LIFE: (i) about 1h to find phosphine in a warm giant around a G star at 10 pc, (ii) about 10 h in H2 or CO2 dominated temperate super-Earths around M star hosts at 5 pc, (iii) and even in 100h it seems very unlikely that phosphine would be detectable in a Venus-Twin with extreme PH3 concentrations at 5 pc. Phosphine in concentrations previously discussed in the literature is detectable in 2 out of the 3 cases and about an order of magnitude faster than comparable cases with JWST. We show that there is a significant number of objects accessible for these classes of observations. These results will be used to prioritize the parameter range for the next steps with more detailed retrieval simulations. They will also inform timely questions in the early design phase of a mission like LIFE and guide the community by providing easy-to-scale first estimates for a large part of detection space of such a mission.

astro-ph.EP↗

arXiv2021

Large Interferometer For Exoplanets (LIFE): I. Improved exoplanet detection yield estimates for a large mid-infrared space-interferometer mission

One of the long-term goals of exoplanet science is the atmospheric characterization of dozens of small exoplanets in order to understand their diversity and search for habitable worlds and potential biosignatures. Achieving this goal requires a space mission of sufficient scale. We seek to quantify the exoplanet detection performance of a space-based mid-infrared nulling interferometer that measures the thermal emission of exoplanets. For this, we have developed an instrument simulator that considers all major astrophysical noise sources and coupled it with Monte Carlo simulations of a synthetic exoplanet population around main-sequence stars within 20 pc. This allows us to quantify the number (and types) of exoplanets that our mission concept could detect over a certain time period. Two different scenarios to distribute the observing time among the stellar targets are discussed and different apertures sizes and wavelength ranges are considered. Within a 2.5-year initial search phase, an interferometer consisting of four 2 m apertures with a total instrument throughput of 5% covering a wavelength range between 4 and 18.5 $\mu$m could detect up to ~550 exoplanets with radii between 0.5 and 6 R$_\oplus$ with an integrated SNR$\ge$7. At least ~160 of the detected exoplanets have radii $\le$1.5 R$_\oplus$. Depending on the observing scenario, ~25-45 rocky exoplanets (objects with radii between 0.5 and 1.5 $_{\oplus}$) orbiting within the empirical habitable zone (eHZ) of their host stars are among the detections. With an aperture size of 3.5 m, the total number of detections can increase to up to ~770, including ~60-80 rocky, eHZ planets. With 1 m aperture size, the maximum detection yield is ~315 exoplanets, including $\le$20 rocky, eHZ planets. In terms of predicted detection yield, such a mission can compete with large single-aperture reflected light missions. (abridged)

astro-ph.EP↗

arXiv2020

Bayesian Analysis of a Future Beta Decay Experiment's Sensitivity to Neutrino Mass Scale and Ordering

Bayesian modeling techniques enable sensitivity analyses that incorporate detailed expectations regarding future experiments. A model-based approach also allows one to evaluate inferences and predicted outcomes, by calibrating (or measuring) the consequences incurred when certain results are reported. We present procedures for calibrating predictions of an experiment's sensitivity to both continuous and discrete parameters. Using these procedures and a new Bayesian model of the $\beta$-decay spectrum, we assess a high-precision $\beta$-decay experiment's sensitivity to the neutrino mass scale and ordering, for one assumed design scenario. We find that such an experiment could measure the electron-weighted neutrino mass within $\sim40\,$meV after 1 year (90$\%$ credibility). Neutrino masses $>500\,$meV could be measured within $\approx5\,$meV. Using only $\beta$-decay and external reactor neutrino data, we find that next-generation $\beta$-decay experiments could potentially constrain the mass ordering using a two-neutrino spectral model analysis. By calibrating mass ordering results, we identify reporting criteria that can be tuned to suppress false ordering claims. In some cases, a two-neutrino analysis can reveal that the mass ordering is inverted, an unobtainable result for the traditional one-neutrino analysis approach.

physics.data-an↗