Users of the La Silla Paranal Observatory have to rely on the ESO Exposure Time Calculator (ETC) to prepare their observations. A project has been started at ESO to modernise the ETC, based on a python backend and an angular-based front-end. The ETC 2.0 will have a programmatic interface to enable the results to be included in an automated quality control loop and to communicate with the Phase 1 proposal preparation and the Phase 2 observation preparation tools, the ESO science archive, as well as with scripts runs by external users or instruments. The first version of an ETC 2.0 has been released for the 4MOST instrument and further versions will be released over the next years for all new La Silla, VLT and ELT instruments. The ETC of the current La Silla and VLT instruments will also be migrated progressively, with improved instrument description.
This document describes the exposure time calculator for the Wide-Field Infrared Survey Telescope (WFIRST) high-latitude survey. The calculator works in both imaging and spectroscopic modes. In addition to the standard ETC functions (e.g. background and S/N determination), the calculator integrates over the galaxy population and forecasts the density and redshift distribution of galaxy shapes usable for weak lensing (in imaging mode) and the detected emission lines (in spectroscopic mode). The source code is made available for public use.
Pandeia is the exposure time calculator (ETC) system developed for the James Webb Space Telescope (JWST) that will be used for creating JWST proposals. It includes a simulation-hybrid Python engine that calculates the two-dimensional pixel-by-pixel signal and noise properties of the JWST instruments. This allows for appropriate handling of realistic point spread functions, MULTIACCUM detector readouts, correlated detector readnoise, and multiple photometric and spectral extraction strategies. Pandeia includes support for all the JWST observing modes, including imaging, slitted/slitless spectro…
We present an exposure-time calculator (ETC) for the Immersion Grating Infrared Spectrograph (IGRINS). The signal and noise values are calculated by taking into account the telluric background emission and absorption, the emission and transmission of the telescope and instrument optics, and the dark current and read noise of the infrared detector arrays. For the atmospheric transmission, we apply models based on the amount of precipitable water vapor along the line of sight to the target. The ETC produces the expected signal-to-noise ratio (S/N) for each resolution element, given the exposure-…
Cross-Model Validation of Coronagraphic Exposure Time Calculators for the Habitable Worlds Observatory: A Report from the Exoplanet Science Yield sub-Working Group
We present the progresses of the simulation tools, the Exposure Time Calculator (ETC) and End-to-End simulator (E2E), for the Son Of X-Shooter (SOXS) instrument at the ESO-NTT 3.58-meter telescope. The SOXS will be a single object spectroscopic facility, made by a two-arms high-efficiency spectrograph, able to cover the spectral range 350-2000 nanometer with a mean resolving power R$\approx$4500. While the purpose of the ETC is the estimate, to the best possible accuracy, of the Signal-to-Noise ratio (SNR), the E2E model allows us to simulate the propagation of photons, starting from the scien…
pyEDITH: the coronagraphic exposure time calculator for the Habitable Worlds Observatory
NASA Goddard Space Flight Center（美国宇航局戈达德太空飞行中心）；Department of Astronomy University of Maryland（马里兰大学天文学系）；Center for Research and Exploration in Space Science and Technology II (CRESST II)（空间科学与技术研究探索中心二期（CRESST II））；Department of Astronomy and Astrobiology Program University of Washington（华盛顿大学天文学与天体生物学项目）；Johns Hopkins APL（约翰斯·霍普金斯大学应用物理实验室）；Space Telescope Science Institute（太空望远镜科学研究所）
WST instrument Exposure Time Calculator: full simulation of multi-mode spectrograph performance from source to detector
INAF – Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）；European Southern Observatory（欧洲南方天文台）；INAF – Osservatorio Astrofisico di Arcetri（意大利国家天体物理研究所阿切特里天文台）；Centre de Recherche Astrophysique de Lyon, Université de Lyon（里昂大学里昂天体物理研究中心）；Dipartimento di Fisica e Astronomia “Augusto Righi”, Università di Bologna（博洛尼塔大学物理与天文学系）；INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna（意大利国家天体物理研究所博洛尼亚空间科学与天体物理观测站）；Leibniz-Institut für Astrophysik Potsdam (AIP)（波茨坦莱布尼茨天体物理研究所）
The effect of satellite constellations on observations in the visible and IR domains is estimated, considering 18 constellations in development by SpaceX, Amazon, OneWeb, and others, with over 26,000 satellites, constituting a representative distribution. This study uses a series of simplifications and assumptions to obtain conservative, order-of-magnitude estimates of the effects. The number of illuminated satellites from the constellations above the horizon ranges from ~1600 right after sunset, decreasing to 1100 at the end of astronomical twilight, most of them (~85%) close to the horizon (…
The Dark Energy Spectroscopic Instrument (DESI) is an ongoing spectroscopic survey to measure the dark energy equation of state to unprecedented precision. We describe the DESI Sky Continuum Monitor System, which tracks the night sky brightness as part of a system that dynamically adjusts the spectroscopic exposure time to produce more uniform data quality and to maximize observing efficiency. The DESI dynamic exposure time calculator (ETC) will combine sky brightness measurements from the Sky Monitor with data from the guider system to calculate the exposure time to achieve uniform signal-to-…
Incorporating Wavefront Error, Wavefront Sensing and Control, and Sensitivities into Exposure Time Calculations for Future Space Missions with the Error Budget Software (EBS)
Space Telescope Science Institute（太空望远镜科学研究所）；Jet Propulsion Laboratory, California Institute of Technology（喷气推进实验室，加州理工学院）
CUBES (Cassegrain U-Band Efficient Spectrograph) is the recently approved high-efficiency VLT spectrograph aimed to observe the sky in the UV ground-based region (305-400 nm) with a high-resolution mode (~20K) and a low-resolution mode (~5K). In this paper we will briefly describe the requirements and the design of the several software packages involved in the project, namely the instrument control software, the exposure time calculator, the end-to-end simulator, and the data reduction software suite. We will discuss how the above mentioned blocks cooperate to build up a "software ecosystem" f…
X-shooter is the first 2nd generation instrument of the ESO Very Large Telescope(VLT). It is a very efficient, single-target, intermediate-resolution spectrograph that was installed at the Cassegrain focus of UT2 in 2009. The instrument covers, in a single exposure, the spectral range from 300 to 2500 nm. It is designed to maximize the sensitivity in this spectral range through dichroic splitting in three arms with optimized optics, coatings, dispersive elements and detectors. It operates at intermediate spectral resolution (R~4,000 - 17,000, depending on wavelength and slit width) with fixed …
As of October 2021 (Period 108), the European Southern Observatory (ESO) offers a new mode of the ESPRESSO spectrograph designed to use the High Resolution grating with 4x2 binning (spatial by spectral; HR42 mode) with the specific objective of observing faint targets with a single Unit Telescope at Paranal. We validated the new HR42 mode using four hours of on-target observations of the quasar J0003-2603, known to host an intervening metal-poor absorber along the line of sight. The capabilities of the ESPRESSO HR42 mode (resolving power R~137 000) were evaluated by comparing to a UVES spectru…
The Roman Coronagraph Community Participation Program: trials and triumphs of designing an observing program for a technology demonstration instrument
The University of Arizona（亚利桑那大学）；Jet Propulsion Laboratory, California Institute of Technology（加州理工学院喷气推进实验室）；University of Edinburgh（爱丁堡大学）；Cornell University（康奈尔大学）；Space Telescope Science Institute（太空望远镜科学研究所）；Laboratoire d’Astrophysique de Marseille（马赛天体物理实验室）；California Institute of Technology（加州理工学院）；Max Planck Institut for Astronomy（马克斯·普朗克天文学研究所）；Astrobiology Center, NINS（日本国立自然科学研究所天体生物学中心）；National Astronomical Observatory of Japan, NINS（日本国立天文台）；Johns Hopkins University（约翰斯·霍普金斯大学）；University of California, Santa Barbara（加利福尼亚大学圣塔芭芭拉分校）；Observatoire de Paris, Université PSL, CNRS, Université Paris Cité, Sorbonne Université（巴黎天文台、巴黎文理研究大学、法国国家科学研究中心、巴黎西岱大学、索邦大学）；Université Côte d’Azur（蔚蓝海岸大学）
As we approach the James Webb Space Telescope (JWST) era, several studies have emerged that aim to: 1) characterize how the instruments will perform and 2) determine what atmospheric spectral features could theoretically be detected using transmission and emission spectroscopy. To some degree, all these studies have relied on modeling of JWST's theoretical instrument noise. With under two years left until launch, it is imperative that the exoplanet community begins to digest and integrate these studies into their observing plans, as well as think about how to leverage the Hubble Space Telescop…
Next year the second generation instrument SPHERE will begin science operations at the Very Large Telecope (ESO). This instrument will be dedicated to the search for exoplanets through the direct imaging techniques, with the new generation extreme adaptive optics. In this poster, we present the performances of one of the focal instruments, the Infra-Red Dual-beam Imaging and Spectroscopy (IRDIS). All the results have been obtained with tests in laboratory, simulating the observing conditions in Paranal. We tested several configurations using the sub-system Integral Field Spectrograph (IFS) in …
The James Webb Space Telescope's NIRSpec instrument will unveil the nature of exoplanet atmospheres across the wealth of planet types, from temperate terrestrial worlds to ultrahot Jupiters. In particular, the 0.6-5.3 micron PRISM mode is especially well-suited for efficient spectroscopic exoplanet observations spanning a number of important spectral features. We analyze a lab-measured NIRSpec PRISM mode Bright Object Time Series (BOTS) observation from the perspective of a JWST user to understand the instrument performance and detector properties. We create two realistic transiting exoplanet …
The 4MOST instrument is a multi-object spectrograph that will address Galactic and extragalactic science cases simultaneously by observing targets from a large number of different surveys within each science exposure. This parallel mode of operation and the survey nature of 4MOST require some distinct 4MOST-specific operational features within the overall operations model of ESO. The main feature is that the 4MOST Consortium will deliver, not only the instrument, but also contractual services to the user community, which is why 4MOST is also described as a facility. This white paper concentrat…
SOXS (Son Of X-Shooter) is a new spectrograph for the ESO NTT telescope, currently in the final design phase. The main instrument goal is to allow the characterization of transient sources based on alerts. It will cover from near-infrared to visible bands with a spectral resolution of $R \sim 4500$ using two separate, wavelength-optimized spectrographs. A visible camera, primarily intended for target acquisition and secondary guiding, will also provide a scientific "light" imaging mode. In this paper we present the current status of the design of the SOXS instrument control software, which is …
Multi-bandpass Photometry for Exoplanet Atmosphere Reconnaissance (MPEAR) with the Habitable Worlds Observatory (HWO) -- I. Differentiating Earth from Neptunes During Discovery
NASA Goddard Space Flight Center（NASA戈达德太空飞行中心）；University of Oslo（奥斯陆大学）；Jet Propulsion Laboratory, California Institute of Technology（加州理工学院喷气推进实验室）
