The Athena X-ray Integral Field Unit (X-IFU)
Event: SPIE Astronomical Telescopes + Instrumentation, 2016, Edinburgh, United Kingdom.
GrailQuest and HERMES: hunting for gravitational wave electromagnetic counterparts and probing space-time quantum foam
GrailQuest (Gamma-ray Astronomy International Laboratory for Quantum Exploration of Space-Time) is an ambitious astrophysical mission concept that uses a fleet of small satellites whose main objective is to search for a dispersion law for light propagation in vacuo. Within Quantum Gravity theories, different models for space-time quantization predict relative discrepancies of the speed of photons w.r.t. the speed of light that depend on the ratio of the photon energy to the Planck energy. This ratio is as small as 10-23 for photons in the γ- ray band (100 keV). Therefore, to detect this effect, light must propagate over enormous distances and the experiment must have extraordinary sensitivi…
GrailQuest: hunting for atoms of space and time hidden in the wrinkle of Space-Time: A swarm of nano/micro/small-satellites to probe the ultimate structure of Space-Time and to provide an all-sky monitor to study high-energy astrophysics phenomena
AbstractGrailQuest(Gamma Ray Astronomy International Laboratory for QUantum Exploration of Space-Time) is a mission concept based on a constellation (hundreds/thousands) of nano/micro/small-satellites in low (or near) Earth orbits. Each satellite hosts a non-collimated array of scintillator crystals coupled with Silicon Drift Detectors with broad energy band coverage (keV-MeV range) and excellent temporal resolution (≤ 100 nanoseconds) each with effective area$\sim 100 \text {cm}^{2}$∼100cm2. This simple and robust design allows for mass-production of the satellites of the fleet. This revolutionary approach implies a huge reduction of costs, flexibility in the segmented launching strategy, …
The HERMES-Technologic and Scientific Pathfinder
HERMES-TP/SP (High Energy Rapid Modular Ensemble of Satellites Technologic and Scientific Pathfinder) is a constellation of six 3U nano-satellites hosting simple but innovative X-ray detectors, characterized by a large energy band and excellent temporal resolution, and thus optimized for the monitoring of Cosmic High Energy transients such as Gamma Ray Bursts and the electromagnetic counterparts of Gravitational Wave Events, and for the determination of their positions. The projects are funded by the Italian Ministry of University and Research and by the Italian Space Agency, and by the European Union Horizon 2020 Research and Innovation Program under Grant Agreement No. 821896. HERMES-TP/S…
The Chandra COSMOS Survey, I: Overview and Point Source Catalog
The Chandra COSMOS Survey (C-COSMOS) is a large, 1.8 Ms, Chandra} program that has imaged the central 0.5 sq.deg of the COSMOS field (centered at 10h, +02deg) with an effective exposure of ~160ksec, and an outer 0.4sq.deg. area with an effective exposure of ~80ksec. The limiting source detection depths are 1.9e-16 erg cm(-2) s(-1) in the Soft (0.5-2 keV) band, 7.3e(-16) erg cm^-2 s^-1 in the Hard (2-10 keV) band, and 5.7e(-16) erg cm(-2) s(-1) in the Full (0.5-10 keV) band. Here we describe the strategy, design and execution of the C-COSMOS survey, and present the catalog of 1761 point sources detected at a probability of being spurious of <2e(-5) (1655 in the Full, 1340 in the Soft, and…
Timing techniques applied to distributed modular high-energy astronomy: the H.E.R.M.E.S. project
The HERMES-TP/SP (High Energy Rapid Modular Ensemble of Satellites -- Technologic and Scientific Pathfinder) is an in-orbit demonstration of the so-called distributed astronomy concept. Conceived as a mini-constellation of six 3U nano-satellites hosting a new miniaturized detector, HERMES-TP/SP aims at the detection and accurate localisation of bright high-energy transients such as Gamma-Ray Bursts. The large energy band, the excellent temporal resolution and the wide field of view that characterize the detectors of the constellation represent the key features for the next generation high-energy all-sky monitor with good localisation capabilities that will play a pivotal role in the future …
The scientific payload on-board the HERMES-TP and HERMES-SP CubeSat missions
HERMES (High Energy Rapid Modular Ensemble of Satellites) Technological and Scientific pathfinder is a space borne mission based on a LEO constellation of nano-satellites. The 3U CubeSat buses host new miniaturized detectors to probe the temporal emission of bright high-energy transients such as Gamma-Ray Bursts (GRBs). Fast transient localization, in a field of view of several steradians and with arcmin-level accuracy, is gained by comparing time delays among the same event detection epochs occurred on at least 3 nano-satellites. With a launch date in 2022, HERMES transient monitoring represents a keystone capability to complement the next generation of gravitational wave experiments. In t…
The XMM-Newton survey of the ELAIS-S1 field
We have surveyed with XMM-Newton the central ~0.6 deg2 region of the ELAIS-S1 field down to flux limits of ~5.5X10-16 cgs (0.5-2 keV, S band), ~2X10-15 cgs (2-10 keV, H band), and ~4X10-15 cgs (5-10 keV, HH band). We detect a total of 478 sources, 395 and 205 of which detected in the S and H bands respectively. We identified 7 clearly extended sources and estimated their redshift through X-ray spectral fits with thermal models. In four cases the redshift is consistent with z=0.4. We have computed the angular correlation function of the sources in the S and H bands, finding best fit correlation angles theta_0=5.2+/-3.8 arcsec and theta_0=12.8+/-7.8 arcsec respectively. A rough estimate of th…
Spectral changes during six years of Scorpius X-1 monitoring with BeppoSAX Wide Field Cameras
We analyse a sample of fifty-five observations of Scorpius X-1 available in the BeppoSAX Wide Field Camera public archive and spanning over the six years of BeppoSAX mission life. Spectral changes are initially analysed by inspection of colour-colour and colour-intensity diagrams, we also discuss the shift of the Z tracks in these diagrams. Then we select two long observations for spectral fitting analysis, a secular shift is evident between the tracks in these observations. We finally extract spectra along the tracks and discuss the best fit model, the parameter variations along the track and between tracks, and their link to the accretion rate.
Six Years of ScoX-1 Monitoring with BeppoSAX Wide Field Cameras
We performed a systematic analysis of 54 Wide Field Camera (WFC) observations of ScoX-1 available in the BeppoSAX public archive. Observations span over the six years of BeppoSAX mission lifetime and include 690 hr of data. We searched for shifts and shape changes of the Z pattern in the color-color diagrams. We find that the Z pattern occupies most of the time the same locus in the color-color diagram. There are however a few exceptions, which are discussed in detail.
The Multi-frequency Robotic facility REM: first results
The REM Observatory, recently installed and commissioned at la Silla Observatory Chile, is the first moderate aperture robotic telescope able to cover simultaneously the visible-NIR (0.45-2.3 microns) wavelength range. Due to its very fast pointing and its full robotization REM is conceived for fast transients observation. The high throughput Infrared Camera (REMIR) and the Visible imaging spectrograph (ROSS), simultaneously fed by a dichroic, allow to collect high S/N data in an unprecedented large spectral range on a telescope of this size. The REMobservatory is an example of a versatile and agile facility necessary complement to large telescopes in fields in which rapid response and/or t…
The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase
The Athena X-ray Integral Unit (X-IFU) is the high resolution X-ray spectrometer, studied since 2015 for flying in the mid-30s on the Athena space X-ray Observatory, a versatile observatory designed to address the Hot and Energetic Universe science theme, selected in November 2013 by the Survey Science Committee. Based on a large format array of Transition Edge Sensors (TES), it aims to provide spatially resolved X-ray spectroscopy, with a spectral resolution of 2.5 eV (up to 7 keV) over an hexagonal field of view of 5 arc minutes (equivalent diameter). The X-IFU entered its System Requirement Review (SRR) in June 2022, at about the same time when ESA called for an overall X-IFU redesign (i…
The ATHENA X-ray Integral Field Unit (X-IFU)
Event: SPIE Astronomical Telescopes + Instrumentation, 2018, Austin, Texas, United States.