We review the properties and behavior of 20 X-ray binaries that contain a dynamically-confirmed black hole, 17 of which are transient systems. During the past decade, many of these transien...

/pdf/x-ray-properties-of-black-hole-binaries-2udxi1i1oe.pdf

X-Ray Properties of Black-Hole Binaries

RHESSI is the sixth in the NASA line of Small Explorer (SMEX) missions and the first managed in the Principal Investigator mode, where the PI is responsible for all aspects of the mission except the launch vehicle. RHESSI is designed to investigate particle acceleration and energy release in solar flares, through imaging and spectroscopy of hard X-ray/gamma-ray continua emitted by energetic electrons, and of gamma-ray lines produced by energetic ions. The single instrument consists of an imager, made up of nine bi-grid rotating modulation collimators (RMCs), in front of a spectrometer with nine cryogenically-cooled germanium detectors (GeDs), one behind each RMC. It provides the first high-resolution hard X-ray imaging spectroscopy, the first high-resolution gamma-ray line spectroscopy, and the first imaging above 100 keV including the first imaging of gamma-ray lines. The spatial resolution is as fine as ~ 2.3 arc sec with a full-Sun (≳ 1°) field of view, and the spectral resolution is ~ 1–10 keV FWHM over the energy range from soft X-rays (3 keV) to gamma-rays (17 MeV). An automated shutter system allows a wide dynamic range (> 107) of flare intensities to be handled without instrument saturation. Data for every photon is stored in a solid-state memory and telemetered to the ground, thus allowing for versatile data analysis keyed to specific science objectives. The spin-stabilized (~ 15 rpm) spacecraft is Sun-pointing to within ~ 0.2° and operates autonomously. RHESSI was launched on 5 February 2002, into a nearly circular, 38° inclination, 600-km altitude orbit and began observations a week later. The mission is operated from Berkeley using a dedicated 11-m antenna for telemetry reception and command uplinks. All data and analysis software are made freely and immediately available to the scientific community.

The Reuven Ramaty High-Energy Solar Spectroscopic Imager (Rhessi)

https://ned.ipac.caltech.edu/level5/March04/Piran2/paper.pdf

Gamma-ray bursts and the fireball model

We present the main results of a study of spectral and energetics properties of twelve gamma-ray bursts (GRBs) with redshift estimates. All GRBs in our sample were detected by BeppoSAX in a broad energy range (2-700 keV). From the redshift estimates and the good-quality BeppoSAX time-integrated spectra we deduce the main properties of GRBs in their cosmological rest frames. All spectra in our sample are satisfactorily represented by the Band model, with no significant soft X-ray excesses or spectral absorptions. We find a positive correlation between the estimated total (isotropic) energies in the 1-10 000 keV energy range (Erad) and redshifts z. Interestingly, more luminous GRBs are characterized also by larger peak energies Ep so f theirEF(E) spectra. Furthermore, more distant GRBs appear to be systematically harder in the X-ray band compared to GRBs with lower redshifts. We discuss how selection and data truncation eects could bias our results and give possible explanations for the correlations that we found.

/pdf/intrinsic-spectra-and-energetics-of-bepposax-gamma-ray-1tu5bipkkt.pdf

Intrinsic spectra and energetics of BeppoSAX Gamma-Ray Bursts with known redshifts

We present early observations of the afterglow of GRB 030329 and the spectroscopic discovery of its associated supernova SN 2003dh. We obtained spectra of the afterglow of GRB 030329 each night from March 30.12 (0.6 days after the burst) to April 8.13 (UT) (9.6 days after the burst). The spectra cover a wavelength range of 350-850 nm. The early spectra consist of a power-law continuum (Fν ν-0.9) with narrow emission lines originating from H II regions in the host galaxy, indicating a low redshift of z = 0.1687. However, our spectra taken after 2003 April 5 show broad peaks in flux characteristic of a supernova. Correcting for the afterglow emission, we find that the spectrum of the supernova is remarkably similar to the Type Ic hypernova SN 1998bw. While the presence of supernovae has been inferred from the light curves and colors of gamma-ray burst afterglows in the past, this is the first direct, spectroscopic confirmation that a subset of classical gamma-ray bursts originate from supernovae.

https://iopscience.iop.org/article/10.1086/376976/pdf

Spectroscopic Discovery of the Supernova 2003dh Associated with GRB 030329

The X-ray satellite SAX, a major program of the Italian Space Agency with participation of the Netherlands Agency for Aereospace Programs, was launched on April 30 1996 from Cape Canaveral. After launch it was renamed BeppoSAX in honour of Giuseppe (Beppo) Occhialini. The payload is characterized by a very wide spectral coverage from 0.1 to 300 keV, with well bal- anced performances both from its low and high energy instrumentation. Its sensitivity will allow the exploitation of the full band for weak sources (1/20 of 3C 273), open- ing new perspectives in the study of spectral shape and variability of several classes of objects. Furthermore, the presence of wide eld cameras will allow monitoring of the long term variability of sources down to 1 mCrab and the discovery of X-ray transient phenomena. In this paper we describe the main aspects of the mission, the operations, the scientic capabilities of the instruments and the sci- entic objectives.

/pdf/bepposax-the-wide-band-mission-for-x-ray-astronomy-2nh3rahn9w.pdf

BeppoSAX, the wide band mission for X-ray astronomy

An energetic cosmic ray event was analyzed using a a. The date of the event, though unspecified, was between Sept., 1959 and May, 1960. The event was recorded at the M.I.T. stution near Albuquerque. The shower center, radius, axis direction, composition, and arrival times at various counters are given. A model for the event is suggested. (T.F.H.)

Extremely Energetic Cosmic-Ray Event

A study has been made of the relative times of arrival of shower particles at large distances (200 to 1500 m) from the shower axis. Data were obtained at the MIT Volcano Ranch Station, using an array of 20 scintillation detectors, one of which was shielded part of the time. The shower size, direction, and core location were determined for each event. We describe the spatial distribution of shower particles at a given instant by means of three curved surfaces: the median surface for the penetrating particles (muons), the median surface for the electrons, and the extreme front. We find that the average median surface for the muons is approximately spherical, the center being located at an atmospheric depth of 320\ifmmode\pm\else\textpm\fi{}70 g ${\mathrm{cm}}^{\ensuremath{-}2}$, and that the average median surface for the electrons has a radius of curvature of about 1 km at a distance from the axis of 450 m. The electron radius of curvature increases at greater distances. Assuming that the extreme front is spherical, its average center must be located above 320 g ${\mathrm{cm}}^{\ensuremath{-}2}$. We measured the radius for curvature of the extreme front for a small number of individual showers, but were not able to improve upon that limit.

Arrival times of air shower particles at large distances from the axis

On n'a detecte aucun signal Rγ provenant des pulsars PSR 0740―28, PSR 0950+08, PSR 1055―52 et PSR 1929+10

Search for pulsed γ-ray emission from radio pulsars in the COS-B data.

In the framework of past and future X-ray missions the SAX satellite, to be launched in March 1996, stands out for its very wide spectral coverage from 0. 1 to 200 keV, with well balanced performances of the low energy andhigh energy instrumentation. The sensitivity ofthe scientific payload will allow the exploitation of the full band of SAX also for weak sources (1/20 of 3C273), opening new perspectives in the study of spectral shape andvariability of several classes of objects. In this paper we briefly describe the main aspects of the mission, with particular regard to its scientific capabilities 1. OVERVIEW OF THE MISSION AND ITS INSTRUMENTS The X-ray Satellite SAX is a major program of the Italian space agency (ASI) with participation of the Netherlands space agency (NIVR). Prime industrial contractors are Alenia for the space segment and NuovaTelespazio for the Ground Segment. The mission development is supported by a consortium of scientific institutes4. SAX will be the first Xray mission (and, of the coming near$uture satellites, the only one) with the capability ofobserving sources over more than tree decades of energy from 0. 1 to 300 keV -with a relatively large area, a

Livio Scarsi

Papers

BeppoSAX, the wide band mission for X-ray astronomy

Extremely Energetic Cosmic-Ray Event

Arrival times of air shower particles at large distances from the axis

Search for pulsed γ-ray emission from radio pulsars in the COS-B data.

SAX: the wideband mission for x-ray astronomy