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The Swift gamma-ray burst mission
The Swift mission will determine the origin of GRB, classify GRBs and search for new types, study the interaction of the ultrarelativistic outflows of GRBs with their surrounding medium, and use GRBs to study the early universe out to z >10.
Statistical methods for astronomical data with upper limits. I - Univariate distributions
The statistical treatment of univariate censored data is discussed. A heuristic derivation of the Kaplan-Meier maximum-likelihood estimator from first principles is presented which results in an
Chandra X-Ray Spectroscopic Imaging of Sagittarius A* and the Central Parsec of the Galaxy
We report the results of the first-epoch observation with the ACIS-I instrument on the Chandra X-Ray Observatory of Sagittarius A* (Sgr A*), the compact radio source associated with the supermassive
Determination of the gas-to-dust ratio in nearby dense clouds using X-ray absorption measurements
We present a comparison of the gas and dust properties of the dense interstellar matter in six nearby star forming regions (d 2) than the galactic value, derived using the standard extinction curve
Statistical Methods for Astronomical Data with Upper Limits
Statistical methods for calculating correlations and regressions in bivariate censored data where the dependent variable can have upper or lower limits are presented. Cox's regression and the
Rapid X-ray flaring from the direction of the supermassive black hole at the Galactic Centre
The discovery of rapid X-ray flaring from the direction of Sagittarius A* provides compelling evidence that the emission is coming from the accretion of gas onto a supermassive black hole at the Galactic Centre.
The Origin of T Tauri X-Ray Emission: New Insights from the Chandra Orion Ultradeep Project
The Chandra Orion Ultradeep Project (COUP) provides the most comprehensive data set ever acquired on the
Linear regression in astronomy. II
Five methods for obtaining linear regression fits to bivariate data with unknown or insignificant measurement errors are discussed: ordinary least-squares (OLS) regression of Y on X, OLS regression
The Evolution of X-Ray Emission in Young Stars
The evolution of magnetic activity in late-type stars is part of the intertwined rotation-age-activity relation which provides an empirical foundation to the theory of magnetic dynamos. We study the
The Chandra Deep Field North Survey. V. 1 Ms Source Catalogs
An extremely deep X-ray survey (≈1 Ms) of the Hubble Deep Field North (HDF-N) and its environs (≈450 arcmin2) has been performed with the Advanced CCD Imaging Spectrometer on board the Chandra X-Ray