Distances from Surface Brightness Fluctuations

The practice of measuring galaxy distances from their spatial fluctuations in surface brightness is now a decade old. While several past articles have included some review material, this is the first intended as a comprehensive review of the surface brightness fluctuation (SBF) method. The method is conceptually quite simple, the basic idea being that nearby (but unresolved) star clusters and galaxies appear "bumpy", while more distant ones appear smooth. This is quantified via a measurement of the amplitude of the Poisson fluctuations in the number of unresolved stars encompassed by a CCD pixel (usually in an image of an elliptical galaxy). Here, we describe the technical details and difficulties involved in making SBF measurements, discuss theoretical and empirical calibrations of the method, and review the numerous applications of the method from the ground and space, in the optical and near-infrared. We include discussions of stellar population effects and the "universality" of the SBF standard candle. A final section considers the future of the method.Comment: Invited review article to appear in: `Post-Hipparcos Cosmic Candles', A. Heck & F. Caputo (Eds), Kluwer Academic Publ., Dordrecht, in press. 22 pages, including 3 postscript figures; uses Kluwer's crckapb.sty LaTex macro file, enclose

Starlink software developments

Various recent changes to the software produced by Starlink are demonstrated. These cover areas such as table handling, time-series analysis, pipeline processing, astrometric calibration, spectral and cube visualisation, and ports to the MacOSX and Cygwin environments. Particular emphasis was given to the applicability to the Virtual Observatory

A 100-kiloparsec wind feeding the circumgalactic medium of a massive compact galaxy

© The Author(s), under exclusive licence to Springer Nature Limited 2019.Ninety per cent of baryons are located outside galaxies, either in the circumgalactic or intergalactic medium1,2. Theory points to galactic winds as the primary source of the enriched and massive circumgalactic medium3,4,5,6. Winds from compact starbursts have been observed to flow to distances somewhat greater than ten kiloparsecs7,8,9,10, but the circumgalactic medium typically extends beyond a hundred kiloparsecs3,4. Here we report optical integral field observations of the massive but compact galaxy SDSS J211824.06+001729.4. The oxygen [O ii] lines at wavelengths of 3726 and 3729 angstroms reveal an ionized outflow spanning 80 by 100 square kiloparsecs, depositing metal-enriched gas at 10,000 kelvin through an hourglass-shaped nebula that resembles an evacuated and limb-brightened bipolar bubble. We also observe neutral gas phases at temperatures of less than 10,000 kelvin reaching distances of 20 kiloparsecs and velocities of around 1,500 kilometres per second. This multi-phase outflow is probably driven by bursts of star formation, consistent with theory11,12.Peer reviewedFinal Accepted Versio