Image Descriptions
These images were produced through scientific endeavours pursued by Columbia faculty, staff, and students and represents the heterogeneity of wavelengths and a variety of topics studied at Columbia. Click on the image to see the original contribution.
	The remnant of the supernova explosion of 1181 CE as observed in a four-day observation with the Chandra X-ray Observatory. This pseudo-color image has red representing low energy X-rays (0.5-2 keV), green medium energy (2-4 keV), and blue high energy (4-8 keV). Over 96% of the emission comes from relaticistic particles generated by the energetic pulsar buried in the bright center of the remnant. This neutron star is cooler than expected for an 820-year old object, requiring nonstandard cooling mechanisms. Slane, Helfand, van der Swaluw, & Murray 2004 ApJ, in press - David Helfand (Professor)
	The Joy of Relativity; Backing into the Einstein Equation for the Space Curvature - from Ed's Relativity Lecture Notes (1919) - Edward A. Spiegel (Professor)
	This image is of shows the orbits of galaxies within a galaxy cluster. The orbits are shown shown as lines that graduate from (white at) the formation time of the cluster to (red) now. The white sphere has a radius of 2Mpch-1. This figure shows the ``rich environment'' of this cluster with galaxy continually falling in over its history. - Stuart Gill (Postdoc)
	The large-scale distribution of gaseous matter in the Universe, from a numerical simulation of a cold-dark mater dominated universe. This image is a perspective volumetric rendering of a cubical section of the simulated universe, 300 Mpc/h on a side. It is color-coding by gas density. Dense clusters of galaxies are shown in red, and are interconnected by a web of lower-density (blue) filaments. Voids in the distribution can be clearly seen. The simulation was computed using 512^3 particles and cells using a parallel cosmological hydrodynamics code. - Greg Bryan (Assistant Professor)
	This image shows the XMM-Newton X-ray view of the Southern Flanking Field of the Orion Nebula, centered on the young low-mass star V1118 Orionis. The star is very young (a few millions years) and is still in a phase when it accretes matter from the nearby molecular cloud surroundings through an accretion disk. In early 2005, V1118 Ori was reported to have experienced an outburst, i.e., its optical magnitude increased significantly due to a massive increase in its accretion rate (from 10^-7 solar masses per year to 10^-4 solar masses per year, i.e., an increase of a factor of 1,000). The X-ray satellites Chandra and XMM-Newton have observed V1118 Ori in outburst and detected a spectral change from a dominantly hot plasma of more than 20 million degrees to a cooler plasma of 8 million degrees. The cause for such a change remains unclear, but could be related to either shocks of an accretion flow onto the stellar surface, or to a reconfiguration of the stellar corona with the hot loops being disrupted. The X-ray behavior of V1118 Orionis is fascinating as it provides important insights onto the origin of the X-ray emission in young accreting stars. More details can be found in Audard et al., ApJ Letters (2005). - Marc Audard (Research Scientist)
	All rotating, turbulent cosmic bodies whose surface features we can resolve are mottled. We see sunpots, Jupiter's red spot and spots on cool stars. Some suspect that there are spots on hot stars as well. There is also evidence for spots on accretion disks. In the stellar and planetary cases, the spots are often caused by either vortex tubes or magnetic flux tubes impinging on the surfaces. Can such structures form in disks? Most disks are turbulent so formation of these coherent stuctures, as they are called, seems likely. But some people have claimed that the Keplerian shears on accretion disks would quickly destroy vortices. In fact, vortices that turn in the direction of the shear --- the cyclonic vortices --- are destroyed. But anticyclonic vortices cancel out the local destructive motions and survive. In the picture, we see anticyclonic vortices that formed spontaneously in a two dimensional Keplerian flow whose initial conditions were turbulent. The turbulence is dying but the vortices persist for a very long time. Bracco, A., Chavanis, P.-H., Provenzale, A. and Spiegel, E.A. ("Particle aggregation in Keplerian Flows", Physics of Fluids 1999, 11, 2280). - Edward A. Spiegel (Professor)
	Ultraviolet image of the nearby spiral galaxy Messier 101 acquired by the Galaxy Evolution Explorer (GALEX). The two color 'false-color' composite was generated from GALEX far-ultraviolet (blue) and near-ultraviolet images (red/yellow). Star-forming regions containing stars less than ten million years old appear hotter or blue-white in this image, while older stellar populations appear redder. Most of the ultraviolet is concentrated in the spiral arms, with faint interarm light revealing an older population and very low surface brightness nebulosity tracing star formation occurring more than 100,000 light years from the galaxy center. - David Schiminovich (Assistant Professor)
	Reproducing the atomic collisions responsible for the spectra observed from cosmic objects is experimentally challenging. Pictured here is the heavy ion Test Storage Ring (TSR) at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. TSR is used by Columbia scientists in a successful collaboration with groups from Heidelberg and Giessen, Germany, to store a beam of highly charged ions which are then merged with a beam of electrons to study electron-ion recombination. This process occurs in a wide range of cosmic sources including active galactic nuclei, H II regions, planetary nebulae, stellar atmospheres, supernova remnants, the intergalactic medium, the interstellar medium, the intracluster medium in clusters of galaxies, and the solar atmosphere. - Daniel Wolf Savin (Research Scientist)